using System;
using System.Collections.Generic;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;

namespace AssetStudio
{
    public class ModelConverter : IImported
    {
        public ImportedFrame RootFrame { get; protected set; }
        public List<ImportedMesh> MeshList { get; protected set; } = new List<ImportedMesh>();
        public List<ImportedMaterial> MaterialList { get; protected set; } = new List<ImportedMaterial>();
        public List<ImportedTexture> TextureList { get; protected set; } = new List<ImportedTexture>();
        public List<ImportedKeyframedAnimation> AnimationList { get; protected set; } = new List<ImportedKeyframedAnimation>();
        public List<ImportedMorph> MorphList { get; protected set; } = new List<ImportedMorph>();

        private Avatar avatar;
        private HashSet<AnimationClip> animationClipHashSet = new HashSet<AnimationClip>();
        private Dictionary<uint, string> bonePathHash = new Dictionary<uint, string>();
        private Dictionary<Texture2D, string> textureNameDictionary = new Dictionary<Texture2D, string>();
        private Dictionary<Transform, ImportedFrame> transformDictionary = new Dictionary<Transform, ImportedFrame>();

        public ModelConverter(GameObject m_GameObject)
        {
            if (m_GameObject.m_Animator != null)
            {
                InitWithAnimator(m_GameObject.m_Animator);
                CollectAnimationClip(m_GameObject.m_Animator);
            }
            else
                InitWithGameObject(m_GameObject);
            ConvertAnimations();
        }

        public ModelConverter(GameObject m_GameObject, AnimationClip[] animationList)
        {
            if (m_GameObject.m_Animator != null)
            {
                InitWithAnimator(m_GameObject.m_Animator);
            }
            else
                InitWithGameObject(m_GameObject);
            foreach (var animationClip in animationList)
            {
                animationClipHashSet.Add(animationClip);
            }
            ConvertAnimations();
        }

        public ModelConverter(Animator m_Animator)
        {
            InitWithAnimator(m_Animator);
            CollectAnimationClip(m_Animator);
            ConvertAnimations();
        }

        public ModelConverter(Animator m_Animator, AnimationClip[] animationList)
        {
            InitWithAnimator(m_Animator);
            foreach (var animationClip in animationList)
            {
                animationClipHashSet.Add(animationClip);
            }
            ConvertAnimations();
        }

        private void InitWithAnimator(Animator m_Animator)
        {
            if (m_Animator.m_Avatar.TryGet(out var m_Avatar))
                avatar = m_Avatar;

            m_Animator.m_GameObject.TryGet(out var m_GameObject);
            InitWithGameObject(m_GameObject, m_Animator.m_HasTransformHierarchy);
        }

        private void InitWithGameObject(GameObject m_GameObject, bool hasTransformHierarchy = true)
        {
            var m_Transform = m_GameObject.m_Transform;
            if (!hasTransformHierarchy)
            {
                ConvertTransforms(m_Transform, null);
                DeoptimizeTransformHierarchy();
            }
            else
            {
                var frameList = new List<ImportedFrame>();
                var tempTransform = m_Transform;
                while (tempTransform.m_Father.TryGet(out var m_Father))
                {
                    frameList.Add(ConvertTransform(m_Father));
                    tempTransform = m_Father;
                }
                if (frameList.Count > 0)
                {
                    RootFrame = frameList[frameList.Count - 1];
                    for (var i = frameList.Count - 2; i >= 0; i--)
                    {
                        var frame = frameList[i];
                        var parent = frameList[i + 1];
                        parent.AddChild(frame);
                    }
                    ConvertTransforms(m_Transform, frameList[0]);
                }
                else
                {
                    ConvertTransforms(m_Transform, null);
                }

                CreateBonePathHash(m_Transform);
            }

            ConvertMeshRenderer(m_Transform);
        }

        private void ConvertMeshRenderer(Transform m_Transform)
        {
            m_Transform.m_GameObject.TryGet(out var m_GameObject);

            if (m_GameObject.m_MeshRenderer != null)
            {
                ConvertMeshRenderer(m_GameObject.m_MeshRenderer);
            }

            if (m_GameObject.m_SkinnedMeshRenderer != null)
            {
                ConvertMeshRenderer(m_GameObject.m_SkinnedMeshRenderer);
            }

            if (m_GameObject.m_Animation != null)
            {
                foreach (var animation in m_GameObject.m_Animation.m_Animations)
                {
                    if (animation.TryGet(out var animationClip))
                    {
                        animationClipHashSet.Add(animationClip);
                    }
                }
            }

