// Copyright (c) 2012-2023 Wojciech Figat. All rights reserved.

#pragma once

#if COMPILE_WITH_MODEL_TOOL

#include "Engine/Core/Config.h"
#include "Engine/Content/Assets/ModelBase.h"
#include "Engine/Physics/CollisionData.h"
#if USE_EDITOR
#include "Engine/Core/ISerializable.h"
#include "Engine/Graphics/Models/ModelData.h"
#include "Engine/Graphics/Models/SkeletonData.h"
#include "Engine/Animations/AnimationData.h"
#include "Engine/Content/Assets/MaterialBase.h"

class JsonWriter;

/// <summary>
/// The model file import data types (used as flags).
/// </summary>
enum class ImportDataTypes : int32
{
    None = 0,

    /// <summary>
    /// Imports materials and meshes.
    /// </summary>
    Geometry = 1 << 0,

    /// <summary>
    /// Imports the skeleton bones hierarchy.
    /// </summary>
    Skeleton = 1 << 1,

    /// <summary>
    /// Imports the animations.
    /// </summary>
    Animations = 1 << 2,

    /// <summary>
    /// Imports the scene nodes hierarchy.
    /// </summary>
    Nodes = 1 << 3,

    /// <summary>
    /// Imports the materials.
    /// </summary>
    Materials = 1 << 4,

    /// <summary>
    /// Imports the textures.
    /// </summary>
    Textures = 1 << 5,
};

DECLARE_ENUM_OPERATORS(ImportDataTypes);

/// <summary>
/// Imported model data container. Represents unified model source file data (meshes, animations, skeleton, materials).
/// </summary>
class ImportedModelData
{
public:
    struct LOD
    {
        Array<MeshData*> Meshes;

        BoundingBox GetBox() const;
    };

    struct Node
    {
        /// <summary>
        /// The parent node index. The root node uses value -1.
        /// </summary>
        int32 ParentIndex;

        /// <summary>
        /// The local transformation of the node, relative to the parent node.
        /// </summary>
        Transform LocalTransform;

        /// <summary>
        /// The name of this node.
        /// </summary>
        String Name;
    };

public:
    /// <summary>
    /// The import data types types.
    /// </summary>
    ImportDataTypes Types;

    /// <summary>
    /// The textures slots.
    /// </summary>
    Array<TextureEntry> Textures;

    /// <summary>
    /// The material slots.
    /// </summary>
    Array<MaterialSlotEntry> Materials;

    /// <summary>
    /// The level of details data.
    /// </summary>
    Array<LOD> LODs;

    /// <summary>
    /// The skeleton data.
    /// </summary>
    SkeletonData Skeleton;

    /// <summary>
    /// The scene nodes.
    /// </summary>
    Array<Node> Nodes;

    /// <summary>
    /// The node animations.
    /// </summary>
    AnimationData Animation;

public:
    /// <summary>
    /// Initializes a new instance of the <see cref="ImportedModelData"/> class.
    /// </summary>
    /// <param name="types">The types.</param>
    ImportedModelData(ImportDataTypes types)
    {
        Types = types;
    }

    /// <summary>
    /// Finalizes an instance of the <see cref="ImportedModelData"/> class.
    /// </summary>
    ~ImportedModelData()
    {
        // Ensure to cleanup data
        for (int32 i = 0; i < LODs.Count(); i++)
            LODs[i].Meshes.ClearDelete();
    }
};

#endif

struct ModelSDFHeader
{
    Float3 LocalToUVWMul;
    float WorldUnitsPerVoxel;
    Float3 LocalToUVWAdd;
    float MaxDistance;
    Float3 LocalBoundsMin;
    int32 MipLevels;
    Float3 LocalBoundsMax;
    int32 Width;
    int32 Height;
    int32 Depth;
    PixelFormat Format;
    float ResolutionScale;
    int32 LOD;

    ModelSDFHeader() = default;
    ModelSDFHeader(const ModelBase::SDFData& sdf, const struct GPUTextureDescription& desc);
};

struct ModelSDFMip
{
    int32 MipIndex;
    uint32 RowPitch;
    uint32 SlicePitch;

    ModelSDFMip() = default;
    ModelSDFMip(int32 mipIndex, uint32 rowPitch, uint32 slicePitch);
    ModelSDFMip(int32 mipIndex, const TextureMipData& mip);
};

/// <summary>
/// Models data importing and processing utility.
/// </summary>
API_CLASS(Namespace="FlaxEngine.Tools", Static) class FLAXENGINE_API ModelTool
{
    DECLARE_SCRIPTING_TYPE_MINIMAL(ModelTool);

