From aae34ba7915c6075b99091b82955f37e40d77989 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Fri, 19 Aug 2022 01:18:11 +0800
Subject: [PATCH 01/26] Add Increment: Level-0

---
 src/main/java/Duke.java | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 5d313334..f4ad96e5 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,10 +1,11 @@
 public class Duke {
     public static void main(String[] args) {
-        String logo = " ____        _        \n"
-                + "|  _ \\ _   _| | _____ \n"
-                + "| | | | | | | |/ / _ \\\n"
-                + "| |_| | |_| |   <  __/\n"
-                + "|____/ \\__,_|_|\\_\\___|\n";
-        System.out.println("Hello from\n" + logo);
+        String logo = "____________________________________________________________\n"
+                + "Hello! I'm Duke\n"
+                + "What can I do for you?\\\n"
+                + "____________________________________________________________\n"
+                + "Bye. Hope to see you again soon!\n"
+                + "____________________________________________________________\n";
+        System.out.println(logo);
     }
 }

From 5701ddc97f05f7313996f2d28d13695fe09af13d Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Fri, 19 Aug 2022 01:59:56 +0800
Subject: [PATCH 02/26] Add Level-1

---
 src/main/java/Duke.java | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index f4ad96e5..958f9eab 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,11 +1,19 @@
+import java.util.Locale;
+import java.util.Scanner;
+
 public class Duke {
     public static void main(String[] args) {
-        String logo = "____________________________________________________________\n"
-                + "Hello! I'm Duke\n"
-                + "What can I do for you?\\\n"
-                + "____________________________________________________________\n"
-                + "Bye. Hope to see you again soon!\n"
-                + "____________________________________________________________\n";
-        System.out.println(logo);
+        String welcomeText = "Hello! I am not Duke.\n"
+                + "I can echo you now.\n";
+        System.out.println(welcomeText);
+        Scanner scanner = new Scanner(System.in);
+        while (true) {
+            String input = scanner.nextLine();
+            if (input.toLowerCase().trim().equals("bye")) {
+                break;
+            }
+            System.out.println(input);
+        }
+        System.out.println("Byebye!!!");
     }
 }

From ba4ed0c556d464e73aa17c3cda10440eea39a509 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Sat, 20 Aug 2022 00:33:19 +0800
Subject: [PATCH 03/26] "Add Level-2"

Improved code formatting
---
 src/main/java/Duke.java | 55 +++++++++++++++++++++++++++++++++++------
 1 file changed, 48 insertions(+), 7 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 958f9eab..032cc818 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -2,18 +2,59 @@
 import java.util.Scanner;
 
 public class Duke {
-    public static void main(String[] args) {
-        String welcomeText = "Hello! I am not Duke.\n"
-                + "I can echo you now.\n";
+    public static void WelcomeUser() {
+        String welcomeText = "-------------------------------------\n"
+                + "Hello! I am not Duke.\n"
+                + "I can echo you now.\n"
+                + "-------------------------------------";
         System.out.println(welcomeText);
+    }
+
+    public static String CleanInput(String input) {
+        return input.toLowerCase().trim();
+    }
+
+    public static void ListWords(String[] list, int listSize) {
+        if (listSize != 0) {
+            for (int i = 0; i < listSize; i++) {
+                System.out.println((i + 1) + ": " + list[i]);
+            }
+        }
+        else {
+            System.out.println("The list is empty, Please add something!");
+        }
+    }
+
+    public static void AddWord(String[] wordList, String word, int pos) {
+        wordList[pos] = word;
+        System.out.println("Added \"" + word + "\"");
+    }
+
+    public static void TrackInput() {
         Scanner scanner = new Scanner(System.in);
+        String[] wordList = new String[100];
+        final String LINEDIVIDER = "-------------------------------------";
+        int wordCount = 0;
         while (true) {
-            String input = scanner.nextLine();
-            if (input.toLowerCase().trim().equals("bye")) {
+            String input = CleanInput(scanner.nextLine());
+            System.out.println(LINEDIVIDER);
+            if (input.equals("bye")) {
+                System.out.println("Bye bye!!! \n" + LINEDIVIDER + "\n");
                 break;
             }
-            System.out.println(input);
+            else if (input.equals("list")) {
+                ListWords(wordList, wordCount);
+            }
+            else {
+                AddWord(wordList, input, wordCount);
+                wordCount++;
+            }
+            System.out.println(LINEDIVIDER);
         }
-        System.out.println("Byebye!!!");
+    }
+
+    public static void main(String[] args) {
+        WelcomeUser();
+        TrackInput();
     }
 }

From 2ab974a4d370feac22168c050f246b8dc70007fc Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Sat, 20 Aug 2022 16:28:11 +0800
Subject: [PATCH 04/26] Add Level-3

Duke can now add tasks and mark/unmark them
---
 src/main/java/Duke.java | 51 +++++++++++++++++++++++++----------------
 src/main/java/Task.java | 27 ++++++++++++++++++++++
 2 files changed, 58 insertions(+), 20 deletions(-)
 create mode 100644 src/main/java/Task.java

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 032cc818..9a018025 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -5,7 +5,13 @@ public class Duke {
     public static void WelcomeUser() {
         String welcomeText = "-------------------------------------\n"
                 + "Hello! I am not Duke.\n"
-                + "I can echo you now.\n"
+                + "Here are a list of commands: \n"
+                + "\tadd <string> : adds a task to the list\n"
+                + "\tlist : shows list of tasks\n"
+                + "\tmark <task id> : marks a task \n"
+                + "\tunmark <task id> : unmarks a task \n"
+                + "\tbye : exits the program \n"
+                + "I WILL CRASH IF YOU DO NOT COMPLY!!!\n"
                 + "-------------------------------------";
         System.out.println(welcomeText);
     }
@@ -14,40 +20,45 @@ public static String CleanInput(String input) {
         return input.toLowerCase().trim();
     }
 
-    public static void ListWords(String[] list, int listSize) {
-        if (listSize != 0) {
-            for (int i = 0; i < listSize; i++) {
-                System.out.println((i + 1) + ": " + list[i]);
+    public static void ListTasks(Task[] list) {
+        if (Task.getTaskCount() != 0) {
+            for (int i = 0; i < Task.getTaskCount(); i++) {
+                System.out.println(list[i].getStatusIcon() + (i + 1) + ": " + list[i].getDescription());
             }
-        }
-        else {
-            System.out.println("The list is empty, Please add something!");
+        } else {
+            System.out.println("The list is empty, please add something!");
         }
     }
 
-    public static void AddWord(String[] wordList, String word, int pos) {
-        wordList[pos] = word;
-        System.out.println("Added \"" + word + "\"");
+    public static void AddTask(Task[] taskList, String taskDescription) {
+        taskList[Task.getTaskCount()] = new Task(taskDescription);
+        System.out.println("Added \"" + taskDescription + "\"");
     }
 
     public static void TrackInput() {
         Scanner scanner = new Scanner(System.in);
-        String[] wordList = new String[100];
+        Task[] taskList = new Task[100];
         final String LINEDIVIDER = "-------------------------------------";
-        int wordCount = 0;
         while (true) {
             String input = CleanInput(scanner.nextLine());
             System.out.println(LINEDIVIDER);
             if (input.equals("bye")) {
                 System.out.println("Bye bye!!! \n" + LINEDIVIDER + "\n");
                 break;
-            }
-            else if (input.equals("list")) {
-                ListWords(wordList, wordCount);
-            }
-            else {
-                AddWord(wordList, input, wordCount);
-                wordCount++;
+            } else if (input.equals("list")) {
+                ListTasks(taskList);
+            } else if (input.startsWith("add ")) {
+                AddTask(taskList, input.substring(4));
+            } else if (input.startsWith("mark ")) {
+                int toMark = Integer.parseInt(input.substring(5)) - 1;
+                System.out.println(taskList[toMark].getDescription() + " marked");
+                taskList[toMark].setDone(true);
+            } else if (input.startsWith("unmark ")) {
+                int toMark = Integer.parseInt(input.substring(7)) - 1;
+                System.out.println(taskList[toMark].getDescription() + " unmarked");
+                taskList[toMark].setDone(false);
+            } else {
+                System.out.println("Invalid command.");
             }
             System.out.println(LINEDIVIDER);
         }
diff --git a/src/main/java/Task.java b/src/main/java/Task.java
new file mode 100644
index 00000000..82d21b35
--- /dev/null
+++ b/src/main/java/Task.java
@@ -0,0 +1,27 @@
+public class Task {
+    protected String description;
+    protected boolean isDone;
+    protected static int taskCount = 0;
+
+    public Task(String description) {
+        this.description = description;
+        this.isDone = false;
+        Task.taskCount++;
+    }
+
+    public void setDone(boolean isDone) {
+        this.isDone = isDone;
+    }
+
+    public String getStatusIcon() {
+        return isDone ? "[X]" : "[ ]";
+    }
+
+    public static int getTaskCount() {
+        return taskCount;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+}

From 8df32c3d4cac65d267aefa712d06d4b911711d75 Mon Sep 17 00:00:00 2001
From: jjtoh <johntohjiajun@gmail.com>
Date: Wed, 24 Aug 2022 22:08:01 +0800
Subject: [PATCH 05/26] Add A-CodingStandard

Edited some code to align it with the given stardards
---
 src/main/java/Duke.java | 82 ++++++++++++++++++++++++++++++-----------
 1 file changed, 61 insertions(+), 21 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 9a018025..3d3ee392 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,8 +1,10 @@
-import java.util.Locale;
 import java.util.Scanner;
 
 public class Duke {
-    public static void WelcomeUser() {
+    /**
+     * Prints the welcome message
+     */
+    public static void welcomeUser() {
         String welcomeText = "-------------------------------------\n"
                 + "Hello! I am not Duke.\n"
                 + "Here are a list of commands: \n"
@@ -16,11 +18,24 @@ public static void WelcomeUser() {
         System.out.println(welcomeText);
     }
 
-    public static String CleanInput(String input) {
+    /**
+     * Sets input to lowercase and removes any
+     * leading and trailing whitespaces.
+     *
+     * @param input Input entered by user.
+     * @return Lowercase and trimmed input.
+     */
+    public static String cleanInput(String input) {
         return input.toLowerCase().trim();
     }
 
-    public static void ListTasks(Task[] list) {
+    /**
+     * Prints the current list of tasks.
+     * If list is empty, print error message.
+     *
+     * @param list List of tasks.
+     */
+    public static void listTasks(Task[] list) {
         if (Task.getTaskCount() != 0) {
             for (int i = 0; i < Task.getTaskCount(); i++) {
                 System.out.println(list[i].getStatusIcon() + (i + 1) + ": " + list[i].getDescription());
@@ -30,42 +45,67 @@ public static void ListTasks(Task[] list) {
         }
     }
 
-    public static void AddTask(Task[] taskList, String taskDescription) {
+    /**
+     * Adds a task to the list of tasks.
+     *
+     * @param taskList        The list of tasks.
+     * @param taskDescription The description of the task to be added.
+     */
+    public static void addTask(Task[] taskList, String taskDescription) {
         taskList[Task.getTaskCount()] = new Task(taskDescription);
         System.out.println("Added \"" + taskDescription + "\"");
     }
 
-    public static void TrackInput() {
+    /**
+     * Marks or unmarks the task that user chooses.
+     *
+     * @param isMark   User's choice to mark or unmark.
+     * @param taskList List of tasks.
+     * @param input    User's input.
+     */
+    public static void markTask(Boolean isMark, Task[] taskList, String input) {
+        if (isMark) {
+            int toMark = Integer.parseInt(input.substring(5)) - 1;
+            System.out.println(taskList[toMark].getDescription() + " marked");
+            taskList[toMark].setDone(true);
+        } else {
+            int toMark = Integer.parseInt(input.substring(7)) - 1;
+            System.out.println(taskList[toMark].getDescription() + " unmarked");
+            taskList[toMark].setDone(false);
+        }
+    }
+
+    /**
+     * Method that takes in the user's input to allow them
+     * to interact with Duke.
+     */
+    public static void trackInput() {
         Scanner scanner = new Scanner(System.in);
         Task[] taskList = new Task[100];
-        final String LINEDIVIDER = "-------------------------------------";
+        final String LINE_DIVIDER = "-------------------------------------";
         while (true) {
-            String input = CleanInput(scanner.nextLine());
-            System.out.println(LINEDIVIDER);
+            String input = cleanInput(scanner.nextLine());
+            System.out.println(LINE_DIVIDER);
             if (input.equals("bye")) {
-                System.out.println("Bye bye!!! \n" + LINEDIVIDER + "\n");
+                System.out.println("Bye bye!!! \n" + LINE_DIVIDER + "\n");
                 break;
             } else if (input.equals("list")) {
-                ListTasks(taskList);
+                listTasks(taskList);
             } else if (input.startsWith("add ")) {
-                AddTask(taskList, input.substring(4));
+                addTask(taskList, input.substring(4));
             } else if (input.startsWith("mark ")) {
-                int toMark = Integer.parseInt(input.substring(5)) - 1;
-                System.out.println(taskList[toMark].getDescription() + " marked");
-                taskList[toMark].setDone(true);
+                markTask(true, taskList, input);
             } else if (input.startsWith("unmark ")) {
-                int toMark = Integer.parseInt(input.substring(7)) - 1;
-                System.out.println(taskList[toMark].getDescription() + " unmarked");
-                taskList[toMark].setDone(false);
+                markTask(false, taskList, input);
             } else {
                 System.out.println("Invalid command.");
             }
-            System.out.println(LINEDIVIDER);
+            System.out.println(LINE_DIVIDER);
         }
     }
 
     public static void main(String[] args) {
-        WelcomeUser();
-        TrackInput();
+        welcomeUser();
+        trackInput();
     }
 }

From e8327470e700b3a4c61bc3d24568596dc569ab5c Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Tue, 30 Aug 2022 03:21:39 +0800
Subject: [PATCH 06/26] Add new java classes for level 4

---
 src/main/java/Deadline.java | 2 ++
 src/main/java/Event.java    | 2 ++
 src/main/java/Todo.java     | 2 ++
 3 files changed, 6 insertions(+)
 create mode 100644 src/main/java/Deadline.java
 create mode 100644 src/main/java/Event.java
 create mode 100644 src/main/java/Todo.java

diff --git a/src/main/java/Deadline.java b/src/main/java/Deadline.java
new file mode 100644
index 00000000..58f2892a
--- /dev/null
+++ b/src/main/java/Deadline.java
@@ -0,0 +1,2 @@
+public class Deadline extends Task {
+}
diff --git a/src/main/java/Event.java b/src/main/java/Event.java
new file mode 100644
index 00000000..ed93f04c
--- /dev/null
+++ b/src/main/java/Event.java
@@ -0,0 +1,2 @@
+public class Event extends Task {
+}
diff --git a/src/main/java/Todo.java b/src/main/java/Todo.java
new file mode 100644
index 00000000..62691524
--- /dev/null
+++ b/src/main/java/Todo.java
@@ -0,0 +1,2 @@
+public class Todo extends Task {
+}

From 751198dbf59dfe6600415d800dec4791ba1a322e Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Wed, 31 Aug 2022 03:01:57 +0800
Subject: [PATCH 07/26] Add some incomplete code for level 4

---
 src/main/java/Deadline.java     |  11 ++++
 src/main/java/Duke.java         | 102 +-------------------------------
 src/main/java/Event.java        |  12 ++++
 src/main/java/InputHandler.java |  33 +++++++++++
 src/main/java/TaskList.java     |  30 ++++++++++
 src/main/java/Todo.java         |   8 +++
 src/main/java/UI.java           |  23 +++++++
 7 files changed, 119 insertions(+), 100 deletions(-)
 create mode 100644 src/main/java/InputHandler.java
 create mode 100644 src/main/java/TaskList.java
 create mode 100644 src/main/java/UI.java

diff --git a/src/main/java/Deadline.java b/src/main/java/Deadline.java
index 58f2892a..573b7b87 100644
--- a/src/main/java/Deadline.java
+++ b/src/main/java/Deadline.java
@@ -1,2 +1,13 @@
 public class Deadline extends Task {
+    protected String by;
+
+    public Deadline(String description, String by) {
+        super(description);
+        this.by = by;
+    }
+
+    @Override
+    public String toString() {
+        return "[D]" + super.toString() + " (by: " + by + ")";
+    }
 }
diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 3d3ee392..aadc28e1 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,107 +1,9 @@
 import java.util.Scanner;
 
 public class Duke {
-    /**
-     * Prints the welcome message
-     */
     public static void welcomeUser() {
-        String welcomeText = "-------------------------------------\n"
-                + "Hello! I am not Duke.\n"
-                + "Here are a list of commands: \n"
-                + "\tadd <string> : adds a task to the list\n"
-                + "\tlist : shows list of tasks\n"
-                + "\tmark <task id> : marks a task \n"
-                + "\tunmark <task id> : unmarks a task \n"
-                + "\tbye : exits the program \n"
-                + "I WILL CRASH IF YOU DO NOT COMPLY!!!\n"
-                + "-------------------------------------";
-        System.out.println(welcomeText);
-    }
-
-    /**
-     * Sets input to lowercase and removes any
-     * leading and trailing whitespaces.
-     *
-     * @param input Input entered by user.
-     * @return Lowercase and trimmed input.
-     */
-    public static String cleanInput(String input) {
-        return input.toLowerCase().trim();
-    }
-
-    /**
-     * Prints the current list of tasks.
-     * If list is empty, print error message.
-     *
-     * @param list List of tasks.
-     */
-    public static void listTasks(Task[] list) {
-        if (Task.getTaskCount() != 0) {
-            for (int i = 0; i < Task.getTaskCount(); i++) {
-                System.out.println(list[i].getStatusIcon() + (i + 1) + ": " + list[i].getDescription());
-            }
-        } else {
-            System.out.println("The list is empty, please add something!");
-        }
-    }
-
-    /**
-     * Adds a task to the list of tasks.
-     *
-     * @param taskList        The list of tasks.
-     * @param taskDescription The description of the task to be added.
-     */
-    public static void addTask(Task[] taskList, String taskDescription) {
-        taskList[Task.getTaskCount()] = new Task(taskDescription);
-        System.out.println("Added \"" + taskDescription + "\"");
-    }
-
-    /**
-     * Marks or unmarks the task that user chooses.
-     *
-     * @param isMark   User's choice to mark or unmark.
-     * @param taskList List of tasks.
-     * @param input    User's input.
-     */
-    public static void markTask(Boolean isMark, Task[] taskList, String input) {
-        if (isMark) {
-            int toMark = Integer.parseInt(input.substring(5)) - 1;
-            System.out.println(taskList[toMark].getDescription() + " marked");
-            taskList[toMark].setDone(true);
-        } else {
-            int toMark = Integer.parseInt(input.substring(7)) - 1;
-            System.out.println(taskList[toMark].getDescription() + " unmarked");
-            taskList[toMark].setDone(false);
-        }
-    }
-
-    /**
-     * Method that takes in the user's input to allow them
-     * to interact with Duke.
-     */
-    public static void trackInput() {
-        Scanner scanner = new Scanner(System.in);
-        Task[] taskList = new Task[100];
-        final String LINE_DIVIDER = "-------------------------------------";
-        while (true) {
-            String input = cleanInput(scanner.nextLine());
-            System.out.println(LINE_DIVIDER);
-            if (input.equals("bye")) {
-                System.out.println("Bye bye!!! \n" + LINE_DIVIDER + "\n");
-                break;
-            } else if (input.equals("list")) {
-                listTasks(taskList);
-            } else if (input.startsWith("add ")) {
-                addTask(taskList, input.substring(4));
-            } else if (input.startsWith("mark ")) {
-                markTask(true, taskList, input);
-            } else if (input.startsWith("unmark ")) {
-                markTask(false, taskList, input);
-            } else {
-                System.out.println("Invalid command.");
-            }
-            System.out.println(LINE_DIVIDER);
-        }
+        UI.welcomeUser();
+        InputHandler.handleInput();
     }
 
     public static void main(String[] args) {
diff --git a/src/main/java/Event.java b/src/main/java/Event.java
index ed93f04c..c0e8dac9 100644
--- a/src/main/java/Event.java
+++ b/src/main/java/Event.java
@@ -1,2 +1,14 @@
 public class Event extends Task {
+    protected String at;
+
+    public Event(String description, String at) {
+        super(description);
+        this.at = at;
+    }
+
+    @Override
+    public String toString() {
+        return "[E]" + super.toString() + " (at: " + at + ")";
+    }
+
 }
diff --git a/src/main/java/InputHandler.java b/src/main/java/InputHandler.java
new file mode 100644
index 00000000..65b0b8bc
--- /dev/null
+++ b/src/main/java/InputHandler.java
@@ -0,0 +1,33 @@
+public class InputHandler {
+
+    private static final String TODO = "todo";
+    private static final String LIST = "list";
+    private static final String DEADLINE = "deadline";
+    private static final String EVENT = "event";
+    private static final String BYE = "bye";
+    private static final String MARK = "add";
+    private static final String UNMARK = "unmark";
+
+    public static void handleInput() {
+        while (true) {
+            String input = UI.getInput();
+            if (input.startsWith(BYE)) {
+                break;
+            } else if (input.startsWith(TODO)) {
+                //do something
+            } else if (input.startsWith(LIST)) {
+                //do something
+            } else if (input.startsWith(DEADLINE)) {
+                //do something
+            } else if (input.startsWith(EVENT)) {
+                //do something
+            } else if (input.startsWith(MARK)) {
+                //do something
+            } else if (input.startsWith(UNMARK)) {
+                //do something
+            } else {
+
+            }
+        }
+    }
+}
diff --git a/src/main/java/TaskList.java b/src/main/java/TaskList.java
new file mode 100644
index 00000000..a4e61bac
--- /dev/null
+++ b/src/main/java/TaskList.java
@@ -0,0 +1,30 @@
+public class TaskList {
+
+    private Task[] tasks;
+    private int taskCount = 0;
+
+    public TaskList() {
+        this.tasks = new Task[100];
+    }
+
+    public void addDeadLine(Deadline deadline) {
+        tasks[taskCount] = deadline;
+        taskCount++;
+    }
+
+    public void addTodo(Todo todo) {
+        tasks[taskCount] = todo;
+        taskCount++;
+    }
+
+    public void addEvent(Event event) {
+        tasks[taskCount] = event;
+        taskCount++;
+    }
+
+    public void printList() {
+        for (int i = 0; i < taskCount; i++) {
+            System.out.println(tasks[taskCount]);
+        }
+    }
+}
diff --git a/src/main/java/Todo.java b/src/main/java/Todo.java
index 62691524..eabef3ab 100644
--- a/src/main/java/Todo.java
+++ b/src/main/java/Todo.java
@@ -1,2 +1,10 @@
 public class Todo extends Task {
+    public Todo(String description) {
+        super(description);
+    }
+
+    @Override
+    public String toString() {
+        return "[T]" + super.toString();
+    }
 }
diff --git a/src/main/java/UI.java b/src/main/java/UI.java
new file mode 100644
index 00000000..6d2f16e8
--- /dev/null
+++ b/src/main/java/UI.java
@@ -0,0 +1,23 @@
+import java.util.Scanner;
+
+public class UI {
+    public static void welcomeUser() {
+        String welcomeText = "-------------------------------------\n"
+                + "Hello! I am not Duke.\n"
+                + "Here are a list of commands: \n"
+                + "\tadd <string> : adds a task to the list\n"
+                + "\tlist : shows list of tasks\n"
+                + "\tmark <task id> : marks a task \n"
+                + "\tunmark <task id> : unmarks a task \n"
+                + "\tbye : exits the program \n"
+                + "I WILL CRASH IF YOU DO NOT COMPLY!!!\n"
+                + "-------------------------------------";
+        System.out.println(welcomeText);
+    }
+
+    public static String getInput() {
+        Scanner sc = new Scanner(System.in);
+        String input = sc.nextLine();
+        return input.trim();
+    }
+}

From ace71c163b9195e074fc062db67a8c85b1067ea4 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 1 Sep 2022 01:25:20 +0800
Subject: [PATCH 08/26] Add Level-4 with some improvements to code quality

Coding quality may need further improvement.
---
 src/main/java/Deadline.java     |  2 +-
 src/main/java/Duke.java         |  5 ++--
 src/main/java/Event.java        |  2 +-
 src/main/java/InputHandler.java | 17 ++++++------
 src/main/java/Task.java         |  6 +---
 src/main/java/TaskHandler.java  | 49 +++++++++++++++++++++++++++++++++
 src/main/java/TaskList.java     | 47 +++++++++++++++++++++++++------
 src/main/java/Todo.java         |  2 +-
 src/main/java/UI.java           |  6 ++--
 9 files changed, 106 insertions(+), 30 deletions(-)
 create mode 100644 src/main/java/TaskHandler.java

diff --git a/src/main/java/Deadline.java b/src/main/java/Deadline.java
index 573b7b87..bca8eece 100644
--- a/src/main/java/Deadline.java
+++ b/src/main/java/Deadline.java
@@ -8,6 +8,6 @@ public Deadline(String description, String by) {
 
