using PureWebSockets;
using System;
using System.Collections.Generic;
using System.Net.WebSockets;
using System.Threading;

namespace SockChatKeepAlive {
    public sealed class SockChatClient : IDisposable {
        private readonly FutamiCommon Common;
        private readonly PersistentData Persist;
        private readonly Func<string[]> GetAuthInfo;
        private PureWebSocket WebSocket;
        private Timer Pinger;

        private readonly object PersistAccess = new();

        public record ChatUser(string Id, string Name, string Colour);
        private Dictionary<string, ChatUser> Users { get; set; } = new();
        public ChatUser MyUser { get; private set; }

        private bool IsDisposed = false;

        private DateTimeOffset LastPong = DateTimeOffset.Now;

        public SockChatClient(
            FutamiCommon common,
            PersistentData persist,
            Func<string[]> getAuthInfo
        ) {
            Common = common;
            Persist = persist;
            GetAuthInfo = getAuthInfo;
        }

        ~SockChatClient() {
            DoDispose();
        }

        public void Dispose() {
            DoDispose();
            GC.SuppressFinalize(this);
        }

        private void DoDispose() {
            if(IsDisposed)
                return;
            IsDisposed = true;

            Disconnect();
        }

        public void Connect() {
            string server = Common.Servers[RNG.Next(Common.Servers.Length)];
            if(server.StartsWith("//"))
                server = "wss:" + server;
            Console.WriteLine($"Connecting to {server}...");

            Disconnect();
            WebSocket = new PureWebSocket(server, new PureWebSocketOptions {
                SubProtocols = new[] { "sockchat" },
            });
            WebSocket.OnOpened += WebSocket_OnOpen;
            WebSocket.OnClosed += WebSocket_OnClose;
            WebSocket.OnMessage += WebSocket_OnMessage;
            WebSocket.Connect();
        }

        public void Disconnect() {
            MyUser = null;

            if(Pinger != null) {
                Pinger.Dispose();
                Pinger = null;
            }

            if(WebSocket == null)
                return;

            try {
                WebSocket.OnOpened -= WebSocket_OnOpen;
                WebSocket.OnClosed -= WebSocket_OnClose;
                WebSocket.OnMessage -= WebSocket_OnMessage;
                WebSocket.Disconnect();
                WebSocket = null;
            } catch { }
        }

        public void SendMessage(string text) {
            if(MyUser == null)
                return;

            Send("2", MyUser.Id, text.Replace("\t", "    "));
        }

        public void SendMessage(object obj)
            => SendMessage(obj.ToString());

        public void SendPing() {
            if(MyUser != null)
                Send("0", MyUser.Id);
        }

        public void Send(params object[] args) {
            WebSocket.Send(string.Join("\t", args));
        }

        private void WebSocket_OnOpen(object sender) {
            Console.WriteLine("WebSocket connected.");
            Console.WriteLine();

            string[] authInfo = GetAuthInfo();
            Send("1", authInfo[0] ?? string.Empty, authInfo[1] ?? string.Empty);
        }

        private void WebSocket_OnClose(object sender, WebSocketCloseStatus reason) {
            Console.WriteLine($"WebSocket disconnected: {reason}");
            Disconnect();

            if(!IsDisposed) {
                lock(PersistAccess)
                    Persist.WasGracefulDisconnect = false;

                Thread.Sleep(10000);
                Connect();
            }
        }

        private void WebSocket_OnMessage(object sender, string data) {
            string[] args = data.Split('\t');
            if(args.Length < 1)
                return;

            switch(args[0]) {
                case "0":
                    TimeSpan pongDiff = DateTimeOffset.Now - LastPong;
                    LastPong = DateTimeOffset.Now;
                    lock(PersistAccess)
                        Persist.SatoriTotalUptime += (long)pongDiff.TotalMilliseconds;
                    break;

                case "1":
                    if(MyUser == null) {
                        if(args[1] == "y") {
                            Pinger = new Timer(x => SendPing(), null, 0, Common.Ping * 1000);
                        } else {
                            Disconnect();
                            return;
                        }
                    }