            foreach (var pptr in m_Transform.m_Children)
            {
                if (pptr.TryGet(out var child))
                    ConvertMeshRenderer(child);
            }
        }

        private void CollectAnimationClip(Animator m_Animator)
        {
            if (m_Animator.m_Controller.TryGet(out var m_Controller))
            {
                switch (m_Controller)
                {
                    case AnimatorOverrideController m_AnimatorOverrideController:
                        {
                            if (m_AnimatorOverrideController.m_Controller.TryGet<AnimatorController>(out var m_AnimatorController))
                            {
                                foreach (var pptr in m_AnimatorController.m_AnimationClips)
                                {
                                    if (pptr.TryGet(out var m_AnimationClip))
                                    {
                                        animationClipHashSet.Add(m_AnimationClip);
                                    }
                                }
                            }
                            break;
                        }

                    case AnimatorController m_AnimatorController:
                        {
                            foreach (var pptr in m_AnimatorController.m_AnimationClips)
                            {
                                if (pptr.TryGet(out var m_AnimationClip))
                                {
                                    animationClipHashSet.Add(m_AnimationClip);
                                }
                            }
                            break;
                        }
                }
            }
        }

        private ImportedFrame ConvertTransform(Transform trans)
        {
            var frame = new ImportedFrame(trans.m_Children.Length);
            transformDictionary.Add(trans, frame);
            trans.m_GameObject.TryGet(out var m_GameObject);
            frame.Name = m_GameObject.m_Name;
            SetFrame(frame, trans.m_LocalPosition, trans.m_LocalRotation, trans.m_LocalScale);
            return frame;
        }

        private static ImportedFrame CreateFrame(string name, Vector3 t, Quaternion q, Vector3 s)
        {
            var frame = new ImportedFrame();
            frame.Name = name;
            SetFrame(frame, t, q, s);
            return frame;
        }

        private static void SetFrame(ImportedFrame frame, Vector3 t, Quaternion q, Vector3 s)
        {
            frame.LocalPosition = new Vector3(-t.X, t.Y, t.Z);
            frame.LocalRotation = Fbx.QuaternionToEuler(new Quaternion(q.X, -q.Y, -q.Z, q.W));
            frame.LocalScale = s;
        }

        private void ConvertTransforms(Transform trans, ImportedFrame parent)
        {
            var frame = ConvertTransform(trans);
            if (parent == null)
            {
                RootFrame = frame;
            }
            else
            {
                parent.AddChild(frame);
            }
            foreach (var pptr in trans.m_Children)
            {
                if (pptr.TryGet(out var child))
                    ConvertTransforms(child, frame);
            }
        }