     @Override
     public String toString() {
-        return "[D]" + super.toString() + " (by: " + by + ")";
+        return "[D]" + super.getStatusIcon() + " " + super.getDescription() + " (by: " + by + ")";
     }
 }
diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index aadc28e1..dd119855 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,13 +1,12 @@
 import java.util.Scanner;
 
 public class Duke {
-    public static void welcomeUser() {
+    public static void startProgram() {
         UI.welcomeUser();
         InputHandler.handleInput();
     }
 
     public static void main(String[] args) {
-        welcomeUser();
-        trackInput();
+        startProgram();
     }
 }
diff --git a/src/main/java/Event.java b/src/main/java/Event.java
index c0e8dac9..74f053b6 100644
--- a/src/main/java/Event.java
+++ b/src/main/java/Event.java
@@ -8,7 +8,7 @@ public Event(String description, String at) {
 
     @Override
     public String toString() {
-        return "[E]" + super.toString() + " (at: " + at + ")";
+        return "[E]" + super.getStatusIcon()+ " " + super.getDescription() + " (at: " + at + ")";
     }
 
 }
diff --git a/src/main/java/InputHandler.java b/src/main/java/InputHandler.java
index 65b0b8bc..6511b11c 100644
--- a/src/main/java/InputHandler.java
+++ b/src/main/java/InputHandler.java
@@ -5,28 +5,29 @@ public class InputHandler {
     private static final String DEADLINE = "deadline";
     private static final String EVENT = "event";
     private static final String BYE = "bye";
-    private static final String MARK = "add";
+    private static final String MARK = "mark";
     private static final String UNMARK = "unmark";
 
     public static void handleInput() {
         while (true) {
             String input = UI.getInput();
             if (input.startsWith(BYE)) {
+                TaskHandler.handleBye();
                 break;
             } else if (input.startsWith(TODO)) {
-                //do something
+                TaskHandler.handleTodo(input);
             } else if (input.startsWith(LIST)) {
-                //do something
+                TaskHandler.handleList();
             } else if (input.startsWith(DEADLINE)) {
-                //do something
+                TaskHandler.handleDeadline(input);
             } else if (input.startsWith(EVENT)) {
-                //do something
+                TaskHandler.handleEvent(input);
             } else if (input.startsWith(MARK)) {
-                //do something
+                TaskHandler.handleMark(input);
             } else if (input.startsWith(UNMARK)) {
-                //do something
+                TaskHandler.handleUnmark(input);
             } else {
-
+                TaskHandler.handleInvalid(input);
             }
         }
     }
diff --git a/src/main/java/Task.java b/src/main/java/Task.java
index 82d21b35..4010f3ad 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Task.java
@@ -1,12 +1,10 @@
 public class Task {
     protected String description;
     protected boolean isDone;
-    protected static int taskCount = 0;
 
     public Task(String description) {
         this.description = description;
         this.isDone = false;
-        Task.taskCount++;
     }
 
     public void setDone(boolean isDone) {
@@ -17,11 +15,9 @@ public String getStatusIcon() {
         return isDone ? "[X]" : "[ ]";
     }
 
-    public static int getTaskCount() {
-        return taskCount;
-    }
 
     public String getDescription() {
         return description;
     }
+
 }
diff --git a/src/main/java/TaskHandler.java b/src/main/java/TaskHandler.java
new file mode 100644
index 00000000..836bba32
--- /dev/null
+++ b/src/main/java/TaskHandler.java
@@ -0,0 +1,49 @@
+public class TaskHandler {
+    private static final String BYE_MESSAGE = "Bye! ;)";
+
+    public static void handleBye() {
+        System.out.println(BYE_MESSAGE);
+    }
+
+    public static void handleTodo(String input) {
+        String[] splitInput = input.split(" ", 2);
+        Todo todo = new Todo(splitInput[1]);
+        TaskList.addTodo(todo);
+    }
+
+    public static void handleList() {
+        TaskList.printList();
+    }
+
+    public static void handleMark(String input) {
+        String[] splitInput = input.split(" ", 2);
+        int target = Integer.parseInt(splitInput[1]);
+        TaskList.markTarget(target);
+
+    }
+
+    public static void handleUnmark(String input) {
+        String[] splitInput = input.split(" ", 2);
+        int target = Integer.parseInt(splitInput[1]);
+        TaskList.unmarkTarget(target);
+    }
+
+    public static void handleDeadline(String input) {
+        String[] splitInput = input.split(" ", 2);
+        String[] splitCommand = splitInput[1].split(" /by ", 2); // 0 is description, 1 is by
+        Deadline deadline = new Deadline(splitCommand[0], splitCommand[1]);
+        TaskList.addDeadLine(deadline);
+    }
+
+    public static void handleEvent(String input) {
+        String[] splitInput = input.split(" ", 2);
+        String[] splitCommand = splitInput[1].split(" /at ", 2); // 0 is description, 1 is by
+        Event event = new Event(splitCommand[0], splitCommand[1]);
+        TaskList.addEvent(event);
+    }
+
+    public static void handleInvalid(String input) {
+        System.out.println("\"" + input + "\"" + " is not a valid command, please try again!");
+    }
+
+}
diff --git a/src/main/java/TaskList.java b/src/main/java/TaskList.java
index a4e61bac..7d63ef04 100644
--- a/src/main/java/TaskList.java
+++ b/src/main/java/TaskList.java
@@ -1,30 +1,59 @@
 public class TaskList {
 
-    private Task[] tasks;
-    private int taskCount = 0;
+    private static Task[] tasks = new Task[100];
+    private static int taskCount = 0;
+    private static final String LINE_DIVIDER = "-------------------------------------";
+    private static final String ROGER_MESSAGE = "Got it. I have added this task:";
 
-    public TaskList() {
-        this.tasks = new Task[100];
+    private static void printRoger(Task task) {
+        System.out.println(ROGER_MESSAGE);
+        System.out.println(task);
+        System.out.println("You now have " + taskCount + " tasks.");
+        System.out.println(LINE_DIVIDER);
     }
 
-    public void addDeadLine(Deadline deadline) {
+    private static void printMark(int target, boolean mark) {
+        if (mark) {
+            System.out.println("Marked this task: \n " + tasks[target - 1]);
+        } else {
+            System.out.println("Unmarked this task: \n" + tasks[target - 1]);
+        }
+        System.out.println(LINE_DIVIDER);
+    }
+
+    public static void addDeadLine(Deadline deadline) {
         tasks[taskCount] = deadline;
         taskCount++;
+        printRoger(deadline);
     }
 
-    public void addTodo(Todo todo) {
+    public static void addTodo(Todo todo) {
         tasks[taskCount] = todo;
         taskCount++;
+        printRoger(todo);
     }
 
-    public void addEvent(Event event) {
+    public static void addEvent(Event event) {
         tasks[taskCount] = event;
         taskCount++;
+        printRoger(event);
+    }
+
+    public static void markTarget(int target) {
+        tasks[target - 1].setDone(true);
+        printMark(target, true);
+    }
+
+    public static void unmarkTarget(int target) {
+        tasks[target - 1].setDone(false);
+        printMark(target, false);
     }
 
-    public void printList() {
+    public static void printList() {
+        System.out.println("Here are a list of your tasks: ");
         for (int i = 0; i < taskCount; i++) {
-            System.out.println(tasks[taskCount]);
+            System.out.println(i + 1 + ". " + tasks[i]);
         }
+        System.out.println(LINE_DIVIDER);
     }
 }
diff --git a/src/main/java/Todo.java b/src/main/java/Todo.java
index eabef3ab..14671a55 100644
--- a/src/main/java/Todo.java
+++ b/src/main/java/Todo.java
@@ -5,6 +5,6 @@ public Todo(String description) {
 
     @Override
     public String toString() {
-        return "[T]" + super.toString();
+        return "[T]" + super.getStatusIcon() + " " + super.getDescription();
     }
 }
diff --git a/src/main/java/UI.java b/src/main/java/UI.java
index 6d2f16e8..dd0bc634 100644
--- a/src/main/java/UI.java
+++ b/src/main/java/UI.java
@@ -5,10 +5,12 @@ public static void welcomeUser() {
         String welcomeText = "-------------------------------------\n"
                 + "Hello! I am not Duke.\n"
                 + "Here are a list of commands: \n"
-                + "\tadd <string> : adds a task to the list\n"
-                + "\tlist : shows list of tasks\n"
+                + "\ttodo <string> : adds a Todo to the list\n"
+                + "\tdeadline <string> /by <string> : adds a deadline and its deadline...\n"
+                + "\tevent <string> /at <string> : adds an event and its time...\n"
                 + "\tmark <task id> : marks a task \n"
                 + "\tunmark <task id> : unmarks a task \n"
+                + "\tlist : lists out all your tasks \n"
                 + "\tbye : exits the program \n"
                 + "I WILL CRASH IF YOU DO NOT COMPLY!!!\n"
                 + "-------------------------------------";

From 5b1fa3667ddd878280f0e4007901d91933233d2e Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 1 Sep 2022 02:06:28 +0800
Subject: [PATCH 09/26] Add test cases

Has issues running the tests
---
 src/main/java/UI.java     |  10 +--
 text-ui-test/EXPECTED.TXT | 138 ++++++++++++++++++++++++++++++++++++--
 text-ui-test/input.txt    |  32 +++++++++
 3 files changed, 168 insertions(+), 12 deletions(-)

diff --git a/src/main/java/UI.java b/src/main/java/UI.java
index dd0bc634..d20622dc 100644
--- a/src/main/java/UI.java
+++ b/src/main/java/UI.java
@@ -4,14 +4,14 @@ public class UI {
     public static void welcomeUser() {
         String welcomeText = "-------------------------------------\n"
                 + "Hello! I am not Duke.\n"
-                + "Here are a list of commands: \n"
+                + "Here are a list of commands:\n"
                 + "\ttodo <string> : adds a Todo to the list\n"
                 + "\tdeadline <string> /by <string> : adds a deadline and its deadline...\n"
                 + "\tevent <string> /at <string> : adds an event and its time...\n"
-                + "\tmark <task id> : marks a task \n"
-                + "\tunmark <task id> : unmarks a task \n"
-                + "\tlist : lists out all your tasks \n"
-                + "\tbye : exits the program \n"
+                + "\tmark <task id> : marks a task\n"
+                + "\tunmark <task id> : unmarks a task\n"
+                + "\tlist : lists out all your tasks\n"
+                + "\tbye : exits the program\n"
                 + "I WILL CRASH IF YOU DO NOT COMPLY!!!\n"
                 + "-------------------------------------";
         System.out.println(welcomeText);
diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 657e74f6..4ab1c857 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -1,7 +1,131 @@
-Hello from
- ____        _        
-|  _ \ _   _| | _____ 
-| | | | | | | |/ / _ \
-| |_| | |_| |   <  __/
-|____/ \__,_|_|\_\___|
-
+-------------------------------------
+Hello! I am not Duke.
+Here are a list of commands:
+    todo <string> : adds a Todo to the list
+    deadline <string> /by <string> : adds a deadline and its deadline...
+    event <string> /at <string> : adds an event and its time...
+    mark <task id> : marks a task
+    unmark <task id> : unmarks a task
+    list : lists out all your tasks
+    bye : exits the program
+I WILL CRASH IF YOU DO NOT COMPLY!!!
+-------------------------------------
+Got it. I have added this task:
+[T][ ] read book
+You now have 1 tasks.
+-------------------------------------
+Marked this task:
+ [T][X] read book
+-------------------------------------
+Here are a list of your tasks:
+1. [T][X] read book
+-------------------------------------
+Unmarked this task:
+[T][ ] read book
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+-------------------------------------
+Got it. I have added this task:
+[D][ ] do dishes (by: midnight)
+You now have 2 tasks.
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+-------------------------------------
+Marked this task:
+ [D][X] do dishes (by: midnight)
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][X] do dishes (by: midnight)
+-------------------------------------
+Unmarked this task:
+[D][ ] do dishes (by: midnight)
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+-------------------------------------
+Got it. I have added this task:
+[E][ ] attend wedding (at: Sunday 1900)
+You now have 3 tasks.
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+3. [E][ ] attend wedding (at: Sunday 1900)
+-------------------------------------
+Marked this task:
+ [E][X] attend wedding (at: Sunday 1900)
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+3. [E][X] attend wedding (at: Sunday 1900)
+-------------------------------------
+Unmarked this task:
+[E][ ] attend wedding (at: Sunday 1900)
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+3. [E][ ] attend wedding (at: Sunday 1900)
+-------------------------------------
+"this is an invalid command" is not a valid command, please try again!
+Got it. I have added this task:
+[T][ ] read book again
+You now have 4 tasks.
+-------------------------------------
+Got it. I have added this task:
+[D][ ] do dishes again (by: morning)
+You now have 5 tasks.
+-------------------------------------
+Got it. I have added this task:
+[E][ ] attend funeral (at: 31st February)
+You now have 6 tasks.
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+3. [E][ ] attend wedding (at: Sunday 1900)
+4. [T][ ] read book again
+5. [D][ ] do dishes again (by: morning)
+6. [E][ ] attend funeral (at: 31st February)
+-------------------------------------
+Marked this task:
+ [T][X] read book again
+-------------------------------------
+Marked this task:
+ [D][X] do dishes again (by: morning)
+-------------------------------------
+Marked this task:
+ [E][X] attend funeral (at: 31st February)
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+3. [E][ ] attend wedding (at: Sunday 1900)
+4. [T][X] read book again
+5. [D][X] do dishes again (by: morning)
+6. [E][X] attend funeral (at: 31st February)
+-------------------------------------
+Unmarked this task:
+[T][ ] read book again
+-------------------------------------
+Unmarked this task:
+[D][ ] do dishes again (by: morning)
+-------------------------------------
+Unmarked this task:
+[E][ ] attend funeral (at: 31st February)
+-------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+2. [D][ ] do dishes (by: midnight)
+3. [E][ ] attend wedding (at: Sunday 1900)
+4. [T][ ] read book again
+5. [D][ ] do dishes again (by: morning)
+6. [E][ ] attend funeral (at: 31st February)
+-------------------------------------
+Bye! ;)
\ No newline at end of file
diff --git a/text-ui-test/input.txt b/text-ui-test/input.txt
index e69de29b..894907db 100644
--- a/text-ui-test/input.txt
+++ b/text-ui-test/input.txt
@@ -0,0 +1,32 @@
+todo read book
+list
+mark 1
+list
+unmark 1
+list
+deadline do dishes /by midnight
+list
+mark 2
+list
+unmark 2
+list
+event attend wedding /at Sunday 1900
+list
+mark 3
+list
+unmark 3
+list
+this is an invalid command
+todo read book again
+deadline do dishes again /by morning
+event attend funeral /at 31st February
+list
+mark 4
+mark 5
+mark 6
+list
+unmark 4
+unmark 5
+unmark 6
+list
+bye

From efd57f2ee564d25204c85f5bec98f03452f84b06 Mon Sep 17 00:00:00 2001
From: jjtoh <johntohjiajun@gmail.com>
Date: Thu, 1 Sep 2022 14:57:45 +0800
Subject: [PATCH 10/26] Change expected output

Testing still has issues
---
 text-ui-test/EXPECTED.TXT | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 4ab1c857..72eff8f5 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -1,19 +1,22 @@
 -------------------------------------
 Hello! I am not Duke.
 Here are a list of commands:
-    todo <string> : adds a Todo to the list
-    deadline <string> /by <string> : adds a deadline and its deadline...
-    event <string> /at <string> : adds an event and its time...
-    mark <task id> : marks a task
-    unmark <task id> : unmarks a task
-    list : lists out all your tasks
-    bye : exits the program
+	todo <string> : adds a Todo to the list
+	deadline <string> /by <string> : adds a deadline and its deadline...
+	event <string> /at <string> : adds an event and its time...
+	mark <task id> : marks a task
+	unmark <task id> : unmarks a task
+	list : lists out all your tasks
+	bye : exits the program
 I WILL CRASH IF YOU DO NOT COMPLY!!!
 -------------------------------------
 Got it. I have added this task:
 [T][ ] read book
 You now have 1 tasks.
 -------------------------------------
+Here are a list of your tasks:
+1. [T][ ] read book
+-------------------------------------
 Marked this task:
  [T][X] read book
 -------------------------------------

From 7b0ca7f64b9b2e8ce7433d8f6edc69f27a11dd59 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 8 Sep 2022 03:54:49 +0800
Subject: [PATCH 11/26] Add Level-5 and A-Exception

---
 src/main/java/Duke.java          |  2 -
 src/main/java/DukeException.java |  3 ++
 src/main/java/Event.java         |  2 +-
 src/main/java/InputHandler.java  | 33 ++++++++++++---
 src/main/java/TaskHandler.java   | 69 +++++++++++++++++++++++---------
 5 files changed, 83 insertions(+), 26 deletions(-)
 create mode 100644 src/main/java/DukeException.java

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index dd119855..ecd8d61e 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,5 +1,3 @@
-import java.util.Scanner;
-
 public class Duke {
     public static void startProgram() {
         UI.welcomeUser();
diff --git a/src/main/java/DukeException.java b/src/main/java/DukeException.java
new file mode 100644
index 00000000..5e322ffd
--- /dev/null
+++ b/src/main/java/DukeException.java
@@ -0,0 +1,3 @@
+public class DukeException extends Exception {
+
+}
diff --git a/src/main/java/Event.java b/src/main/java/Event.java
index 74f053b6..cb6b346e 100644
--- a/src/main/java/Event.java
+++ b/src/main/java/Event.java
@@ -8,7 +8,7 @@ public Event(String description, String at) {
 
     @Override
     public String toString() {
-        return "[E]" + super.getStatusIcon()+ " " + super.getDescription() + " (at: " + at + ")";
+        return "[E]" + super.getStatusIcon() + " " + super.getDescription() + " (at: " + at + ")";
     }
 
 }
diff --git a/src/main/java/InputHandler.java b/src/main/java/InputHandler.java
index 6511b11c..27bda554 100644
--- a/src/main/java/InputHandler.java
+++ b/src/main/java/InputHandler.java
@@ -15,17 +15,40 @@ public static void handleInput() {
                 TaskHandler.handleBye();
                 break;
             } else if (input.startsWith(TODO)) {
-                TaskHandler.handleTodo(input);
+                try {
+                    TaskHandler.handleTodo(input);
+                } catch (DukeException e) {
+                    System.out.println("todo what?");
+                }
             } else if (input.startsWith(LIST)) {
                 TaskHandler.handleList();
             } else if (input.startsWith(DEADLINE)) {
-                TaskHandler.handleDeadline(input);
+                try {
+                    TaskHandler.handleDeadline(input);
+                } catch (DukeException e) {
+                    System.out.println("deadline missing some info...");
+                    ;
+                }
             } else if (input.startsWith(EVENT)) {
-                TaskHandler.handleEvent(input);
+                try {
+                    TaskHandler.handleEvent(input);
+                } catch (DukeException e) {
+                    System.out.println("event missing some info...");
+                    ;
+                }
             } else if (input.startsWith(MARK)) {
-                TaskHandler.handleMark(input);
+                try {
+                    TaskHandler.handleMark(input);
+                } catch (DukeException e) {
+                    System.out.println("mark what");
+                    ;
+                }
             } else if (input.startsWith(UNMARK)) {
-                TaskHandler.handleUnmark(input);
+                try {
+                    TaskHandler.handleUnmark(input);
+                } catch (DukeException e) {
+                    System.out.println("unmark what");
+                }
             } else {
                 TaskHandler.handleInvalid(input);
             }
diff --git a/src/main/java/TaskHandler.java b/src/main/java/TaskHandler.java
index 836bba32..735338ba 100644
--- a/src/main/java/TaskHandler.java
+++ b/src/main/java/TaskHandler.java
@@ -1,12 +1,16 @@
 public class TaskHandler {
     private static final String BYE_MESSAGE = "Bye! ;)";
+    public static final int SPLIT_AMOUNT = 2;
 
     public static void handleBye() {
         System.out.println(BYE_MESSAGE);
     }
 
-    public static void handleTodo(String input) {
-        String[] splitInput = input.split(" ", 2);
+    public static void handleTodo(String input) throws DukeException {
+        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
+        if (splitInput.length != SPLIT_AMOUNT) {
+            throw new DukeException();
+        }
         Todo todo = new Todo(splitInput[1]);
         TaskList.addTodo(todo);
     }
@@ -15,30 +19,59 @@ public static void handleList() {
         TaskList.printList();
     }
 
-    public static void handleMark(String input) {
-        String[] splitInput = input.split(" ", 2);
-        int target = Integer.parseInt(splitInput[1]);
-        TaskList.markTarget(target);
+    public static void handleMark(String input) throws DukeException {
+        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
+        if (splitInput.length != SPLIT_AMOUNT) {
+            throw new DukeException();
+        }
+        try {
+            int target = Integer.parseInt(splitInput[1]);
+            TaskList.markTarget(target);
+        } catch (NullPointerException e) {
+            System.out.println("There is no task with that index");
+        } catch (NumberFormatException e) {
+            System.out.println("Index is a number...");
+        }
+    }
 
+    public static void handleUnmark(String input) throws DukeException {
+        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
+        if (splitInput.length != SPLIT_AMOUNT) {
+            throw new DukeException();
+        }
+        try {
+            int target = Integer.parseInt(splitInput[1]);
+            TaskList.markTarget(target);
+        } catch (NullPointerException e) {
+            System.out.println("There is no task with that index");
+        } catch (NumberFormatException e) {
+            System.out.println("Index is a number...");
+        }
     }
 
-    public static void handleUnmark(String input) {
-        String[] splitInput = input.split(" ", 2);
-        int target = Integer.parseInt(splitInput[1]);
-        TaskList.unmarkTarget(target);
+    public static String[] splitTaskTime(String input) throws DukeException {
+        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
+        if (splitInput.length != SPLIT_AMOUNT) {
+            throw new DukeException();
+        }
+        return splitInput[1].split(" /by ", SPLIT_AMOUNT);
     }
 
-    public static void handleDeadline(String input) {
-        String[] splitInput = input.split(" ", 2);
-        String[] splitCommand = splitInput[1].split(" /by ", 2); // 0 is description, 1 is by
-        Deadline deadline = new Deadline(splitCommand[0], splitCommand[1]);
+    public static void handleDeadline(String input) throws DukeException {
+        String[] splitCommand = splitTaskTime(input);
+        if (splitCommand.length != SPLIT_AMOUNT) {
+            throw new DukeException();
+        }
+        Deadline deadline = new Deadline(splitCommand[0], splitCommand[1]); //index 0 is description, index 1 is time
         TaskList.addDeadLine(deadline);
     }
 
-    public static void handleEvent(String input) {
-        String[] splitInput = input.split(" ", 2);
-        String[] splitCommand = splitInput[1].split(" /at ", 2); // 0 is description, 1 is by
-        Event event = new Event(splitCommand[0], splitCommand[1]);
+    public static void handleEvent(String input) throws DukeException {
+        String[] splitCommand = splitTaskTime(input);
+        if (splitCommand.length != SPLIT_AMOUNT) {
+            throw new DukeException();
+        }
+        Event event = new Event(splitCommand[0], splitCommand[1]); //index 0 is description, index 1 is time
         TaskList.addEvent(event);
     }
 

From ae8e7eb3a92115fdced1ba0cac7fcf32eda9e098 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 8 Sep 2022 04:04:28 +0800
Subject: [PATCH 12/26] Add A-Packages

