using UnityEngine;

/// <summary>
/// 挂在被 GfxController 池化的特效实例上，记录它来自哪个 prefab，
/// 并在复用前把会被逐次修改的可视状态（粒子起始色/循环、拖尾渐变、材质属性块）
/// 还原到首次实例化时的原始值，保证复用后的视觉与 Instantiate 全新实例完全等价。
/// </summary>
public class GfxPooledItem : MonoBehaviour
{
    public GameObject prefabKey;
    public GfxController owner;

    // 防止同一实例被重复回收（粒子回调 + 计时回收等路径）。
    [System.NonSerialized] public bool released;

    private ParticleSystem[] _particles;
    private ParticleSystem.MinMaxGradient[] _origStartColors;
    private bool[] _origLoops;

    private TrailRenderer[] _trails;
    private Gradient[] _origTrailGradients;

    private Renderer[] _renderers;

    private bool _captured;

    /// <summary>首次实例化后调用一次，快照原始可视状态。</summary>
    public void CaptureOriginals()
    {
        _particles = GetComponentsInChildren<ParticleSystem>(true);
        _origStartColors = new ParticleSystem.MinMaxGradient[_particles.Length];
        _origLoops = new bool[_particles.Length];
        for (int i = 0; i < _particles.Length; i++)
        {
            var main = _particles[i].main;
            _origStartColors[i] = main.startColor;
            _origLoops[i] = main.loop;
        }

        _trails = GetComponentsInChildren<TrailRenderer>(true);
        _origTrailGradients = new Gradient[_trails.Length];
        for (int i = 0; i < _trails.Length; i++)
        {
            _origTrailGradients[i] = CloneGradient(_trails[i].colorGradient);
        }

        _renderers = GetComponentsInChildren<Renderer>(true);
        _captured = true;
    }

    /// <summary>复用前还原到原始状态。</summary>
    public void ResetToOriginal()
    {
        if (!_captured) return;

        for (int i = 0; i < _particles.Length; i++)
        {
            if (_particles[i] == null) continue;
            var main = _particles[i].main;
            main.startColor = _origStartColors[i];
            main.loop = _origLoops[i];
        }

        for (int i = 0; i < _trails.Length; i++)
        {
            if (_trails[i] == null) continue;
            _trails[i].Clear();
            _trails[i].colorGradient = CloneGradient(_origTrailGradients[i]);
        }

        for (int i = 0; i < _renderers.Length; i++)
        {
            if (_renderers[i] != null) _renderers[i].SetPropertyBlock(null);
        }
    }

    // 粒子播放完毕（root 的 stopAction 设为 Callback）时回收整个特效。
    private void OnParticleSystemStopped()
    {
        if (owner != null) owner.ReleaseFx(gameObject);
    }

    private static Gradient CloneGradient(Gradient src)
    {
        if (src == null) return null;
        var g = new Gradient();
        g.SetKeys(src.colorKeys, src.alphaKeys);
        g.mode = src.mode;
        return g;
    }
}