Add IRC API

lib/api/irc_api.dart

@@ -0,0 +1,65 @@
+import 'package:frosty/models/irc_message.dart';
+
+class Irc {
+  static IrcMessage parse(String whole) {
+    // We have three parts:
+    // 1. The tags of the IRC message
+    // 2. The metadata (user, command, and channel)
+    // 3. The message itself
+
+    // First, slice the message tags (1) and set aside the rest for later.
+    // Each part is separated by a space, so we'll start off by breaking off the tags and parsing them.
+
+    // Obtain the index to break off the tags.
+    final tagAndIrcMessageDivider = whole.indexOf(' ');
+
+    // Get the tags substring and escape characters.
+    // IRC messages escape spaces with \s.
+    final tags = whole.substring(1, tagAndIrcMessageDivider).replaceAll('\\s', ' ');
+
+    // Next, parse and map the tags.
+    final mappedTags = <String, String>{};
+
+    // Loop through each tag and store their key value pairs into the map.
+    for (final tag in tags.split(';')) {
+      // Skip if the tag has no value.
+      if (tag.endsWith('=')) continue;
+
+      final tagSplit = tag.split('=');
+      mappedTags[tagSplit[0]] = tagSplit[1];
+    }
+
+    // Now we'll parse the message itself.
+    // Obtain the entire substring after the tags and excluding the first : (colon)
+    final ircMessage = whole.substring(tagAndIrcMessageDivider + 2);
+
+    // Split each section of the message (part 2 and its subparts and part 3).
+    // Index 0 contains the username of sender (user) or tmi.twitch.tv depending on the command
+    // Index 1 is command type
+    // Index 2 is #channel name that we are currently connected to
+    // Index 3 and beyond is the :message (word by word) that is sent by the user or empty depending on the command
+    final splitMessage = ircMessage.split(' ');
+
+    // If the username exists, set it.
+    final String? user = splitMessage[0] == 'tmi.twitch.tv' ? null : splitMessage[0].substring(0, splitMessage[0].indexOf('!'));
+
+    // If there is a message, set it.
+    final String? message = splitMessage.length > 3 ? splitMessage.sublist(3).join(' ').substring(1) : null;
+
+    return IrcMessage(tags: mappedTags, command: splitMessage[1], user: user, message: message);
+  }
+
+  static clearChat() {}
+
+  static clearMsg() {}
+
+  static globalUserState() {}
+
+  static privmsg() {}
+
+  static roomState() {}
+
+  static userNotice() {}
+
+  static userState() {}
+}