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

namespace RPS.Server
{
    public sealed class RpsServerRoom : IGameServerRoom
    {
        public const ushort SnapshotOpcode = 1;
        public const ushort ChoiceOpcode = 1; // 客户端出招消息 opcode

        private readonly RpsLogic _logic = new RpsLogic();
        private IRoomCtx _ctx;
        private RpsState _state;
        private readonly Dictionary<int, int> _seatOf = new Dictionary<int, int>(); // playerId->seat
        private readonly int[] _pidOfSeat = new int[2]; // seat->playerId（结算用；AI 也有 pid）
        private bool _ended;

        public void OnRoomStart(IReadOnlyList<PlayerInfo> players, IRoomCtx ctx)
        {
            _ctx = ctx;
            _state = _logic.CreateInitial(new RoomConfig { GameId = "rps", Version = 1, Seed = 1, PlayerCount = players.Count }, ctx.Random);
            for (int i = 0; i < players.Count && i < 2; i++)
            {
                _seatOf[players[i].PlayerId] = i;
                _pidOfSeat[i] = players[i].PlayerId;
                _state.IsAi[i] = players[i].IsAI;
            }
            Broadcast();
        }

        public void OnMessage(int playerId, NetMessage message)
        {
            if (message.Opcode != ChoiceOpcode) return;
            if (!_seatOf.TryGetValue(playerId, out int seat)) return;
            var r = new PacketReader(message.Payload);
            var choice = (Choice)r.ReadByte();
            _state = _logic.Step(_state, RpsInput.Choose(seat, choice), _ctx.Random).State;
        }

        public void OnTick(float dt)
        {
            if (_ended) return;
            // Choosing 阶段：AI 座位等概率出招（不读对手），仅在尚未出招时
            if (_state.Phase == RpsPhase.Choosing)
                for (int seat = 0; seat < 2; seat++)
                    if (_state.IsAi[seat] && _state.Choices[seat] == Choice.None)
                    {
                        var c = new[] { Choice.Rock, Choice.Paper, Choice.Scissors }[_ctx.Random.Next(3)];
                        _state = _logic.Step(_state, RpsInput.Choose(seat, c), _ctx.Random).State;
                    }

            var res = _logic.Step(_state, RpsInput.Tick(dt), _ctx.Random);
            _state = res.State;
            Broadcast();

            if (_state.Phase == RpsPhase.Finished)
            {
                _ended = true;
                int s0 = _state.Scores[0], s1 = _state.Scores[1];
                bool draw = _state.Winner == 2;
                _ctx.Logger.Info($"rps finished, winner seat={_state.Winner}, scores {s0}:{s1}");
                _ctx.EndRoom(new RoomEndResult
                {
                    WinnerPlayerId = draw ? 0 : _pidOfSeat[_state.Winner],
                    ResultBlob = Encoding.UTF8.GetBytes(draw ? $"平局 {s0} : {s1}" : $"最终比分 {s0} : {s1}")
                });
            }
        }

        public void OnRoomEnd() => _ctx.Logger.Info("rps room end");

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