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

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

        public void Dispatch(SockChatClientCommandContext ctx) {
            string channelName = ctx.Args.FirstOrDefault() ?? string.Empty;
            string password = string.Join(' ', ctx.Args.Skip(1));

            ChannelInfo? channelInfo = ctx.Chat.Channels.Get(channelName, SockChatUtility.SanitiseChannelName);
            if(channelInfo == null) {
                ctx.Chat.SendTo(ctx.User, new ChannelNotFoundErrorS2CPacket(channelName));
                ctx.Chat.SendTo(ctx.User, new UserChannelForceJoinS2CPacket(ctx.Channel.Name));
                return;
            }

            if(channelInfo.Name.Equals(ctx.Channel.Name, StringComparison.InvariantCultureIgnoreCase)) {
                // this is where the elusive commented out "samechan" error would go!
                // https://patchii.net/sockchat/sockchat/src/commit/6c2111fb4b0241f9ef31060b0f86e7176664f572/server/lib/context.php#L61
                ctx.Chat.SendTo(ctx.User, new UserChannelForceJoinS2CPacket(ctx.Channel.Name));
                return;
            }

            if(!ctx.User.Permissions.HasFlag(UserPermissions.JoinAnyChannel) && channelInfo.OwnerId != ctx.User.UserId) {
                if(channelInfo.Rank > ctx.User.Rank) {
                    ctx.Chat.SendTo(ctx.User, new ChannelRankTooLowErrorS2CPacket(channelInfo.Name));
                    ctx.Chat.SendTo(ctx.User, new UserChannelForceJoinS2CPacket(ctx.Channel.Name));
                    return;
                }

                if(!string.IsNullOrEmpty(channelInfo.Password) && channelInfo.Password.Equals(password)) {
                    ctx.Chat.SendTo(ctx.User, new ChannelPasswordWrongErrorS2CPacket(channelInfo.Name));
                    ctx.Chat.SendTo(ctx.User, new UserChannelForceJoinS2CPacket(ctx.Channel.Name));
                    return;
                }
            }

            DateTimeOffset now = DateTimeOffset.UtcNow;
            ctx.Chat.Events.Dispatch("chan:leave", now, ctx.Channel, ctx.User);
            ctx.Chat.Events.Dispatch("chan:join", now, channelInfo, ctx.User);
        }
    }
}