Improved parsing of more IRC message types, and added optional tracking of which users are in the stream.

TwitchIrcClient/IRC/Messages/ReceivedMessage.cs

@@ -0,0 +1,128 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Reflection.Metadata.Ecma335;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace TwitchLogger.IRC.Messages
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <remarks>
+    /// This is designed according to <see href="https://ircv3.net/specs/extensions/message-tags.html"/>
+    /// but only implementing features used by Twitch chat. See <see href="https://dev.twitch.tv/docs/irc/"/> for
+    /// specifics about Twitch chat's use of IRC. Currently messages are not fully validated.
+    /// </remarks>
+    public class ReceivedMessage
+    {
+        public IrcMessageType MessageType { get; protected set; }
+        public string? Prefix { get; protected set; }
+        public string? Source { get; protected set; }
+        public List<string> Parameters { get; } = [];
+        public string RawParameters { get; protected set; }
+        public string RawText { get; protected set; }
+        public MessageTags MessageTags { get; protected set; } = [];
+
+        protected ReceivedMessage()
+        {
+
+        }
+        protected ReceivedMessage(ReceivedMessage other)
+        {
+            MessageType = other.MessageType;
+            Prefix = other.Prefix;
+            Source = other.Source;
+            Parameters = [.. other.Parameters];
+            RawParameters = other.RawParameters;
+            RawText = other.RawText;
+            MessageTags = [.. other.MessageTags];
+        }
+
+        /// <summary>
+        /// Parses an IRC message into the proper message type
+        /// </summary>
+        /// <param name="s"></param>
+        /// <returns>the parsed message</returns>
+        public static ReceivedMessage Parse(string s)
+        {
+            ReceivedMessage message = new();
+            message.RawText = s;
+            //message has tags
+            if (s.StartsWith('@'))
+            {
+                s = s[1..];
+                //first ' ' acts as the delimeter
+                var split = s.Split(' ', 2);
+                Debug.Assert(split.Length == 2, "no space found to end tag section");
+                string tagString = split[0];
+                s = split[1].TrimStart(' ');
+                message.MessageTags = MessageTags.Parse(tagString);
+            }
+            //message has source
+            if (s.StartsWith(':'))
+            {
+                s = s[1..];
+                var split = s.Split(' ', 2);
+                Debug.Assert(split.Length == 2, "no space found to end prefix");
+                message.Prefix = split[0];
+                s = split[1].TrimStart(' ');
+            }
+            var spl_command = s.Split(' ', 2);
+            message.MessageType = IrcMessageTypeHelper.Parse(spl_command[0]);
+            //message has parameters
+            if (spl_command.Length >= 2)
+            {
+                s = spl_command[1];
+                message.RawParameters = s;
+                //message has single parameter marked as the final parameter
+                //this needs to be handled specially because the leading ' '
+                //is stripped
+                if (s.StartsWith(':'))
+                {
+                    message.Parameters.Add(s.Substring(1));
+                }
+                else
+                {
+                    var spl_final = s.Split(" :", 2);
+                    var spl_initial = spl_final[0].Split(' ', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                    message.Parameters.AddRange(spl_initial);
+                    if (spl_final.Length >= 2)
+                        message.Parameters.Add(spl_final[1]);
+                }
+            }
+            switch (message.MessageType)
+            {
+                case IrcMessageType.PRIVMSG:
+                    return new Privmsg(message);
+                case IrcMessageType.CLEARCHAT:
+                    return new ClearChat(message);
+                case IrcMessageType.CLEARMSG:
+                    return new ClearMsg(message);
+                case IrcMessageType.NOTICE:
+                    return new Notice(message);
+                case IrcMessageType.JOIN:
+                    return new Join(message);
+                case IrcMessageType.PART:
+                    return new Part(message);
+                case IrcMessageType.RPL_NAMREPLY:
+                    return new NamReply(message);
+                default:
+                    return message;
+            }
+        }
+        /// <summary>
+        /// Tries to get the value of the tag.
+        /// </summary>
+        /// <param name="s"></param>
+        /// <returns>the value of the tag, or "" if not found</returns>
+        protected string TryGetTag(string s)
+        {
+            if (!MessageTags.TryGetValue(s, out string? value))
+                return "";
+            return value ?? "";
+        }
+    }
+}