        private void ConvertMeshRenderer(Renderer meshR)
        {
            var mesh = GetMesh(meshR);
            if (mesh == null)
                return;
            var iMesh = new ImportedMesh();
            meshR.m_GameObject.TryGet(out var m_GameObject2);
            iMesh.Path = GetTransformPath(m_GameObject2.m_Transform);
            iMesh.SubmeshList = new List<ImportedSubmesh>();
            var subHashSet = new HashSet<int>();
            var combine = false;
            int firstSubMesh = 0;
            if (meshR.m_StaticBatchInfo?.subMeshCount > 0)
            {
                firstSubMesh = meshR.m_StaticBatchInfo.firstSubMesh;
                var finalSubMesh = meshR.m_StaticBatchInfo.firstSubMesh + meshR.m_StaticBatchInfo.subMeshCount;
                for (int i = meshR.m_StaticBatchInfo.firstSubMesh; i < finalSubMesh; i++)
                {
                    subHashSet.Add(i);
                }
                combine = true;
            }
            else if (meshR.m_SubsetIndices?.Length > 0)
            {
                firstSubMesh = (int)meshR.m_SubsetIndices.Min(x => x);
                foreach (var index in meshR.m_SubsetIndices)
                {
                    subHashSet.Add((int)index);
                }
                combine = true;
            }
            int firstFace = 0;
            for (int i = 0; i < mesh.m_SubMeshes.Length; i++)
            {
                int numFaces = (int)mesh.m_SubMeshes[i].indexCount / 3;
                if (subHashSet.Count > 0 && !subHashSet.Contains(i))
                {
                    firstFace += numFaces;
                    continue;
                }
                var submesh = mesh.m_SubMeshes[i];
                var iSubmesh = new ImportedSubmesh();
                Material mat = null;
                if (i - firstSubMesh < meshR.m_Materials.Length)
                {
                    if (meshR.m_Materials[i - firstSubMesh].TryGet(out var m_Material))
                    {
                        mat = m_Material;
                    }
                }
                ImportedMaterial iMat = ConvertMaterial(mat);
                iSubmesh.Material = iMat.Name;
                iSubmesh.VertexList = new List<ImportedVertex>((int)submesh.vertexCount);
                var vertexColours = mesh.m_Colors != null && (mesh.m_Colors.Length == mesh.m_VertexCount * 3 || mesh.m_Colors.Length == mesh.m_VertexCount * 4);
                for (var j = mesh.m_SubMeshes[i].firstVertex; j < mesh.m_SubMeshes[i].firstVertex + mesh.m_SubMeshes[i].vertexCount; j++)
                {
                    var iVertex = vertexColours ? new ImportedVertexWithColour() : new ImportedVertex();
                    //Vertices
                    int c = 3;
                    if (mesh.m_Vertices.Length == mesh.m_VertexCount * 4)
                    {
                        c = 4;
                    }
                    iVertex.Position = new Vector3(-mesh.m_Vertices[j * c], mesh.m_Vertices[j * c + 1], mesh.m_Vertices[j * c + 2]);
                    //Normals
                    if (mesh.m_Normals?.Length > 0)
                    {
                        if (mesh.m_Normals.Length == mesh.m_VertexCount * 3)
                        {
                            c = 3;
                        }
                        else if (mesh.m_Normals.Length == mesh.m_VertexCount * 4)
                        {
                            c = 4;
                        }
                        iVertex.Normal = new Vector3(-mesh.m_Normals[j * c], mesh.m_Normals[j * c + 1], mesh.m_Normals[j * c + 2]);
                    }
                    //Colors
                    if (vertexColours)
                    {
                        if (mesh.m_Colors.Length == mesh.m_VertexCount * 3)
                        {
                            ((ImportedVertexWithColour)iVertex).Colour = new Color(mesh.m_Colors[j * 3], mesh.m_Colors[j * 3 + 1], mesh.m_Colors[j * 3 + 2], 1.0f);
                        }
                        else
                        {
                            ((ImportedVertexWithColour)iVertex).Colour = new Color(mesh.m_Colors[j * 4], mesh.m_Colors[j * 4 + 1], mesh.m_Colors[j * 4 + 2], mesh.m_Colors[j * 4 + 3]);
                        }
                    }
                    //UV
                    if (mesh.m_UV0 != null && mesh.m_UV0.Length == mesh.m_VertexCount * 2)
                    {
                        iVertex.UV = new[] { mesh.m_UV0[j * 2], mesh.m_UV0[j * 2 + 1] };
                    }
                    else if (mesh.m_UV1 != null && mesh.m_UV1.Length == mesh.m_VertexCount * 2)
                    {
                        iVertex.UV = new[] { mesh.m_UV1[j * 2], mesh.m_UV1[j * 2 + 1] };
                    }
                    //Tangent
                    if (mesh.m_Tangents != null && mesh.m_Tangents.Length == mesh.m_VertexCount * 4)
                    {
                        iVertex.Tangent = new Vector4(-mesh.m_Tangents[j * 4], mesh.m_Tangents[j * 4 + 1], mesh.m_Tangents[j * 4 + 2], -mesh.m_Tangents[j * 4 + 3]);
                    }
                    //BoneInfluence
                    if (mesh.m_Skin?.Length > 0)
                    {
                        var inf = mesh.m_Skin[j];
                        iVertex.BoneIndices = new int[4];
                        iVertex.Weights = new float[4];
                        for (var k = 0; k < 4; k++)
                        {
                            iVertex.BoneIndices[k] = inf.boneIndex[k];
                            iVertex.Weights[k] = inf.weight[k];
                        }
                    }
                    iSubmesh.VertexList.Add(iVertex);
                }
                //Face
                iSubmesh.FaceList = new List<ImportedFace>(numFaces);
                var end = firstFace + numFaces;
                for (int f = firstFace; f < end; f++)
                {
                    var face = new ImportedFace();
                    face.VertexIndices = new int[3];
                    face.VertexIndices[0] = (int)(mesh.m_Indices[f * 3 + 2] - submesh.firstVertex);
                    face.VertexIndices[1] = (int)(mesh.m_Indices[f * 3 + 1] - submesh.firstVertex);
                    face.VertexIndices[2] = (int)(mesh.m_Indices[f * 3] - submesh.firstVertex);
                    iSubmesh.FaceList.Add(face);
                }
                firstFace = end;
                iMesh.SubmeshList.Add(iSubmesh);
            }

