using System.Collections;
using System.Linq;
using Animancer;
using UnityEngine;

namespace BaseGames.Enemies.Abilities
{
    /// <summary>
    /// 面向玩家能力：朝向玩家后播放转身/翻转动画并等待完成。
    /// CanUse 重写：仅在无其他技能运行且玩家在背后时可用。
    /// 可复用于任何需要"检测背后玩家并翻转"的敌人。
    /// </summary>
    public class FacePlayerAbility : EnemyAbilityBase
    {
        [SerializeField] private ClipTransition _faceClip;

        public override bool CanUse =>
            base.CanUse
            && !_enemy.Abilities.All.Any(a => a != this && a.IsRunning)
            && IsPlayerBehind();

        private bool IsPlayerBehind()
        {
            if (_enemy.PlayerTransform == null) return false;
            float dx = _enemy.PlayerTransform.position.x - _enemy.transform.position.x;
            int facing = _enemy.Movement?.FacingDirection ?? 1;
            return (facing > 0 && dx < 0) || (facing < 0 && dx > 0);
        }

        protected override IEnumerator ExecuteCoroutine()
        {
            Phase = AbilityRunState.Active;

            _enemy.FacePlayer();

            if (_faceClip.Clip == null) yield break;

            _animancer.Play(_faceClip);
            yield return EnemyAbilityWaits.Get(_faceClip.Clip.length);
        }
    }
}