sharp-chat/SharpChat/Commands/ChannelJoinCommand.cs

using SharpChat.Packet;
using System.Linq;

namespace SharpChat.Commands {
    public class ChannelJoinCommand : IChatCommand {
        public bool IsMatch(ChatCommandContext ctx) {
            return ctx.NameEquals("join");
        }

        public void Dispatch(ChatCommandContext ctx) {
            string joinChanStr = ctx.Args.FirstOrDefault() ?? string.Empty;
            ChatChannel? joinChan = ctx.Chat.Channels.Values.FirstOrDefault(c => c.NameEquals(joinChanStr));

            if(joinChan == null) {
                ctx.Chat.SendTo(ctx.User, new ChannelNotFoundErrorPacket(joinChanStr));
                ctx.Chat.ForceChannel(ctx.User);
                return;
            }

            ctx.Chat.SwitchChannel(ctx.User, joinChan, string.Join(' ', ctx.Args.Skip(1)));
        }
    }
}