            if (meshR is SkinnedMeshRenderer sMesh)
            {
                //Bone
                if (sMesh.m_Bones.Length > 0)
                {
                    var boneMax = Math.Min(sMesh.m_Bones.Length, mesh.m_BindPose.Length);
                    iMesh.BoneList = new List<ImportedBone>(boneMax);
                    for (int i = 0; i < boneMax; i++)
                    {
                        var bone = new ImportedBone();
                        if (sMesh.m_Bones[i].TryGet(out var m_Transform))
                        {
                            bone.Path = GetTransformPath(m_Transform);
                        }
                        if (!string.IsNullOrEmpty(bone.Path))
                        {
                            var convert = Matrix4x4.Scale(new Vector3(-1, 1, 1));
                            bone.Matrix = convert * mesh.m_BindPose[i] * convert;
                            iMesh.BoneList.Add(bone);
                        }
                    }
                }
                if (iMesh.BoneList == null || iMesh.BoneList.Count == 0)
                {
                    if (mesh.m_BindPose.Length > 0 && mesh.m_BoneNameHashes?.Length > 0)
                    {
                        var boneMax = Math.Min(mesh.m_BindPose.Length, mesh.m_BoneNameHashes.Length);
                        iMesh.BoneList = new List<ImportedBone>(boneMax);
                        for (int i = 0; i < boneMax; i++)
                        {
                            var bone = new ImportedBone();
                            var boneHash = mesh.m_BoneNameHashes[i];
                            var path = GetPathFromHash(boneHash);
                            bone.Path = FixBonePath(path);
                            if (!string.IsNullOrEmpty(bone.Path))
                            {
                                var convert = Matrix4x4.Scale(new Vector3(-1, 1, 1));
                                bone.Matrix = convert * mesh.m_BindPose[i] * convert;
                                iMesh.BoneList.Add(bone);
                            }
                        }
                    }
                }

                //Morphs
                if (mesh.m_Shapes?.shapes != null)
                {
                    if (mesh.m_Shapes.shapes.Length > 0)
                    {
                        ImportedMorph morph = null;
                        string lastGroup = "";
                        for (int i = 0; i < mesh.m_Shapes.channels.Length; i++)
                        {
                            string group = BlendShapeNameGroup(mesh, i);
                            if (group != lastGroup)
                            {
                                morph = new ImportedMorph();
                                MorphList.Add(morph);
                                morph.Path = iMesh.Path;
                                morph.ClipName = group;
                                morph.Channels = new List<Tuple<float, int, int>>(mesh.m_Shapes.channels.Length);
                                morph.KeyframeList = new List<ImportedMorphKeyframe>(mesh.m_Shapes.shapes.Length);
                                lastGroup = group;
                            }

                            morph.Channels.Add(new Tuple<float, int, int>(i < sMesh.m_BlendShapeWeights.Length ? sMesh.m_BlendShapeWeights[i] : 0f, morph.KeyframeList.Count, mesh.m_Shapes.channels[i].frameCount));
                            for (int frameIdx = 0; frameIdx < mesh.m_Shapes.channels[i].frameCount; frameIdx++)
                            {
                                ImportedMorphKeyframe keyframe = new ImportedMorphKeyframe();
                                keyframe.Name = BlendShapeNameExtension(mesh, i) + "_" + frameIdx;
                                int shapeIdx = mesh.m_Shapes.channels[i].frameIndex + frameIdx;
                                keyframe.VertexList = new List<ImportedVertex>((int)mesh.m_Shapes.shapes[shapeIdx].vertexCount);
                                keyframe.MorphedVertexIndices = new List<ushort>((int)mesh.m_Shapes.shapes[shapeIdx].vertexCount);
                                keyframe.Weight = shapeIdx < mesh.m_Shapes.fullWeights.Length ? mesh.m_Shapes.fullWeights[shapeIdx] : 100f;
                                int lastVertIndex = (int)(mesh.m_Shapes.shapes[shapeIdx].firstVertex + mesh.m_Shapes.shapes[shapeIdx].vertexCount);
                                for (int j = (int)mesh.m_Shapes.shapes[shapeIdx].firstVertex; j < lastVertIndex; j++)
                                {
                                    var morphVert = mesh.m_Shapes.vertices[j];
                                    ImportedVertex vert = GetSourceVertex(iMesh.SubmeshList, (int)morphVert.index);
                                    ImportedVertex destVert = new ImportedVertex();
                                    Vector3 morphPos = morphVert.vertex;
                                    morphPos.X *= -1;
                                    destVert.Position = vert.Position + morphPos;
                                    Vector3 morphNormal = morphVert.normal;
                                    morphNormal.X *= -1;
                                    destVert.Normal = morphNormal;
                                    Vector4 morphTangent = new Vector4(morphVert.tangent, 0);
                                    morphTangent.X *= -1;
                                    destVert.Tangent = morphTangent;
                                    keyframe.VertexList.Add(destVert);
                                    keyframe.MorphedVertexIndices.Add((ushort)morphVert.index);
                                }

