using System.Collections;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

public class MaterialUtil
{
    //拷贝材质上的属性到另一个材质
    public static void CopyMaterialProp(Material mat1, Material mat2)
    {
        mat2.mainTexture = mat1.mainTexture;
        mat2.color = mat1.color;
    }

    //拷贝材质上的属性到新的指定shader材质
    public static Material CopyMaterialWithShader(Material mat1, Shader shader = null)
    {
        shader = shader ? shader : mat1.shader;
        var mat2 = new Material(shader)
        {
            name = mat1.name
        };
        CopyMaterialProp(mat1, mat2);
        return mat2;
    }

    //以指定shader替换gameobject上的所有材质,此函数会新建材质
    public static List<Material> ReplaceMaterialOnGameObject(GameObject go, Shader shader = null)
    {
        if (!EditorUtility.IsPersistent(go))
        {
            Debug.LogError($"当前gameobject不是asset中的预制体!");
            return null;
        }

        List<Material> result = new();
        var meshRenderers = go.GetComponentsInChildren<MeshRenderer>();
        foreach (var meshRenderer in meshRenderers)
        {
            var mats = meshRenderer.sharedMaterials;
            for (int i = 0; i < mats.Length; i++)
            {
                mats[i] = CopyMaterialWithShader(mats[i], shader);
                result.Add(mats[i]);
            }

            meshRenderer.sharedMaterials = mats;
        }

        return result;
    }

    public static List<Material> CreateMaterialWithShaderOnGameObject(GameObject go, Shader shader)
    {
        if (!EditorUtility.IsPersistent(go))
        {
            Debug.LogError($"当前gameobject不是asset中的预制体!");
            return null;
        }

        List<Material> result = new();
        var meshRenderers = go.GetComponentsInChildren<MeshRenderer>();
        foreach (var meshRenderer in meshRenderers)
        {
            var mats = meshRenderer.sharedMaterials;
            for (int i = 0; i < mats.Length; i++)
            {
                var newMat = CopyMaterialWithShader(mats[i], shader);
                result.Add(newMat);
            }
        }

        return result;
    }
}