                    Users[args[2]] = new(args[2], args[3], args[4]);

                    if(MyUser == null) {
                        MyUser = Users[args[2]];

                        lock(PersistAccess) {
                            if(Persist.WasGracefulDisconnect)
                                Persist.AFKString = MyUser.Name.StartsWith("&lt;")
                                    ? MyUser.Name[4..MyUser.Name.IndexOf("&gt;_")]
                                    : string.Empty;
                            else {
                                string afkString = Persist.AFKString;
                                if(!string.IsNullOrWhiteSpace(afkString))
                                    SendMessage($"/afk {afkString}");
                            }
                        }
                    } else
                        Console.WriteLine($"!! {args[2]} <{args[3]}> joined.");
                    break;

                case "2":
                    Console.Write($":: {{{args[4]}}} [{DateTimeOffset.FromUnixTimeSeconds(long.Parse(args[1])):G}] ");
                    if(Users.ContainsKey(args[2]))
                        Console.Write($"{Users[args[2]].Id} <{Users[args[2]].Name}>");
                    else
                        Console.Write("*");
                    Console.WriteLine();

                    foreach(string line in args[3].Split(" <br/> ")) {
                        Console.Write("> ");
                        Console.WriteLine(line.Replace('\f', '\t').Trim());
                    }
                    Console.WriteLine();
                    break;

                case "3":
                    Users.Remove(args[1]);
                    Console.WriteLine($"!! {args[1]} left.");
                    break;

                case "5":
                    switch(args[1]) {
                        case "0":
                            Users[args[2]] = new(args[2], args[3], args[4]);
                            Console.WriteLine($"!! {args[2]} <{args[3]}> entered channel.");
                            break;

                        case "1":
                            Users.Remove(args[2]);
                            Console.WriteLine($"!! {args[2]} switched channel.");
                            break;
                    }
                    break;

                case "6":
                    Console.WriteLine($"!! Message {args[1]} was deleted.");
                    break;

                case "7":
                    if(args.Length < 2)
                        break;

                    switch(args[1]) {
                        case "0":
                            if(args.Length < 3 || !int.TryParse(args[2], out int amount))
                                break;

                            int offset = 3;
                            for(int i = 0; i < amount; i++) {
                                Users[args[offset++]] = new(args[offset], args[offset++], args[offset++]);
                                offset += 2;
                            }
                            break;

                        case "1":
                            Console.Write($":: {{{args[8]}}} [{DateTimeOffset.FromUnixTimeSeconds(long.Parse(args[2])):G}] ");
                            if(args[3].Equals("-1", StringComparison.Ordinal))
                                Console.Write("*");
                            else
                                Console.Write($"{args[3]} <{args[4]}>");
                            Console.WriteLine();

                            foreach(string line in args[7].Split(" <br/> ")) {
                                Console.Write("> ");
                                Console.WriteLine(line.Replace('\f', '\t').Trim());
                            }
                            Console.WriteLine();
                            break;
                    }
                    break;

                case "8":
                    if(args[1] is "0" or "4")
                        Console.WriteLine("!! Message list cleared");

                    if(args[1] is "1" or "3" or "4") {
                        Console.WriteLine("!! User list cleared");
                        Users.Clear();
                        Users.Add(MyUser.Id, MyUser);
                    }

                    if(args[1] is "2" or "3" or "4")
                        Console.WriteLine("!! Channel list cleared");
                    break;

                case "9":
                    Console.WriteLine($"!! Kicked from server: {args[1]} {args[2]}");
                    break;

                case "10":
                    Users[args[1]] = new(args[1], args[2], args[3]);
                    Console.WriteLine($"!! {args[1]} updated: {args[2]}.");

                    if(MyUser.Id == args[1]) {
                        MyUser = Users[args[1]];

                        lock(PersistAccess)
                            Persist.AFKString = MyUser.Name.StartsWith("&lt;")
                                ? MyUser.Name[4..MyUser.Name.IndexOf("&gt;_")]
                                : string.Empty;
                    }
                    break;
            }
        }
    }
}