                                morph.KeyframeList.Add(keyframe);
                            }
                        }
                    }
                }
            }

            //TODO combine mesh
            if (combine)
            {
                meshR.m_GameObject.TryGet(out var m_GameObject);
                var frame = RootFrame.FindChild(m_GameObject.m_Name);
                if (frame != null)
                {
                    frame.LocalPosition = RootFrame.LocalPosition;
                    frame.LocalRotation = RootFrame.LocalRotation;
                    while (frame.Parent != null)
                    {
                        frame = frame.Parent;
                        frame.LocalPosition = RootFrame.LocalPosition;
                        frame.LocalRotation = RootFrame.LocalRotation;
                    }
                }
            }

            MeshList.Add(iMesh);
        }

        private static Mesh GetMesh(Renderer meshR)
        {
            if (meshR is SkinnedMeshRenderer sMesh)
            {
                if (sMesh.m_Mesh.TryGet(out var m_Mesh))
                {
                    return m_Mesh;
                }
            }
            else
            {
                meshR.m_GameObject.TryGet(out var m_GameObject);
                if (m_GameObject.m_MeshFilter != null)
                {
                    if (m_GameObject.m_MeshFilter.m_Mesh.TryGet(out var m_Mesh))
                    {
                        return m_Mesh;
                    }
                }
            }

            return null;
        }

        private string GetTransformPath(Transform transform)
        {
            if (transformDictionary.TryGetValue(transform, out var frame))
            {
                return frame.Path;
            }
            return null;
        }

        private string FixBonePath(string path)
        {
            var frame = RootFrame.FindFrameByPath(path);
            return frame?.Path;
        }

        private static string GetTransformPathByFather(Transform transform)
        {
            transform.m_GameObject.TryGet(out var m_GameObject);
            if (transform.m_Father.TryGet(out var father))
            {
                return GetTransformPathByFather(father) + "/" + m_GameObject.m_Name;
            }

            return m_GameObject.m_Name;
        }

        private ImportedMaterial ConvertMaterial(Material mat)
        {
            ImportedMaterial iMat;
            if (mat != null)
            {
                iMat = ImportedHelpers.FindMaterial(mat.m_Name, MaterialList);
                if (iMat != null)
                {
                    return iMat;
                }
                iMat = new ImportedMaterial();
                iMat.Name = mat.m_Name;
                foreach (var col in mat.m_SavedProperties.m_Colors)
                {
                    switch (col.Key)
                    {
                        case "_Color":
                            iMat.Diffuse = col.Value;
                            break;
                        case "_SColor":
                            iMat.Ambient = col.Value;
                            break;
                        case "_EmissionColor":
                            iMat.Emissive = col.Value;
                            break;
                        case "_SpecularColor":
                        case "_SpecColor":
                            iMat.Specular = col.Value;
                            break;
                        case "_ReflectColor":
                            iMat.Reflection = col.Value;
                            break;
                    }
                }

                foreach (var flt in mat.m_SavedProperties.m_Floats)
                {
                    switch (flt.Key)
                    {
                        case "_Shininess":
                            iMat.Shininess = flt.Value;
                            break;
                        case "_Transparency":
                            iMat.Transparency = flt.Value;
                            break;
                    }
                }

                //textures
                iMat.Textures = new List<ImportedMaterialTexture>();
                foreach (var texEnv in mat.m_SavedProperties.m_TexEnvs)
                {
                    if (!texEnv.Value.m_Texture.TryGet<Texture2D>(out var m_Texture2D)) //TODO other Texture
                    {
                        continue;
                    }

                    var texture = new ImportedMaterialTexture();
                    iMat.Textures.Add(texture);

                    int dest = -1;
                    if (texEnv.Key == "_MainTex")
                        dest = 0;
                    else if (texEnv.Key == "_BumpMap")
                        dest = 3;
                    else if (texEnv.Key.Contains("Specular"))
                        dest = 2;
                    else if (texEnv.Key.Contains("Normal"))
                        dest = 1;

                    texture.Dest = dest;