---
 src/main/java/Duke.java                          | 3 +++
 src/main/java/{ => exception}/DukeException.java | 2 ++
 src/main/java/{ => handler}/InputHandler.java    | 5 +++++
 src/main/java/{ => handler}/TaskHandler.java     | 8 ++++++++
 src/main/java/{ => task}/Deadline.java           | 2 ++
 src/main/java/{ => task}/Event.java              | 2 ++
 src/main/java/{ => task}/Task.java               | 2 ++
 src/main/java/{ => task}/TaskList.java           | 2 ++
 src/main/java/{ => task}/Todo.java               | 2 ++
 src/main/java/{ => ui}/UI.java                   | 2 ++
 10 files changed, 30 insertions(+)
 rename src/main/java/{ => exception}/DukeException.java (71%)
 rename src/main/java/{ => handler}/InputHandler.java (96%)
 rename src/main/java/{ => handler}/TaskHandler.java (95%)
 rename src/main/java/{ => task}/Deadline.java (95%)
 rename src/main/java/{ => task}/Event.java (95%)
 rename src/main/java/{ => task}/Task.java (96%)
 rename src/main/java/{ => task}/TaskList.java (99%)
 rename src/main/java/{ => task}/Todo.java (94%)
 rename src/main/java/{ => ui}/UI.java (98%)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index ecd8d61e..f9dec8e2 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,3 +1,6 @@
+import handler.InputHandler;
+import ui.UI;
+
 public class Duke {
     public static void startProgram() {
         UI.welcomeUser();
diff --git a/src/main/java/DukeException.java b/src/main/java/exception/DukeException.java
similarity index 71%
rename from src/main/java/DukeException.java
rename to src/main/java/exception/DukeException.java
index 5e322ffd..c449019f 100644
--- a/src/main/java/DukeException.java
+++ b/src/main/java/exception/DukeException.java
@@ -1,3 +1,5 @@
+package exception;
+
 public class DukeException extends Exception {
 
 }
diff --git a/src/main/java/InputHandler.java b/src/main/java/handler/InputHandler.java
similarity index 96%
rename from src/main/java/InputHandler.java
rename to src/main/java/handler/InputHandler.java
index 27bda554..d7dc919f 100644
--- a/src/main/java/InputHandler.java
+++ b/src/main/java/handler/InputHandler.java
@@ -1,3 +1,8 @@
+package handler;
+
+import ui.UI;
+import exception.DukeException;
+
 public class InputHandler {
 
     private static final String TODO = "todo";
diff --git a/src/main/java/TaskHandler.java b/src/main/java/handler/TaskHandler.java
similarity index 95%
rename from src/main/java/TaskHandler.java
rename to src/main/java/handler/TaskHandler.java
index 735338ba..df6b8d1b 100644
--- a/src/main/java/TaskHandler.java
+++ b/src/main/java/handler/TaskHandler.java
@@ -1,3 +1,11 @@
+package handler;
+
+import task.Deadline;
+import task.Event;
+import task.TaskList;
+import task.Todo;
+import exception.DukeException;
+
 public class TaskHandler {
     private static final String BYE_MESSAGE = "Bye! ;)";
     public static final int SPLIT_AMOUNT = 2;
diff --git a/src/main/java/Deadline.java b/src/main/java/task/Deadline.java
similarity index 95%
rename from src/main/java/Deadline.java
rename to src/main/java/task/Deadline.java
index bca8eece..9f1fc775 100644
--- a/src/main/java/Deadline.java
+++ b/src/main/java/task/Deadline.java
@@ -1,3 +1,5 @@
+package task;
+
 public class Deadline extends Task {
     protected String by;
 
diff --git a/src/main/java/Event.java b/src/main/java/task/Event.java
similarity index 95%
rename from src/main/java/Event.java
rename to src/main/java/task/Event.java
index cb6b346e..6d00cc0d 100644
--- a/src/main/java/Event.java
+++ b/src/main/java/task/Event.java
@@ -1,3 +1,5 @@
+package task;
+
 public class Event extends Task {
     protected String at;
 
diff --git a/src/main/java/Task.java b/src/main/java/task/Task.java
similarity index 96%
rename from src/main/java/Task.java
rename to src/main/java/task/Task.java
index 4010f3ad..a768cbcf 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/task/Task.java
@@ -1,3 +1,5 @@
+package task;
+
 public class Task {
     protected String description;
     protected boolean isDone;
diff --git a/src/main/java/TaskList.java b/src/main/java/task/TaskList.java
similarity index 99%
rename from src/main/java/TaskList.java
rename to src/main/java/task/TaskList.java
index 7d63ef04..7f43bdf8 100644
--- a/src/main/java/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -1,3 +1,5 @@
+package task;
+
 public class TaskList {
 
     private static Task[] tasks = new Task[100];
diff --git a/src/main/java/Todo.java b/src/main/java/task/Todo.java
similarity index 94%
rename from src/main/java/Todo.java
rename to src/main/java/task/Todo.java
index 14671a55..710e5f95 100644
--- a/src/main/java/Todo.java
+++ b/src/main/java/task/Todo.java
@@ -1,3 +1,5 @@
+package task;
+
 public class Todo extends Task {
     public Todo(String description) {
         super(description);
diff --git a/src/main/java/UI.java b/src/main/java/ui/UI.java
similarity index 98%
rename from src/main/java/UI.java
rename to src/main/java/ui/UI.java
index d20622dc..40b94133 100644
--- a/src/main/java/UI.java
+++ b/src/main/java/ui/UI.java
@@ -1,3 +1,5 @@
+package ui;
+
 import java.util.Scanner;
 
 public class UI {

From 3ff482fb97a35061a04e932c312b47f66fb72584 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Wed, 14 Sep 2022 01:48:54 +0800
Subject: [PATCH 13/26] Add some temporary code

Nothing of value is added
---
 src/main/java/handler/InputHandler.java |  9 +++++----
 src/main/java/handler/TaskHandler.java  |  2 +-
 src/main/java/task/TaskList.java        | 23 +++++++++++++----------
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/src/main/java/handler/InputHandler.java b/src/main/java/handler/InputHandler.java
index d7dc919f..3fec967e 100644
--- a/src/main/java/handler/InputHandler.java
+++ b/src/main/java/handler/InputHandler.java
@@ -12,6 +12,7 @@ public class InputHandler {
     private static final String BYE = "bye";
     private static final String MARK = "mark";
     private static final String UNMARK = "unmark";
+    private static final String DELETE = "DELETE";
 
     public static void handleInput() {
         while (true) {
@@ -32,21 +33,18 @@ public static void handleInput() {
                     TaskHandler.handleDeadline(input);
                 } catch (DukeException e) {
                     System.out.println("deadline missing some info...");
-                    ;
                 }
             } else if (input.startsWith(EVENT)) {
                 try {
                     TaskHandler.handleEvent(input);
                 } catch (DukeException e) {
                     System.out.println("event missing some info...");
-                    ;
                 }
             } else if (input.startsWith(MARK)) {
                 try {
                     TaskHandler.handleMark(input);
                 } catch (DukeException e) {
                     System.out.println("mark what");
-                    ;
                 }
             } else if (input.startsWith(UNMARK)) {
                 try {
@@ -54,7 +52,10 @@ public static void handleInput() {
                 } catch (DukeException e) {
                     System.out.println("unmark what");
                 }
-            } else {
+            } else if (input.startsWith(DELETE)) {
+                
+            }
+            else {
                 TaskHandler.handleInvalid(input);
             }
         }
diff --git a/src/main/java/handler/TaskHandler.java b/src/main/java/handler/TaskHandler.java
index df6b8d1b..f2e29fb8 100644
--- a/src/main/java/handler/TaskHandler.java
+++ b/src/main/java/handler/TaskHandler.java
@@ -49,7 +49,7 @@ public static void handleUnmark(String input) throws DukeException {
         }
         try {
             int target = Integer.parseInt(splitInput[1]);
-            TaskList.markTarget(target);
+            TaskList.unmarkTarget(target);
         } catch (NullPointerException e) {
             System.out.println("There is no task with that index");
         } catch (NumberFormatException e) {
diff --git a/src/main/java/task/TaskList.java b/src/main/java/task/TaskList.java
index 7f43bdf8..9f195dae 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -1,8 +1,10 @@
 package task;
 
+import java.util.ArrayList;
+
 public class TaskList {
 
-    private static Task[] tasks = new Task[100];
+    private static final ArrayList<Task> tasks = new ArrayList<>();
     private static int taskCount = 0;
     private static final String LINE_DIVIDER = "-------------------------------------";
     private static final String ROGER_MESSAGE = "Got it. I have added this task:";
@@ -16,45 +18,46 @@ private static void printRoger(Task task) {
 
     private static void printMark(int target, boolean mark) {
         if (mark) {
-            System.out.println("Marked this task: \n " + tasks[target - 1]);
+            System.out.println("Marked this task: \n " + tasks.get(target - 1));
         } else {
-            System.out.println("Unmarked this task: \n" + tasks[target - 1]);
+            System.out.println("Unmarked this task: \n" + tasks.get(target - 1));
         }
         System.out.println(LINE_DIVIDER);
     }
 
     public static void addDeadLine(Deadline deadline) {
-        tasks[taskCount] = deadline;
+        tasks.add(deadline);
         taskCount++;
         printRoger(deadline);
     }
 
     public static void addTodo(Todo todo) {
-        tasks[taskCount] = todo;
+        tasks.add(todo);
         taskCount++;
         printRoger(todo);
     }
 
     public static void addEvent(Event event) {
-        tasks[taskCount] = event;
+        tasks.add(event);
         taskCount++;
         printRoger(event);
     }
 
     public static void markTarget(int target) {
-        tasks[target - 1].setDone(true);
+        tasks.get(target - 1).setDone(true);
         printMark(target, true);
     }
 
     public static void unmarkTarget(int target) {
-        tasks[target - 1].setDone(false);
+        tasks.get(target - 1).setDone(false);
         printMark(target, false);
     }
 
     public static void printList() {
         System.out.println("Here are a list of your tasks: ");
-        for (int i = 0; i < taskCount; i++) {
-            System.out.println(i + 1 + ". " + tasks[i]);
+        int index = 1;
+        for (Task task : tasks) {
+            System.out.println(index + ". " + task);
         }
         System.out.println(LINE_DIVIDER);
     }

From eaa8d407bdf639b0dba91d6e5e275767a0539b12 Mon Sep 17 00:00:00 2001
From: jjtoh <johntohjiajun@gmail.com>
Date: Wed, 14 Sep 2022 03:42:48 +0800
Subject: [PATCH 14/26] Add ability to delete

Can merge as level 6
---
 src/main/java/handler/InputHandler.java | 110 +++++++++++++++++++-----
 src/main/java/handler/TaskHandler.java  |  77 +++++++++--------
 src/main/java/task/TaskList.java        |   9 ++
 3 files changed, 140 insertions(+), 56 deletions(-)

diff --git a/src/main/java/handler/InputHandler.java b/src/main/java/handler/InputHandler.java
index 3fec967e..937823d2 100644
--- a/src/main/java/handler/InputHandler.java
+++ b/src/main/java/handler/InputHandler.java
@@ -12,52 +12,120 @@ public class InputHandler {
     private static final String BYE = "bye";
     private static final String MARK = "mark";
     private static final String UNMARK = "unmark";
-    private static final String DELETE = "DELETE";
+    private static final String DELETE = "delete";
 
     public static void handleInput() {
-        while (true) {
+        boolean exit = false;
+        while (!exit) {
             String input = UI.getInput();
-            if (input.startsWith(BYE)) {
+            String command = getCommand(input);
+            switch (command) {
+            case (BYE):
                 TaskHandler.handleBye();
+                exit = true;
                 break;
-            } else if (input.startsWith(TODO)) {
+            case (TODO):
                 try {
-                    TaskHandler.handleTodo(input);
-                } catch (DukeException e) {
+                    TaskHandler.handleTodo(getAction(input));
+                } catch (ArrayIndexOutOfBoundsException e) {
                     System.out.println("todo what?");
                 }
-            } else if (input.startsWith(LIST)) {
+                break;
+            case (LIST):
                 TaskHandler.handleList();
-            } else if (input.startsWith(DEADLINE)) {
+                break;
+            case (DEADLINE):
                 try {
-                    TaskHandler.handleDeadline(input);
+                    TaskHandler.handleDeadline(getAction(input));
                 } catch (DukeException e) {
                     System.out.println("deadline missing some info...");
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("deadline what?");
                 }
-            } else if (input.startsWith(EVENT)) {
+                break;
+            case (EVENT):
                 try {
-                    TaskHandler.handleEvent(input);
+                    TaskHandler.handleEvent(getAction(input));
                 } catch (DukeException e) {
                     System.out.println("event missing some info...");
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("event what?");
                 }
-            } else if (input.startsWith(MARK)) {
+                break;
+            case (MARK):
                 try {
-                    TaskHandler.handleMark(input);
-                } catch (DukeException e) {
+                    TaskHandler.handleMark(getAction(input));
+                } catch (ArrayIndexOutOfBoundsException e) {
                     System.out.println("mark what");
                 }
-            } else if (input.startsWith(UNMARK)) {
+                break;
+            case (UNMARK):
                 try {
-                    TaskHandler.handleUnmark(input);
-                } catch (DukeException e) {
+                    TaskHandler.handleUnmark(getAction(input));
+                } catch (ArrayIndexOutOfBoundsException e) {
                     System.out.println("unmark what");
                 }
-            } else if (input.startsWith(DELETE)) {
-                
-            }
-            else {
+                break;
+            case (DELETE):
+                try {
+                    TaskHandler.handleDelete(getAction(input));
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("delete what?");
+                }
+                break;
+            default:
                 TaskHandler.handleInvalid(input);
             }
+//            if (input.startsWith(BYE)) {
+//                TaskHandler.handleBye();
+//                break;
+//            } else if (input.startsWith(TODO)) {
+//                try {
+//                    TaskHandler.handleTodo(input);
+//                } catch (DukeException e) {
+//                    System.out.println("todo what?");
+//                }
+//            } else if (input.startsWith(LIST)) {
+//                TaskHandler.handleList();
+//            } else if (input.startsWith(DEADLINE)) {
+//                try {
+//                    TaskHandler.handleDeadline(input);
+//                } catch (DukeException e) {
+//                    System.out.println("deadline missing some info...");
+//                }
+//            } else if (input.startsWith(EVENT)) {
+//                try {
+//                    TaskHandler.handleEvent(input);
+//                } catch (DukeException e) {
+//                    System.out.println("event missing some info...");
+//                }
+//            } else if (input.startsWith(MARK)) {
+//                try {
+//                    TaskHandler.handleMark(input);
+//                } catch (DukeException e) {
+//                    System.out.println("mark what");
+//                }
+//            } else if (input.startsWith(UNMARK)) {
+//                try {
+//                    TaskHandler.handleUnmark(input);
+//                } catch (DukeException e) {
+//                    System.out.println("unmark what");
+//                }
+//            } else if (input.startsWith(DELETE)) {
+//
+//            }
+//            else {
+//                TaskHandler.handleInvalid(input);
+//            }
         }
     }
+
+    private static String getCommand(String input) {
+        return input.split(" ", 2)[0].trim();
+    }
+
+    private static String getAction(String input) throws ArrayIndexOutOfBoundsException {
+        return input.split(" ", 2)[1].trim();
+    }
+
 }
diff --git a/src/main/java/handler/TaskHandler.java b/src/main/java/handler/TaskHandler.java
index f2e29fb8..9f002556 100644
--- a/src/main/java/handler/TaskHandler.java
+++ b/src/main/java/handler/TaskHandler.java
@@ -8,18 +8,14 @@
 
 public class TaskHandler {
     private static final String BYE_MESSAGE = "Bye! ;)";
-    public static final int SPLIT_AMOUNT = 2;
+    private static final int SPLIT_AMOUNT = 2;
 
     public static void handleBye() {
         System.out.println(BYE_MESSAGE);
     }
 
-    public static void handleTodo(String input) throws DukeException {
-        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
-        if (splitInput.length != SPLIT_AMOUNT) {
-            throw new DukeException();
-        }
-        Todo todo = new Todo(splitInput[1]);
+    public static void handleTodo(String input) {
+        Todo todo = new Todo(input);
         TaskList.addTodo(todo);
     }
 
@@ -27,64 +23,75 @@ public static void handleList() {
         TaskList.printList();
     }
 
-    public static void handleMark(String input) throws DukeException {
-        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
-        if (splitInput.length != SPLIT_AMOUNT) {
-            throw new DukeException();
-        }
+    public static void handleMark(String input) {
         try {
-            int target = Integer.parseInt(splitInput[1]);
+            int target = Integer.parseInt(input);
             TaskList.markTarget(target);
-        } catch (NullPointerException e) {
+        } catch (IndexOutOfBoundsException e) {
             System.out.println("There is no task with that index");
         } catch (NumberFormatException e) {
             System.out.println("Index is a number...");
         }
     }
 
-    public static void handleUnmark(String input) throws DukeException {
-        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
-        if (splitInput.length != SPLIT_AMOUNT) {
-            throw new DukeException();
-        }
+    public static void handleUnmark(String input) {
+        int index = readIndex(input);
         try {
-            int target = Integer.parseInt(splitInput[1]);
-            TaskList.unmarkTarget(target);
-        } catch (NullPointerException e) {
-            System.out.println("There is no task with that index");
-        } catch (NumberFormatException e) {
-            System.out.println("Index is a number...");
+            TaskList.unmarkTarget(index);
+        } catch (IndexOutOfBoundsException e) {
+            System.out.println("Index does not exist");
         }
     }
 
-    public static String[] splitTaskTime(String input) throws DukeException {
-        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
-        if (splitInput.length != SPLIT_AMOUNT) {
-            throw new DukeException();
-        }
-        return splitInput[1].split(" /by ", SPLIT_AMOUNT);
+    private static String[] splitDeadlineTime(String input) throws DukeException {
+        return input.split(" /by ", SPLIT_AMOUNT);
+    }
+    private static String[] splitEventTime(String input) throws DukeException {
+        return input.split(" /at ", SPLIT_AMOUNT);
     }
 
     public static void handleDeadline(String input) throws DukeException {
-        String[] splitCommand = splitTaskTime(input);
+        String[] splitCommand = splitDeadlineTime(input);
         if (splitCommand.length != SPLIT_AMOUNT) {
             throw new DukeException();
         }
-        Deadline deadline = new Deadline(splitCommand[0], splitCommand[1]); //index 0 is description, index 1 is time
+        String description = splitCommand[0];
+        String by = splitCommand[1];
+        Deadline deadline = new Deadline(description, by);
         TaskList.addDeadLine(deadline);
     }
 
     public static void handleEvent(String input) throws DukeException {
-        String[] splitCommand = splitTaskTime(input);
+        String[] splitCommand = splitEventTime(input);
         if (splitCommand.length != SPLIT_AMOUNT) {
             throw new DukeException();
         }
-        Event event = new Event(splitCommand[0], splitCommand[1]); //index 0 is description, index 1 is time
+        String description = splitCommand[0];
+        String at = splitCommand[1];
+        Event event = new Event(description, at);
         TaskList.addEvent(event);
     }
 
+    public static void handleDelete(String input) {
+        int index = readIndex(input);
+        try {
+            TaskList.deleteTask(index);
+        } catch (IndexOutOfBoundsException e) {
+            System.out.println("Index does not exist.");
+        }
+    }
+
+    private static int readIndex(String input) {
+        try {
+            return Integer.parseInt(input);
+        } catch (NumberFormatException e) {
+            System.out.println("Index is a number...");
+        }
+        return -1;
+    }
     public static void handleInvalid(String input) {
         System.out.println("\"" + input + "\"" + " is not a valid command, please try again!");
     }
 
+
 }
diff --git a/src/main/java/task/TaskList.java b/src/main/java/task/TaskList.java
index 9f195dae..868cb105 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -58,7 +58,16 @@ public static void printList() {
         int index = 1;
         for (Task task : tasks) {
             System.out.println(index + ". " + task);
+            index++;
         }
         System.out.println(LINE_DIVIDER);
     }
+
+    public static void deleteTask(int index) {
+        System.out.println(tasks.get(index - 1) + " has been removed");
+        tasks.remove(index - 1);
+        taskCount--;
+        System.out.println("There are " + taskCount + "tasks left");
+        System.out.println(LINE_DIVIDER);
+    }
 }

From 3e345a1996e0879fdfad259a6b21e338d62ba04e Mon Sep 17 00:00:00 2001
From: jjtoh <johntohjiajun@gmail.com>
Date: Wed, 14 Sep 2022 21:26:19 +0800
Subject: [PATCH 15/26] Shift some code around

---
 src/main/java/handler/InputHandler.java | 41 -------------------------
 src/main/java/handler/TaskHandler.java  | 18 +++++------
 2 files changed, 9 insertions(+), 50 deletions(-)

diff --git a/src/main/java/handler/InputHandler.java b/src/main/java/handler/InputHandler.java
index 937823d2..ac4155c7 100644
--- a/src/main/java/handler/InputHandler.java
+++ b/src/main/java/handler/InputHandler.java
@@ -76,47 +76,6 @@ public static void handleInput() {
             default:
                 TaskHandler.handleInvalid(input);
             }
-//            if (input.startsWith(BYE)) {
-//                TaskHandler.handleBye();
-//                break;
-//            } else if (input.startsWith(TODO)) {
-//                try {
-//                    TaskHandler.handleTodo(input);
-//                } catch (DukeException e) {
-//                    System.out.println("todo what?");
-//                }
-//            } else if (input.startsWith(LIST)) {
-//                TaskHandler.handleList();
-//            } else if (input.startsWith(DEADLINE)) {
-//                try {
-//                    TaskHandler.handleDeadline(input);
-//                } catch (DukeException e) {
-//                    System.out.println("deadline missing some info...");
-//                }
-//            } else if (input.startsWith(EVENT)) {
-//                try {
-//                    TaskHandler.handleEvent(input);
-//                } catch (DukeException e) {
-//                    System.out.println("event missing some info...");
-//                }
-//            } else if (input.startsWith(MARK)) {
-//                try {
-//                    TaskHandler.handleMark(input);
-//                } catch (DukeException e) {
-//                    System.out.println("mark what");
-//                }
-//            } else if (input.startsWith(UNMARK)) {
-//                try {
-//                    TaskHandler.handleUnmark(input);
-//                } catch (DukeException e) {
-//                    System.out.println("unmark what");
-//                }
-//            } else if (input.startsWith(DELETE)) {
-//
-//            }
-//            else {
-//                TaskHandler.handleInvalid(input);
-//            }
         }
     }
 
diff --git a/src/main/java/handler/TaskHandler.java b/src/main/java/handler/TaskHandler.java
index 9f002556..5a6bed6e 100644
--- a/src/main/java/handler/TaskHandler.java
+++ b/src/main/java/handler/TaskHandler.java
@@ -8,6 +8,7 @@
 
 public class TaskHandler {
     private static final String BYE_MESSAGE = "Bye! ;)";
+    private static final String INDEX_NOT_FOUND = "There are no tasks with that index";
     private static final int SPLIT_AMOUNT = 2;
 
     public static void handleBye() {
@@ -25,8 +26,8 @@ public static void handleList() {
 
     public static void handleMark(String input) {
         try {
-            int target = Integer.parseInt(input);
-            TaskList.markTarget(target);
+            int index = readIndex(input);
+            TaskList.markTarget(index);
         } catch (IndexOutOfBoundsException e) {
             System.out.println("There is no task with that index");
         } catch (NumberFormatException e) {
@@ -35,9 +36,11 @@ public static void handleMark(String input) {
     }
 
     public static void handleUnmark(String input) {
-        int index = readIndex(input);
         try {
+            int index = readIndex(input);
             TaskList.unmarkTarget(index);
+        } catch (NumberFormatException e) {
+            System.out.println("Index is an integer");
         } catch (IndexOutOfBoundsException e) {
             System.out.println("Index does not exist");
         }
@@ -73,25 +76,22 @@ public static void handleEvent(String input) throws DukeException {
     }
 
     public static void handleDelete(String input) {
-        int index = readIndex(input);
         try {
+            int index = readIndex(input);
             TaskList.deleteTask(index);
         } catch (IndexOutOfBoundsException e) {
             System.out.println("Index does not exist.");
         }
     }
 
-    private static int readIndex(String input) {
+    private static int readIndex(String input) throws NumberFormatException {
         try {
             return Integer.parseInt(input);
         } catch (NumberFormatException e) {
-            System.out.println("Index is a number...");
+            throw e;
         }
-        return -1;
     }
     public static void handleInvalid(String input) {
         System.out.println("\"" + input + "\"" + " is not a valid command, please try again!");
     }
-
-
 }

From 86eff83149fd518d06bd9b1d51d320ecd7c0814f Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 15 Sep 2022 03:36:22 +0800
Subject: [PATCH 16/26] Shift some code around

---
 src/main/java/handler/TaskHandler.java | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/main/java/handler/TaskHandler.java b/src/main/java/handler/TaskHandler.java
index 5a6bed6e..3ff9b87e 100644
--- a/src/main/java/handler/TaskHandler.java
+++ b/src/main/java/handler/TaskHandler.java
@@ -46,13 +46,6 @@ public static void handleUnmark(String input) {
         }
     }
 
