using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Module.Log;
using UnityEditor;
using UnityEngine;
using UnityEngine.SceneManagement;
using Object = UnityEngine.Object;

public class ExtractSceneMesh
{
    [MenuItem("Scene/Extract SceneMesh Combined")]
    public static void Extract()
    {
        if (EditorUtility.DisplayDialog("导出场景模型", "将场景的所有物体导出为合并模型？", "确认", "取消"))
        {
            var vertices = new List<Vector3>();
            var uv = new List<Vector2>();
            var normal = new List<Vector3>();
            var triangles = new List<int>();
            var meshFilters = Object.FindObjectsOfType<MeshFilter>();
            for (var i = 0; i < meshFilters.Length; i++)
            {
                var filter = meshFilters[i];
                if (!filter.gameObject.activeInHierarchy)
                {
                }
                else if (filter.sharedMesh == null)
                {
                    LogModule.ErrorLog("Filter has no mesh " + filter.transform.GetHierarchyName());
                }
                else if (!filter.sharedMesh.isReadable)
                {
                    LogModule.WarningLog("Mesh isn't readable " + filter.sharedMesh.name);
                }
                else
                {
                    var start = vertices.Count;
                    var trs = Matrix4x4.TRS(filter.transform.position, filter.transform.rotation,
                        filter.transform.localScale);
                    var meshVertices = filter.sharedMesh.vertices;
                    var meshUv = filter.sharedMesh.uv;
                    var meshNormal = filter.sharedMesh.normals;
                    var subMeshCount = filter.sharedMesh.subMeshCount;
                    for (var j = 0; j < meshVertices.Length; j++)
                        vertices.Add(trs.MultiplyPoint3x4(meshVertices[j]));
                    for (var j = 0; j < meshNormal.Length; j++)
                        normal.Add(filter.transform.rotation * meshNormal[j]);
                    for (var j = 0; j < meshUv.Length; j++)
                        uv.Add(meshUv[j]);
                    for (var k = 0; k < subMeshCount; k++)
                    {
                        var meshTriangle = filter.sharedMesh.GetTriangles(k);
                        for (var j = 0; j < meshTriangle.Length; j++)
                            triangles.Add(meshTriangle[j] + start);
                    }
                }
            }
            //
            //        var mesh = new Mesh();
            //        mesh.SetVertices(vertices);
            //        mesh.SetNormals(normal);
            //        mesh.SetUVs(0, uv);
            //        mesh.SetTriangles(triangles, 0);
            //        LogModule.WarningLog("V Count " + vertices.Count);
            //        var meshObj = new GameObject("Mesh");
            //        var meshFilter = meshObj.AddComponent<MeshFilter>();
            //        meshFilter.sharedMesh = mesh;
            //        meshObj.AddComponent<MeshRenderer>();

            //ObjExtractHelp.DoExport(mesh);
            var sceneName = SceneManager.GetActiveScene().name;
            if (string.IsNullOrEmpty(sceneName))
                sceneName = "NewScene";
            var path = Application.dataPath + "/_Test/SceneMesh";
            if (!Directory.Exists(path))
                Directory.CreateDirectory(path);
            path += "/" + sceneName + "SceneMesh.obj";
            ObjExtract(vertices, uv, normal, triangles, path);
            AssetDatabase.Refresh();
            LogModule.WarningLog("Mesh Exported at " + path);
        }
    }

    public static void ObjExtract(IList<Vector3> vertices, IList<Vector2> uv, IList<Vector3> normal, IList<int> triangleList, string path)
    {
        var builder = new StringBuilder();
        var sceneName = Path.GetFileNameWithoutExtension(path);
        builder.Append("#" + sceneName + ".obj"
                       + "\n#" + DateTime.Now.ToLongDateString()
                       + "\n#" + DateTime.Now.ToLongTimeString()
                       + "\n#-------"
                       + "\n\n");
        builder.Append("g ").Append(sceneName).Append("\n");
        builder.Append("#").Append(sceneName).Append("\n#-------").Append("\n");
        foreach (var v in vertices)
            builder.Append(string.Format("v {0} {1} {2}\n", -v.x, v.y, v.z));
        builder.Append("\n");
        foreach (var v in normal)
            builder.Append(string.Format("vn {0} {1} {2}\n", -v.x, v.y, v.z));
        builder.Append("\n");
        foreach (var v in uv)
            builder.Append(string.Format("vt {0} {1}\n", v.x, v.y));
        builder.Append("\n");
        builder.Append("usemtl ").Append("Dummy").Append("\n");
        builder.Append("usemap ").Append("Dummy").Append("\n");
        var triangles = triangleList;
        for (var i = 0; i < triangles.Count; i += 3)
            builder.Append(string.Format("f {0}/{0}/{0} {2}/{2}/{2} {1}/{1}/{1}\n",
                triangles[i] + 1, triangles[i + 1] + 1, triangles[i + 2] + 1));
        File.WriteAllText(path, builder.ToString());
    }
    
//    
//    public static void MeshToString(StringBuilder builder, Mesh m)
//    {
//        foreach (var v in m.vertices)
//            builder.Append(string.Format("v {0} {1} {2}\n", -v.x, v.y, v.z));
//        builder.Append("\n");
//        foreach (var v in m.normals)
//            builder.Append(string.Format("vn {0} {1} {2}\n", -v.x, v.y, v.z));
//        builder.Append("\n");
//        foreach (var v in m.uv)
//            builder.Append(string.Format("vt {0} {1}\n", v.x, v.y));
//        builder.Append("\n");
//        builder.Append("usemtl ").Append("Dummy").Append("\n");
//        builder.Append("usemap ").Append("Dummy").Append("\n");
//        var triangles = m.triangles;
//        for (var i = 0; i < triangles.Length; i += 3)
//            builder.Append(string.Format("f {0}/{0}/{0} {1}/{1}/{1} {2}/{2}/{2}\n",
//                triangles[i] + 1, triangles[i + 1] + 1, triangles[i + 2] + 1));
//    }
}
//
//public static class ObjExtractScript
//{
//
//}
//
//public static class ObjExtractHelp
//{
//    public static void DoExport(Mesh mesh)
//    {
//        var builder = new StringBuilder();
//        var sceneName = SceneManager.GetActiveScene().name;
//        if (string.IsNullOrEmpty(sceneName))
//            sceneName = "NewScene";
//        builder.Append("#" + sceneName + ".obj"
//                       + "\n#" + DateTime.Now.ToLongDateString()
//                       + "\n#" + DateTime.Now.ToLongTimeString()
//                       + "\n#-------"
//                       + "\n\n");
//        builder.Append("g ").Append(sceneName).Append("\n");
//        builder.Append("#").Append(sceneName).Append("\n#-------").Append("\n");
//        ObjExtractScript.MeshToString(builder, mesh);
//        var path = Application.dataPath + "/_Test/SceneMesh";
//        if (!Directory.Exists(path))
//            Directory.CreateDirectory(path);
//        path += "/" + sceneName + "SceneMesh.obj";
//        File.WriteAllText(path, builder.ToString());
//        AssetDatabase.Refresh();
//        LogModule.WarningLog("Mesh Exported at " + path);
//    }
//}