using System.Collections;
using UnityEngine;
using BaseGames.Feedback;

namespace BaseGames.VFX
{
    /// <summary>
    /// 受伤闪白效果控制器。
    /// 通过 MaterialPropertyBlock 修改 SpriteRenderer 材质的 _FlashAmount 参数（0~1）；
    /// 对应 Shader 需暴露 _FlashColor 与 _FlashAmount 两个属性。
    /// 调用 Flash() 触发一次闪白动画（Coroutine 实现，不依赖 UniTask）。
    /// </summary>
    public class HurtFlashController : MonoBehaviour
    {
        [SerializeField] private SpriteRenderer  _renderer;
        [SerializeField] private FeedbackConfigSO _config;

        private static readonly int FlashColorID  = Shader.PropertyToID("_FlashColor");
        private static readonly int FlashAmountID = Shader.PropertyToID("_FlashAmount");

        private MaterialPropertyBlock _block;
        private Coroutine             _flashCoroutine;
        private WaitForSeconds        _waitForFlash;

        private void Awake()
        {
            Debug.Assert(_config != null, "[HurtFlashController] _config 未赋值，请在 Inspector 中指定 FeedbackConfigSO。", this);
            if (_renderer == null)
                _renderer = GetComponent<SpriteRenderer>();
            _block = new MaterialPropertyBlock();
            if (_config != null)
                _waitForFlash = new WaitForSeconds(_config.HurtFlashDuration);
        }

        /// <summary>触发一次闪白动画。若上一次闪白未结束则重置计时器。</summary>
        public void Flash()
        {
            if (_flashCoroutine != null)
                StopCoroutine(_flashCoroutine);
            _flashCoroutine = StartCoroutine(FlashCoroutine());
        }

        private IEnumerator FlashCoroutine()
        {
            SetFlash(1f);
            yield return _waitForFlash ?? new WaitForSeconds(_config.HurtFlashDuration);
            SetFlash(0f);
            _flashCoroutine = null;
        }

        private void SetFlash(float amount)
        {
            _renderer.GetPropertyBlock(_block);
            _block.SetColor(FlashColorID, _config.HurtFlashColor);
            _block.SetFloat(FlashAmountID, amount);
            _renderer.SetPropertyBlock(_block);
        }
    }
}