using UnityEngine;
using UnityEditor;
using UnityEditor.SceneManagement;

[InitializeOnLoad]
public class ParticleSystemHierarchyEditor
{
    static ParticleSystemHierarchyEditor()
    {
        // 注册 Hierarchy 窗口的绘制回调
        EditorApplication.hierarchyWindowItemOnGUI += OnHierarchyWindowItemGUI;
    }

    private static void OnHierarchyWindowItemGUI(int instanceID, Rect selectionRect)
    {
        // 获取当前绘制的 GameObject
        GameObject obj = EditorUtility.InstanceIDToObject(instanceID) as GameObject;
        if (obj == null) return;

        // 检查是否包含 ParticleSystem 和 ParticleSystemRenderer
        ParticleSystem particleSystem = obj.GetComponent<ParticleSystem>();
        ParticleSystemRenderer particleRenderer = obj.GetComponent<ParticleSystemRenderer>();
        if (particleSystem == null || particleRenderer == null) return;

        // 设置绘制区域（Hierarchy 右侧）
        Rect rect = new Rect(selectionRect);
        rect.x += rect.width - 150; // 调整位置，留出空间显示控件
        rect.height = EditorGUIUtility.singleLineHeight;

        // 显示当前 Sorting Layer 名称（只读）
        rect.width = 60; // 层名称显示宽度
        GUIStyle labelStyle = new GUIStyle(EditorStyles.label) { fontSize = 10 };
        EditorGUI.LabelField(rect, particleRenderer.sortingLayerName, labelStyle);

        // 显示当前 Sorting Order 数值（只读）
        rect.x += rect.width + 5;
        rect.width = 30; // 数值显示宽度
        EditorGUI.LabelField(rect, particleRenderer.sortingOrder.ToString(), labelStyle);

        // 绘制“+”按钮
        rect.x += rect.width + 5;
        rect.width = 20; // 按钮宽度
        if (GUI.Button(rect, "+"))
        {
            RecordPrefabChange(particleRenderer, obj, "Increment Particle System Sorting Order");
            particleRenderer.sortingOrder += 1;
            MarkDirty(particleRenderer, obj);
            Debug.Log($"Incremented Sorting Order of {obj.name} to {particleRenderer.sortingOrder}");
        }

        // 绘制“-”按钮
        rect.x += rect.width + 2;
        rect.width = 20; // 按钮宽度
        if (GUI.Button(rect, "-"))
        {
            RecordPrefabChange(particleRenderer, obj, "Decrement Particle System Sorting Order");
            particleRenderer.sortingOrder -= 1;
            MarkDirty(particleRenderer, obj);
            Debug.Log($"Decremented Sorting Order of {obj.name} to {particleRenderer.sortingOrder}");
        }
    }

    // 记录预制件修改，支持 Undo
    private static void RecordPrefabChange(Object target, GameObject obj, string undoMessage)
    {
        Undo.RecordObject(target, undoMessage);
        // 如果在预制件编辑模式中，记录预制件根对象的修改
        if (PrefabStageUtility.GetCurrentPrefabStage() != null)
        {
            var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
            if (prefabStage.prefabContentsRoot == obj || obj.transform.IsChildOf(prefabStage.prefabContentsRoot.transform))
            {
                Undo.RecordObject(prefabStage.prefabContentsRoot, undoMessage);
            }
        }
    }

    // 标记对象为脏，确保修改保存
    private static void MarkDirty(Object target, GameObject obj)
    {
        EditorUtility.SetDirty(target);
        EditorUtility.SetDirty(obj);
        // 如果在预制件编辑模式中，保存预制件
        if (PrefabStageUtility.GetCurrentPrefabStage() != null)
        {
            var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
            if (prefabStage.prefabContentsRoot == obj || obj.transform.IsChildOf(prefabStage.prefabContentsRoot.transform))
            {
                PrefabUtility.SavePrefabAsset(prefabStage.prefabContentsRoot);
            }
        }
    }
}