using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using SystemX.Core.Communication;

namespace HubX.Library.Socket.Packet
{
    public class PacketManager
    {
        #region Singleton
        static PacketManager _instance = new PacketManager();
        public static PacketManager Instance { get { return _instance; } }
        #endregion

        PacketManager()
        {
            Register();
        }

        Dictionary<ushort, Action<PacketSession, ArraySegment<byte>, ushort>> _onRecv = new Dictionary<ushort, Action<PacketSession, ArraySegment<byte>, ushort>>();
        Dictionary<ushort, Action<PacketSession, ArraySegment<byte>>> _handler = new Dictionary<ushort, Action<PacketSession, ArraySegment<byte>>>();

        public Action<PacketSession, ArraySegment<byte>, ushort> CustomHandler { get; set; }

        public void Register()
        {
            _onRecv.Add((ushort)EnumMessageId.C2S_INSERT_UniqueKey, MakePacket<C2S_INSERT_UniqueKey>);
            _handler.Add((ushort)EnumMessageId.C2S_INSERT_UniqueKey, PacketHandler.C2S_INSERT_UniqueKeyHandler);

            _onRecv.Add((ushort)EnumMessageId.C2S_SELECT_UniqueKey, MakePacket<C2S_SELECT_UniqueKey>);
            _handler.Add((ushort)EnumMessageId.C2S_SELECT_UniqueKey, PacketHandler.C2S_SELECT_UniqueKeyHandler);

            _onRecv.Add((ushort)EnumMessageId.C2S_UPDATE_UniqueKey, MakePacket<C2S_UPDATE_UniqueKey>);
            _handler.Add((ushort)EnumMessageId.C2S_UPDATE_UniqueKey, PacketHandler.C2S_UPDATE_UniqueKeyHandler);
        }

        public void OnRecvPacket(PacketSession session, ArraySegment<byte> buffer)
        {
            ushort count = 0;

            ushort size = BitConverter.ToUInt16(buffer.Array, buffer.Offset);
            count += 2;
            ushort id = BitConverter.ToUInt16(buffer.Array, buffer.Offset + count);
            count += 2;

            ushort packetSize = (ushort)(buffer.Count - count);
            byte[] packet = new byte[packetSize];
            Array.Copy(buffer.ToArray(), count, packet, 0, packetSize);
          
            if (_onRecv.TryGetValue(id, out var action))
                action.Invoke(session, packet, id);
        }

        void MakePacket<T>(PacketSession session, ArraySegment<byte> buffer, ushort id) where T : new()
        {
            if (CustomHandler != null)
            {
                CustomHandler.Invoke(session, buffer, id);
            }
            else
            {
                Action<PacketSession, ArraySegment<byte>> action = null;
                if (_handler.TryGetValue(id, out action))
                    action.Invoke(session, buffer);
            }
        }

        public Action<PacketSession, ArraySegment<byte>> GetPacketHandler(ushort id)
        {
            Action<PacketSession, ArraySegment<byte>> action = null;
            if (_handler.TryGetValue(id, out action))
                return action;
            return null;
        }
    }
}