using System.Collections;
using Animancer;
using UnityEngine;

namespace BaseGames.World
{
    /// <summary>
    /// 同场景成对门传送组件。两扇门互相引用，玩家进入其中一扇门时被传送到另一扇。
    /// <para>
    /// 触发流程：
    /// <list type="number">
    ///   <item>玩家进入触发器或按交互键 → 播放 <see cref="_openClip"/> 开门动画（本门）</item>
    ///   <item>传送玩家到 <see cref="_linkedDoor"/> 的出生位置，并设定朝向</item>
    ///   <item>目标门播放 <see cref="_enterClip"/> 玩家走出动画</item>
    /// </list>
    /// </para>
    /// <para>不涉及场景加载；适用于同房间内不同小区域之间的传送门、电梯、秘道等。</para>
    /// </summary>
    [RequireComponent(typeof(Collider2D))]
    public class LinkedDoorTransition : MonoBehaviour, IInteractable
    {
        [Header("配对")]
        [Tooltip("与此门配对的另一扇门。玩家进入本门后传送到此目标门的出生点。")]
        [SerializeField] private LinkedDoorTransition _linkedDoor;

        [Header("出生配置")]
        [Tooltip("传送后玩家在此门的出生位置偏移（相对于本 GameObject 中心，默认 0）。")]
        [SerializeField] private Vector2 _spawnOffset = new Vector2(0f, 0f);

        [Tooltip("传送到此门后玩家的朝向（+1 = 朝右，-1 = 朝左）。")]
        [SerializeField] private int _facingDirectionOnArrive = 1;

        [Header("触发方式")]
        [Tooltip("true = 玩家进入触发器自动触发；false = 需玩家按交互键。")]
        [SerializeField] private bool _autoTrigger = false;

        [Header("门动画")]
        [SerializeField] private AnimancerComponent _animancer;

        [Tooltip("玩家从外侧进入时的开门动画。留空则跳过。")]
        [SerializeField] private AnimationClip _openClip;

        [Tooltip("玩家从内侧走出时的动画（目标门调用）。留空则跳过。")]
        [SerializeField] private AnimationClip _enterClip;

        [Header("钥匙物品校验")]
        [SerializeField] private bool   _requiresKeyItem;
        [SerializeField] private string _requiredItemId;

        [Header("世界状态")]
        [SerializeField] private WorldStateRegistry _worldState;

        // 传送后短暂冷却，防止玩家在目标门处被立即再次传回
        [Header("冷却")]
        [Tooltip("传送完成后本门的冷却时间（秒）。防止玩家被反复来回传送。")]
        [SerializeField] private float _cooldown = 1.5f;

        private bool  _triggered;
        private float _cooldownUntil;

        // ── IInteractable ─────────────────────────────────────────────────────

        public bool   CanInteract    => !_autoTrigger;
        public string InteractPrompt => "进入";

        public void Interact(Transform player) => TryTrigger(player);

        public void OnPlayerEnterRange(Transform player) { }
        public void OnPlayerExitRange() { }

        // ── 触发 ──────────────────────────────────────────────────────────────

        private void OnTriggerEnter2D(Collider2D other)
        {
            if (!_autoTrigger) return;
            if (!other.CompareTag("Player")) return;
            TryTrigger(other.transform);
        }

        private void TryTrigger(Transform player)
        {
            if (_triggered) return;
            if (Time.time < _cooldownUntil) return;
            if (_linkedDoor == null)
            {
                Debug.LogWarning($"[LinkedDoorTransition] {name}：未配置 _linkedDoor，传送中止。");
                return;
            }
            if (_requiresKeyItem && !HasItem(_requiredItemId)) return;

            _triggered = true;
            StartCoroutine(TransitionCoroutine(player));
        }

        private void OnDisable() => _triggered = false;

        // ── 传送流程 ──────────────────────────────────────────────────────────

        private IEnumerator TransitionCoroutine(Transform player)
        {
            // 1. 播放本门开门动画
            if (_animancer != null && _openClip != null)
            {
                var state = _animancer.Play(_openClip);
                yield return state;
            }

            // 2. 传送玩家到目标门
            Vector3 destination = _linkedDoor.GetSpawnWorldPosition();
            player.position = destination;

            // 朝向（通过 localScale X 翻转，或通知 PlayerController）
            ApplyFacing(player, _linkedDoor._facingDirectionOnArrive);

            // 3. 目标门播放玩家走出动画，并进入冷却
            _linkedDoor.PlayEnterAnimation();
            _linkedDoor.StartCooldown(_cooldown);

            _triggered = false;
        }

        /// <summary>玩家从门内侧走出时的动画。由传送发起方在传送完成后调用。</summary>
        public void PlayEnterAnimation()
        {
            if (_animancer != null && _enterClip != null)
                _animancer.Play(_enterClip);
        }

        /// <summary>启动传送冷却，在此期间本门不会再次触发传送。</summary>
        public void StartCooldown(float duration)
        {
            _cooldownUntil = Time.time + duration;
        }

        // ── 辅助 ──────────────────────────────────────────────────────────────

        /// <summary>返回传送目标门的出生世界坐标（含偏移）。</summary>
        public Vector3 GetSpawnWorldPosition()
            => transform.position + new Vector3(_spawnOffset.x, _spawnOffset.y, 0f);

        private static void ApplyFacing(Transform player, int facing)
        {
            if (facing == 0) return;
            Vector3 s = player.localScale;
            float absX = Mathf.Abs(s.x);
            s.x = facing > 0 ? absX : -absX;
            player.localScale = s;
        }

        private bool HasItem(string itemId)
        {
            if (string.IsNullOrEmpty(itemId)) return true;
            if (_worldState == null)
            {
                Debug.LogWarning($"[LinkedDoorTransition] WorldStateRegistry 未配置，钥匙 {itemId} 检查跳过");
                return false;
            }
            return _worldState.IsCollected(itemId);
        }

        private void OnDrawGizmos()
        {
            var col = GetComponent<Collider2D>();
            if (col != null)
            {
                // 青色区分成对门
                Gizmos.color = new Color(0.2f, 0.9f, 0.9f, 0.7f);
                Gizmos.DrawWireCube(transform.position, col.bounds.size);
                Gizmos.color = new Color(0.2f, 0.9f, 0.9f, 0.2f);
                Gizmos.DrawCube(transform.position, col.bounds.size);
            }

            // 出生点
            Vector3 spawn = GetSpawnWorldPosition();
            Gizmos.color = Color.cyan;
            Gizmos.DrawWireSphere(spawn, 0.2f);

            // 配对连线
            if (_linkedDoor != null)
            {
                Gizmos.color = new Color(0.2f, 0.9f, 0.9f, 0.8f);
                Gizmos.DrawLine(spawn, _linkedDoor.GetSpawnWorldPosition());
            }
        }
    }
}