using UnityEngine;
using OctoberStudio.VAT;

namespace OctoberStudio
{
    /// <summary>
    /// 把 VAT prefab 挂到原 EnemyBehavior 上,作为视觉替换层。
    /// - 隐藏原 SpriteRenderer / Animator(留 Shadow)
    /// - Spawn VAT view 作为子物体
    /// - 朝向: 把 EnemyBehavior.ExternalFacingOverride 设 true,EnemyBehavior 不再写 transform.localScale.x,
    ///   sign 通过 OnFacingSignChanged event 推给本组件 → 调 VATAnimationController.SetFacing。
    ///   一律走 Y 旋转,完全不依赖 localScale。
    /// </summary>
    [DisallowMultipleComponent]
    public class EnemyVATAttachment : MonoBehaviour
    {
        [Header("VAT Source")]
        [Tooltip("烤好的 VAT prefab (e.g. mon1001_VAT.prefab)")]
        [SerializeField] private GameObject vatPrefab;

        [Header("View Transform")]
        [SerializeField] private Vector3 localOffset = new Vector3(0f, 0.3f, 0f);
        [SerializeField] private Vector3 localScale = new Vector3(0.5f, 0.5f, 0.5f);

        [Header("Hide Originals")]
        [Tooltip("不禁用名字含此关键字的 SpriteRenderer (默认 Shadow 阴影保留)")]
        [SerializeField] private string keepNameContains = "Shadow";

        private GameObject _spawnedView;
        private VATAnimationController _vatCtrl;
        private EnemyBehavior _enemy;

        private void Awake()
        {
            _enemy = GetComponent<EnemyBehavior>();
            HideOriginalSprites();
            SpawnVATView();
            if (_spawnedView != null)
            {
                _vatCtrl = _spawnedView.GetComponent<VATAnimationController>();
            }

            // 接管 EnemyBehavior 朝向:不再写 transform.localScale.x,sign 走 event
            if (_enemy != null)
            {
                _enemy.ExternalFacingOverride = true;
                _enemy.OnFacingSignChanged += HandleEnemyFacingChanged;
            }

            // 出生时同步一次初始朝向(VATAnimationController.OnEnable 默认 SetFacing(+1) 已先跑过,
            // 这里覆盖一次以应对对象池复用或 prefab 上 root.scale.x 非常规情况)
            if (_vatCtrl != null) _vatCtrl.SetFacing(1);
        }

        private void OnDestroy()
        {
            if (_enemy != null) _enemy.OnFacingSignChanged -= HandleEnemyFacingChanged;
        }

        private void HandleEnemyFacingChanged(int sign)
        {
            if (_vatCtrl != null) _vatCtrl.SetFacing(sign);
        }

        private void HideOriginalSprites()
        {
            var all = GetComponentsInChildren<SpriteRenderer>(true);
            foreach (var sr in all)
            {
                if (!string.IsNullOrEmpty(keepNameContains) &&
                    sr.gameObject.name.IndexOf(keepNameContains, System.StringComparison.OrdinalIgnoreCase) >= 0)
                    continue;
                sr.enabled = false;
            }

            // 子物体上的 Animator 也禁用(主 Sprite 那个,Animator 切 Sprite 已无用,省 CPU)
            var animators = GetComponentsInChildren<Animator>(true);
            foreach (var an in animators)
            {
                if (!string.IsNullOrEmpty(keepNameContains) &&
                    an.gameObject.name.IndexOf(keepNameContains, System.StringComparison.OrdinalIgnoreCase) >= 0)
                    continue;
                an.enabled = false;
            }
        }

        private void SpawnVATView()
        {
            if (vatPrefab == null) return;
            _spawnedView = Instantiate(vatPrefab, transform);
            _spawnedView.name = "_VAT_View";
            _spawnedView.transform.localPosition = localOffset;
            _spawnedView.transform.localScale = localScale;
            // 注意: 不在这里写 localRotation = identity!
            // VATAnimationController.OnEnable 已在 Instantiate 中调过 SetFacing(),把 Y 设成了 ±facing 值,
            // 这里 reset 会把它抹成 0,导致 LateUpdate 第一次跑之前 view 朝向是错的。
            // VAT prefab 的 root rotation 本身就是 identity,无需重置。
        }

#if UNITY_EDITOR
        // 仅给 Editor 工具读
        public GameObject VATPrefab
        {
            get => vatPrefab;
            set => vatPrefab = value;
        }

        public Vector3 LocalScale
        {
            get => localScale;
            set => localScale = value;
        }

        public Vector3 LocalOffset
        {
            get => localOffset;
            set => localOffset = value;
        }
#endif
    }
}