using System.Collections.Generic;
using System.Text;
using Fighter3D.Core;
using XWorld.Framework;
using XWorld.Framework.Protocol;

namespace Fighter3D.Server
{
    public sealed class FighterServerRoom : IGameServerRoom
    {
        public const ushort InputOpcode = 1;
        public const ushort SnapshotOpcode = 100;

        private readonly FighterLogic _logic = new FighterLogic();
        private readonly Dictionary<int, int> _seatOfPlayer = new Dictionary<int, int>();
        private readonly int[] _playerOfSeat = new int[2];
        private IRoomCtx _ctx;
        private FighterState _state;
        private bool _ended;

        public void OnRoomStart(IReadOnlyList<PlayerInfo> players, IRoomCtx ctx)
        {
            _ctx = ctx;
            _state = _logic.CreateInitial(
                new RoomConfig { GameId = "fighter3d", Version = 1, Seed = 1, PlayerCount = players.Count },
                ctx.Random);

            for (int i = 0; i < players.Count && i < 2; i++)
            {
                _seatOfPlayer[players[i].PlayerId] = i;
                _playerOfSeat[i] = players[i].PlayerId;
            }

            Broadcast();
        }

        public void OnMessage(int playerId, NetMessage message)
        {
            if (_ended || message.Opcode != InputOpcode)
                return;

            if (!_seatOfPlayer.TryGetValue(playerId, out int seat))
                return;

            try
            {
                var reader = new PacketReader(message.Payload);
                int axis = reader.ReadVarInt();
                var buttons = (FighterButtons)reader.ReadByte();
                _state = _logic.Step(_state, FighterInput.Controls(seat, axis, buttons), _ctx.Random).State;
            }
            catch (System.Exception ex)
            {
                _ctx.Logger.Error($"fighter3d input decode failed: {ex.Message}");
            }
        }

        public void OnTick(float deltaTime)
        {
            if (_ended)
                return;

            var result = _logic.Step(_state, FighterInput.Tick(deltaTime), _ctx.Random);
            _state = result.State;
            Broadcast();

            if (_state.Phase == FighterPhase.Finished)
                EndRoomOnce();
        }

        public void OnRoomEnd()
        {
            _ctx?.Logger.Info("fighter3d room end");
        }

        private void Broadcast()
        {
            _ctx.Broadcast(new NetMessage(SnapshotOpcode, _logic.Encode(_state)));
        }

        private void EndRoomOnce()
        {
            if (_ended)
                return;

            _ended = true;
            int winnerPid = _state.WinnerSeat >= 0 && _state.WinnerSeat < 2
                ? _playerOfSeat[_state.WinnerSeat]
                : 0;

            string text = _state.WinnerSeat == 2
                ? "Fighter3D draw"
                : $"Fighter3D winner seat {_state.WinnerSeat}";

            _ctx.EndRoom(new RoomEndResult
            {
                WinnerPlayerId = winnerPid,
                ResultBlob = Encoding.UTF8.GetBytes(text)
            });
        }
    }
}