    // Optional: inputModel or modelData
    // Optional: outputSDF or null, outputStream or null
    static bool GenerateModelSDF(class Model* inputModel, class ModelData* modelData, float resolutionScale, int32 lodIndex, ModelBase::SDFData* outputSDF, class MemoryWriteStream* outputStream, const StringView& assetName, float backfacesThreshold = 0.6f);

#if USE_EDITOR

public:
    /// <summary>
    /// Declares the imported data type.
    /// </summary>
    API_ENUM(Attributes="HideInEditor") enum class ModelType : int32
    {
        // The model asset.
        Model = 0,
        // The skinned model asset.
        SkinnedModel = 1,
        // The animation asset.
        Animation = 2,
    };

    /// <summary>
    /// Declares the imported animation clip duration.
    /// </summary>
    API_ENUM(Attributes="HideInEditor") enum class AnimationDuration : int32
    {
        // The imported duration.
        Imported = 0,
        // The custom duration specified via keyframes range.
        Custom = 1,
    };

    /// <summary>
    /// Model import options.
    /// </summary>
    API_STRUCT(Attributes="HideInEditor") struct FLAXENGINE_API Options : public ISerializable
    {
        DECLARE_SCRIPTING_TYPE_MINIMAL(Options);

        // Type of the imported asset.
        API_FIELD(Attributes="EditorOrder(0)")
        ModelType Type = ModelType::Model;

    public: // Geometry

        // Enable model normal vectors re-calculating.
        API_FIELD(Attributes="EditorOrder(20), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowGeometry))")
        bool CalculateNormals = false;
        // Specifies the maximum angle (in degrees) that may be between two face normals at the same vertex position before they are smoothed together. The default value is 175.
        API_FIELD(Attributes="EditorOrder(30), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowSmoothingNormalsAngle)), Limit(0, 175, 0.1f)")
        float SmoothingNormalsAngle = 175.0f;
        // If checked, the imported normal vectors of the mesh will be flipped (scaled by -1).
        API_FIELD(Attributes="EditorOrder(35), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowGeometry))")
        bool FlipNormals = false;
        // Enable model tangent vectors re-calculating.
        API_FIELD(Attributes="EditorOrder(40), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowGeometry))")
        bool CalculateTangents = false;
        // Specifies the maximum angle (in degrees) that may be between two vertex tangents before their tangents and bi-tangents are smoothed. The default value is 45.
        API_FIELD(Attributes="EditorOrder(45), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowSmoothingTangentsAngle)), Limit(0, 45, 0.1f)")
        float SmoothingTangentsAngle = 45.0f;
        // Enable/disable meshes geometry optimization.
        API_FIELD(Attributes="EditorOrder(50), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowGeometry))")
        bool OptimizeMeshes = true;
        // Enable/disable geometry merge for meshes with the same materials. Index buffer will be reordered to improve performance and other modifications will be applied. However, importing time will be increased.
        API_FIELD(Attributes="EditorOrder(60), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowGeometry))")
        bool MergeMeshes = true;
        // Enable/disable importing meshes Level of Details.
        API_FIELD(Attributes="EditorOrder(70), EditorDisplay(\"Geometry\", \"Import LODs\"), VisibleIf(nameof(ShowGeometry))")
        bool ImportLODs = true;
        // Enable/disable importing vertex colors (channel 0 only).
        API_FIELD(Attributes="EditorOrder(80), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowModel))")
        bool ImportVertexColors = true;
        // Enable/disable importing blend shapes (morph targets).
        API_FIELD(Attributes="EditorOrder(85), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowSkinnedModel))")
        bool ImportBlendShapes = false;
        // Enable skeleton bones offset matrices re-calculating.
        API_FIELD(Attributes="EditorOrder(86), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowSkinnedModel))")
        bool CalculateBoneOffsetMatrices = false;
        // The lightmap UVs source.
        API_FIELD(Attributes="EditorOrder(90), EditorDisplay(\"Geometry\", \"Lightmap UVs Source\"), VisibleIf(nameof(ShowModel))")
        ModelLightmapUVsSource LightmapUVsSource = ModelLightmapUVsSource::Disable;
        // If specified, all meshes that name starts with this prefix in the name will be imported as a separate collision data asset (excluded used for rendering).
        API_FIELD(Attributes="EditorOrder(100), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowGeometry))")
        String CollisionMeshesPrefix = TEXT("");
        // The type of collision that should be generated if the mesh has a collision prefix specified.
        API_FIELD(Attributes = "EditorOrder(105), EditorDisplay(\"Geometry\"), VisibleIf(nameof(ShowGeometry))")
        CollisionDataType CollisionType = CollisionDataType::TriangleMesh;

