using UnityEngine;
using BaseGames.Core;
using BaseGames.Core.Events;
using BaseGames.Input;
using BaseGames.Player;
using BaseGames.Player.States;
using BaseGames.Progression;

namespace BaseGames.Support.AntiSoftlock
{
    /// <summary>
    /// 防软锁系统（架构 16_SupportingModules §5）。
    /// 检测玩家长时间静止且无法移动的情况，提供逃脱选项。
    /// </summary>
    public class AntiSoftlockSystem : MonoBehaviour
    {
        [Header("配置")]
        [Tooltip("玩家静止超过此秒数后显示逃脱提示")]
        [SerializeField] private float _stuckThresholdSeconds = 30f;
        [Tooltip("移动速度低于此值视为静止")]
        [SerializeField] private float _minVelocityThreshold  = 0.1f;

        [Header("逃脱路径列表（按优先级降序排列）")]
        [SerializeField] private RoomEscapeInfoSO[] _escapeOptions;

        [Header("事件频道")]
        [SerializeField] private SceneLoadRequestEventChannelSO _onSceneLoadRequest;
        [SerializeField] private VoidEventChannelSO             _onShowEscapeUI;
        [SerializeField] private VoidEventChannelSO             _onHideEscapeUI;
        /// <summary>
        /// 玩家生成事件频道（PlayerController.Start() 广播）。
        /// 替代 FindFirstObjectByType 的全场景扫描。
        /// </summary>
        [SerializeField] private TransformEventChannelSO _onPlayerSpawned;

        [Header("引用")]
        [SerializeField] private InputReaderSO _input;

        private PlayerController _player;
        private Rigidbody2D      _playerRb;
        private float            _stuckTimer;
        private bool             _escapeUIVisible;
        private Vector2          _lastPos;

        private readonly BaseGames.Core.Events.CompositeDisposable _subs = new();

        private void OnEnable()
        {
            if (_onPlayerSpawned != null)
                _onPlayerSpawned.Subscribe(OnPlayerSpawned).AddTo(_subs);
        }

        private void OnDisable() => _subs.Clear();

        private void OnPlayerSpawned(Transform playerTransform)
        {
            if (playerTransform == null) return;
            _player   = playerTransform.GetComponent<PlayerController>();
            _playerRb = playerTransform.GetComponent<Rigidbody2D>();
            _lastPos  = playerTransform.position;
            _stuckTimer = 0f;
        }

        private void Update()
        {
            if (_player == null || !_player.Stats.IsAlive) return;

            Vector2 pos = _player.transform.position;
            float   vel = _playerRb != null ? _playerRb.velocity.magnitude : Vector2.Distance(pos, _lastPos) / Time.deltaTime;

            if (vel > _minVelocityThreshold)
            {
                _stuckTimer = 0f;
                _lastPos    = pos;
                if (_escapeUIVisible) HideEscapeUI();
                return;
            }

            _lastPos = pos;
            _stuckTimer += Time.deltaTime;

            if (_stuckTimer >= _stuckThresholdSeconds && !_escapeUIVisible)
                ShowEscapeUI();
        }

        private void ShowEscapeUI()
        {
            _escapeUIVisible = true;
            _onShowEscapeUI?.Raise();
        }

        private void HideEscapeUI()
        {
            _escapeUIVisible = false;
            _onHideEscapeUI?.Raise();
        }

        /// <summary>执行最优先的逃脱路径（由 UI 按钮调用）。</summary>
        public void ExecuteEscape()
        {
            var escape = ChooseBestEscape();
            HideEscapeUI();

            var sm = ServiceLocator.GetOrDefault<ISaveService>();
            string scene = string.IsNullOrEmpty(escape?.targetScene)
                ? sm?.LastCheckpointScene
                : escape.targetScene;
            string spawn = string.IsNullOrEmpty(escape?.spawnId)
                ? sm?.LastCheckpointSpawnId
                : escape.spawnId;

            _onSceneLoadRequest?.Raise(new SceneLoadRequest
            {
                SceneName         = scene,
                EntryId           = spawn,
                TransitionType    = TransitionType.Scene,
                IsRespawn         = true,
            });
        }

        private RoomEscapeInfoSO ChooseBestEscape()
        {
            if (_escapeOptions == null || _escapeOptions.Length == 0) return null;
            RoomEscapeInfoSO best = null;
            int bestPriority = int.MinValue;
            foreach (var opt in _escapeOptions)
            {
                if (opt == null) continue;
                if (opt.requiredAbility != BaseGames.Player.AbilityType.None
                    && (_player?.Stats.HasAbility(opt.requiredAbility) == false)) continue;
                if (opt.priority > bestPriority)
                {
                    bestPriority = opt.priority;
                    best         = opt;
                }
            }
            return best;
        }
    }
}