                    if (textureNameDictionary.TryGetValue(m_Texture2D, out var textureName))
                    {
                        texture.Name = textureName;
                    }
                    else if (ImportedHelpers.FindTexture(m_Texture2D.m_Name + ".png", TextureList) != null) //已有相同名字的图片
                    {
                        for (int i = 1; ; i++)
                        {
                            var name = m_Texture2D.m_Name + $" ({i}).png";
                            if (ImportedHelpers.FindTexture(name, TextureList) == null)
                            {
                                texture.Name = name;
                                textureNameDictionary.Add(m_Texture2D, name);
                                break;
                            }
                        }
                    }
                    else
                    {
                        texture.Name = m_Texture2D.m_Name + ".png";
                        textureNameDictionary.Add(m_Texture2D, texture.Name);
                    }

                    texture.Offset = texEnv.Value.m_Offset;
                    texture.Scale = texEnv.Value.m_Scale;
                    ConvertTexture2D(m_Texture2D, texture.Name);
                }

                MaterialList.Add(iMat);
            }
            else
            {
                iMat = new ImportedMaterial();
            }
            return iMat;
        }

        private void ConvertTexture2D(Texture2D tex2D, string name)
        {
            var iTex = ImportedHelpers.FindTexture(name, TextureList);
            if (iTex != null)
            {
                return;
            }

            var bitmap = new Texture2DConverter(tex2D).ConvertToBitmap(true);
            if (bitmap != null)
            {
                using (var stream = new MemoryStream())
                {
                    bitmap.Save(stream, ImageFormat.Png);
                    iTex = new ImportedTexture(stream, name);
                    TextureList.Add(iTex);
                    bitmap.Dispose();
                }
            }
        }

        private void ConvertAnimations()
        {
            foreach (var animationClip in animationClipHashSet)
            {
                var iAnim = new ImportedKeyframedAnimation();
                var name = animationClip.m_Name;
                if (AnimationList.Exists(x => x.Name == name))
                {
                    for (int i = 1; ; i++)
                    {
                        var fixName = name + $"_{i}";
                        if (!AnimationList.Exists(x => x.Name == fixName))
                        {
                            name = fixName;
                            break;
                        }
                    }
                }
                iAnim.Name = name;
                iAnim.TrackList = new List<ImportedAnimationKeyframedTrack>();
                AnimationList.Add(iAnim);
                if (animationClip.m_Legacy)
                {
                    foreach (var m_CompressedRotationCurve in animationClip.m_CompressedRotationCurves)
                    {
                        var track = iAnim.FindTrack(FixBonePath(m_CompressedRotationCurve.m_Path));

                        var numKeys = m_CompressedRotationCurve.m_Times.m_NumItems;
                        var data = m_CompressedRotationCurve.m_Times.UnpackInts();
                        var times = new float[numKeys];
                        int t = 0;
                        for (int i = 0; i < numKeys; i++)
                        {
                            t += data[i];
                            times[i] = t * 0.01f;
                        }
                        var quats = m_CompressedRotationCurve.m_Values.UnpackQuats();

