sharp-chat/SharpChat.SockChat/Commands/WhoCommand.cs

using SharpChat.SockChat.PacketsS2C;
using System.Linq;

namespace SharpChat.SockChat.Commands {
    public class WhoCommand : ISockChatClientCommand {
        public bool IsMatch(SockChatClientCommandContext ctx) {
            return ctx.NameEquals("who");
        }

        public void Dispatch(SockChatClientCommandContext ctx) {
            string? channelName = ctx.Args.FirstOrDefault();

            if(string.IsNullOrEmpty(channelName)) {
                ctx.Chat.SendTo(ctx.User, new WhoServerResponseS2CPacket(
                    ctx.Chat.Users.All.Select(u => SockChatUtility.GetUserName(u, ctx.Chat.UserStatuses.Get(u))).ToArray(),
                    SockChatUtility.GetUserName(ctx.User)
                ));
                return;
            }

            ChannelInfo? channel = ctx.Chat.Channels.Get(channelName, SockChatUtility.SanitiseChannelName);

            if(channel == null) {
                ctx.Chat.SendTo(ctx.User, new ChannelNotFoundErrorS2CPacket(channelName));
                return;
            }

            if(channel.Rank > ctx.User.Rank || (channel.HasPassword && !ctx.User.Permissions.HasFlag(UserPermissions.JoinAnyChannel))) {
                ctx.Chat.SendTo(ctx.User, new WhoChannelNotFoundErrorS2CPacket(channelName));
                return;
            }

            UserInfo[] userInfos = ctx.Chat.Users.GetMany(
                ctx.Chat.ChannelsUsers.GetChannelUserIds(channel)
            );

            ctx.Chat.SendTo(ctx.User, new WhoChannelResponseS2CPacket(
                channel.Name,
                userInfos.Select(user => SockChatUtility.GetUserName(user, ctx.Chat.UserStatuses.Get(user))).ToArray(),
                SockChatUtility.GetUserName(ctx.User, ctx.Chat.UserStatuses.Get(ctx.User))
            ));
        }
    }
}