-    private static String[] splitDeadlineTime(String input) throws DukeException {
-        return input.split(" /by ", SPLIT_AMOUNT);
-    }
-    private static String[] splitEventTime(String input) throws DukeException {
-        return input.split(" /at ", SPLIT_AMOUNT);
-    }
-
     public static void handleDeadline(String input) throws DukeException {
         String[] splitCommand = splitDeadlineTime(input);
         if (splitCommand.length != SPLIT_AMOUNT) {
@@ -91,6 +84,15 @@ private static int readIndex(String input) throws NumberFormatException {
             throw e;
         }
     }
+
+    private static String[] splitDeadlineTime(String input) throws DukeException {
+        return input.split(" /by ", SPLIT_AMOUNT);
+    }
+
+    private static String[] splitEventTime(String input) throws DukeException {
+        return input.split(" /at ", SPLIT_AMOUNT);
+    }
+
     public static void handleInvalid(String input) {
         System.out.println("\"" + input + "\"" + " is not a valid command, please try again!");
     }

From 3ea366921c50a4a47deaaee44479cd9c75383914 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Fri, 16 Sep 2022 03:35:52 +0800
Subject: [PATCH 17/26] Add Level-7

Merge with level 7 branch in future
---
 data/tasks.txt                      |   0
 src/main/java/Duke.java             |  10 ++-
 src/main/java/file/FileManager.java | 110 ++++++++++++++++++++++++++++
 src/main/java/task/Deadline.java    |   4 +
 src/main/java/task/Event.java       |   3 +
 src/main/java/task/Task.java        |   3 +
 src/main/java/task/TaskList.java    |  13 ++++
 7 files changed, 141 insertions(+), 2 deletions(-)
 create mode 100644 data/tasks.txt
 create mode 100644 src/main/java/file/FileManager.java

diff --git a/data/tasks.txt b/data/tasks.txt
new file mode 100644
index 00000000..e69de29b
diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index f9dec8e2..0af67e4c 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,13 +1,19 @@
+import file.FileManager;
 import handler.InputHandler;
+import task.TaskList;
 import ui.UI;
 
+import java.io.FileNotFoundException;
+
 public class Duke {
     public static void startProgram() {
-        UI.welcomeUser();
-        InputHandler.handleInput();
+            UI.welcomeUser();
+            FileManager.startReading();
+            InputHandler.handleInput();
     }
 
     public static void main(String[] args) {
         startProgram();
+        TaskList.storeTasks();
     }
 }
diff --git a/src/main/java/file/FileManager.java b/src/main/java/file/FileManager.java
new file mode 100644
index 00000000..a145f128
--- /dev/null
+++ b/src/main/java/file/FileManager.java
@@ -0,0 +1,110 @@
+package file;
+
+import task.*;
+
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.Scanner;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class FileManager {
+
+    private static Path taskDataPath = Paths.get(System.getProperty("user.dir"), "data", "tasks.txt");
+
+    private static Path dataDirPath = Paths.get(System.getProperty("user.dir"), "data");
+
+    public static void writeToFile(Task task) throws IOException {
+        FileWriter fw = new FileWriter(taskDataPath.toString(), true);
+        String textToAdd = taskToText(task);
+        fw.write(textToAdd);
+        fw.close();
+    }
+
+
+    public static void startReading() {
+        try {
+            makeMissingDirectory();
+            readFile();
+        } catch (FileNotFoundException e) {
+            System.out.println("File cannot be found");
+        } catch (IOException e) {
+            System.out.println("Some IO error has occurred");
+        }
+    }
+
+    private static void readFile() throws FileNotFoundException {
+        String filePath = taskDataPath.toString();
+        File f = new File(filePath);
+        Scanner s = new Scanner(f);
+        while (s.hasNext()) {
+            String[] input = s.nextLine().split(" | ");
+            switch (input[0]) {
+            case ("T"):
+                insertTodo(input);
+                break;
+            case ("D"):
+                insertDeadline(input);
+                break;
+            case ("E"):
+                insertEvent(input);
+                break;
+            }
+        }
+    }
+
+    private static void makeMissingDirectory() throws IOException {
+        File dir = new File(dataDirPath.toString());
+        if (!dir.exists()) {
+            dir.mkdir();
+        } else {
+            return;
+        }
+        FileWriter fw = new FileWriter(taskDataPath.toString());
+    }
+
+    private static void insertTodo(String[] input) {
+        Todo todo = new Todo(input[2]);
+        if (input[1].equals("1")) {
+            todo.setDone(true);
+        } else {
+            todo.setDone(false);
+        }
+        TaskList.addTodo(todo);
+    }
+
+    private static void insertDeadline(String[] input) {
+        Deadline deadline = new Deadline(input[2], input[3]);
+        if (input[1].equals("1")) {
+            deadline.setDone(true);
+        } else {
+            deadline.setDone(false);
+        }
+        TaskList.addDeadLine(deadline);
+    }
+
+    private static void insertEvent(String[] input) {
+        Event event = new Event(input[2], input[3]);
+        if (input[1].equals("1")) {
+            event.setDone(true);
+        } else {
+            event.setDone(false);
+        }
+        TaskList.addEvent(event);
+    }
+
+    private static String taskToText(Task task) {
+        if (task.getClass() == Todo.class) {
+            return "T | " + task.getStatusInNumber() + " | " + task.getDescription() + "\n";
+        } else if (task.getClass() == Deadline.class) {
+            return "D | " + task.getStatusInNumber() + " | "
+                    + task.getDescription() + " | " + ((Deadline) task).getBy() + "\n";
+        } else {
+            return "E | " + task.getStatusInNumber() + " | "
+                    + task.getDescription() + " | " + ((Event) task).getAt() + "\n";
+        }
+    }
+}
diff --git a/src/main/java/task/Deadline.java b/src/main/java/task/Deadline.java
index 9f1fc775..f4e34971 100644
--- a/src/main/java/task/Deadline.java
+++ b/src/main/java/task/Deadline.java
@@ -8,6 +8,10 @@ public Deadline(String description, String by) {
         this.by = by;
     }
 
+    public String getBy() {
+        return by;
+    }
+
     @Override
     public String toString() {
         return "[D]" + super.getStatusIcon() + " " + super.getDescription() + " (by: " + by + ")";
diff --git a/src/main/java/task/Event.java b/src/main/java/task/Event.java
index 6d00cc0d..4d331e79 100644
--- a/src/main/java/task/Event.java
+++ b/src/main/java/task/Event.java
@@ -8,6 +8,9 @@ public Event(String description, String at) {
         this.at = at;
     }
 
+    public String getAt() {
+        return at;
+    }
     @Override
     public String toString() {
         return "[E]" + super.getStatusIcon() + " " + super.getDescription() + " (at: " + at + ")";
diff --git a/src/main/java/task/Task.java b/src/main/java/task/Task.java
index a768cbcf..e7ccc456 100644
--- a/src/main/java/task/Task.java
+++ b/src/main/java/task/Task.java
@@ -17,6 +17,9 @@ public String getStatusIcon() {
         return isDone ? "[X]" : "[ ]";
     }
 
+    public int getStatusInNumber() {
+        return isDone ? 1 : 0;
+    }
 
     public String getDescription() {
         return description;
diff --git a/src/main/java/task/TaskList.java b/src/main/java/task/TaskList.java
index 868cb105..8b8aa770 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -1,5 +1,8 @@
 package task;
 
+import file.FileManager;
+
+import java.io.IOException;
 import java.util.ArrayList;
 
 public class TaskList {
@@ -70,4 +73,14 @@ public static void deleteTask(int index) {
         System.out.println("There are " + taskCount + "tasks left");
         System.out.println(LINE_DIVIDER);
     }
+
+    public static void storeTasks() {
+        try {
+            for (Task task : tasks) {
+                FileManager.writeToFile(task);
+            }
+        } catch (IOException e) {
+            System.out.println("An IO error has occurred");
+        }
+    }
 }

From 94554eeda815c2da603e1e0fbba5846a9b718994 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Fri, 16 Sep 2022 03:43:37 +0800
Subject: [PATCH 18/26] Add jar file

---
 src/main/java/META-INF/MANIFEST.MF | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 src/main/java/META-INF/MANIFEST.MF

diff --git a/src/main/java/META-INF/MANIFEST.MF b/src/main/java/META-INF/MANIFEST.MF
new file mode 100644
index 00000000..9f37e4e0
--- /dev/null
+++ b/src/main/java/META-INF/MANIFEST.MF
@@ -0,0 +1,3 @@
+Manifest-Version: 1.0
+Main-Class: Duke
+

From f143ba184d4c5ad20ea2e4ef367790799fae5c5c Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Fri, 16 Sep 2022 04:16:37 +0800
Subject: [PATCH 19/26] Revert "Add Level-7"

This reverts commit 3ea366921c50a4a47deaaee44479cd9c75383914.
---
 data/tasks.txt                      |   0
 src/main/java/Duke.java             |  10 +--
 src/main/java/file/FileManager.java | 110 ----------------------------
 src/main/java/task/Deadline.java    |   4 -
 src/main/java/task/Event.java       |   3 -
 src/main/java/task/Task.java        |   3 -
 src/main/java/task/TaskList.java    |  13 ----
 7 files changed, 2 insertions(+), 141 deletions(-)
 delete mode 100644 data/tasks.txt
 delete mode 100644 src/main/java/file/FileManager.java

diff --git a/data/tasks.txt b/data/tasks.txt
deleted file mode 100644
index e69de29b..00000000
diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 0af67e4c..f9dec8e2 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,19 +1,13 @@
-import file.FileManager;
 import handler.InputHandler;
-import task.TaskList;
 import ui.UI;
 
-import java.io.FileNotFoundException;
-
 public class Duke {
     public static void startProgram() {
-            UI.welcomeUser();
-            FileManager.startReading();
-            InputHandler.handleInput();
+        UI.welcomeUser();
+        InputHandler.handleInput();
     }
 
     public static void main(String[] args) {
         startProgram();
-        TaskList.storeTasks();
     }
 }
diff --git a/src/main/java/file/FileManager.java b/src/main/java/file/FileManager.java
deleted file mode 100644
index a145f128..00000000
--- a/src/main/java/file/FileManager.java
+++ /dev/null
@@ -1,110 +0,0 @@
-package file;
-
-import task.*;
-
-import java.io.FileWriter;
-import java.io.IOException;
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.util.Scanner;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-
-public class FileManager {
-
-    private static Path taskDataPath = Paths.get(System.getProperty("user.dir"), "data", "tasks.txt");
-
-    private static Path dataDirPath = Paths.get(System.getProperty("user.dir"), "data");
-
-    public static void writeToFile(Task task) throws IOException {
-        FileWriter fw = new FileWriter(taskDataPath.toString(), true);
-        String textToAdd = taskToText(task);
-        fw.write(textToAdd);
-        fw.close();
-    }
-
-
-    public static void startReading() {
-        try {
-            makeMissingDirectory();
-            readFile();
-        } catch (FileNotFoundException e) {
-            System.out.println("File cannot be found");
-        } catch (IOException e) {
-            System.out.println("Some IO error has occurred");
-        }
-    }
-
-    private static void readFile() throws FileNotFoundException {
-        String filePath = taskDataPath.toString();
-        File f = new File(filePath);
-        Scanner s = new Scanner(f);
-        while (s.hasNext()) {
-            String[] input = s.nextLine().split(" | ");
-            switch (input[0]) {
-            case ("T"):
-                insertTodo(input);
-                break;
-            case ("D"):
-                insertDeadline(input);
-                break;
-            case ("E"):
-                insertEvent(input);
-                break;
-            }
-        }
-    }
-
-    private static void makeMissingDirectory() throws IOException {
-        File dir = new File(dataDirPath.toString());
-        if (!dir.exists()) {
-            dir.mkdir();
-        } else {
-            return;
-        }
-        FileWriter fw = new FileWriter(taskDataPath.toString());
-    }
-
-    private static void insertTodo(String[] input) {
-        Todo todo = new Todo(input[2]);
-        if (input[1].equals("1")) {
-            todo.setDone(true);
-        } else {
-            todo.setDone(false);
-        }
-        TaskList.addTodo(todo);
-    }
-
-    private static void insertDeadline(String[] input) {
-        Deadline deadline = new Deadline(input[2], input[3]);
-        if (input[1].equals("1")) {
-            deadline.setDone(true);
-        } else {
-            deadline.setDone(false);
-        }
-        TaskList.addDeadLine(deadline);
-    }
-
-    private static void insertEvent(String[] input) {
-        Event event = new Event(input[2], input[3]);
-        if (input[1].equals("1")) {
-            event.setDone(true);
-        } else {
-            event.setDone(false);
-        }
-        TaskList.addEvent(event);
-    }
-
-    private static String taskToText(Task task) {
-        if (task.getClass() == Todo.class) {
-            return "T | " + task.getStatusInNumber() + " | " + task.getDescription() + "\n";
-        } else if (task.getClass() == Deadline.class) {
-            return "D | " + task.getStatusInNumber() + " | "
-                    + task.getDescription() + " | " + ((Deadline) task).getBy() + "\n";
-        } else {
-            return "E | " + task.getStatusInNumber() + " | "
-                    + task.getDescription() + " | " + ((Event) task).getAt() + "\n";
-        }
-    }
-}
diff --git a/src/main/java/task/Deadline.java b/src/main/java/task/Deadline.java
index f4e34971..9f1fc775 100644
--- a/src/main/java/task/Deadline.java
+++ b/src/main/java/task/Deadline.java
@@ -8,10 +8,6 @@ public Deadline(String description, String by) {
         this.by = by;
     }
 
-    public String getBy() {
-        return by;
-    }
-
     @Override
     public String toString() {
         return "[D]" + super.getStatusIcon() + " " + super.getDescription() + " (by: " + by + ")";
diff --git a/src/main/java/task/Event.java b/src/main/java/task/Event.java
index 4d331e79..6d00cc0d 100644
--- a/src/main/java/task/Event.java
+++ b/src/main/java/task/Event.java
@@ -8,9 +8,6 @@ public Event(String description, String at) {
         this.at = at;
     }
 
-    public String getAt() {
-        return at;
-    }
     @Override
     public String toString() {
         return "[E]" + super.getStatusIcon() + " " + super.getDescription() + " (at: " + at + ")";
diff --git a/src/main/java/task/Task.java b/src/main/java/task/Task.java
index e7ccc456..a768cbcf 100644
--- a/src/main/java/task/Task.java
+++ b/src/main/java/task/Task.java
@@ -17,9 +17,6 @@ public String getStatusIcon() {
         return isDone ? "[X]" : "[ ]";
     }
 
-    public int getStatusInNumber() {
-        return isDone ? 1 : 0;
-    }
 
     public String getDescription() {
         return description;
diff --git a/src/main/java/task/TaskList.java b/src/main/java/task/TaskList.java
index 8b8aa770..868cb105 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -1,8 +1,5 @@
 package task;
 
-import file.FileManager;
-
-import java.io.IOException;
 import java.util.ArrayList;
 
 public class TaskList {
@@ -73,14 +70,4 @@ public static void deleteTask(int index) {
         System.out.println("There are " + taskCount + "tasks left");
         System.out.println(LINE_DIVIDER);
     }
-
-    public static void storeTasks() {
-        try {
-            for (Task task : tasks) {
-                FileManager.writeToFile(task);
-            }
-        } catch (IOException e) {
-            System.out.println("An IO error has occurred");
-        }
-    }
 }

From e06c4e320a02953d4c43354cee43c3aec7967ac1 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Fri, 16 Sep 2022 04:36:23 +0800
Subject: [PATCH 20/26] Add level 7

---
 data/tasks.txt                      |   0
 src/main/java/Duke.java             |  10 ++-
 src/main/java/META-INF/MANIFEST.MF  |   3 -
 src/main/java/file/FileManager.java | 110 ++++++++++++++++++++++++++++
 src/main/java/task/Deadline.java    |   4 +
 src/main/java/task/Event.java       |   3 +
 src/main/java/task/Task.java        |   3 +
 src/main/java/task/TaskList.java    |  13 ++++
 8 files changed, 141 insertions(+), 5 deletions(-)
 create mode 100644 data/tasks.txt
 delete mode 100644 src/main/java/META-INF/MANIFEST.MF
 create mode 100644 src/main/java/file/FileManager.java

diff --git a/data/tasks.txt b/data/tasks.txt
new file mode 100644
index 00000000..e69de29b
diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index f9dec8e2..0af67e4c 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,13 +1,19 @@
+import file.FileManager;
 import handler.InputHandler;
+import task.TaskList;
 import ui.UI;
 
+import java.io.FileNotFoundException;
+
 public class Duke {
     public static void startProgram() {
-        UI.welcomeUser();
-        InputHandler.handleInput();
+            UI.welcomeUser();
+            FileManager.startReading();
+            InputHandler.handleInput();
     }
 
     public static void main(String[] args) {
         startProgram();
+        TaskList.storeTasks();
     }
 }
diff --git a/src/main/java/META-INF/MANIFEST.MF b/src/main/java/META-INF/MANIFEST.MF
deleted file mode 100644
index 9f37e4e0..00000000
--- a/src/main/java/META-INF/MANIFEST.MF
+++ /dev/null
@@ -1,3 +0,0 @@
-Manifest-Version: 1.0
-Main-Class: Duke
-
diff --git a/src/main/java/file/FileManager.java b/src/main/java/file/FileManager.java
new file mode 100644
index 00000000..a145f128
--- /dev/null
+++ b/src/main/java/file/FileManager.java
@@ -0,0 +1,110 @@
+package file;
+
+import task.*;
+
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.Scanner;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+public class FileManager {
+
+    private static Path taskDataPath = Paths.get(System.getProperty("user.dir"), "data", "tasks.txt");
+
+    private static Path dataDirPath = Paths.get(System.getProperty("user.dir"), "data");
+
+    public static void writeToFile(Task task) throws IOException {
+        FileWriter fw = new FileWriter(taskDataPath.toString(), true);
+        String textToAdd = taskToText(task);
+        fw.write(textToAdd);
+        fw.close();
+    }
+
+
+    public static void startReading() {
+        try {
+            makeMissingDirectory();
+            readFile();
+        } catch (FileNotFoundException e) {
+            System.out.println("File cannot be found");
+        } catch (IOException e) {
+            System.out.println("Some IO error has occurred");
+        }
+    }
+
+    private static void readFile() throws FileNotFoundException {
+        String filePath = taskDataPath.toString();
+        File f = new File(filePath);
+        Scanner s = new Scanner(f);
+        while (s.hasNext()) {
+            String[] input = s.nextLine().split(" | ");
+            switch (input[0]) {
+            case ("T"):
+                insertTodo(input);
+                break;
+            case ("D"):
+                insertDeadline(input);
+                break;
+            case ("E"):
+                insertEvent(input);
+                break;
+            }
+        }
+    }
+
+    private static void makeMissingDirectory() throws IOException {
+        File dir = new File(dataDirPath.toString());
+        if (!dir.exists()) {
+            dir.mkdir();
+        } else {
+            return;
+        }
+        FileWriter fw = new FileWriter(taskDataPath.toString());
+    }
+
+    private static void insertTodo(String[] input) {
+        Todo todo = new Todo(input[2]);
+        if (input[1].equals("1")) {
+            todo.setDone(true);
+        } else {
+            todo.setDone(false);
+        }
+        TaskList.addTodo(todo);
+    }
+
+    private static void insertDeadline(String[] input) {
+        Deadline deadline = new Deadline(input[2], input[3]);
+        if (input[1].equals("1")) {
+            deadline.setDone(true);
+        } else {
+            deadline.setDone(false);
+        }
+        TaskList.addDeadLine(deadline);
+    }
+
+    private static void insertEvent(String[] input) {
+        Event event = new Event(input[2], input[3]);
+        if (input[1].equals("1")) {
+            event.setDone(true);
+        } else {
+            event.setDone(false);
+        }
+        TaskList.addEvent(event);
+    }
+
+    private static String taskToText(Task task) {
+        if (task.getClass() == Todo.class) {
+            return "T | " + task.getStatusInNumber() + " | " + task.getDescription() + "\n";
+        } else if (task.getClass() == Deadline.class) {
+            return "D | " + task.getStatusInNumber() + " | "
+                    + task.getDescription() + " | " + ((Deadline) task).getBy() + "\n";
+        } else {
+            return "E | " + task.getStatusInNumber() + " | "
+                    + task.getDescription() + " | " + ((Event) task).getAt() + "\n";
+        }
+    }
+}
diff --git a/src/main/java/task/Deadline.java b/src/main/java/task/Deadline.java
index 9f1fc775..f4e34971 100644
--- a/src/main/java/task/Deadline.java
+++ b/src/main/java/task/Deadline.java
@@ -8,6 +8,10 @@ public Deadline(String description, String by) {
         this.by = by;
     }
 
+    public String getBy() {
+        return by;
+    }
+
     @Override
     public String toString() {
         return "[D]" + super.getStatusIcon() + " " + super.getDescription() + " (by: " + by + ")";
diff --git a/src/main/java/task/Event.java b/src/main/java/task/Event.java
index 6d00cc0d..4d331e79 100644
--- a/src/main/java/task/Event.java
+++ b/src/main/java/task/Event.java
@@ -8,6 +8,9 @@ public Event(String description, String at) {
         this.at = at;
     }
 
+    public String getAt() {
+        return at;
+    }
     @Override
     public String toString() {
         return "[E]" + super.getStatusIcon() + " " + super.getDescription() + " (at: " + at + ")";
diff --git a/src/main/java/task/Task.java b/src/main/java/task/Task.java
index a768cbcf..e7ccc456 100644
--- a/src/main/java/task/Task.java
+++ b/src/main/java/task/Task.java
@@ -17,6 +17,9 @@ public String getStatusIcon() {
         return isDone ? "[X]" : "[ ]";
     }
 
+    public int getStatusInNumber() {
+        return isDone ? 1 : 0;
+    }
 
     public String getDescription() {
         return description;
diff --git a/src/main/java/task/TaskList.java b/src/main/java/task/TaskList.java
index 868cb105..8b8aa770 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -1,5 +1,8 @@
 package task;
 
+import file.FileManager;
+
+import java.io.IOException;
 import java.util.ArrayList;
 
 public class TaskList {
@@ -70,4 +73,14 @@ public static void deleteTask(int index) {
         System.out.println("There are " + taskCount + "tasks left");
         System.out.println(LINE_DIVIDER);
     }
+
+    public static void storeTasks() {
+        try {
+            for (Task task : tasks) {
+                FileManager.writeToFile(task);
+            }
+        } catch (IOException e) {
+            System.out.println("An IO error has occurred");
+        }
+    }
 }

From f56c21082d6faaf2ed8fbbd65f90360bdfbebbb0 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Fri, 16 Sep 2022 04:48:01 +0800
Subject: [PATCH 21/26] Add jar file

---
 src/main/java/META-INF/MANIFEST.MF | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 src/main/java/META-INF/MANIFEST.MF

diff --git a/src/main/java/META-INF/MANIFEST.MF b/src/main/java/META-INF/MANIFEST.MF
new file mode 100644
index 00000000..9f37e4e0
--- /dev/null
+++ b/src/main/java/META-INF/MANIFEST.MF
@@ -0,0 +1,3 @@
+Manifest-Version: 1.0
+Main-Class: Duke
+

From 8e3a781f61283bdaaac11298e941984641f64fb0 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Wed, 28 Sep 2022 22:01:42 +0800
Subject: [PATCH 22/26] Add more OOP

