Added ability to construct IRC messages from parts when sending them.

TwitchIrcClient/IRC/IrcConnection.cs

@@ -139,12 +139,52 @@ namespace TwitchIrcClient.IRC
             var bytes = Encoding.UTF8.GetBytes(line + ENDL);
             _Stream.Write(bytes, 0, bytes.Length);
         }
+        //TODO make this unit testable?
+        /// <summary>
+        /// Construct an IRC message from parts and sends it. Does little to no validation on inputs.
+        /// </summary>
+        /// <param name="command"></param>
+        /// <param name="parameters"></param>
+        /// <param name="tags"></param>
+        /// <param name="prefix"></param>
+        public void SendMessage(IrcMessageType command, IEnumerable<string>? parameters = null,
+            Dictionary<string, string?>? tags = null, string? prefix = null)
+        {
+            var message = "";
+            if (tags is not null && tags.Count != 0)
+            {
+                message = "@" + string.Join(';',
+                    tags.OrderBy(p => p.Key).Select(p => $"{p.Key}={EscapeTagValue(p.Value)}"))
+                    + " ";
+            }
+            if (prefix is not null && !string.IsNullOrWhiteSpace(prefix))
+                message += ":" + prefix + " ";
+            message += command.ToCommand() + " ";
+            if (parameters is not null && parameters.Any())
+            {
+                message += string.Join(' ', parameters.SkipLast(1));
+                message += " :" + parameters.Last();
+            }
+            SendLine(message);
+        }
+        private static string EscapeTagValue(string? s)
+        {
+            if (s is null)
+                return "";
+            return string.Join("", s.Select(c => c switch
+                {
+                    ';' => @"\:",
+                    ' ' => @"\s",
+                    '\\' => @"\\",
+                    '\r' => @"\r",
+                    '\n' => @"\n",
+                    char ch => ch.ToString(),
+                }));
+        }
         public void Authenticate(string? user, string? pass)
         {
-            if (user == null)
-                user = $"justinfan{Random.Shared.NextInt64(10000):D4}";
-            if (pass == null)
-                pass = "pass";
+            user ??= $"justinfan{Random.Shared.NextInt64(10000):D4}";
+            pass ??= "pass";
             SendLine($"NICK {user}");
             SendLine($"PASS {pass}");
         }

TwitchIrcClient/IRC/IrcMessageType.cs

@@ -6,6 +6,9 @@ using System.Threading.Tasks;
 
 namespace TwitchIrcClient.IRC
 {
+    /// <summary>
+    /// Represents the "command" of an IRC message.
+    /// </summary>
     public enum IrcMessageType
     {
         //twitch standard messages
@@ -174,12 +177,26 @@ namespace TwitchIrcClient.IRC
     }
     public static class IrcMessageTypeHelper
     {
-        //parses a string that is either a numeric code or the command name
+        /// <summary>
+        /// Parses a string that is either a numeric code or the command name.
+        /// </summary>
+        /// <param name="s"></param>
+        /// <returns></returns>
+        /// <remarks>
+        /// The value range 000-999 is reserved for numeric commands, and will
+        /// be converted to a numeric string when forming a message.
+        /// </remarks>
         public static IrcMessageType Parse(string s)
         {
             if (int.TryParse(s, out int result))
                 return (IrcMessageType)result;
             return Enum.Parse<IrcMessageType>(s);
         }
+        public static string ToCommand(this IrcMessageType type)
+        {
+            if ((int)type >= 0 && (int)type < 1000)
+                return $"{(int)type,3}";
+            return type.ToString();
+        }
     }
 }

TwitchIrcClient/Program.cs

@@ -9,11 +9,9 @@ RateLimiter limiter = new(20, 30);
 bool ssl = true;
 async Task<IrcConnection> CreateConnection(string channel)
 {
-    IrcConnection connection;
-    if (ssl)
-        connection = new IrcConnection("irc.chat.twitch.tv", 6697, limiter, true, true);
-    else
-        connection = new IrcConnection("irc.chat.twitch.tv", 6667, limiter, true, false);
+    IrcConnection connection = ssl
+        ? connection = new IrcConnection("irc.chat.twitch.tv", 6697, limiter, true, true)
+        : connection = new IrcConnection("irc.chat.twitch.tv", 6667, limiter, true, false);
     connection.AddCallback(new MessageCallbackItem(
         (o, m) =>
         {
@@ -51,7 +49,7 @@ async Task<IrcConnection> CreateConnection(string channel)
 }
 Console.Write("Channel: ");
 var channelName = Console.ReadLine();
-ArgumentNullException.ThrowIfNull(channelName, nameof(Channel));
+ArgumentNullException.ThrowIfNullOrWhiteSpace(channelName, nameof(channelName));
 var connection = await CreateConnection(channelName);
 while (true)
 {