using UnityEngine;
using BaseGames.Combat;

namespace BaseGames.Combat
{
    /// <summary>
    /// 技能 HitBox 实例（架构 09_ProgressionModule §9 SkillHitBoxInstance）。
    /// 挂载于技能 HitBox Prefab 根节点。
    /// 命名规范: Assets/Prefabs/Skills/SKL_{skillId}_HitBox.prefab
    ///
    /// Prefab 内部层级示例（近战 AoE 技能）：
    ///   [SKL_SkySlash_HitBox]
    ///   └── [HitBox]    ← 扇形/圆形 PolygonCollider2D
    ///       └── HitBox.cs
    /// </summary>
    public class SkillHitBoxInstance : MonoBehaviour
    {
        [SerializeField] private HitBox[] _hitBoxes;  // 技能可有多个 HitBox（多段伤害）

        public event System.Action<DamageInfo> OnHitConfirmed;

        private Coroutine   _returnCoroutine;
        // 按 duration 缓存 WaitForSeconds，同一技能复用无 GC 分配
        private WaitForSeconds _cachedWait;
        private float          _cachedWaitDuration = float.NaN;

        private void Awake()
        {
            foreach (var hb in _hitBoxes)
            {
                if (hb == null) continue;
                hb.OnHitConfirmed += info => OnHitConfirmed?.Invoke(info);
            }
        }

        /// <summary>激活所有 HitBox，传入伤害数据源和攻击者 Transform。</summary>
        public void Activate(DamageSourceSO source, Transform attacker)
        {
            foreach (var hb in _hitBoxes)
                hb?.Activate(source, attacker);
        }

        /// <summary>
        /// duration 秒后归还对象池（SetActive false）。
        /// 由 SkillManager 对象池调用；替代旧版 Destroy 流程。
        /// </summary>
        public void AutoReturnAfter(float duration)
        {
            if (!Mathf.Approximately(_cachedWaitDuration, duration))
            {
                _cachedWaitDuration = duration;
                _cachedWait         = new WaitForSeconds(duration);
            }
            if (_returnCoroutine != null) StopCoroutine(_returnCoroutine);
            _returnCoroutine = StartCoroutine(ReturnCoroutine());
        }

        private System.Collections.IEnumerator ReturnCoroutine()
        {
            yield return _cachedWait;
            foreach (var hb in _hitBoxes)
                hb?.Deactivate();
            _returnCoroutine = null;
            gameObject.SetActive(false);  // 触发对象池回收
        }

        /// <summary>duration 秒后销毁（非池化路径，保留向后兼容）。</summary>
        public void AutoDestroyAfter(float duration)
            => Destroy(gameObject, Mathf.Max(0f, duration));

        private void OnDestroy()
        {
            foreach (var hb in _hitBoxes)
                hb?.Deactivate();
        }
    }
}