---
 data/tasks.txt                                |   2 +
 src/main/java/Duke.java                       |  28 ++--
 src/main/java/exception/DukeException.java    |   3 +
 src/main/java/handler/InputHandler.java       |  90 ------------
 src/main/java/handler/TaskHandler.java        |  99 -------------
 src/main/java/parser/Parser.java              | 134 ++++++++++++++++++
 .../FileManager.java => storage/Storage.java} |  41 +++---
 src/main/java/task/Task.java                  |   4 +
 src/main/java/task/TaskList.java              |  71 +++++-----
 src/main/java/task/command/ByeCommand.java    |  13 ++
 src/main/java/task/command/Command.java       |  10 ++
 .../java/task/command/DeadlineCommand.java    |  22 +++
 src/main/java/task/command/DeleteCommand.java |  20 +++
 src/main/java/task/command/EventCommand.java  |  21 +++
 .../java/task/command/InvalidCommand.java     |  12 ++
 src/main/java/task/command/ListCommand.java   |  17 +++
 src/main/java/task/command/MarkCommand.java   |  19 +++
 src/main/java/task/command/TodoCommand.java   |  22 +++
 src/main/java/task/command/UnmarkCommand.java |  19 +++
 src/main/java/ui/UI.java                      |  90 +++++++++---
 20 files changed, 464 insertions(+), 273 deletions(-)
 delete mode 100644 src/main/java/handler/InputHandler.java
 delete mode 100644 src/main/java/handler/TaskHandler.java
 create mode 100644 src/main/java/parser/Parser.java
 rename src/main/java/{file/FileManager.java => storage/Storage.java} (73%)
 create mode 100644 src/main/java/task/command/ByeCommand.java
 create mode 100644 src/main/java/task/command/Command.java
 create mode 100644 src/main/java/task/command/DeadlineCommand.java
 create mode 100644 src/main/java/task/command/DeleteCommand.java
 create mode 100644 src/main/java/task/command/EventCommand.java
 create mode 100644 src/main/java/task/command/InvalidCommand.java
 create mode 100644 src/main/java/task/command/ListCommand.java
 create mode 100644 src/main/java/task/command/MarkCommand.java
 create mode 100644 src/main/java/task/command/TodoCommand.java
 create mode 100644 src/main/java/task/command/UnmarkCommand.java

diff --git a/data/tasks.txt b/data/tasks.txt
index e69de29b..95e08e18 100644
--- a/data/tasks.txt
+++ b/data/tasks.txt
@@ -0,0 +1,2 @@
+T | 0 | hello
+T | 0 | hello
diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 0af67e4c..6d4cf8a0 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,19 +1,27 @@
-import file.FileManager;
-import handler.InputHandler;
+import storage.Storage;
+import parser.Parser;
 import task.TaskList;
 import ui.UI;
 
-import java.io.FileNotFoundException;
-
 public class Duke {
-    public static void startProgram() {
-            UI.welcomeUser();
-            FileManager.startReading();
-            InputHandler.handleInput();
+
+    private static Storage storage;
+    public static UI ui;
+    private static TaskList tasks;
+
+    public Duke () {
+        Duke.storage = new Storage();
+        Duke.ui = new UI();
+        Duke.tasks = new TaskList(storage.startReading());
+    }
+
+    public void start() {
+        ui.welcomeUser();
+        Parser parser = new Parser();
+        parser.executeCommands(ui, tasks, storage);
     }
 
     public static void main(String[] args) {
-        startProgram();
-        TaskList.storeTasks();
+        new Duke().start();
     }
 }
diff --git a/src/main/java/exception/DukeException.java b/src/main/java/exception/DukeException.java
index c449019f..5500ba15 100644
--- a/src/main/java/exception/DukeException.java
+++ b/src/main/java/exception/DukeException.java
@@ -2,4 +2,7 @@
 
 public class DukeException extends Exception {
 
+    public DukeException(String message) {
+        super(message);
+    }
 }
diff --git a/src/main/java/handler/InputHandler.java b/src/main/java/handler/InputHandler.java
deleted file mode 100644
index ac4155c7..00000000
--- a/src/main/java/handler/InputHandler.java
+++ /dev/null
@@ -1,90 +0,0 @@
-package handler;
-
-import ui.UI;
-import exception.DukeException;
-
-public class InputHandler {
-
-    private static final String TODO = "todo";
-    private static final String LIST = "list";
-    private static final String DEADLINE = "deadline";
-    private static final String EVENT = "event";
-    private static final String BYE = "bye";
-    private static final String MARK = "mark";
-    private static final String UNMARK = "unmark";
-    private static final String DELETE = "delete";
-
-    public static void handleInput() {
-        boolean exit = false;
-        while (!exit) {
-            String input = UI.getInput();
-            String command = getCommand(input);
-            switch (command) {
-            case (BYE):
-                TaskHandler.handleBye();
-                exit = true;
-                break;
-            case (TODO):
-                try {
-                    TaskHandler.handleTodo(getAction(input));
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("todo what?");
-                }
-                break;
-            case (LIST):
-                TaskHandler.handleList();
-                break;
-            case (DEADLINE):
-                try {
-                    TaskHandler.handleDeadline(getAction(input));
-                } catch (DukeException e) {
-                    System.out.println("deadline missing some info...");
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("deadline what?");
-                }
-                break;
-            case (EVENT):
-                try {
-                    TaskHandler.handleEvent(getAction(input));
-                } catch (DukeException e) {
-                    System.out.println("event missing some info...");
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("event what?");
-                }
-                break;
-            case (MARK):
-                try {
-                    TaskHandler.handleMark(getAction(input));
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("mark what");
-                }
-                break;
-            case (UNMARK):
-                try {
-                    TaskHandler.handleUnmark(getAction(input));
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("unmark what");
-                }
-                break;
-            case (DELETE):
-                try {
-                    TaskHandler.handleDelete(getAction(input));
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("delete what?");
-                }
-                break;
-            default:
-                TaskHandler.handleInvalid(input);
-            }
-        }
-    }
-
-    private static String getCommand(String input) {
-        return input.split(" ", 2)[0].trim();
-    }
-
-    private static String getAction(String input) throws ArrayIndexOutOfBoundsException {
-        return input.split(" ", 2)[1].trim();
-    }
-
-}
diff --git a/src/main/java/handler/TaskHandler.java b/src/main/java/handler/TaskHandler.java
deleted file mode 100644
index 3ff9b87e..00000000
--- a/src/main/java/handler/TaskHandler.java
+++ /dev/null
@@ -1,99 +0,0 @@
-package handler;
-
-import task.Deadline;
-import task.Event;
-import task.TaskList;
-import task.Todo;
-import exception.DukeException;
-
-public class TaskHandler {
-    private static final String BYE_MESSAGE = "Bye! ;)";
-    private static final String INDEX_NOT_FOUND = "There are no tasks with that index";
-    private static final int SPLIT_AMOUNT = 2;
-
-    public static void handleBye() {
-        System.out.println(BYE_MESSAGE);
-    }
-
-    public static void handleTodo(String input) {
-        Todo todo = new Todo(input);
-        TaskList.addTodo(todo);
-    }
-
-    public static void handleList() {
-        TaskList.printList();
-    }
-
-    public static void handleMark(String input) {
-        try {
-            int index = readIndex(input);
-            TaskList.markTarget(index);
-        } catch (IndexOutOfBoundsException e) {
-            System.out.println("There is no task with that index");
-        } catch (NumberFormatException e) {
-            System.out.println("Index is a number...");
-        }
-    }
-
-    public static void handleUnmark(String input) {
-        try {
-            int index = readIndex(input);
-            TaskList.unmarkTarget(index);
-        } catch (NumberFormatException e) {
-            System.out.println("Index is an integer");
-        } catch (IndexOutOfBoundsException e) {
-            System.out.println("Index does not exist");
-        }
-    }
-
-    public static void handleDeadline(String input) throws DukeException {
-        String[] splitCommand = splitDeadlineTime(input);
-        if (splitCommand.length != SPLIT_AMOUNT) {
-            throw new DukeException();
-        }
-        String description = splitCommand[0];
-        String by = splitCommand[1];
-        Deadline deadline = new Deadline(description, by);
-        TaskList.addDeadLine(deadline);
-    }
-
-    public static void handleEvent(String input) throws DukeException {
-        String[] splitCommand = splitEventTime(input);
-        if (splitCommand.length != SPLIT_AMOUNT) {
-            throw new DukeException();
-        }
-        String description = splitCommand[0];
-        String at = splitCommand[1];
-        Event event = new Event(description, at);
-        TaskList.addEvent(event);
-    }
-
-    public static void handleDelete(String input) {
-        try {
-            int index = readIndex(input);
-            TaskList.deleteTask(index);
-        } catch (IndexOutOfBoundsException e) {
-            System.out.println("Index does not exist.");
-        }
-    }
-
-    private static int readIndex(String input) throws NumberFormatException {
-        try {
-            return Integer.parseInt(input);
-        } catch (NumberFormatException e) {
-            throw e;
-        }
-    }
-
-    private static String[] splitDeadlineTime(String input) throws DukeException {
-        return input.split(" /by ", SPLIT_AMOUNT);
-    }
-
-    private static String[] splitEventTime(String input) throws DukeException {
-        return input.split(" /at ", SPLIT_AMOUNT);
-    }
-
-    public static void handleInvalid(String input) {
-        System.out.println("\"" + input + "\"" + " is not a valid command, please try again!");
-    }
-}
diff --git a/src/main/java/parser/Parser.java b/src/main/java/parser/Parser.java
new file mode 100644
index 00000000..8c7a39bd
--- /dev/null
+++ b/src/main/java/parser/Parser.java
@@ -0,0 +1,134 @@
+package parser;
+
+import storage.Storage;
+import task.*;
+import task.command.*;
+import ui.UI;
+import exception.DukeException;
+
+public class Parser {
+
+    private final String TODO = "todo";
+    private final String LIST = "list";
+    private final String DEADLINE = "deadline";
+    private final String EVENT = "event";
+    private final String BYE = "bye";
+    private final String MARK = "mark";
+    private final String UNMARK = "unmark";
+    private final String DELETE = "delete";
+    private final String FIND = "FIND";
+    private final int SPLIT_AMOUNT = 2;
+    private boolean exit = false;
+
+    public void executeCommands(UI ui, TaskList tasks, Storage storage) {
+        while (!exit) {
+            try {
+                Command command = handleCommand(ui);
+                command.execute(tasks, ui, storage);
+            }
+            catch (DukeException e) {
+                System.out.println(e.getMessage());
+            }
+        }
+    }
+
+    public Command handleCommand(UI ui) throws DukeException {
+        String input = ui.getInput();
+        String command = getCommand(input);
+        switch (command) {
+        case (BYE):
+            exit = true;
+            return new ByeCommand();
+        case (LIST):
+            return new ListCommand();
+        case (TODO):
+            Todo todo = handleTodo(getAction(input));
+            return new TodoCommand(todo);
+        case (DEADLINE):
+            Deadline deadline = handleDeadline(getAction(input));
+            return new DeadlineCommand(deadline);
+        case (EVENT):
+            Event event = handleEvent(getAction(input));
+            return new EventCommand(event);
+        case (MARK):
+            int markIndex = readIndex(getAction(input));
+            return new MarkCommand(markIndex);
+        case (UNMARK):
+            int unmarkIndex = readIndex(getAction(input));
+            return new UnmarkCommand(unmarkIndex);
+        case (DELETE):
+            int deleteIndex = readIndex(getAction(input));
+            return new DeleteCommand(deleteIndex);
+        default:
+            return new InvalidCommand();
+        }
+    }
+
+
+    private String getCommand(String input) {
+        return input.split(" ", 2)[0].trim();
+    }
+
+    private String getAction(String input) throws DukeException {
+        String[] splitInput = input.split(" ", 2);
+        if (splitInput.length != 2) {
+            if (splitInput[1].equals(TODO) || splitInput[1].equals(DEADLINE) || splitInput[1].equals(EVENT)
+                    ||splitInput[1].equals(FIND)) {
+                throw new DukeException("Missing input for command, input the command in this format: " +
+                        splitInput[0] + "{TASK}");
+            } else {
+                throw new DukeException("Missing input for command, input the command in this format: " +
+                        splitInput[0] + "{ID}");
+            }
+
+        }
+        return splitInput[1];
+    }
+
+    public Todo handleTodo(String input) {
+        return new Todo(input);
+    }
+
+
+    public Deadline handleDeadline(String input) throws DukeException {
+        String[] splitCommand = splitDeadlineTime(input);
+        if (splitCommand.length != SPLIT_AMOUNT) {
+            throw new DukeException("Deadline is missing a timing.");
+        }
+        String description = splitCommand[0];
+        String by = splitCommand[1];
+        return new Deadline(description, by);
+    }
+
+    public Event handleEvent(String input) throws DukeException {
+        String[] splitCommand = splitEventTime(input);
+        if (splitCommand.length != SPLIT_AMOUNT) {
+            throw new DukeException("Event is missing a timing.");
+        }
+        String description = splitCommand[0];
+        String at = splitCommand[1];
+        return new Event(description, at);
+    }
+
+
+    public int readIndex(String input) throws DukeException {
+        try {
+            int index = Integer.parseInt(input);
+            if (index < 1 || index > TaskList.getTaskCount()) {
+                throw new DukeException("Index out of bound.");
+            }
+            return index;
+        } catch (NumberFormatException e) {
+            throw new DukeException("A valid numeric number must be entered.");
+        }
+    }
+
+    private String[] splitDeadlineTime(String input) throws DukeException {
+        return input.split(" /by ", SPLIT_AMOUNT);
+    }
+
+    private String[] splitEventTime(String input) throws DukeException {
+        return input.split(" /at ", SPLIT_AMOUNT);
+    }
+
+}
diff --git a/src/main/java/file/FileManager.java b/src/main/java/storage/Storage.java
similarity index 73%
rename from src/main/java/file/FileManager.java
rename to src/main/java/storage/Storage.java
index a145f128..d305852f 100644
--- a/src/main/java/file/FileManager.java
+++ b/src/main/java/storage/Storage.java
@@ -1,4 +1,4 @@
-package file;
+package storage;
 
 import task.*;
 
@@ -6,18 +6,18 @@
 import java.io.IOException;
 import java.io.File;
 import java.io.FileNotFoundException;
+import java.util.ArrayList;
 import java.util.Scanner;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 
-public class FileManager {
+public class Storage {
 
     private static Path taskDataPath = Paths.get(System.getProperty("user.dir"), "data", "tasks.txt");
-
     private static Path dataDirPath = Paths.get(System.getProperty("user.dir"), "data");
+    private ArrayList<Task> tasks = new ArrayList<>();
 
-    public static void writeToFile(Task task) throws IOException {
+    public void writeToFile(Task task) throws IOException {
         FileWriter fw = new FileWriter(taskDataPath.toString(), true);
         String textToAdd = taskToText(task);
         fw.write(textToAdd);
@@ -25,7 +25,7 @@ public static void writeToFile(Task task) throws IOException {
     }
 
 
-    public static void startReading() {
+    public ArrayList<Task> startReading() {
         try {
             makeMissingDirectory();
             readFile();
@@ -34,23 +34,24 @@ public static void startReading() {
         } catch (IOException e) {
             System.out.println("Some IO error has occurred");
         }
+        return tasks;
     }
 
-    private static void readFile() throws FileNotFoundException {
+    private void readFile() throws FileNotFoundException {
         String filePath = taskDataPath.toString();
         File f = new File(filePath);
         Scanner s = new Scanner(f);
         while (s.hasNext()) {
-            String[] input = s.nextLine().split(" | ");
+            String[] input = s.nextLine().split(" \\| ");
             switch (input[0]) {
             case ("T"):
-                insertTodo(input);
+                insertTodo(input, tasks);
                 break;
             case ("D"):
-                insertDeadline(input);
+                insertDeadline(input, tasks);
                 break;
             case ("E"):
-                insertEvent(input);
+                insertEvent(input, tasks);
                 break;
             }
         }
@@ -66,37 +67,37 @@ private static void makeMissingDirectory() throws IOException {
         FileWriter fw = new FileWriter(taskDataPath.toString());
     }
 
-    private static void insertTodo(String[] input) {
+    private void insertTodo(String[] input, ArrayList<Task> tasks) {
         Todo todo = new Todo(input[2]);
         if (input[1].equals("1")) {
             todo.setDone(true);
         } else {
             todo.setDone(false);
         }
-        TaskList.addTodo(todo);
+        tasks.add(todo);
     }
 
-    private static void insertDeadline(String[] input) {
+    private void insertDeadline(String[] input, ArrayList<Task> tasks) {
         Deadline deadline = new Deadline(input[2], input[3]);
         if (input[1].equals("1")) {
             deadline.setDone(true);
         } else {
             deadline.setDone(false);
         }
-        TaskList.addDeadLine(deadline);
+        tasks.add(deadline);
     }
 
-    private static void insertEvent(String[] input) {
+    private void insertEvent(String[] input, ArrayList<Task> tasks) {
         Event event = new Event(input[2], input[3]);
         if (input[1].equals("1")) {
             event.setDone(true);
         } else {
             event.setDone(false);
         }
-        TaskList.addEvent(event);
+        tasks.add(event);
     }
 
-    private static String taskToText(Task task) {
+    private String taskToText(Task task) {
         if (task.getClass() == Todo.class) {
             return "T | " + task.getStatusInNumber() + " | " + task.getDescription() + "\n";
         } else if (task.getClass() == Deadline.class) {
@@ -107,4 +108,8 @@ private static String taskToText(Task task) {
                     + task.getDescription() + " | " + ((Event) task).getAt() + "\n";
         }
     }
+
+    public void deleteContent() throws IOException {
+        new FileWriter(taskDataPath.toString()).close();
+    }
 }
diff --git a/src/main/java/task/Task.java b/src/main/java/task/Task.java
index e7ccc456..69a5c81b 100644
--- a/src/main/java/task/Task.java
+++ b/src/main/java/task/Task.java
@@ -13,6 +13,10 @@ public void setDone(boolean isDone) {
         this.isDone = isDone;
     }
 
+    public boolean getDone() {
+        return isDone;
+    }
+
     public String getStatusIcon() {
         return isDone ? "[X]" : "[ ]";
     }
diff --git a/src/main/java/task/TaskList.java b/src/main/java/task/TaskList.java
index 8b8aa770..86f43de6 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -1,59 +1,38 @@
 package task;
 
-import file.FileManager;
+import storage.Storage;
 
 import java.io.IOException;
 import java.util.ArrayList;
 
 public class TaskList {
 
-    private static final ArrayList<Task> tasks = new ArrayList<>();
+    private static ArrayList<Task> tasks;
     private static int taskCount = 0;
     private static final String LINE_DIVIDER = "-------------------------------------";
     private static final String ROGER_MESSAGE = "Got it. I have added this task:";
 
-    private static void printRoger(Task task) {
-        System.out.println(ROGER_MESSAGE);
-        System.out.println(task);
-        System.out.println("You now have " + taskCount + " tasks.");
-        System.out.println(LINE_DIVIDER);
+    public TaskList(ArrayList<Task> tasks) {
+        TaskList.tasks = tasks;
+        TaskList.taskCount = tasks.size();
     }
 
-    private static void printMark(int target, boolean mark) {
-        if (mark) {
-            System.out.println("Marked this task: \n " + tasks.get(target - 1));
-        } else {
-            System.out.println("Unmarked this task: \n" + tasks.get(target - 1));
-        }
-        System.out.println(LINE_DIVIDER);
+    public static int getTaskCount() {
+        return taskCount;
     }
 
-    public static void addDeadLine(Deadline deadline) {
-        tasks.add(deadline);
+    public void addTask(Task task) {
+        tasks.add(task);
         taskCount++;
-        printRoger(deadline);
     }
 
-    public static void addTodo(Todo todo) {
-        tasks.add(todo);
-        taskCount++;
-        printRoger(todo);
-    }
 
-    public static void addEvent(Event event) {
-        tasks.add(event);
-        taskCount++;
-        printRoger(event);
-    }
-
-    public static void markTarget(int target) {
+    public void markTarget(int target) {
         tasks.get(target - 1).setDone(true);
-        printMark(target, true);
     }
 
-    public static void unmarkTarget(int target) {
+    public void unmarkTarget(int target) {
         tasks.get(target - 1).setDone(false);
-        printMark(target, false);
     }
 
     public static void printList() {
@@ -66,21 +45,35 @@ public static void printList() {
         System.out.println(LINE_DIVIDER);
     }
 
-    public static void deleteTask(int index) {
-        System.out.println(tasks.get(index - 1) + " has been removed");
+    public void deleteTask(int index) {
         tasks.remove(index - 1);
         taskCount--;
-        System.out.println("There are " + taskCount + "tasks left");
-        System.out.println(LINE_DIVIDER);
     }
 
-    public static void storeTasks() {
+    public ArrayList<Task> getTasks() {
+        return tasks;
+    }
+
+    public Task getTask(int index) {
+        return tasks.get(index);
+    }
+
+    public void storeTask(Task task, Storage storage) {
+        try {
+            storage.writeToFile(task);
+        } catch (IOException e) {
+            System.out.println("File not found/missing directory.");
+        }
+    }
+
+    public void rewriteFile(Storage storage) {
         try {
+            storage.deleteContent();
             for (Task task : tasks) {
-                FileManager.writeToFile(task);
+                storage.writeToFile(task);
             }
         } catch (IOException e) {
-            System.out.println("An IO error has occurred");
+            System.out.println("File is not found/missing directory.");
         }
     }
 }
diff --git a/src/main/java/task/command/ByeCommand.java b/src/main/java/task/command/ByeCommand.java
new file mode 100644
index 00000000..d16d175c
--- /dev/null
+++ b/src/main/java/task/command/ByeCommand.java
@@ -0,0 +1,13 @@
+package task.command;
+
+import storage.Storage;
+import task.TaskList;
+import ui.UI;
+
+public class ByeCommand extends Command {
+
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        ui.byeMessage();
+    }
+}
diff --git a/src/main/java/task/command/Command.java b/src/main/java/task/command/Command.java
new file mode 100644
index 00000000..60f80051
--- /dev/null
+++ b/src/main/java/task/command/Command.java
@@ -0,0 +1,10 @@
+package task.command;
+
+import storage.Storage;
+import task.TaskList;
+import ui.UI;
+
+public abstract class Command {
+
+    public abstract void execute(TaskList tasks, UI ui, Storage storage);
+}
diff --git a/src/main/java/task/command/DeadlineCommand.java b/src/main/java/task/command/DeadlineCommand.java
new file mode 100644
index 00000000..61eaa64d
--- /dev/null
+++ b/src/main/java/task/command/DeadlineCommand.java
@@ -0,0 +1,22 @@
+package task.command;
+
+import storage.Storage;
+import task.Deadline;
+import task.TaskList;
+import ui.UI;
+
+public class DeadlineCommand extends Command {
+
+    private Deadline deadline;
+
+    public DeadlineCommand(Deadline deadline) {
+        this.deadline = deadline;
+    }
+
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        tasks.addTask(deadline);
+        ui.addMessage(deadline, tasks);
+        tasks.storeTask(deadline, storage);
+    }
+}
diff --git a/src/main/java/task/command/DeleteCommand.java b/src/main/java/task/command/DeleteCommand.java
new file mode 100644
index 00000000..e9252854
--- /dev/null
+++ b/src/main/java/task/command/DeleteCommand.java
@@ -0,0 +1,20 @@
+package task.command;
+
+import storage.Storage;
+import task.TaskList;
+import ui.UI;
+
+public class DeleteCommand extends Command {
+
+    private int index;
+
+    public DeleteCommand(int index) {
+        this.index = index;
+    }
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        ui.deleteMessage(tasks, index);
+        tasks.deleteTask(index);
+        tasks.rewriteFile(storage);
+    }
+}
diff --git a/src/main/java/task/command/EventCommand.java b/src/main/java/task/command/EventCommand.java
new file mode 100644
index 00000000..be9fc6f4
--- /dev/null
+++ b/src/main/java/task/command/EventCommand.java
@@ -0,0 +1,21 @@
+package task.command;
+
+import storage.Storage;
+import task.Event;
+import task.TaskList;
+import ui.UI;
+
+public class EventCommand extends Command {
+    private Event event;
+
+    public EventCommand(Event event) {
+        this.event = event;
+    }
+
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        tasks.addTask(event);
+        ui.addMessage(event, tasks);
+        tasks.storeTask(event, storage);
+    }
+}
diff --git a/src/main/java/task/command/InvalidCommand.java b/src/main/java/task/command/InvalidCommand.java
new file mode 100644
index 00000000..bdaed012
--- /dev/null
+++ b/src/main/java/task/command/InvalidCommand.java
@@ -0,0 +1,12 @@
+package task.command;
+
+import storage.Storage;
+import task.TaskList;
+import ui.UI;
+
+public class InvalidCommand extends Command{
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        ui.invalidCommand();
+    }
+}
diff --git a/src/main/java/task/command/ListCommand.java b/src/main/java/task/command/ListCommand.java
new file mode 100644
index 00000000..f242f87c
--- /dev/null
+++ b/src/main/java/task/command/ListCommand.java
@@ -0,0 +1,17 @@
+package task.command;
+
+import storage.Storage;
+import task.Task;
+import task.TaskList;
+import ui.UI;
+
+import java.util.ArrayList;
+
+public class ListCommand extends Command {
+
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        ArrayList<Task> list = tasks.getTasks();
+        ui.printList(list);
+    }
+}
diff --git a/src/main/java/task/command/MarkCommand.java b/src/main/java/task/command/MarkCommand.java
new file mode 100644
index 00000000..d88e898d
--- /dev/null
+++ b/src/main/java/task/command/MarkCommand.java
@@ -0,0 +1,19 @@
+package task.command;
+
+import storage.Storage;
+import task.TaskList;
+import ui.UI;
+
+public class MarkCommand extends Command {
+    private int index;
+    public MarkCommand(int index) {
+        this.index = index;
+    }
+
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        tasks.markTarget(index);
+        ui.markMessage(tasks, index);
+        tasks.rewriteFile(storage);
+    }
+}
diff --git a/src/main/java/task/command/TodoCommand.java b/src/main/java/task/command/TodoCommand.java
new file mode 100644
index 00000000..1a1a0811
--- /dev/null
+++ b/src/main/java/task/command/TodoCommand.java
@@ -0,0 +1,22 @@
+package task.command;
+
+import storage.Storage;
+import task.Task;
+import task.TaskList;
+import task.Todo;
+import ui.UI;
+
+public class TodoCommand extends Command {
+    private Todo todo;
+
+    public TodoCommand(Todo todo) {
+        this.todo = todo;
+    }
+
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        tasks.addTask(todo);
+        ui.addMessage(todo, tasks);
+        tasks.storeTask(todo, storage);
+    }
+}
diff --git a/src/main/java/task/command/UnmarkCommand.java b/src/main/java/task/command/UnmarkCommand.java
new file mode 100644
index 00000000..cd69c127
--- /dev/null
+++ b/src/main/java/task/command/UnmarkCommand.java
@@ -0,0 +1,19 @@
+package task.command;
+
+import storage.Storage;
+import task.TaskList;
+import ui.UI;
+
+public class UnmarkCommand extends Command {
+    private int index;
+    public UnmarkCommand(int index) {
+        this.index = index;
+    }
+
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage)  {
+        tasks.unmarkTarget(index);
+        ui.markMessage(tasks, index);
+        tasks.rewriteFile(storage);
+    }
+}
diff --git a/src/main/java/ui/UI.java b/src/main/java/ui/UI.java
index 40b94133..450882a6 100644
--- a/src/main/java/ui/UI.java
+++ b/src/main/java/ui/UI.java
@@ -1,25 +1,81 @@
 package ui;
 
