using System;
using System.Collections.Generic;

namespace XWorld.Framework
{
    public interface IRoomPlayerService
    {
        IReadOnlyList<PlayerInfo> GetRoomPlayers();
        bool TryGetRoomPlayer(int playerId, out PlayerInfo player);
        void RequestPlayerInfo(int playerId, Action<PlayerInfo> onLoaded);
    }

    public sealed class RoomPlayerService : IRoomPlayerService
    {
        private readonly List<PlayerInfo> _players = new List<PlayerInfo>();
        private readonly Dictionary<int, PlayerInfo> _byId = new Dictionary<int, PlayerInfo>();

        public void SetRoomPlayers(IEnumerable<PlayerInfo> players)
        {
            _players.Clear();
            _byId.Clear();

            if (players == null)
            {
                return;
            }

            foreach (PlayerInfo player in players)
            {
                if (player == null)
                {
                    continue;
                }

                PlayerInfo copy = Clone(player);
                _players.Add(copy);
                _byId[copy.PlayerId] = copy;
            }
        }

        public IReadOnlyList<PlayerInfo> GetRoomPlayers()
        {
            var copy = new List<PlayerInfo>(_players.Count);
            for (int i = 0; i < _players.Count; i++)
            {
                copy.Add(Clone(_players[i]));
            }
            return copy;
        }

        public bool TryGetRoomPlayer(int playerId, out PlayerInfo player)
        {
            if (_byId.TryGetValue(playerId, out PlayerInfo cached))
            {
                player = Clone(cached);
                return true;
            }

            player = null;
            return false;
        }

        public void RequestPlayerInfo(int playerId, Action<PlayerInfo> onLoaded)
        {
            TryGetRoomPlayer(playerId, out PlayerInfo player);
            onLoaded?.Invoke(player);
        }

        private static PlayerInfo Clone(PlayerInfo source)
        {
            return new PlayerInfo
            {
                PlayerId = source.PlayerId,
                Name = source.Name,
                IsAI = source.IsAI,
                Level = source.Level,
                AppearanceType = source.AppearanceType,
                AvatarId = source.AvatarId,
            };
        }
    }
}