using System.IO;
using UnityEditor;
using UnityEngine;
using System.Collections;

public class ModelMatTool : AssetPostprocessor
{
    private static bool _needWaiting = false;

    /// <summary>
    /// 是否启用删除操作
    /// OnPostprocessModel回调在模型导入的时候就会调到，
    /// 通过这个标记位保证只在调用脚本函数的时候执行。
    /// </summary>
    private static bool _enableDelete = false;

    /// <summary>
    /// 批量删除模型上的材质
    /// </summary>
    public static IEnumerator DelModelMats(Object[] models)
    {
        foreach (Object obj in models)
        {
            while (_needWaiting) yield return null;
            DelModelMat(obj as GameObject);
        }
    }

    /// <summary>
    /// 删除模型上绑定的材质
    /// </summary>
    /// <param name="model">模型对象</param>
    public static void DelModelMat(GameObject model)
    {
        if (null == model) return;
        string assetPath = AssetDatabase.GetAssetPath(model);
        ModelImporter importer = AssetImporter.GetAtPath(assetPath) as ModelImporter;
        if (null == importer) return;
        _enableDelete = true;
        _needWaiting = true;

        AssetDatabase.ImportAsset(assetPath);
    }

    public static void DelModelMatByPath(string assetPath)
    {
        ModelImporter importer = AssetImporter.GetAtPath(assetPath) as ModelImporter;
        if (null == importer) return;
        _enableDelete = true;
        _needWaiting = true;

        
        AssetDatabase.ImportAsset(assetPath);
    }
    private void OnPostprocessModel(GameObject model)
    {
        if (null == model) return;

        if (!_enableDelete) return;
        _enableDelete = false;

        Renderer[] renders = model.GetComponentsInParent<Renderer>();
        if (null == renders) return;
        foreach (Renderer render in renders)
        {
            render.sharedMaterials = new Material[render.sharedMaterials.Length];
        }
        renders = model.GetComponentsInChildren<Renderer>();
        if (null == renders) return;
        foreach (Renderer render in renders)
        {
            render.sharedMaterials = new Material[render.sharedMaterials.Length];
        }

        _needWaiting = false;
    }

    [MenuItem("Tools/删除模型的默认材质")]
    static void DelSelectedModelMat()
    {
        /*
        Object[] objs = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
        if ( objs != null)
        {
            DelModelMat(objs[0] as GameObject);
            return;
        }
        */

        string[] m_folder = { "Assets" };
        var mesh_assets = AssetDatabase.FindAssets("t:mesh", m_folder);
        var i = 0;
        foreach(var meshGuid in mesh_assets)
        {
            var assetPath_ = AssetDatabase.GUIDToAssetPath(meshGuid);
            DelModelMatByPath(assetPath_);
            EditorUtility.DisplayProgressBar("重新导出assets", string.Format("更改Mesh的材质 {0}/{1}", i, mesh_assets.Length), (i * 1.0f) / mesh_assets.Length);
            i++;
        }
        EditorUtility.ClearProgressBar();
    }
}