+import task.Task;
+import task.TaskList;
+
+import java.util.ArrayList;
 import java.util.Scanner;
 
 public class UI {
-    public static void welcomeUser() {
-        String welcomeText = "-------------------------------------\n"
-                + "Hello! I am not Duke.\n"
-                + "Here are a list of commands:\n"
-                + "\ttodo <string> : adds a Todo to the list\n"
-                + "\tdeadline <string> /by <string> : adds a deadline and its deadline...\n"
-                + "\tevent <string> /at <string> : adds an event and its time...\n"
-                + "\tmark <task id> : marks a task\n"
-                + "\tunmark <task id> : unmarks a task\n"
-                + "\tlist : lists out all your tasks\n"
-                + "\tbye : exits the program\n"
-                + "I WILL CRASH IF YOU DO NOT COMPLY!!!\n"
-                + "-------------------------------------";
-        System.out.println(welcomeText);
-    }
-
-    public static String getInput() {
+
+    public final String LINE_DIVIDER = "-------------------------------------\n";
+    public final String WELCOME_TEXT = "Hello I am Duke. Here are a list of command:\n"
+            + "todo {task} : Creates a todo\n"
+            + "deadline {deadline /by time} : Creates a deadline by time\n"
+            + "event {event /at time} : Creates an event at time\n"
+            + "mark/unmark {index} : Marks a task\n"
+            + "delete {index} : Deletes a task\n"
+            + "list : List all current tasks\n"
+            + "bye : Exits the program";
+    public final String BYE_MESSAGE = "Goodbye, hope to see you again.";
+
+    public void welcomeUser() {
+        formatMessage(WELCOME_TEXT);
+    }
+
+    private void formatMessage(String message) {
+        System.out.print(LINE_DIVIDER + message + "\n" + LINE_DIVIDER);
+    }
+
+    public void byeMessage() {
+        formatMessage(BYE_MESSAGE);
+    }
+
+    public void addMessage(Task task, TaskList tasks) {
+        formatMessage("Got it. I have added this task:\n" + task
+                + "\nYou now have " + tasks.getTaskCount() + " tasks.");
+    }
+
+    public void printList(ArrayList<Task> tasks) {
+        if (tasks.isEmpty()) {
+            formatMessage("You have no tasks currently.");
+        } else {
+            int size = tasks.size();
+            String message = "Here is the list of your tasks: \n";
+            for (int i = 0; i < size; i++) {
+                if (i == size - 1) {
+                    message += (i + 1) + ". " + tasks.get(i);
+                } else {
+                    message += (i + 1) + ". " + tasks.get(i) + "\n";
+                }
+            }
+            formatMessage(message);
+        }
+    }
+
+    public void markMessage(TaskList tasks, int index) {
+        Task task = tasks.getTask(index - 1);
+        if (!task.getDone()) {
+            formatMessage("Unmarked the following task:\n "
+                    + task);
+        } else {
+            formatMessage("Marked the following task:\n"
+                    + task);
+        }
+    }
+
+    public void invalidCommand() {
+        formatMessage("You have entered an invalid command.");
+    }
+
+    public void deleteMessage(TaskList tasks, int index) {
+        Task deletedTask = tasks.getTask(index - 1);
+        formatMessage("The following task has been deleted: \n"
+                + deletedTask + "\nYou now have " + (tasks.getTaskCount() - 1)
+                + " tasks.");
+    }
+
+    public String getInput() {
         Scanner sc = new Scanner(System.in);
         String input = sc.nextLine();
         return input.trim();

From 9413857f0763eb685290cc8f25890efcea6a7ff7 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 29 Sep 2022 00:44:16 +0800
Subject: [PATCH 23/26] Add Level 9

---
 data/tasks.txt                                |   2 -
 src/main/java/exception/DukeException.java    |   8 ++
 src/main/java/parser/Parser.java              | 112 ++++++++++++++----
 src/main/java/storage/Storage.java            |  87 +++++++++++++-
 src/main/java/task/Deadline.java              |  20 ++++
 src/main/java/task/Event.java                 |  20 ++++
 src/main/java/task/Task.java                  |  33 ++++++
 src/main/java/task/TaskList.java              |  85 ++++++++-----
 src/main/java/task/Todo.java                  |  14 +++
 src/main/java/task/command/ByeCommand.java    |  11 ++
 src/main/java/task/command/Command.java       |  10 ++
 .../java/task/command/DeadlineCommand.java    |  19 ++-
 src/main/java/task/command/DeleteCommand.java |  20 +++-
 src/main/java/task/command/EventCommand.java  |  18 ++-
 src/main/java/task/command/FindCommand.java   |  41 +++++++
 .../java/task/command/InvalidCommand.java     |  13 +-
 src/main/java/task/command/ListCommand.java   |  11 ++
 src/main/java/task/command/MarkCommand.java   |  19 ++-
 src/main/java/task/command/TodoCommand.java   |  19 ++-
 src/main/java/task/command/UnmarkCommand.java |  19 ++-
 src/main/java/ui/UI.java                      |  18 +++
 21 files changed, 537 insertions(+), 62 deletions(-)
 create mode 100644 src/main/java/task/command/FindCommand.java

diff --git a/data/tasks.txt b/data/tasks.txt
index 95e08e18..e69de29b 100644
--- a/data/tasks.txt
+++ b/data/tasks.txt
@@ -1,2 +0,0 @@
-T | 0 | hello
-T | 0 | hello
diff --git a/src/main/java/exception/DukeException.java b/src/main/java/exception/DukeException.java
index 5500ba15..878184fd 100644
--- a/src/main/java/exception/DukeException.java
+++ b/src/main/java/exception/DukeException.java
@@ -2,7 +2,15 @@
 
 public class DukeException extends Exception {
 
+    private String message;
+
+    /**
+     * Constructor for DukeException
+     *
+     * @param message The error message to be displayed
+     */
     public DukeException(String message) {
         super(message);
+        this.message = message;
     }
 }
diff --git a/src/main/java/parser/Parser.java b/src/main/java/parser/Parser.java
index 8c7a39bd..7c15f9c7 100644
--- a/src/main/java/parser/Parser.java
+++ b/src/main/java/parser/Parser.java
@@ -6,6 +6,10 @@
 import ui.UI;
 import exception.DukeException;
 
+/**
+ * An object that deals with anything that the user inputs so that logic
+ * can be performed on them.
+ */
 public class Parser {
 
     private final String TODO = "todo";
@@ -16,22 +20,35 @@ public class Parser {
     private final String MARK = "mark";
     private final String UNMARK = "unmark";
     private final String DELETE = "delete";
-    private final String FIND = "FIND";
+    private final String FIND = "find";
     private final int SPLIT_AMOUNT = 2;
     private boolean exit = false;
 
+    /**
+     * This method calls the execute method of the commands that the user inputs.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     public void executeCommands(UI ui, TaskList tasks, Storage storage) {
         while (!exit) {
             try {
                 Command command = handleCommand(ui);
                 command.execute(tasks, ui, storage);
-            }
-            catch (DukeException e) {
+            } catch (DukeException e) {
                 System.out.println(e.getMessage());
             }
         }
     }
 
+    /**
+     * The method that identifies the command that the user is inputting.
+     *
+     * @param ui Object that handles all user interaction.
+     * @return Command object based on what the user inputs.
+     * @throws DukeException If user enters an invalid input.
+     */
     public Command handleCommand(UI ui) throws DukeException {
         String input = ui.getInput();
         String command = getCommand(input);
@@ -42,54 +59,79 @@ public Command handleCommand(UI ui) throws DukeException {
         case (LIST):
             return new ListCommand();
         case (TODO):
-            Todo todo = handleTodo(getAction(input));
+            Todo todo = handleTodo(getArgument(input));
             return new TodoCommand(todo);
         case (DEADLINE):
-            Deadline deadline = handleDeadline(getAction(input));
+            Deadline deadline = handleDeadline(getArgument(input));
             return new DeadlineCommand(deadline);
         case (EVENT):
-            Event event = handleEvent(getAction(input));
+            Event event = handleEvent(getArgument(input));
             return new EventCommand(event);
         case (MARK):
-            int markIndex = readIndex(getAction(input));
+            int markIndex = readIndex(getArgument(input));
             return new MarkCommand(markIndex);
         case (UNMARK):
-            int unmarkIndex = readIndex(getAction(input));
+            int unmarkIndex = readIndex(getArgument(input));
             return new UnmarkCommand(unmarkIndex);
         case (DELETE):
-            int deleteIndex = readIndex(getAction(input));
+            int deleteIndex = readIndex(getArgument(input));
             return new DeleteCommand(deleteIndex);
+        case (FIND):
+            String target = getArgument(input);
+            return new FindCommand(target);
         default:
             return new InvalidCommand();
         }
     }
 
-
+    /**
+     * Gets the specific command the user inputs.
+     *
+     * @param input What the user inputs in the CLI.
+     * @return The first word, which is the command that the user inputs.
+     */
     private String getCommand(String input) {
-        return input.split(" ", 2)[0].trim();
+        return input.split(" ", 2)[0].trim().toLowerCase();
     }
 
-    private String getAction(String input) throws DukeException {
-        String[] splitInput = input.split(" ", 2);
-        if (splitInput.length != 2) {
-            if (splitInput[1].equals(TODO) || splitInput[1].equals(DEADLINE) || splitInput[1].equals(EVENT)
-                    ||splitInput[1].equals(FIND)) {
+    /**
+     * Gets the argument that the user inputs.
+     *
+     * @param input What the user inputs in the CLI.
+     * @return The string after the first word, which is the argument.
+     * @throws DukeException If the user did not input the command.
+     */
+    private String getArgument(String input) throws DukeException {
+        String[] splitInput = input.split(" ", SPLIT_AMOUNT);
+        if (splitInput.length != SPLIT_AMOUNT) {
+            if (splitInput[0].equals(TODO) || splitInput[0].equals(DEADLINE) || splitInput[0].equals(EVENT)
+                    || splitInput[0].equals(FIND)) {
                 throw new DukeException("Missing input for command, input the command in this format: " +
-                        splitInput[0] + "{TASK}");
+                        splitInput[0] + " {TASK}");
             } else {
                 throw new DukeException("Missing input for command, input the command in this format: " +
-                        splitInput[0] + "{ID}");
+                        splitInput[0] + " {ID}");
             }
-
         }
         return splitInput[1];
     }
 
+    /**
+     * Creates a Todo object from the user's argument.
+     *
+     * @param input The argument that the user inputs.
+     * @return A new Todo object based on user inputs.
+     */
     public Todo handleTodo(String input) {
         return new Todo(input);
     }
 
-
+    /**
+     * Creates a Deadline object from the user's argument by identifying the description and timing.
+     * @param input The argument the user inputs.
+     * @return A new Deadline object based on the user's input.
+     * @throws DukeException If the user does not input the proper argument.
+     */
     public Deadline handleDeadline(String input) throws DukeException {
         String[] splitCommand = splitDeadlineTime(input);
         if (splitCommand.length != SPLIT_AMOUNT) {
@@ -100,6 +142,12 @@ public Deadline handleDeadline(String input) throws DukeException {
         return new Deadline(description, by);
     }
 
+    /**
+     * Creates an Event object from the user's argument by identifying the description and timing.
+     * @param input The argument the user inputs.
+     * @return A new Event object based on the user's input.
+     * @throws DukeException If the user does not input the proper argument.
+     */
     public Event handleEvent(String input) throws DukeException {
         String[] splitCommand = splitEventTime(input);
         if (splitCommand.length != SPLIT_AMOUNT) {
@@ -110,7 +158,13 @@ public Event handleEvent(String input) throws DukeException {
         return new Event(description, at);
     }
 
-
+    /**
+     * Converts the user argument into an integer.
+     *
+     * @param input The argument the user inputs.
+     * @return An integer based on user's input.
+     * @throws DukeException If the user's argument cannot be converted into an integer.
+     */
     public int readIndex(String input) throws DukeException {
         try {
             int index = Integer.parseInt(input);
@@ -123,11 +177,23 @@ public int readIndex(String input) throws DukeException {
         }
     }
 
-    private String[] splitDeadlineTime(String input) throws DukeException {
+    /**
+     * Splits the user's deadline argument into its description and time.
+     *
+     * @param input The argument the user inputs.
+     * @return An array of strings that contain the deadline's description and time respectively.
+     */
+    private String[] splitDeadlineTime(String input) {
         return input.split(" /by ", SPLIT_AMOUNT);
     }
 
-    private String[] splitEventTime(String input) throws DukeException {
+    /**
+     * Splits the user's event argument into its description and time.
+     *
+     * @param input The argument the user inputs.
+     * @return An array of strings that contain the event's description and time respectively.
+     */
+    private String[] splitEventTime(String input) {
         return input.split(" /at ", SPLIT_AMOUNT);
     }
 
diff --git a/src/main/java/storage/Storage.java b/src/main/java/storage/Storage.java
index d305852f..cf7f2367 100644
--- a/src/main/java/storage/Storage.java
+++ b/src/main/java/storage/Storage.java
@@ -11,12 +11,21 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 
+/**
+ * A class that handles the writing and reading of files in the local storage.
+ */
 public class Storage {
 
     private static Path taskDataPath = Paths.get(System.getProperty("user.dir"), "data", "tasks.txt");
     private static Path dataDirPath = Paths.get(System.getProperty("user.dir"), "data");
     private ArrayList<Task> tasks = new ArrayList<>();
 
+    /**
+     * Adds a task to the file by appending to it.
+     *
+     * @param task The task to be added.
+     * @throws IOException If the file is missing.
+     */
     public void writeToFile(Task task) throws IOException {
         FileWriter fw = new FileWriter(taskDataPath.toString(), true);
         String textToAdd = taskToText(task);
@@ -24,7 +33,12 @@ public void writeToFile(Task task) throws IOException {
         fw.close();
     }
 
-
+    /**
+     * Method that populates an ArrayList based on the tasks in the file.
+     * This method will create the file and its directory if they are missing.
+     *
+     * @return An ArrayList of tasks in the text file.
+     */
     public ArrayList<Task> startReading() {
         try {
             makeMissingDirectory();
@@ -37,6 +51,11 @@ public ArrayList<Task> startReading() {
         return tasks;
     }
 
+    /**
+     * Reads the file from start to finish and identifies the tasks in it.
+     *
+     * @throws FileNotFoundException If file is not found.
+     */
     private void readFile() throws FileNotFoundException {
         String filePath = taskDataPath.toString();
         File f = new File(filePath);
@@ -57,7 +76,12 @@ private void readFile() throws FileNotFoundException {
         }
     }
 
-    private static void makeMissingDirectory() throws IOException {
+    /**
+     * Makes the directory if it is missing.
+     *
+     * @throws IOException if the path is not found.
+     */
+    private void makeMissingDirectory() throws IOException {
         File dir = new File(dataDirPath.toString());
         if (!dir.exists()) {
             dir.mkdir();
@@ -67,6 +91,12 @@ private static void makeMissingDirectory() throws IOException {
         FileWriter fw = new FileWriter(taskDataPath.toString());
     }
 
+    /**
+     * Inserts a Todo object into the list of tasks.
+     *
+     * @param input The substrings a single line in the text file separated by |.
+     * @param tasks The list that contains all tasks in the text file.
+     */
     private void insertTodo(String[] input, ArrayList<Task> tasks) {
         Todo todo = new Todo(input[2]);
         if (input[1].equals("1")) {
@@ -77,6 +107,12 @@ private void insertTodo(String[] input, ArrayList<Task> tasks) {
         tasks.add(todo);
     }
 
+    /**
+     * Inserts a Deadline object into the list of tasks.
+     *
+     * @param input The substrings a single line in the text file separated by |.
+     * @param tasks The list that contains all tasks in the text file.
+     */
     private void insertDeadline(String[] input, ArrayList<Task> tasks) {
         Deadline deadline = new Deadline(input[2], input[3]);
         if (input[1].equals("1")) {
@@ -87,6 +123,12 @@ private void insertDeadline(String[] input, ArrayList<Task> tasks) {
         tasks.add(deadline);
     }
 
+    /**
+     * Inserts an Event object into the list of tasks.
+     *
+     * @param input The substrings a single line in the text file separated by |.
+     * @param tasks The list that contains all tasks in the text file.
+     */
     private void insertEvent(String[] input, ArrayList<Task> tasks) {
         Event event = new Event(input[2], input[3]);
         if (input[1].equals("1")) {
@@ -97,6 +139,12 @@ private void insertEvent(String[] input, ArrayList<Task> tasks) {
         tasks.add(event);
     }
 
+    /**
+     * Converts a task into its text representation.
+     *
+     * @param task The task to be converted.
+     * @return The text representation of the task.
+     */
     private String taskToText(Task task) {
         if (task.getClass() == Todo.class) {
             return "T | " + task.getStatusInNumber() + " | " + task.getDescription() + "\n";
@@ -109,7 +157,42 @@ private String taskToText(Task task) {
         }
     }
 
+    /**
+     * Deletes everything in the text file.
+     *
+     * @throws IOException If file is missing.
+     */
     public void deleteContent() throws IOException {
         new FileWriter(taskDataPath.toString()).close();
     }
+
+    /**
+     * Stores a task into the local text file.
+     *
+     * @param task The task to be stored.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
+    public void storeTask(Task task, Storage storage) {
+        try {
+            storage.writeToFile(task);
+        } catch (IOException e) {
+            System.out.println("File not found/missing directory.");
+        }
+    }
+
+    /**
+     * Empties the text file and repopulates it with the updated tasks.
+     *
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
+    public void rewriteFile(Storage storage) {
+        try {
+            storage.deleteContent();
+            for (Task task : tasks) {
+                storage.writeToFile(task);
+            }
+        } catch (IOException e) {
+            System.out.println("File is not found/missing directory.");
+        }
+    }
 }
diff --git a/src/main/java/task/Deadline.java b/src/main/java/task/Deadline.java
index f4e34971..53492a42 100644
--- a/src/main/java/task/Deadline.java
+++ b/src/main/java/task/Deadline.java
@@ -1,17 +1,37 @@
 package task;
 
+/**
+ * A class that represents a deadline.
+ */
 public class Deadline extends Task {
     protected String by;
 
+    /**
+     * Constructor for Deadline.
+     *
+     * @param description Description of this deadline.
+     * @param by Due date of this deadline.
+     */
     public Deadline(String description, String by) {
         super(description);
         this.by = by;
     }
 
+    /**
+     * Gets the due date of this deadline.
+     *
+     * @return Due date of this deadline.
+     */
     public String getBy() {
         return by;
     }
 
+    /**
+     * Fixes how this deadline would look like if it were to be converted into a string
+     * based on its description and due date.
+     *
+     * @return The string representation of this deadline.
+     */
     @Override
     public String toString() {
         return "[D]" + super.getStatusIcon() + " " + super.getDescription() + " (by: " + by + ")";
diff --git a/src/main/java/task/Event.java b/src/main/java/task/Event.java
index 4d331e79..b0fdeac9 100644
--- a/src/main/java/task/Event.java
+++ b/src/main/java/task/Event.java
@@ -1,16 +1,36 @@
 package task;
 
+/**
+ * A class representing an event.
+ */
 public class Event extends Task {
     protected String at;
 
+    /**
+     * Constructor for Event.
+     *
+     * @param description Description of this event.
+     * @param at When this event is at.
+     */
     public Event(String description, String at) {
         super(description);
         this.at = at;
     }
 
+    /**
+     * Gets the date when the event is occurring.
+     *
+     * @return When the event is at.
+     */
     public String getAt() {
         return at;
     }
+    /**
+     * Fixes how this deadline would look like if it were to be converted into a string
+     * based on its description and occurring date
+     *
+     * @return The string representation of this event.
+     */
     @Override
     public String toString() {
         return "[E]" + super.getStatusIcon() + " " + super.getDescription() + " (at: " + at + ")";
diff --git a/src/main/java/task/Task.java b/src/main/java/task/Task.java
index 69a5c81b..c8fb5be9 100644
--- a/src/main/java/task/Task.java
+++ b/src/main/java/task/Task.java
@@ -1,30 +1,63 @@
 package task;
 
+/**
+ * A class that represents the different forms of tasks in Duke.
+ */
 public class Task {
     protected String description;
     protected boolean isDone;
 
+    /**
+     * Constructor for Task.
+     *
+     * @param description The task description.
+     */
     public Task(String description) {
         this.description = description;
         this.isDone = false;
     }
 
+    /**
+     *  Sets the done state of this task.
+     *
+     * @param isDone Whether this task is to be marked as done.
+     */
     public void setDone(boolean isDone) {
         this.isDone = isDone;
     }
 
+    /**
+     * Gets the done state of this task.
+     *
+     * @return Whether this task is done.
+     */
     public boolean getDone() {
         return isDone;
     }
 
+    /**
+     * Gets the status icon.
+     *
+     * @return [X] if isDone, [] otherwise.
+     */
     public String getStatusIcon() {
         return isDone ? "[X]" : "[ ]";
     }
 
+    /**
+     * Gets the status in terms of 1 and 0.
+     *
+     * @return 1 if isDone, 0 otherwise.
+     */
     public int getStatusInNumber() {
         return isDone ? 1 : 0;
     }
 
+    /**
+     * Gets task description
+     *
+     * @return Description of this task.
+     */
     public String getDescription() {
         return description;
     }
diff --git a/src/main/java/task/TaskList.java b/src/main/java/task/TaskList.java
index 86f43de6..7e025914 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/task/TaskList.java
@@ -5,75 +5,104 @@
 import java.io.IOException;
 import java.util.ArrayList;
 
+/**
+ * A class that handles all the user's inputted tasks.
+ */
 public class TaskList {
 
     private static ArrayList<Task> tasks;
     private static int taskCount = 0;
-    private static final String LINE_DIVIDER = "-------------------------------------";
-    private static final String ROGER_MESSAGE = "Got it. I have added this task:";
 
+    /**
+     * Constructor for TaskList.
+     *
+     * @param tasks The list of tasks.
+     */
     public TaskList(ArrayList<Task> tasks) {
         TaskList.tasks = tasks;
         TaskList.taskCount = tasks.size();
     }
 
+    /**
+     * Gets the number of tasks in the list.
+     *
+     * @return The number of tasks.
+     */
     public static int getTaskCount() {
         return taskCount;
     }
 
+    /**
+     * Adds a task to the list.
+     *
+     * @param task The task to be added.
+     */
     public void addTask(Task task) {
         tasks.add(task);
         taskCount++;
     }
 
-
+    /**
+     * Marks a task on the list.
+     *
+     * @param target The index of the task to be marked.
+     */
     public void markTarget(int target) {
         tasks.get(target - 1).setDone(true);
     }
 
