using System.Collections;
using UnityEngine;
using BaseGames.Combat;

namespace BaseGames.Enemies.Abilities
{
    /// <summary>
    /// 挂顶下落能力：怪物初始挂在天花板（kinematic，重力 0）。能力触发后：
    /// 1. 切换为 dynamic + 恢复重力
    /// 2. 自由落体到接触地面
    /// 3. 落地播放 AoE HitBox + 砸地反馈
    /// </summary>
    [RequireComponent(typeof(Rigidbody2D))]
    public sealed class CeilingDropAbility : EnemyAbilityBase
    {
        [Header("下落")]
        [SerializeField] private float _fallGravityScale = 3.5f;
        [SerializeField] private float _maxFallTime      = 3f;
        [SerializeField] private LayerMask _groundMask;

        [Header("落地")]
        [SerializeField] private HitBox _landingHitBox;
        [SerializeField] private float  _hitBoxActiveTime = 0.2f;
        [SerializeField] private float  _recoveryTime     = 0.4f;

        private Rigidbody2D _rb;
        private RigidbodyType2D _origBodyType;
        private float           _origGravityScale;

        protected override void Awake()
        {
            base.Awake();
            _rb = GetComponentInParent<Rigidbody2D>();
        }

        protected override IEnumerator ExecuteCoroutine()
        {
            if (_rb == null) yield break;
            var atk = (_config.attackSequence != null && _config.attackSequence.Length > 0)
                ? _config.attackSequence[0] : null;

            Phase = AbilityRunState.Active;

            // 切换到动态 + 恢复重力
            _origBodyType    = _rb.bodyType;
            _origGravityScale = _rb.gravityScale;
            _rb.bodyType    = RigidbodyType2D.Dynamic;
            _rb.gravityScale = _fallGravityScale;
            _rb.velocity    = Vector2.zero;

            float t = 0f;
            while (t < _maxFallTime)
            {
                t += Time.fixedDeltaTime;
                yield return new WaitForFixedUpdate();
                if (t > 0.05f && IsGrounded()) break;
            }

            _rb.velocity = Vector2.zero;

            if (_landingHitBox != null)
            {
                _landingHitBox.Activate(atk != null ? atk.damageSource : null, _transform);
                yield return EnemyAbilityWaits.Get(_hitBoxActiveTime);
                _landingHitBox.Deactivate();
            }

            yield return EnemyAbilityWaits.Get(_recoveryTime);

            // 落地后不恢复挂顶状态（一般转为地面行为），保持动态 Rigidbody
        }

        private bool IsGrounded()
        {
            var hit = Physics2D.Raycast(_rb.position, Vector2.down, 0.6f, _groundMask);
            return hit.collider != null;
        }

        protected override void OnInterrupted(InterruptReason reason)
        {
            if (_landingHitBox != null && _landingHitBox.IsActive) _landingHitBox.Deactivate();
            // 中断时恢复 Rigidbody 原始状态，防止物理参数泄漏
            if (_rb != null)
            {
                _rb.velocity     = Vector2.zero;
                _rb.bodyType     = _origBodyType;
                _rb.gravityScale = _origGravityScale;
            }
        }
    }
}