Bot saves drawing submissions (#30)

* add code for storing info about drawing submissions

* shuffle functions around

so handleDrawingSubmission isn't redefined all the time

* filter out non-image submissions

* remove a console.log statement

drawings.json

@@ -0,0 +1 @@
+[]

src/drawing-handlers.js

@@ -0,0 +1,28 @@
+const fs = require("fs");
+const { promisify } = require("util");
+
+async function addImageToList(drawingInfo) {
+  // throws error if file doesn't exist
+  const drawingsListJson = await promisify(fs.readFile)(
+    "./drawings.json",
+    "utf-8"
+  );
+
+  // throws error if file is blank
+  let drawingsList = JSON.parse(drawingsListJson);
+
+  // just in case drawings.json has some other type at the root of structure
+  if (!Array.isArray(drawingsList)) {
+    drawingsList = [];
+  }
+
+  drawingsList.push(drawingInfo);
+
+  const newJson = JSON.stringify(drawingsList, null, 2);
+
+  return promisify(fs.writeFile)("./drawings.json", newJson);
+}
+
+module.exports = {
+  addImageToList
+};

src/rtm-handlers.js

@@ -1,5 +1,6 @@
 const fs = require("fs");
 const prompts = require("./prompt-handlers");
+const drawings = require("./drawing-handlers");
 const RtmClient = require("@slack/client").RtmClient;
 const CLIENT_EVENTS = require("@slack/client").CLIENT_EVENTS;
 const RTM_EVENTS = require("@slack/client").RTM_EVENTS;
@@ -77,17 +78,47 @@ function onReceiveMessage(env) {
           responseText =
             "Hi I'm Penny; I can do the following if you `@` mention me!\n";
           responseText += "`@penny_bot give prompt` \n";
-          responseText += "`@penny_bot, submit prompt '<your prompt here>'`";
+          responseText += "`@penny_bot, submit prompt '<your prompt here>'`\n ";
+          responseText +=
+            "You can also DM me your drawings as attachments with the comment `submit drawing`";
 
           // Channel to respond in
           message.channel == "C63GFH05V"
             ? env.rtm.sendMessage(responseText, "C63GFH05V")
             : env.rtm.sendMessage(responseText, message.channel);
       }
     }
+
+    /**
+     * DMs to penny with attachments might not include penny's user id in the
+     * message, so this check happens outside the other if statement
+     */
+    if (checkMessage("submit drawing") && message.channel === "D63S3TAM7") {
+      handleDrawingSubmission(env, message);
+    }
   });
 }
 
+const validFileTypes = ["jpg", "png", "gif"];
+
+function handleDrawingSubmission(env, message) {
+  if (!message.file) {
+    env.rtm.sendMessage("Where is drawing?", message.channel);
+  } else if (message.file && !validFileTypes.includes(message.file.filetype)) {
+    env.rtm.sendMessage(
+      "I don't think you attached a drawing. Make sure you send me a .png, .jpg, or .gif",
+      message.channel
+    );
+  } else {
+    env.rtm.sendMessage("Got drawing!", message.channel);
+
+    drawings
+      .addImageToList(message.file)
+      .then(result => console.log("saved image info", result))
+      .catch(error => console.error("error", error));
+  }
+}
+
 function startRtm(env) {
   env.rtm.start();
 }