+    /**
+     * Unmarks a task on the list.
+     *
+     * @param target The index of the task to be unmarked.
+     */
     public void unmarkTarget(int target) {
         tasks.get(target - 1).setDone(false);
     }
 
-    public static void printList() {
-        System.out.println("Here are a list of your tasks: ");
-        int index = 1;
-        for (Task task : tasks) {
-            System.out.println(index + ". " + task);
-            index++;
-        }
-        System.out.println(LINE_DIVIDER);
-    }
-
+    /**
+     * Deletes a task from the list.
+     *
+     * @param index The index of the task to be deleted.
+     */
     public void deleteTask(int index) {
         tasks.remove(index - 1);
         taskCount--;
     }
 
+    /**
+     * Gets a copy of all the current tasks in the list.
+     *
+     * @return The list of all tasks.
+     */
     public ArrayList<Task> getTasks() {
         return tasks;
     }
 
+    /**
+     * Gets the task of a specific index in the list.
+     *
+     * @param index The index of the task to get.
+     * @return The task of that index in the list.
+     */
     public Task getTask(int index) {
         return tasks.get(index);
     }
 
-    public void storeTask(Task task, Storage storage) {
-        try {
-            storage.writeToFile(task);
-        } catch (IOException e) {
-            System.out.println("File not found/missing directory.");
-        }
-    }
-
-    public void rewriteFile(Storage storage) {
-        try {
-            storage.deleteContent();
-            for (Task task : tasks) {
-                storage.writeToFile(task);
+    /**
+     * Searches through all the tasks in the list to find for tasks that have
+     * descriptions containing a certain target word.
+     *
+     * @param target The word to be searched for.
+     * @return The list of all tasks that have descriptions containing that word.
+     */
+    public ArrayList<Task> findInList(String target) {
+        ArrayList<Task> found = new ArrayList<>();
+        for (Task task : tasks) {
+            if (task.getDescription().contains(target)) {
+                found.add(task);
             }
-        } catch (IOException e) {
-            System.out.println("File is not found/missing directory.");
         }
+        return found;
     }
 }
diff --git a/src/main/java/task/Todo.java b/src/main/java/task/Todo.java
index 710e5f95..ae3a324b 100644
--- a/src/main/java/task/Todo.java
+++ b/src/main/java/task/Todo.java
@@ -1,10 +1,24 @@
 package task;
 
+/**
+ * A clas representing a todo.
+ */
 public class Todo extends Task {
+    /**
+     * Constructor for Todo
+     *
+     * @param description Description of this todo.
+     */
     public Todo(String description) {
         super(description);
     }
 
+    /**
+     * Fixes how this Todo would look like if it were to be converted into a string
+     * based on its description.
+     *
+     * @return The string representation of this Todo.
+     */
     @Override
     public String toString() {
         return "[T]" + super.getStatusIcon() + " " + super.getDescription();
diff --git a/src/main/java/task/command/ByeCommand.java b/src/main/java/task/command/ByeCommand.java
index d16d175c..19bd5344 100644
--- a/src/main/java/task/command/ByeCommand.java
+++ b/src/main/java/task/command/ByeCommand.java
@@ -4,8 +4,19 @@
 import task.TaskList;
 import ui.UI;
 
+/**
+ * A class that represents a bye command
+ */
 public class ByeCommand extends Command {
 
+    /**
+     * Executes the bye command by displaying the exit message
+     * when the user quits the program.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         ui.byeMessage();
diff --git a/src/main/java/task/command/Command.java b/src/main/java/task/command/Command.java
index 60f80051..d0f136d4 100644
--- a/src/main/java/task/command/Command.java
+++ b/src/main/java/task/command/Command.java
@@ -4,7 +4,17 @@
 import task.TaskList;
 import ui.UI;
 
+/**
+ * An abstract class that can represent all other commands within Duke.
+ */
 public abstract class Command {
 
+    /**
+     * An abstract method represents the execution of a command.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     public abstract void execute(TaskList tasks, UI ui, Storage storage);
 }
diff --git a/src/main/java/task/command/DeadlineCommand.java b/src/main/java/task/command/DeadlineCommand.java
index 61eaa64d..ccad3c0c 100644
--- a/src/main/java/task/command/DeadlineCommand.java
+++ b/src/main/java/task/command/DeadlineCommand.java
@@ -5,18 +5,35 @@
 import task.TaskList;
 import ui.UI;
 
+/**
+ * A class that represents a deadline command.
+ */
 public class DeadlineCommand extends Command {
 
     private Deadline deadline;
 
+    /**
+     * Constructor for DeadlineCommand.
+     *
+     * @param deadline A deadline object.
+     */
     public DeadlineCommand(Deadline deadline) {
         this.deadline = deadline;
     }
 
+    /**
+     * Executes the deadline command by adding a deadline in the list
+     * and storing it in the local storage.
+     * Displays a message telling user that the task has been added.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         tasks.addTask(deadline);
         ui.addMessage(deadline, tasks);
-        tasks.storeTask(deadline, storage);
+        storage.storeTask(deadline, storage);
     }
 }
diff --git a/src/main/java/task/command/DeleteCommand.java b/src/main/java/task/command/DeleteCommand.java
index e9252854..5f74c60f 100644
--- a/src/main/java/task/command/DeleteCommand.java
+++ b/src/main/java/task/command/DeleteCommand.java
@@ -4,17 +4,35 @@
 import task.TaskList;
 import ui.UI;
 
+/**
+ * A class that represents a delete command.
+ */
 public class DeleteCommand extends Command {
 
     private int index;
 
+    /**
+     * Constructor for DeleteCommand.
+     *
+     * @param index Index of task to be deleted.
+     */
     public DeleteCommand(int index) {
         this.index = index;
     }
+
+    /**
+     * Executes the delete command by removing the task from the list
+     * and the local storage.
+     * Displays a message telling user that the task has been deleted.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         ui.deleteMessage(tasks, index);
         tasks.deleteTask(index);
-        tasks.rewriteFile(storage);
+        storage.rewriteFile(storage);
     }
 }
diff --git a/src/main/java/task/command/EventCommand.java b/src/main/java/task/command/EventCommand.java
index be9fc6f4..22a77ac2 100644
--- a/src/main/java/task/command/EventCommand.java
+++ b/src/main/java/task/command/EventCommand.java
@@ -5,17 +5,33 @@
 import task.TaskList;
 import ui.UI;
 
+/**
+ * A class that represents a event command.
+ */
 public class EventCommand extends Command {
     private Event event;
 
+    /**
+     * Constructor for EventCommand.
+     * @param event An event object
+     */
     public EventCommand(Event event) {
         this.event = event;
     }
 
+    /**
+     * Executes the event command by adding an event into the list
+     * and storing it in the local storage.
+     * Displays a message telling user that the task has been added.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         tasks.addTask(event);
         ui.addMessage(event, tasks);
-        tasks.storeTask(event, storage);
+        storage.storeTask(event, storage);
     }
 }
diff --git a/src/main/java/task/command/FindCommand.java b/src/main/java/task/command/FindCommand.java
new file mode 100644
index 00000000..b4ebfa93
--- /dev/null
+++ b/src/main/java/task/command/FindCommand.java
@@ -0,0 +1,41 @@
+package task.command;
+
+import storage.Storage;
+import task.Task;
+import task.TaskList;
+import ui.UI;
+
+import java.util.ArrayList;
+
+/**
+ * A class that represents a find command.
+ */
+public class FindCommand extends Command {
+
+    private String target;
+
+    /**
+     * Constructor for FindCommand.
+     *
+     * @param target String that user wants to find in list.
+     */
+    public FindCommand(String target) {
+        this.target = target;
+    }
+
+    /**
+     * Executes the find command by searching the list of tasks for any
+     * occurence of the target string.
+     * Displays the list of matching items or shows a message that no matching
+     * items are found.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
+    @Override
+    public void execute(TaskList tasks, UI ui, Storage storage) {
+        ArrayList<Task> found = tasks.findInList(target);
+        ui.printFound(found);
+    }
+}
diff --git a/src/main/java/task/command/InvalidCommand.java b/src/main/java/task/command/InvalidCommand.java
index bdaed012..063635a1 100644
--- a/src/main/java/task/command/InvalidCommand.java
+++ b/src/main/java/task/command/InvalidCommand.java
@@ -4,7 +4,18 @@
 import task.TaskList;
 import ui.UI;
 
-public class InvalidCommand extends Command{
+/**
+ * A class that represents an invalid command.
+ */
+public class InvalidCommand extends Command {
+    /**
+     * Executes the invalid command by displaying a message telling the user
+     * that their command is invalid.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         ui.invalidCommand();
diff --git a/src/main/java/task/command/ListCommand.java b/src/main/java/task/command/ListCommand.java
index f242f87c..11ceb143 100644
--- a/src/main/java/task/command/ListCommand.java
+++ b/src/main/java/task/command/ListCommand.java
@@ -7,8 +7,19 @@
 
 import java.util.ArrayList;
 
+/**
+ * A class that represents a list command.
+ */
 public class ListCommand extends Command {
 
+    /**
+     * Executes the list command by displaying the list of all tasks current
+     * in the list, or tells user that the list is empty.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         ArrayList<Task> list = tasks.getTasks();
diff --git a/src/main/java/task/command/MarkCommand.java b/src/main/java/task/command/MarkCommand.java
index d88e898d..4ffc8e8b 100644
--- a/src/main/java/task/command/MarkCommand.java
+++ b/src/main/java/task/command/MarkCommand.java
@@ -4,16 +4,33 @@
 import task.TaskList;
 import ui.UI;
 
+/**
+ * A class that represents the mark command.
+ */
 public class MarkCommand extends Command {
     private int index;
+
+    /**
+     * Construstor for MarkCommand.
+     *
+     * @param index Index of task to be marked.
+     */
     public MarkCommand(int index) {
         this.index = index;
     }
 
+    /**
+     * Executes the mark command by marking the tasks of the index.
+     * Displays a message telling the user that the task has been marked.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         tasks.markTarget(index);
         ui.markMessage(tasks, index);
-        tasks.rewriteFile(storage);
+        storage.rewriteFile(storage);
     }
 }
diff --git a/src/main/java/task/command/TodoCommand.java b/src/main/java/task/command/TodoCommand.java
index 1a1a0811..2ee30a2e 100644
--- a/src/main/java/task/command/TodoCommand.java
+++ b/src/main/java/task/command/TodoCommand.java
@@ -6,17 +6,34 @@
 import task.Todo;
 import ui.UI;
 
+/**
+ * A class that represents the todo command.
+ */
 public class TodoCommand extends Command {
     private Todo todo;
 
+    /**
+     * Constructor for TodoCommand.
+     *
+     * @param todo A Todo object.
+     */
     public TodoCommand(Todo todo) {
         this.todo = todo;
     }
 
+    /**
+     * Executes the todo command by adding a task todo into the list
+     * and storing it in the local storage.
+     * Displays a message telling user that the task has been added.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage) {
         tasks.addTask(todo);
         ui.addMessage(todo, tasks);
-        tasks.storeTask(todo, storage);
+        storage.storeTask(todo, storage);
     }
 }
diff --git a/src/main/java/task/command/UnmarkCommand.java b/src/main/java/task/command/UnmarkCommand.java
index cd69c127..45275730 100644
--- a/src/main/java/task/command/UnmarkCommand.java
+++ b/src/main/java/task/command/UnmarkCommand.java
@@ -4,16 +4,33 @@
 import task.TaskList;
 import ui.UI;
 
+/**
+ * A class representing an unmark command.
+ */
 public class UnmarkCommand extends Command {
     private int index;
+
+    /**
+     * Constructor for UnmarkCommand.
+     *
+     * @param index Index of task to be unmarked.
+     */
     public UnmarkCommand(int index) {
         this.index = index;
     }
 
+    /**
+     * Executes the mark command by unmarking the tasks of the index.
+     * Displays a message telling the user that the task has been unmarked.
+     *
+     * @param ui Object that handles all user interaction.
+     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param storage Object that handles saving the user's task into the local storage.
+     */
     @Override
     public void execute(TaskList tasks, UI ui, Storage storage)  {
         tasks.unmarkTarget(index);
         ui.markMessage(tasks, index);
-        tasks.rewriteFile(storage);
+        storage.rewriteFile(storage);
     }
 }
diff --git a/src/main/java/ui/UI.java b/src/main/java/ui/UI.java
index 450882a6..cbaab28d 100644
--- a/src/main/java/ui/UI.java
+++ b/src/main/java/ui/UI.java
@@ -75,6 +75,24 @@ public void deleteMessage(TaskList tasks, int index) {
                 + " tasks.");
     }
 
+    public void printFound(ArrayList<Task> found) {
+        String message = "Here are the matching tasks in your list:\n";
+        int size = found.size();
+        if (size == 0) {
+            message = "Found no matching tasks in your list.";
+        } else {
+            for (int i = 0; i < size; i++) {
+                if (i == size - 1)
+                {
+                    message += (i + 1) + ". " + found.get(i);
+                } else {
+                    message += (i + 1) + ". " + found.get(i) + "\n";
+                }
+            }
+        }
+        formatMessage(message);
+    }
+
     public String getInput() {
         Scanner sc = new Scanner(System.in);
         String input = sc.nextLine();

From d0aba840be2782bae560690d7bf4a04ba8328e33 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 29 Sep 2022 01:01:45 +0800
Subject: [PATCH 24/26] Add JavaDoc

Repackaged some files
---
 src/main/java/META-INF/MANIFEST.MF                  |  2 +-
 src/main/java/{ => duke}/Duke.java                  | 10 ++++++----
 .../java/{ => duke}/exception/DukeException.java    |  2 +-
 src/main/java/{ => duke}/parser/Parser.java         | 12 ++++++------
 src/main/java/{ => duke}/storage/Storage.java       |  4 ++--
 src/main/java/{ => duke}/task/Deadline.java         |  2 +-
 src/main/java/{ => duke}/task/Event.java            |  2 +-
 src/main/java/{ => duke}/task/Task.java             |  2 +-
 src/main/java/{ => duke}/task/TaskList.java         |  5 +----
 src/main/java/{ => duke}/task/Todo.java             |  2 +-
 .../java/{ => duke}/task/command/ByeCommand.java    | 10 +++++-----
 src/main/java/{ => duke}/task/command/Command.java  |  8 ++++----
 .../{ => duke}/task/command/DeadlineCommand.java    | 12 ++++++------
 .../java/{ => duke}/task/command/DeleteCommand.java | 10 +++++-----
 .../java/{ => duke}/task/command/EventCommand.java  | 12 ++++++------
 .../java/{ => duke}/task/command/FindCommand.java   | 12 ++++++------
 .../{ => duke}/task/command/InvalidCommand.java     | 10 +++++-----
 .../java/{ => duke}/task/command/ListCommand.java   | 12 ++++++------
 .../java/{ => duke}/task/command/MarkCommand.java   | 10 +++++-----
 .../java/{ => duke}/task/command/TodoCommand.java   | 13 ++++++-------
 .../java/{ => duke}/task/command/UnmarkCommand.java | 10 +++++-----
 src/main/java/{ => duke}/ui/UI.java                 |  6 +++---
 22 files changed, 83 insertions(+), 85 deletions(-)
 rename src/main/java/{ => duke}/Duke.java (81%)
 rename src/main/java/{ => duke}/exception/DukeException.java (92%)
 rename src/main/java/{ => duke}/parser/Parser.java (97%)
 rename src/main/java/{ => duke}/storage/Storage.java (99%)
 rename src/main/java/{ => duke}/task/Deadline.java (97%)
 rename src/main/java/{ => duke}/task/Event.java (97%)
 rename src/main/java/{ => duke}/task/Task.java (98%)
 rename src/main/java/{ => duke}/task/TaskList.java (97%)
 rename src/main/java/{ => duke}/task/Todo.java (96%)
 rename src/main/java/{ => duke}/task/command/ByeCommand.java (75%)
 rename src/main/java/{ => duke}/task/command/Command.java (83%)
 rename src/main/java/{ => duke}/task/command/DeadlineCommand.java (81%)
 rename src/main/java/{ => duke}/task/command/DeleteCommand.java (83%)
 rename src/main/java/{ => duke}/task/command/EventCommand.java (81%)
 rename src/main/java/{ => duke}/task/command/FindCommand.java (82%)
 rename src/main/java/{ => duke}/task/command/InvalidCommand.java (74%)
 rename src/main/java/{ => duke}/task/command/ListCommand.java (74%)
 rename src/main/java/{ => duke}/task/command/MarkCommand.java (82%)
 rename src/main/java/{ => duke}/task/command/TodoCommand.java (81%)
 rename src/main/java/{ => duke}/task/command/UnmarkCommand.java (82%)
 rename src/main/java/{ => duke}/ui/UI.java (97%)

diff --git a/src/main/java/META-INF/MANIFEST.MF b/src/main/java/META-INF/MANIFEST.MF
index 9f37e4e0..2c9a9745 100644
--- a/src/main/java/META-INF/MANIFEST.MF
+++ b/src/main/java/META-INF/MANIFEST.MF
@@ -1,3 +1,3 @@
 Manifest-Version: 1.0
-Main-Class: Duke
+Main-Class: duke.Duke
 
diff --git a/src/main/java/Duke.java b/src/main/java/duke/Duke.java
similarity index 81%
rename from src/main/java/Duke.java
rename to src/main/java/duke/Duke.java
index 6d4cf8a0..23c14634 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/duke/Duke.java
@@ -1,7 +1,9 @@
-import storage.Storage;
-import parser.Parser;
-import task.TaskList;
-import ui.UI;
+package duke;
+
+import duke.storage.Storage;
+import duke.parser.Parser;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 public class Duke {
 
diff --git a/src/main/java/exception/DukeException.java b/src/main/java/duke/exception/DukeException.java
similarity index 92%
rename from src/main/java/exception/DukeException.java
rename to src/main/java/duke/exception/DukeException.java
index 878184fd..581c603e 100644
--- a/src/main/java/exception/DukeException.java
+++ b/src/main/java/duke/exception/DukeException.java
@@ -1,4 +1,4 @@
-package exception;
+package duke.exception;
 
 public class DukeException extends Exception {
 
diff --git a/src/main/java/parser/Parser.java b/src/main/java/duke/parser/Parser.java
similarity index 97%
rename from src/main/java/parser/Parser.java
rename to src/main/java/duke/parser/Parser.java
index 7c15f9c7..82082d80 100644
--- a/src/main/java/parser/Parser.java
+++ b/src/main/java/duke/parser/Parser.java
@@ -1,10 +1,10 @@
-package parser;
+package duke.parser;
 
-import storage.Storage;
-import task.*;
-import task.command.*;
-import ui.UI;
-import exception.DukeException;
+import duke.storage.Storage;
+import duke.task.*;
+import duke.task.command.*;
+import duke.ui.UI;
+import duke.exception.DukeException;
 
 /**
  * An object that deals with anything that the user inputs so that logic
diff --git a/src/main/java/storage/Storage.java b/src/main/java/duke/storage/Storage.java
similarity index 99%
rename from src/main/java/storage/Storage.java
rename to src/main/java/duke/storage/Storage.java
index cf7f2367..fa021946 100644
--- a/src/main/java/storage/Storage.java
+++ b/src/main/java/duke/storage/Storage.java
@@ -1,6 +1,6 @@
-package storage;
+package duke.storage;
 
-import task.*;
+import duke.task.*;
 
 import java.io.FileWriter;
 import java.io.IOException;
diff --git a/src/main/java/task/Deadline.java b/src/main/java/duke/task/Deadline.java
similarity index 97%
rename from src/main/java/task/Deadline.java
rename to src/main/java/duke/task/Deadline.java
index 53492a42..e61fb4f6 100644
--- a/src/main/java/task/Deadline.java
+++ b/src/main/java/duke/task/Deadline.java
@@ -1,4 +1,4 @@
-package task;
+package duke.task;
 
 /**
  * A class that represents a deadline.
diff --git a/src/main/java/task/Event.java b/src/main/java/duke/task/Event.java
similarity index 97%
rename from src/main/java/task/Event.java
rename to src/main/java/duke/task/Event.java
index b0fdeac9..164a2e41 100644
--- a/src/main/java/task/Event.java
+++ b/src/main/java/duke/task/Event.java
@@ -1,4 +1,4 @@
-package task;
+package duke.task;
 
 /**
  * A class representing an event.
diff --git a/src/main/java/task/Task.java b/src/main/java/duke/task/Task.java
similarity index 98%
rename from src/main/java/task/Task.java
rename to src/main/java/duke/task/Task.java
index c8fb5be9..d10042a7 100644
--- a/src/main/java/task/Task.java
+++ b/src/main/java/duke/task/Task.java
@@ -1,4 +1,4 @@
-package task;
+package duke.task;
 
 /**
  * A class that represents the different forms of tasks in Duke.
diff --git a/src/main/java/task/TaskList.java b/src/main/java/duke/task/TaskList.java
similarity index 97%
rename from src/main/java/task/TaskList.java
rename to src/main/java/duke/task/TaskList.java
index 7e025914..e68e8218 100644
--- a/src/main/java/task/TaskList.java
+++ b/src/main/java/duke/task/TaskList.java
@@ -1,8 +1,5 @@
-package task;
+package duke.task;
 
-import storage.Storage;
-
-import java.io.IOException;
 import java.util.ArrayList;
 
 /**
diff --git a/src/main/java/task/Todo.java b/src/main/java/duke/task/Todo.java
similarity index 96%
rename from src/main/java/task/Todo.java
rename to src/main/java/duke/task/Todo.java
index ae3a324b..ebf0fb74 100644
--- a/src/main/java/task/Todo.java
+++ b/src/main/java/duke/task/Todo.java
@@ -1,4 +1,4 @@
-package task;
+package duke.task;
 
 /**
  * A clas representing a todo.
diff --git a/src/main/java/task/command/ByeCommand.java b/src/main/java/duke/task/command/ByeCommand.java
similarity index 75%
rename from src/main/java/task/command/ByeCommand.java
rename to src/main/java/duke/task/command/ByeCommand.java
index 19bd5344..2f60085f 100644
--- a/src/main/java/task/command/ByeCommand.java
+++ b/src/main/java/duke/task/command/ByeCommand.java
@@ -1,8 +1,8 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * A class that represents a bye command
@@ -10,7 +10,7 @@
 public class ByeCommand extends Command {
 
     /**
-     * Executes the bye command by displaying the exit message
+     * Executes this bye command by displaying the exit message
      * when the user quits the program.
      *
      * @param ui Object that handles all user interaction.
diff --git a/src/main/java/task/command/Command.java b/src/main/java/duke/task/command/Command.java
similarity index 83%
rename from src/main/java/task/command/Command.java
rename to src/main/java/duke/task/command/Command.java
index d0f136d4..3298c410 100644
--- a/src/main/java/task/command/Command.java
+++ b/src/main/java/duke/task/command/Command.java
@@ -1,8 +1,8 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * An abstract class that can represent all other commands within Duke.
diff --git a/src/main/java/task/command/DeadlineCommand.java b/src/main/java/duke/task/command/DeadlineCommand.java
similarity index 81%
rename from src/main/java/task/command/DeadlineCommand.java
rename to src/main/java/duke/task/command/DeadlineCommand.java
index ccad3c0c..60f86991 100644
--- a/src/main/java/task/command/DeadlineCommand.java
+++ b/src/main/java/duke/task/command/DeadlineCommand.java
@@ -1,9 +1,9 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.Deadline;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.Deadline;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * A class that represents a deadline command.
@@ -22,7 +22,7 @@ public DeadlineCommand(Deadline deadline) {
     }
 
     /**
-     * Executes the deadline command by adding a deadline in the list
+     * Executes this deadline command by adding a deadline in the list
      * and storing it in the local storage.
      * Displays a message telling user that the task has been added.
      *
diff --git a/src/main/java/task/command/DeleteCommand.java b/src/main/java/duke/task/command/DeleteCommand.java
similarity index 83%
rename from src/main/java/task/command/DeleteCommand.java
rename to src/main/java/duke/task/command/DeleteCommand.java
index 5f74c60f..03efaf7a 100644
--- a/src/main/java/task/command/DeleteCommand.java
+++ b/src/main/java/duke/task/command/DeleteCommand.java
@@ -1,8 +1,8 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * A class that represents a delete command.
@@ -21,7 +21,7 @@ public DeleteCommand(int index) {
     }
 