                        for (int i = 0; i < numKeys; i++)
                        {
                            var quat = quats[i];
                            var value = Fbx.QuaternionToEuler(new Quaternion(quat.X, -quat.Y, -quat.Z, quat.W));
                            track.Rotations.Add(new ImportedKeyframe<Vector3>(times[i], value));
                        }
                    }
                    foreach (var m_RotationCurve in animationClip.m_RotationCurves)
                    {
                        var track = iAnim.FindTrack(FixBonePath(m_RotationCurve.path));
                        foreach (var m_Curve in m_RotationCurve.curve.m_Curve)
                        {
                            var value = Fbx.QuaternionToEuler(new Quaternion(m_Curve.value.X, -m_Curve.value.Y, -m_Curve.value.Z, m_Curve.value.W));
                            track.Rotations.Add(new ImportedKeyframe<Vector3>(m_Curve.time, value));
                        }
                    }
                    foreach (var m_PositionCurve in animationClip.m_PositionCurves)
                    {
                        var track = iAnim.FindTrack(FixBonePath(m_PositionCurve.path));
                        foreach (var m_Curve in m_PositionCurve.curve.m_Curve)
                        {
                            track.Translations.Add(new ImportedKeyframe<Vector3>(m_Curve.time, new Vector3(-m_Curve.value.X, m_Curve.value.Y, m_Curve.value.Z)));
                        }
                    }
                    foreach (var m_ScaleCurve in animationClip.m_ScaleCurves)
                    {
                        var track = iAnim.FindTrack(FixBonePath(m_ScaleCurve.path));
                        foreach (var m_Curve in m_ScaleCurve.curve.m_Curve)
                        {
                            track.Scalings.Add(new ImportedKeyframe<Vector3>(m_Curve.time, new Vector3(m_Curve.value.X, m_Curve.value.Y, m_Curve.value.Z)));
                        }
                    }
                    if (animationClip.m_EulerCurves != null)
                    {
                        foreach (var m_EulerCurve in animationClip.m_EulerCurves)
                        {
                            var track = iAnim.FindTrack(FixBonePath(m_EulerCurve.path));
                            foreach (var m_Curve in m_EulerCurve.curve.m_Curve)
                            {
                                track.Rotations.Add(new ImportedKeyframe<Vector3>(m_Curve.time, new Vector3(m_Curve.value.X, -m_Curve.value.Y, -m_Curve.value.Z)));
                            }
                        }
                    }
                }
                else
                {
                    var m_Clip = animationClip.m_MuscleClip.m_Clip;
                    var streamedFrames = m_Clip.m_StreamedClip.ReadData();
                    var m_ClipBindingConstant = animationClip.m_ClipBindingConstant;
                    for (int frameIndex = 1; frameIndex < streamedFrames.Count - 1; frameIndex++)
                    {
                        var frame = streamedFrames[frameIndex];
                        var streamedValues = frame.keyList.Select(x => x.value).ToArray();
                        for (int curveIndex = 0; curveIndex < frame.keyList.Length;)
                        {
                            ReadCurveData(iAnim, m_ClipBindingConstant, frame.keyList[curveIndex].index, frame.time, streamedValues, 0, ref curveIndex);
                        }
                    }
                    var m_DenseClip = m_Clip.m_DenseClip;
                    var streamCount = m_Clip.m_StreamedClip.curveCount;
                    for (int frameIndex = 0; frameIndex < m_DenseClip.m_FrameCount; frameIndex++)
                    {
                        var time = m_DenseClip.m_BeginTime + frameIndex / m_DenseClip.m_SampleRate;
                        var frameOffset = frameIndex * m_DenseClip.m_CurveCount;
                        for (int curveIndex = 0; curveIndex < m_DenseClip.m_CurveCount;)
                        {
                            var index = streamCount + curveIndex;
                            ReadCurveData(iAnim, m_ClipBindingConstant, (int)index, time, m_DenseClip.m_SampleArray, (int)frameOffset, ref curveIndex);
                        }
                    }
                    if (m_Clip.m_ConstantClip != null)
                    {
                        var m_ConstantClip = m_Clip.m_ConstantClip;
                        var denseCount = m_Clip.m_DenseClip.m_CurveCount;
                        var time2 = 0.0f;
                        for (int i = 0; i < 2; i++)
                        {
                            for (int curveIndex = 0; curveIndex < m_ConstantClip.data.Length;)
                            {
                                var index = streamCount + denseCount + curveIndex;
                                ReadCurveData(iAnim, m_ClipBindingConstant, (int)index, time2, m_ConstantClip.data, 0, ref curveIndex);
                            }
                            time2 = animationClip.m_MuscleClip.m_StopTime;
                        }
                    }
                }
            }
        }

        private void ReadCurveData(ImportedKeyframedAnimation iAnim, AnimationClipBindingConstant m_ClipBindingConstant, int index, float time, float[] data, int offset, ref int curveIndex)
        {
            var binding = m_ClipBindingConstant.FindBinding(index);
            if (binding.path == 0)
            {
                curveIndex++;
                return;
            }

            var path = FixBonePath(GetPathFromHash(binding.path));
            var track = iAnim.FindTrack(path);

            switch (binding.attribute)
            {
                case 1:
                    track.Translations.Add(new ImportedKeyframe<Vector3>(time, new Vector3
                    (
                        -data[curveIndex++ + offset],
                        data[curveIndex++ + offset],
                        data[curveIndex++ + offset]
                    )));
                    break;
                case 2:
                    var value = Fbx.QuaternionToEuler(new Quaternion
                    (
                        data[curveIndex++ + offset],
                        -data[curveIndex++ + offset],
                        -data[curveIndex++ + offset],
                        data[curveIndex++ + offset]
                    ));
                    track.Rotations.Add(new ImportedKeyframe<Vector3>(time, value));
                    break;
                case 3:
                    track.Scalings.Add(new ImportedKeyframe<Vector3>(time, new Vector3
                    (
                        data[curveIndex++ + offset],
                        data[curveIndex++ + offset],
                        data[curveIndex++ + offset]
                    )));
                    break;
                case 4:
                    track.Rotations.Add(new ImportedKeyframe<Vector3>(time, new Vector3
                    (
                        data[curveIndex++ + offset],
                        -data[curveIndex++ + offset],
                        -data[curveIndex++ + offset]
                    )));
                    break;
                default:
                    //track.Curve.Add(new ImportedKeyframe<float>(time, data[curveIndex++]));
                    curveIndex++;
                    break;
            }
        }

