port code from simple remote config

lib/dart_gsheet_remote_config.dart

@@ -1,3 +1,2 @@
-int calculate() {
-  return 6 * 7;
-}
+export 'dart_gsheet_remote_config.dart';
+export 'src/sheet_remote_config.dart';

lib/src/sheet_remote_config.dart

@@ -0,0 +1,174 @@
+import 'package:http/http.dart' as http;
+
+import 'sheet_remote_config_exception.dart';
+
+/// A [SheetRemoteConfig] class that fetches a JSON config from a URL and
+/// provides a way to access the config values.
+class SheetRemoteConfig {
+  SheetRemoteConfig({http.Client? client}) : _client = client ?? http.Client();
+
+  final http.Client _client;
+
+  /// In-memory cache for the config values.
+  final _inMemoryCachedConfig = <String, dynamic>{};
+
+  /// Fetches the config from the given URL and stores it in the in-memory cache.
+  ///
+  /// *Parameters:*
+  ///
+  /// [configUrl] - The URL to fetch the config from.
+  ///
+  ///
+  /// *Exceptions:*
+  ///
+  /// Throws a [SheetRemoteConfigException] if the request fails, no connection, invalid json config format, etc...
+  Future<void> initilize({
+    required String id,
+    String? sheetName,
+  }) {
+    return _initilize(id: id, sheetName: sheetName);
+  }
+
+  Future<void> _initilize({
+    required String id,
+    String? sheetName,
+  }) async {
+    try {
+      final requestUri = _buildSheetUri(id: id, sheetName: sheetName);
+      final response = await _client.get(requestUri);
+      if (response.statusCode == 200) {
+        final payload = response.body;
+      } else {
+        throw Exception('Failed to load remote config');
+      }
+    } catch (e) {
+      throw SheetRemoteConfigException(
+          message: switch (e) {
+        FormatException() => 'Invalid remote config',
+        _ => 'Error when handling: $e',
+      });
+    }
+  }
+
+  Uri _buildSheetUri({required String id, String? sheetName}) {
+    return Uri.https(
+        'docs.google.com',
+        '/spreadsheets/d/$id/gviz/tq?',
+        {
+          'tqx': 'out:json',
+          'sheet': sheetName,
+        }.filterValues((value) => value != null));
+  }
+
+  /// Returns the value of the given key from the in-memory cache.
+  /// {@template get_value}
+  ///
+  /// *Parameters:*
+  ///
+  /// [key] - The key to get the value for.
+  ///
+  /// [defaultValue] - The default value to return if the key is not found in the cache.
+  ///
+  /// Returns:
+  ///
+  /// The value of the given key from the in-memory cache, or the default value if the key is not found.
+  ///
+  /// Example:
+  ///
+  /// ```dart
+  /// final config = SheetRemoteConfig();
+  /// await config.initilize(configUrl: 'http://example.com/config'); // {"key1": "value1", "key2": true, "key3": 1.0, "key4": 100, "key5": { "key6": "value5" }}
+  ///
+  /// final value = config.getString('key1');
+  /// print(value); // value1
+  ///
+  /// final value2 = config.getBool('key2');
+  /// print(value2); // true
+  ///
+  /// final value3 = config.getDouble('key3');
+  /// print(value3); // 1.0
+  ///
+  /// final value4 = config.getInt('key4');
+  /// print(value4); // 100
+  ///
+  /// final value5 = config.getMap('key5');
+  /// print(value5); // { "key6": "value5" }
+  ///
+  /// final value6 = config.getString('key7');
+  /// print(value6); // null
+  ///
+  /// final value6Default = config.getString('key7', defaultValue: 'default value');
+  /// print(value6Default); // default value
+  /// ```
+  /// {@endtemplate}
+  T? _get<T>(String key, {T? defaultValue}) {
+    try {
+      final value = _inMemoryCachedConfig[key] as T?;
+      return value ?? defaultValue;
+    } catch (e) {
+      return defaultValue;
+    }
+  }
+
+  /// Return the value of the given key from the in-memory cache as a [String].
+  ///
+  /// If the key is not found, return the default value.
+  ///
+  /// {@macro get_value}
+  String? getString(String key, {String? defaultValue}) {
+    return _get<String>(key, defaultValue: defaultValue);
+  }
+
+  /// Return the value of the given key from the in-memory cache as a [bool].
+  ///
+  /// If the key is not found, return the default value.
+  ///
+  /// {@macro get_value}
+  bool? getBool(String key, {bool? defaultValue}) {
+    return _get<bool>(key, defaultValue: defaultValue);
+  }
+
+  /// Return the value of the given key from the in-memory cache as an [int].
+  ///
+  /// If the key is not found, return the default value.
+  ///
+  /// {@macro get_value}
+  int? getInt(String key, {int? defaultValue}) {
+    return _get<int>(key, defaultValue: defaultValue);
+  }
+
+  /// Return the value of the given key from the in-memory cache as a [double].
+  ///
+  /// If the key is not found, return the default value.
+  ///
+  /// {@macro get_value}
+  double? getDouble(String key, {double? defaultValue}) {
+    return _get<double>(key, defaultValue: defaultValue);
+  }
+
+  /// Return the value of the given key from the in-memory cache as a [Map].
+  ///
+  /// If the key is not found, return the default value.
+  ///
+  /// {@macro get_value}
+  Map<String, dynamic>? getMap(
+    String key, {
+    Map<String, dynamic>? defaultValue,
+  }) {
+    return _get<Map<String, dynamic>>(key, defaultValue: defaultValue);
+  }
+
+  /// Return all the values from the in-memory cache.
+  ///
+  /// Returns:
+  /// A [Map] containing all the values from the in-memory cache.
+  Map<String, dynamic> getAll() {
+    return _inMemoryCachedConfig;
+  }
+}
+
+extension _MapExtension<K, V> on Map<K, V> {
+  Map<K, V> filterValues(bool Function(V value) test) {
+    return Map.fromEntries(entries.where((element) => test(element.value)));
+  }
+}

lib/src/sheet_remote_config_exception.dart

@@ -0,0 +1,35 @@
+/// A [SheetRemoteConfigException] class for handling errors related to the Simple Remote Config.
+///
+/// This exception can be used to indicate various issues that may arise when
+/// working with the Simple Remote Config, such as network errors, parsing errors,
+/// or configuration issues.
+///
+/// Example usage:
+/// ```dart
+/// try {
+///   // Code that might throw a `SheetRemoteConfigException`
+/// } catch (e) {
+///   if (e is SheetRemoteConfigException) {
+///     // Handle the exception
+///   }
+/// }
+/// ```
+class SheetRemoteConfigException implements Exception {
+  /// The error message associated with this exception.
+  final String message;
+
+  /// The stack trace associated with this exception.
+  final StackTrace? stackTrace;
+
+  SheetRemoteConfigException({required this.message, StackTrace? stackTrace})
+      : stackTrace = stackTrace ?? StackTrace.current;
+
+  @override
+  String toString() {
+    return 'SheetRemoteConfigException: $message';
+  }
+}
+
+class UnauthorizedException extends SheetRemoteConfigException {
+  UnauthorizedException({super.message = 'Unauthorized'});
+}