     /**
-     * Executes the delete command by removing the task from the list
+     * Executes this delete command by removing the task from the list
      * and the local storage.
      * Displays a message telling user that the task has been deleted.
      *
diff --git a/src/main/java/task/command/EventCommand.java b/src/main/java/duke/task/command/EventCommand.java
similarity index 81%
rename from src/main/java/task/command/EventCommand.java
rename to src/main/java/duke/task/command/EventCommand.java
index 22a77ac2..76b63a52 100644
--- a/src/main/java/task/command/EventCommand.java
+++ b/src/main/java/duke/task/command/EventCommand.java
@@ -1,9 +1,9 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.Event;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.Event;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * A class that represents a event command.
@@ -20,7 +20,7 @@ public EventCommand(Event event) {
     }
 
     /**
-     * Executes the event command by adding an event into the list
+     * Executes this event command by adding an event into the list
      * and storing it in the local storage.
      * Displays a message telling user that the task has been added.
      *
diff --git a/src/main/java/task/command/FindCommand.java b/src/main/java/duke/task/command/FindCommand.java
similarity index 82%
rename from src/main/java/task/command/FindCommand.java
rename to src/main/java/duke/task/command/FindCommand.java
index b4ebfa93..fa88428b 100644
--- a/src/main/java/task/command/FindCommand.java
+++ b/src/main/java/duke/task/command/FindCommand.java
@@ -1,9 +1,9 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.Task;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.Task;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 import java.util.ArrayList;
 
@@ -24,7 +24,7 @@ public FindCommand(String target) {
     }
 
     /**
-     * Executes the find command by searching the list of tasks for any
+     * Executes this find command by searching the list of tasks for any
      * occurence of the target string.
      * Displays the list of matching items or shows a message that no matching
      * items are found.
diff --git a/src/main/java/task/command/InvalidCommand.java b/src/main/java/duke/task/command/InvalidCommand.java
similarity index 74%
rename from src/main/java/task/command/InvalidCommand.java
rename to src/main/java/duke/task/command/InvalidCommand.java
index 063635a1..73b8755a 100644
--- a/src/main/java/task/command/InvalidCommand.java
+++ b/src/main/java/duke/task/command/InvalidCommand.java
@@ -1,15 +1,15 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * A class that represents an invalid command.
  */
 public class InvalidCommand extends Command {
     /**
-     * Executes the invalid command by displaying a message telling the user
+     * Executes this invalid command by displaying a message telling the user
      * that their command is invalid.
      *
      * @param ui Object that handles all user interaction.
diff --git a/src/main/java/task/command/ListCommand.java b/src/main/java/duke/task/command/ListCommand.java
similarity index 74%
rename from src/main/java/task/command/ListCommand.java
rename to src/main/java/duke/task/command/ListCommand.java
index 11ceb143..94ed29fa 100644
--- a/src/main/java/task/command/ListCommand.java
+++ b/src/main/java/duke/task/command/ListCommand.java
@@ -1,9 +1,9 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.Task;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.Task;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 import java.util.ArrayList;
 
@@ -13,7 +13,7 @@
 public class ListCommand extends Command {
 
     /**
-     * Executes the list command by displaying the list of all tasks current
+     * Executes this list command by displaying the list of all tasks current
      * in the list, or tells user that the list is empty.
      *
      * @param ui Object that handles all user interaction.
diff --git a/src/main/java/task/command/MarkCommand.java b/src/main/java/duke/task/command/MarkCommand.java
similarity index 82%
rename from src/main/java/task/command/MarkCommand.java
rename to src/main/java/duke/task/command/MarkCommand.java
index 4ffc8e8b..bf6dff81 100644
--- a/src/main/java/task/command/MarkCommand.java
+++ b/src/main/java/duke/task/command/MarkCommand.java
@@ -1,8 +1,8 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * A class that represents the mark command.
@@ -20,7 +20,7 @@ public MarkCommand(int index) {
     }
 
     /**
-     * Executes the mark command by marking the tasks of the index.
+     * Executes this mark command by marking the tasks of the index.
      * Displays a message telling the user that the task has been marked.
      *
      * @param ui Object that handles all user interaction.
diff --git a/src/main/java/task/command/TodoCommand.java b/src/main/java/duke/task/command/TodoCommand.java
similarity index 81%
rename from src/main/java/task/command/TodoCommand.java
rename to src/main/java/duke/task/command/TodoCommand.java
index 2ee30a2e..bf929228 100644
--- a/src/main/java/task/command/TodoCommand.java
+++ b/src/main/java/duke/task/command/TodoCommand.java
@@ -1,10 +1,9 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.Task;
-import task.TaskList;
-import task.Todo;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.task.Todo;
+import duke.ui.UI;
 
 /**
  * A class that represents the todo command.
@@ -22,7 +21,7 @@ public TodoCommand(Todo todo) {
     }
 
     /**
-     * Executes the todo command by adding a task todo into the list
+     * Executes this todo command by adding a task todo into the list
      * and storing it in the local storage.
      * Displays a message telling user that the task has been added.
      *
diff --git a/src/main/java/task/command/UnmarkCommand.java b/src/main/java/duke/task/command/UnmarkCommand.java
similarity index 82%
rename from src/main/java/task/command/UnmarkCommand.java
rename to src/main/java/duke/task/command/UnmarkCommand.java
index 45275730..86b4ef64 100644
--- a/src/main/java/task/command/UnmarkCommand.java
+++ b/src/main/java/duke/task/command/UnmarkCommand.java
@@ -1,8 +1,8 @@
-package task.command;
+package duke.task.command;
 
-import storage.Storage;
-import task.TaskList;
-import ui.UI;
+import duke.storage.Storage;
+import duke.task.TaskList;
+import duke.ui.UI;
 
 /**
  * A class representing an unmark command.
@@ -20,7 +20,7 @@ public UnmarkCommand(int index) {
     }
 
     /**
-     * Executes the mark command by unmarking the tasks of the index.
+     * Executes this unmark command by unmarking the tasks of the index.
      * Displays a message telling the user that the task has been unmarked.
      *
      * @param ui Object that handles all user interaction.
diff --git a/src/main/java/ui/UI.java b/src/main/java/duke/ui/UI.java
similarity index 97%
rename from src/main/java/ui/UI.java
rename to src/main/java/duke/ui/UI.java
index cbaab28d..5e0f6f01 100644
--- a/src/main/java/ui/UI.java
+++ b/src/main/java/duke/ui/UI.java
@@ -1,7 +1,7 @@
-package ui;
+package duke.ui;
 
-import task.Task;
-import task.TaskList;
+import duke.task.Task;
+import duke.task.TaskList;
 
 import java.util.ArrayList;
 import java.util.Scanner;

From 9a13001fceb6f4526c7c8349d4cc33e1f8c1d715 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 29 Sep 2022 02:05:46 +0800
Subject: [PATCH 25/26] Update README.md

---
 docs/README.md | 169 +++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 157 insertions(+), 12 deletions(-)

diff --git a/docs/README.md b/docs/README.md
index 8077118e..ce576a17 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -1,29 +1,174 @@
 # User Guide
+Duke is a robot that allows you to track tasks. These tasks can be in either Todos, Deadlines or Events.
+You can also get your tasks in a .txt file for you to do whatever you want with it!
+## Features
+- [Adding a Todo: todo](#adding-a-todo-todo)
+- [Adding a Deadline: deadline](#adding-a-deadline-deadline)
+- [Adding an Event: event](#adding-an-event-event)
+- [Marking a Task: mark](#marking-a-task-mark)
+- [Unmarking a Task: unmark](#unmarking-a-task-unmark)
+- [Deleting a Task: delete](#deleting-a-task-delete)
+- [View all tasks: list](#view-all-tasks-list)
+- [Exiting the program: bye](#exiting-the-program-bye)
 
-## Features 
+### Adding a Todo: `todo`
+Adds a Todo to the list
 
-### Feature-ABC
+Use the command:
 
-Description of the feature.
+`todo sometask`
 
-### Feature-XYZ
+Example of Usage:
 
-Description of the feature.
+`todo Math Tutorial`
 
-## Usage
+Expected outcome:
+
+```
+-------------------------------------
+Got it. I have added this task:
+[T][ ] Math Tutorial
+You now have 1 tasks.
+-------------------------------------
+```
+
+### Adding a Deadline: `deadline`
+Adds a Deadline to the list
+
+Use the command:
+
+`deadline sometask /by somedate`
+
+Example of Usage:
+
+`deadline Group Project /by Friday`
+
+Expected outcome:
+
+```
+-------------------------------------
+Got it. I have added this task:
+[D][ ] Group Project (by: Friday)
+You now have 2 tasks.
+-------------------------------------
+```
+
+### Adding an Event: `event`
+Adds an Event to the list
+
+Use the command:
+
+`event sometask /at somedate`
+
+Example of Usage:
+
+`event Concert /at Sunday 1900`
+
+Expected outcome:
+
+```
+-------------------------------------
+Got it. I have added this task:
+[E][ ] Concert (at: Sunday 1900)
+You now have 3 tasks.
+-------------------------------------
+```
+
+### Marking a Task: `mark`
+
+Marks a task.
+
+Use the command:
+
+`mark index`
+
+Example of usage:
+
+`mark 2`
+
+Expected outcome:
+
+```
+-------------------------------------
+Marked the following task:
+[D][X] Group Project (by: Friday)
+-------------------------------------
+```
+
+### Unmarking a Task: `unmark`
 
-### `Keyword` - Describe action
+Unmarks a task.
 
-Describe the action and its outcome.
+Use the command:
 
-Example of usage: 
+`unmark index`
 
-`keyword (optional arguments)`
+Example of usage:
+
+`unmark 2`
 
 Expected outcome:
 
-Description of the outcome.
+```
+-------------------------------------
+Unmarked the following task:
+[D][ ] Group Project (by: Friday)
+-------------------------------------
+```
+
+### Deleting a Task: `delete`
+
+Deletes a task.
+
+Use the command:
+
+`Delete index`
+
+Example of usage:
+
+`delete 2`
+
+Expected outcome:
 
 ```
-expected output
+-------------------------------------
+The following task has been deleted: 
+[D][ ] Group Project (by: Friday)
+You now have 2 tasks.
+-------------------------------------
 ```
+
+### View all tasks: `list`
+
+Displays all the tasks currently in the list.
+
+Use the command:
+
+`list`
+
+Expected outcome:
+
+```
+-------------------------------------
+Here is the list of your tasks: 
+1. [T][ ] Math Tutorial
+2. [E][ ] Concert (at: Sunday 1900)
+-------------------------------------
+```
+
+### Exiting the program: `bye`
+
+Stops the execution of Duke.
+
+Use the command:
+
+`bye`
+
+Expected outcome:
+
+```
+-------------------------------------
+Goodbye, hope to see you again.
+-------------------------------------
+```
+

From bef3c36623d7525787612aa309292a22c74d6de5 Mon Sep 17 00:00:00 2001
From: John <johntohjiajun@gmail.com>
Date: Thu, 29 Sep 2022 03:54:27 +0800
Subject: [PATCH 26/26] Update some code logic

---
 src/main/java/duke/Duke.java                  |  4 +--
 src/main/java/duke/parser/Parser.java         | 25 +++++++++++++------
 src/main/java/duke/storage/Storage.java       |  2 +-
 src/main/java/duke/task/Deadline.java         |  2 +-
 src/main/java/duke/task/Event.java            |  3 ++-
 src/main/java/duke/task/Task.java             |  2 +-
 .../java/duke/task/command/ByeCommand.java    |  4 +--
 src/main/java/duke/task/command/Command.java  |  4 +--
 .../duke/task/command/DeadlineCommand.java    |  4 +--
 .../java/duke/task/command/DeleteCommand.java |  4 +--
 .../java/duke/task/command/EventCommand.java  |  5 ++--
 .../java/duke/task/command/FindCommand.java   |  6 ++---
 .../duke/task/command/InvalidCommand.java     |  4 +--
 .../java/duke/task/command/ListCommand.java   |  4 +--
 .../java/duke/task/command/MarkCommand.java   |  4 +--
 .../java/duke/task/command/TodoCommand.java   |  4 +--
 .../java/duke/task/command/UnmarkCommand.java |  6 ++---
 src/main/java/duke/ui/UI.java                 | 13 +++++++---
 18 files changed, 58 insertions(+), 42 deletions(-)

diff --git a/src/main/java/duke/Duke.java b/src/main/java/duke/Duke.java
index 23c14634..784484ac 100644
--- a/src/main/java/duke/Duke.java
+++ b/src/main/java/duke/Duke.java
@@ -17,13 +17,13 @@ public Duke () {
         Duke.tasks = new TaskList(storage.startReading());
     }
 
-    public void start() {
+    public void run() {
         ui.welcomeUser();
         Parser parser = new Parser();
         parser.executeCommands(ui, tasks, storage);
     }
 
     public static void main(String[] args) {
-        new Duke().start();
+        new Duke().run();
     }
 }
diff --git a/src/main/java/duke/parser/Parser.java b/src/main/java/duke/parser/Parser.java
index 82082d80..dc50270e 100644
--- a/src/main/java/duke/parser/Parser.java
+++ b/src/main/java/duke/parser/Parser.java
@@ -37,7 +37,7 @@ public void executeCommands(UI ui, TaskList tasks, Storage storage) {
                 Command command = handleCommand(ui);
                 command.execute(tasks, ui, storage);
             } catch (DukeException e) {
-                System.out.println(e.getMessage());
+                ui.printErrorMessage(e);
             }
         }
     }
@@ -104,13 +104,22 @@ private String getCommand(String input) {
     private String getArgument(String input) throws DukeException {
         String[] splitInput = input.split(" ", SPLIT_AMOUNT);
         if (splitInput.length != SPLIT_AMOUNT) {
-            if (splitInput[0].equals(TODO) || splitInput[0].equals(DEADLINE) || splitInput[0].equals(EVENT)
-                    || splitInput[0].equals(FIND)) {
-                throw new DukeException("Missing input for command, input the command in this format: " +
-                        splitInput[0] + " {TASK}");
-            } else {
-                throw new DukeException("Missing input for command, input the command in this format: " +
-                        splitInput[0] + " {ID}");
+            switch(splitInput[0]) {
+            case (TODO):
+                throw new DukeException("Missing input for command, input the command in this format:\n"
+                        + TODO + " taskname");
+            case (DEADLINE):
+                throw new DukeException("Missing input for command, input the command in this format:\n"
+                        + DEADLINE + " taskname /by date");
+            case (EVENT):
+                throw new DukeException("Missing input for command, input the command in this format:\n"
+                        + EVENT + " taskname /at date");
+            case (FIND):
+                throw new DukeException("Missing input for command, input the command in this format:\n"
+                        + FIND + " something");
+            default:
+                throw new DukeException("Missing input for command, input the command in this format:\n"
+                        + splitInput[0] + " id");
             }
         }
         return splitInput[1];
diff --git a/src/main/java/duke/storage/Storage.java b/src/main/java/duke/storage/Storage.java
index fa021946..cd693713 100644
--- a/src/main/java/duke/storage/Storage.java
+++ b/src/main/java/duke/storage/Storage.java
@@ -169,7 +169,7 @@ public void deleteContent() throws IOException {
     /**
      * Stores a task into the local text file.
      *
-     * @param task The task to be stored.
+     * @param task    The task to be stored.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     public void storeTask(Task task, Storage storage) {
diff --git a/src/main/java/duke/task/Deadline.java b/src/main/java/duke/task/Deadline.java
index e61fb4f6..b305db70 100644
--- a/src/main/java/duke/task/Deadline.java
+++ b/src/main/java/duke/task/Deadline.java
@@ -10,7 +10,7 @@ public class Deadline extends Task {
      * Constructor for Deadline.
      *
      * @param description Description of this deadline.
-     * @param by Due date of this deadline.
+     * @param by          Due date of this deadline.
      */
     public Deadline(String description, String by) {
         super(description);
diff --git a/src/main/java/duke/task/Event.java b/src/main/java/duke/task/Event.java
index 164a2e41..427cdab5 100644
--- a/src/main/java/duke/task/Event.java
+++ b/src/main/java/duke/task/Event.java
@@ -10,7 +10,7 @@ public class Event extends Task {
      * Constructor for Event.
      *
      * @param description Description of this event.
-     * @param at When this event is at.
+     * @param at          When this event is at.
      */
     public Event(String description, String at) {
         super(description);
@@ -25,6 +25,7 @@ public Event(String description, String at) {
     public String getAt() {
         return at;
     }
+
     /**
      * Fixes how this deadline would look like if it were to be converted into a string
      * based on its description and occurring date
diff --git a/src/main/java/duke/task/Task.java b/src/main/java/duke/task/Task.java
index d10042a7..5aeabf0e 100644
--- a/src/main/java/duke/task/Task.java
+++ b/src/main/java/duke/task/Task.java
@@ -18,7 +18,7 @@ public Task(String description) {
     }
 
     /**
-     *  Sets the done state of this task.
+     * Sets the done state of this task.
      *
      * @param isDone Whether this task is to be marked as done.
      */
diff --git a/src/main/java/duke/task/command/ByeCommand.java b/src/main/java/duke/task/command/ByeCommand.java
index 2f60085f..3eded4d5 100644
--- a/src/main/java/duke/task/command/ByeCommand.java
+++ b/src/main/java/duke/task/command/ByeCommand.java
@@ -13,8 +13,8 @@ public class ByeCommand extends Command {
      * Executes this bye command by displaying the exit message
      * when the user quits the program.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/Command.java b/src/main/java/duke/task/command/Command.java
index 3298c410..08fad6a3 100644
--- a/src/main/java/duke/task/command/Command.java
+++ b/src/main/java/duke/task/command/Command.java
@@ -12,8 +12,8 @@ public abstract class Command {
     /**
      * An abstract method represents the execution of a command.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     public abstract void execute(TaskList tasks, UI ui, Storage storage);
diff --git a/src/main/java/duke/task/command/DeadlineCommand.java b/src/main/java/duke/task/command/DeadlineCommand.java
index 60f86991..e616f015 100644
--- a/src/main/java/duke/task/command/DeadlineCommand.java
+++ b/src/main/java/duke/task/command/DeadlineCommand.java
@@ -26,8 +26,8 @@ public DeadlineCommand(Deadline deadline) {
      * and storing it in the local storage.
      * Displays a message telling user that the task has been added.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/DeleteCommand.java b/src/main/java/duke/task/command/DeleteCommand.java
index 03efaf7a..3c115634 100644
--- a/src/main/java/duke/task/command/DeleteCommand.java
+++ b/src/main/java/duke/task/command/DeleteCommand.java
@@ -25,8 +25,8 @@ public DeleteCommand(int index) {
      * and the local storage.
      * Displays a message telling user that the task has been deleted.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/EventCommand.java b/src/main/java/duke/task/command/EventCommand.java
index 76b63a52..aca4a9b2 100644
--- a/src/main/java/duke/task/command/EventCommand.java
+++ b/src/main/java/duke/task/command/EventCommand.java
@@ -13,6 +13,7 @@ public class EventCommand extends Command {
 
     /**
      * Constructor for EventCommand.
+     *
      * @param event An event object
      */
     public EventCommand(Event event) {
@@ -24,8 +25,8 @@ public EventCommand(Event event) {
      * and storing it in the local storage.
      * Displays a message telling user that the task has been added.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/FindCommand.java b/src/main/java/duke/task/command/FindCommand.java
index fa88428b..f4cec963 100644
--- a/src/main/java/duke/task/command/FindCommand.java
+++ b/src/main/java/duke/task/command/FindCommand.java
@@ -12,7 +12,7 @@
  */
 public class FindCommand extends Command {
 
-    private String target;
+    private final String target;
 
     /**
      * Constructor for FindCommand.
@@ -29,8 +29,8 @@ public FindCommand(String target) {
      * Displays the list of matching items or shows a message that no matching
      * items are found.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/InvalidCommand.java b/src/main/java/duke/task/command/InvalidCommand.java
index 73b8755a..b1095cca 100644
--- a/src/main/java/duke/task/command/InvalidCommand.java
+++ b/src/main/java/duke/task/command/InvalidCommand.java
@@ -12,8 +12,8 @@ public class InvalidCommand extends Command {
      * Executes this invalid command by displaying a message telling the user
      * that their command is invalid.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/ListCommand.java b/src/main/java/duke/task/command/ListCommand.java
index 94ed29fa..7473fa0f 100644
--- a/src/main/java/duke/task/command/ListCommand.java
+++ b/src/main/java/duke/task/command/ListCommand.java
@@ -16,8 +16,8 @@ public class ListCommand extends Command {
      * Executes this list command by displaying the list of all tasks current
      * in the list, or tells user that the list is empty.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/MarkCommand.java b/src/main/java/duke/task/command/MarkCommand.java
index bf6dff81..b40ef482 100644
--- a/src/main/java/duke/task/command/MarkCommand.java
+++ b/src/main/java/duke/task/command/MarkCommand.java
@@ -23,8 +23,8 @@ public MarkCommand(int index) {
      * Executes this mark command by marking the tasks of the index.
      * Displays a message telling the user that the task has been marked.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/TodoCommand.java b/src/main/java/duke/task/command/TodoCommand.java
index bf929228..7154615b 100644
--- a/src/main/java/duke/task/command/TodoCommand.java
+++ b/src/main/java/duke/task/command/TodoCommand.java
@@ -25,8 +25,8 @@ public TodoCommand(Todo todo) {
      * and storing it in the local storage.
      * Displays a message telling user that the task has been added.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
diff --git a/src/main/java/duke/task/command/UnmarkCommand.java b/src/main/java/duke/task/command/UnmarkCommand.java
index 86b4ef64..b50119a2 100644
--- a/src/main/java/duke/task/command/UnmarkCommand.java
+++ b/src/main/java/duke/task/command/UnmarkCommand.java
@@ -23,12 +23,12 @@ public UnmarkCommand(int index) {
      * Executes this unmark command by unmarking the tasks of the index.
      * Displays a message telling the user that the task has been unmarked.
      *
-     * @param ui Object that handles all user interaction.
-     * @param tasks Object that handles and tracks all tasks that the user has added.
+     * @param ui      Object that handles all user interaction.
+     * @param tasks   Object that handles and tracks all tasks that the user has added.
      * @param storage Object that handles saving the user's task into the local storage.
      */
     @Override
-    public void execute(TaskList tasks, UI ui, Storage storage)  {
+    public void execute(TaskList tasks, UI ui, Storage storage) {
         tasks.unmarkTarget(index);
         ui.markMessage(tasks, index);
         storage.rewriteFile(storage);
diff --git a/src/main/java/duke/ui/UI.java b/src/main/java/duke/ui/UI.java
index 5e0f6f01..3a4360fb 100644
--- a/src/main/java/duke/ui/UI.java
+++ b/src/main/java/duke/ui/UI.java
@@ -1,5 +1,6 @@
 package duke.ui;
 
+import duke.exception.DukeException;
 import duke.task.Task;
 import duke.task.TaskList;
 
@@ -17,6 +18,7 @@ public class UI {
             + "delete {index} : Deletes a task\n"
             + "list : List all current tasks\n"
             + "bye : Exits the program";
+
     public final String BYE_MESSAGE = "Goodbye, hope to see you again.";
 
     public void welcomeUser() {
@@ -33,7 +35,7 @@ public void byeMessage() {
 
     public void addMessage(Task task, TaskList tasks) {
         formatMessage("Got it. I have added this task:\n" + task
-                + "\nYou now have " + tasks.getTaskCount() + " tasks.");
+                + "\nYou now have " + TaskList.getTaskCount() + " tasks.");
     }
 
     public void printList(ArrayList<Task> tasks) {
@@ -71,7 +73,7 @@ public void invalidCommand() {
     public void deleteMessage(TaskList tasks, int index) {
         Task deletedTask = tasks.getTask(index - 1);
         formatMessage("The following task has been deleted: \n"
-                + deletedTask + "\nYou now have " + (tasks.getTaskCount() - 1)
+                + deletedTask + "\nYou now have " + (TaskList.getTaskCount() - 1)
                 + " tasks.");
     }
 
@@ -82,8 +84,7 @@ public void printFound(ArrayList<Task> found) {
             message = "Found no matching tasks in your list.";
         } else {
             for (int i = 0; i < size; i++) {
-                if (i == size - 1)
-                {
+                if (i == size - 1) {
                     message += (i + 1) + ". " + found.get(i);
                 } else {
                     message += (i + 1) + ". " + found.get(i) + "\n";
@@ -93,6 +94,10 @@ public void printFound(ArrayList<Task> found) {
         formatMessage(message);
     }
 
+    public void printErrorMessage(DukeException e) {
+        formatMessage(e.getMessage());
+    }
+
     public String getInput() {
         Scanner sc = new Scanner(System.in);
         String input = sc.nextLine();