Add Join and Play handlers, Expand Command Builder functionality

Bot/Handler/MusicPlayer/Extensions.cs

@@ -0,0 +1,61 @@
+using Discord;
+using Discord.Commands;
+using Discord.WebSocket;
+using Victoria.Node;
+
+namespace Lunaris2.Handler.MusicPlayer
+{
+    public static class Extensions
+    {
+        public static SocketGuild GetGuild(this SocketSlashCommand message, DiscordSocketClient client)
+        {
+            if (message.GuildId == null)
+            {
+                throw new Exception("Guild ID is null!");
+            }
+            
+            return client.GetGuild(message.GuildId.Value);
+        }
+        
+        public static IVoiceState GetVoiceState(this SocketSlashCommand message)
+        {
+            var voiceState = message.User as IVoiceState;
+            
+            if (voiceState?.VoiceChannel == null)
+            {
+                throw new Exception("You must be connected to a voice channel!");
+            }
+
+            return voiceState;
+        }
+        
+        public static async Task RespondAsync(this SocketSlashCommand message, string content)
+        {
+            await message.RespondAsync(content, ephemeral: true);
+        }
+        
+        public static async Task EnsureConnected(this LavaNode lavaNode)
+        {
+            if(!lavaNode.IsConnected)
+                await lavaNode.ConnectAsync();
+        }
+        
+        public static async Task JoinVoiceChannel(this SocketSlashCommand context, LavaNode lavaNode)
+        {
+            try
+            {
+                var textChannel = context.Channel as ITextChannel;
+                await lavaNode.JoinAsync(context.GetVoiceState().VoiceChannel, textChannel);
+                await context.RespondAsync($"Joined {context.GetVoiceState().VoiceChannel.Name}!");
+            }
+            catch (Exception exception) {
+                Console.WriteLine(exception);
+            }
+        }
+        
+        public static string GetOptionValueByName(this SocketSlashCommand command, string optionName)
+        {
+            return command.Data.Options.FirstOrDefault(option => option.Name == optionName)?.Value.ToString() ?? string.Empty;
+        }
+    }
+}