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

namespace MyFrameworkPure
{
    /// <summary>
    /// 批量生成预设窗口
    /// </summary>
    public class BatchCreatePrefabWindow : EditorWindow
    {
        [MenuItem("Tools/批量生成Prefab")]

        static void AddWindow()
        {
            //创建窗口
            BatchCreatePrefabWindow window = (BatchCreatePrefabWindow)EditorWindow.GetWindow(typeof(BatchCreatePrefabWindow), false, "批量生成Prefab");
            window.Show();

        }

        //输入文字的内容
        private string PrefabPath = "Assets/Resources/";
        private string ObjPath = @"Assets/Obj/";
        GameObject[] selectedGameObjects;



        [InitializeOnLoadMethod]
        public void Awake()
        {
            OnSelectionChange();
        }
        void OnGUI()
        {
            GUIStyle text_style = new GUIStyle();
            text_style.fontSize = 15;
            text_style.alignment = TextAnchor.MiddleCenter;

            EditorGUILayout.BeginHorizontal();
            GUILayout.Label("Prefab导出路径:");
            PrefabPath = EditorGUILayout.TextField(PrefabPath);
            if (GUILayout.Button("浏览"))
            { EditorApplication.delayCall += OpenPrefabFolder; }
            EditorGUILayout.EndHorizontal();
            EditorGUILayout.BeginHorizontal();

            GUILayout.Label("    Obj导出路径:");
            ObjPath = EditorGUILayout.TextField(ObjPath);
            if (GUILayout.Button("浏览"))
            { EditorApplication.delayCall += OpenObjFolder; }
            EditorGUILayout.EndHorizontal();

            GUILayout.Label("当前选中了" + selectedGameObjects.Length + "个物体", text_style);
            if (GUILayout.Button("如果包含动态创建的Mesh，请先点击生成Obj", GUILayout.MinHeight(20)))
            {
                foreach (GameObject m in selectedGameObjects)
                {
                    CreateObj(m);
                }
                AssetDatabase.Refresh();
            }
            if (GUILayout.Button("生成当前选中物体的Prefab", GUILayout.MinHeight(20)))
            {
                if (selectedGameObjects.Length <= 0)
                {
                    //打开一个通知栏  
                    this.ShowNotification(new GUIContent("未选择所要导出的物体"));
                    return;
                }
                if (!Directory.Exists(PrefabPath))
                {
                    Directory.CreateDirectory(PrefabPath);
                }
                foreach (GameObject m in selectedGameObjects)
                {
                    CreatePrefab(m, m.name);
                }
                AssetDatabase.Refresh();
            }
        }

        void OpenPrefabFolder()
        {
            string path = EditorUtility.OpenFolderPanel("选择要导出的路径", "", "");
            if (!path.Contains(Application.dataPath))
            {
                Debug.LogError("导出路径应在当前工程目录下");
                return;
            }
            if (path.Length != 0)
            {
                int firstindex = path.IndexOf("Assets");
                PrefabPath = path.Substring(firstindex) + "/";
                EditorUtility.FocusProjectWindow();
            }
        }

        void OpenObjFolder()
        {
            string path = EditorUtility.OpenFolderPanel("选择要导出的路径", "", "");
            if (!path.Contains(Application.dataPath))
            {
                Debug.LogError("导出路径应在当前工程目录下");
                return;
            }
            if (path.Length != 0)
            {
                int firstindex = path.IndexOf("Assets");
                ObjPath = path.Substring(firstindex) + "/";
                EditorUtility.FocusProjectWindow();
            }
        }

        void CreateObj(GameObject go)
        {
            if (!Directory.Exists(ObjPath))
            {
                Directory.CreateDirectory(ObjPath);
            }
            MeshFilter[] meshfilters = go.GetComponentsInChildren<MeshFilter>();
            if (meshfilters.Length > 0)
            {
                for (int i = 0; i < meshfilters.Length; i++)
                {
                    ObjExporter.MeshToFile(meshfilters[i], ObjPath + meshfilters[i].gameObject.name + ".obj");

                }
            }
        }
        /// <summary>
        /// 此函数用来根据某物体创建指定名字的Prefab
        /// </summary>
        /// <param name="go">选定的某物体</param>
        /// <param name="name">物体名</param>
        /// <returns>void</returns>
        void CreatePrefab(GameObject go, string name)
        {
            //先创建一个空的预制物体
            //预制物体保存在工程中路径，可以修改("Assets/" + name + ".prefab");
            GameObject tempPrefab = PrefabUtility.SaveAsPrefabAsset(go, PrefabPath + name + ".prefab");

            MeshFilter[] meshfilters = go.GetComponentsInChildren<MeshFilter>();
            if (meshfilters.Length > 0)
            {
                MeshFilter[] prefabmeshfilters = tempPrefab.GetComponentsInChildren<MeshFilter>();
                for (int i = 0; i < meshfilters.Length; i++)
                {
                    Mesh m_mesh = AssetDatabase.LoadAssetAtPath<Mesh>(ObjPath + meshfilters[i].gameObject.name + ".obj");
                    prefabmeshfilters[i].sharedMesh = m_mesh;
                }
            }

            PrefabUtility.ConnectGameObjectToPrefab(go, tempPrefab);
            //返回创建后的预制物体
        }

        void OnInspectorUpdate()
        {
            //这里开启窗口的重绘，不然窗口信息不会刷新
            this.Repaint();
        }

        void OnSelectionChange()
        {
            //当窗口出去开启状态，并且在Hierarchy视图中选择某游戏对象时调用
            selectedGameObjects = Selection.gameObjects;

        }
    }


    public class ObjExporter
    {

        public static string MeshToString(MeshFilter mf)
        {
            Mesh m = mf.sharedMesh;
            //  Material[] mats = mf.GetComponent<MeshRenderer>().sharedMaterials;

            StringBuilder sb = new StringBuilder();

            sb.Append("g ").Append(mf.name).Append("\n");
            for (int i = 0; i < m.vertices.Length; i++)
                sb.Append(string.Format("v {0} {1} {2}\n", -m.vertices[i].x, m.vertices[i].y, m.vertices[i].z));
            sb.Append("\n");
            for (int i = 0; i < m.normals.Length; i++)
                sb.Append(string.Format("vn {0} {1} {2}\n", -m.normals[i].x, m.normals[i].y, m.normals[i].z));
            sb.Append("\n");
            for (int i = 0; i < m.uv.Length; i++)
                sb.Append(string.Format("vt {0} {1}\n", m.uv[i].x, m.uv[i].y));

            for (int material = 0; material < m.subMeshCount; material++)
            {
                sb.Append("\n");

                int[] triangles = m.GetTriangles(material);
                for (int i = 0; i < triangles.Length; i += 3)
                {
                    //Because we inverted the x-component, we also needed to alter the triangle winding.
                    sb.Append(string.Format("f {1}/{1}/{1} {0}/{0}/{0} {2}/{2}/{2}\n",
                        triangles[i] + 1, triangles[i + 1] + 1, triangles[i + 2] + 1));
                }
            }
            return sb.ToString();
        }

        public static void MeshToFile(MeshFilter mf, string filename)
        {
            using (StreamWriter sw = new StreamWriter(filename))
            {
                sw.Write(MeshToString(mf));
            }
        }
    }
}