        private string GetPathFromHash(uint hash)
        {
            bonePathHash.TryGetValue(hash, out var boneName);
            if (string.IsNullOrEmpty(boneName))
            {
                boneName = avatar?.FindBonePath(hash);
            }
            if (string.IsNullOrEmpty(boneName))
            {
                boneName = "unknown " + hash;
            }
            return boneName;
        }

        private static string BlendShapeNameGroup(Mesh mesh, int index)
        {
            string name = mesh.m_Shapes.channels[index].name;
            int dotPos = name.IndexOf('.');
            if (dotPos >= 0)
            {
                return name.Substring(0, dotPos);
            }
            return "Ungrouped";
        }

        private static string BlendShapeNameExtension(Mesh mesh, int index)
        {
            string name = mesh.m_Shapes.channels[index].name;
            int dotPos = name.IndexOf('.');
            if (dotPos >= 0)
            {
                return name.Substring(dotPos + 1);
            }
            return name;
        }

        private static ImportedVertex GetSourceVertex(List<ImportedSubmesh> submeshList, int morphVertIndex)
        {
            foreach (var submesh in submeshList)
            {
                var vertList = submesh.VertexList;
                if (morphVertIndex < vertList.Count)
                {
                    return vertList[morphVertIndex];
                }
                morphVertIndex -= vertList.Count;
            }
            return null;
        }

        private void CreateBonePathHash(Transform m_Transform)
        {
            var name = GetTransformPathByFather(m_Transform);
            var crc = new SevenZip.CRC();
            var bytes = Encoding.UTF8.GetBytes(name);
            crc.Update(bytes, 0, (uint)bytes.Length);
            bonePathHash[crc.GetDigest()] = name;
            int index;
            while ((index = name.IndexOf("/", StringComparison.Ordinal)) >= 0)
            {
                name = name.Substring(index + 1);
                crc = new SevenZip.CRC();
                bytes = Encoding.UTF8.GetBytes(name);
                crc.Update(bytes, 0, (uint)bytes.Length);
                bonePathHash[crc.GetDigest()] = name;
            }
            foreach (var pptr in m_Transform.m_Children)
            {
                if (pptr.TryGet(out var child))
                    CreateBonePathHash(child);
            }
        }

        private void DeoptimizeTransformHierarchy()
        {
            if (avatar == null)
                throw new Exception("Transform hierarchy has been optimized, but can't find Avatar to deoptimize.");
            // 1. Figure out the skeletonPaths from the unstripped avatar
            var skeletonPaths = new List<string>();
            foreach (var id in avatar.m_Avatar.m_AvatarSkeleton.m_ID)
            {
                var path = avatar.FindBonePath(id);
                skeletonPaths.Add(path);
            }
            // 2. Restore the original transform hierarchy
            // Prerequisite: skeletonPaths follow pre-order traversal
            for (var i = 1; i < skeletonPaths.Count; i++) // start from 1, skip the root transform because it will always be there.
            {
                var path = skeletonPaths[i];
                var strs = path.Split('/');
                string transformName;
                ImportedFrame parentFrame;
                if (strs.Length == 1)
                {
                    transformName = path;
                    parentFrame = RootFrame;
                }
                else
                {
                    transformName = strs.Last();
                    var parentFrameName = strs[strs.Length - 2];
                    parentFrame = RootFrame.FindChild(parentFrameName);
                    //var parentFramePath = path.Substring(0, path.LastIndexOf('/'));
                    //parentFrame = RootFrame.FindFrameByPath(parentFramePath);
                }

                var skeletonPose = avatar.m_Avatar.m_DefaultPose;
                var xform = skeletonPose.m_X[i];

                var frame = RootFrame.FindChild(transformName);
                if (frame != null)
                {
                    SetFrame(frame, xform.t, xform.q, xform.s);
                    parentFrame.AddChild(frame);
                }
                else
                {
                    frame = CreateFrame(transformName, xform.t, xform.q, xform.s);
                    parentFrame.AddChild(frame);
                }
            }
        }
    }
}