    public: // Transform

        // Custom uniform import scale.
        API_FIELD(Attributes="EditorOrder(500), EditorDisplay(\"Transform\")")
        float Scale = 1.0f;
        // Custom import geometry rotation.
        API_FIELD(Attributes="EditorOrder(510), EditorDisplay(\"Transform\")")
        Quaternion Rotation = Quaternion::Identity;
        // Custom import geometry offset.
        API_FIELD(Attributes="EditorOrder(520), EditorDisplay(\"Transform\")")
        Float3 Translation = Float3::Zero;
        // If checked, the imported geometry will be shifted to its local transform origin.
        API_FIELD(Attributes="EditorOrder(530), EditorDisplay(\"Transform\")")
        bool UseLocalOrigin = false;
        // If checked, the imported geometry will be shifted to the center of mass.
        API_FIELD(Attributes="EditorOrder(540), EditorDisplay(\"Transform\")")
        bool CenterGeometry = false;

    public: // Animation

        // Imported animation duration mode. Can use the original value or be overriden by settings.
        API_FIELD(Attributes="EditorOrder(1000), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation))")
        AnimationDuration Duration = AnimationDuration::Imported;
        // Imported animation first/last frame index. Used only if Duration mode is set to Custom.
        API_FIELD(Attributes="EditorOrder(1010), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowFramesRange)), Limit(0)")
        Float2 FramesRange = Float2::Zero;
        // The imported animation default frame rate. Can specify the default frames per second amount for imported animations. If the value is 0 then the original animation frame rate will be used.
        API_FIELD(Attributes="EditorOrder(1020), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation)), Limit(0, 1000, 0.01f)")
        float DefaultFrameRate = 0.0f;
        // The imported animation sampling rate. If value is 0 then the original animation speed will be used.
        API_FIELD(Attributes="EditorOrder(1030), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation)), Limit(0, 1000, 0.01f)")
        float SamplingRate = 0.0f;
        // The imported animation will have tracks with no keyframes or unspecified data removed.
        API_FIELD(Attributes="EditorOrder(1040), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation))")
        bool SkipEmptyCurves = true;
        // The imported animation channels will be optimized to remove redundant keyframes.
        API_FIELD(Attributes="EditorOrder(1050), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation))")
        bool OptimizeKeyframes = true;
        // If checked, the importer will import scale animation tracks (otherwise scale animation will be ignored).
        API_FIELD(Attributes="EditorOrder(1055), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation))")
        bool ImportScaleTracks = false;
        // Enables root motion extraction support from this animation.
        API_FIELD(Attributes="EditorOrder(1060), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation))")
        bool EnableRootMotion = false;
        // The custom node name to be used as a root motion source. If not specified the actual root node will be used.
        API_FIELD(Attributes="EditorOrder(1070), EditorDisplay(\"Animation\"), VisibleIf(nameof(ShowAnimation))")
        String RootNodeName = TEXT("");

    public: // Level Of Detail

        // If checked, the importer will generate a sequence of LODs based on the base LOD index.
        API_FIELD(Attributes="EditorOrder(1100), EditorDisplay(\"Level Of Detail\", \"Generate LODs\"), VisibleIf(nameof(ShowGeometry))")
        bool GenerateLODs = false;
        // The index of the LOD from the source model data to use as a reference for following LODs generation.
        API_FIELD(Attributes="EditorOrder(1110), EditorDisplay(\"Level Of Detail\", \"Base LOD\"), VisibleIf(nameof(ShowGeometry)), Limit(0, 5)")
        int32 BaseLOD = 0;
        // The amount of LODs to include in the model (all remaining ones starting from Base LOD will be generated).
        API_FIELD(Attributes="EditorOrder(1120), EditorDisplay(\"Level Of Detail\", \"LOD Count\"), VisibleIf(nameof(ShowGeometry)), Limit(1, 6)")
        int32 LODCount = 4;
        // The target amount of triangles for the generated LOD (based on the higher LOD). Normalized to range 0-1. For instance 0.4 cuts the triangle count to 40%.
        API_FIELD(Attributes="EditorOrder(1130), EditorDisplay(\"Level Of Detail\"), VisibleIf(nameof(ShowGeometry)), Limit(0, 1, 0.001f)")
        float TriangleReduction = 0.5f;
        // Whether to do a sloppy mesh optimization. This is faster but does not follow the topology of the original mesh.
        API_FIELD(Attributes="EditorOrder(1140), EditorDisplay(\"Level Of Detail\"), VisibleIf(nameof(ShowGeometry))")
        bool SloppyOptimization = false;
        // Only used if Sloppy is false. Target error is an approximate measure of the deviation from the original mesh using distance normalized to [0..1] range (e.g. 1e-2f means that simplifier will try to maintain the error to be below 1% of the mesh extents).
        API_FIELD(Attributes="EditorOrder(1150), EditorDisplay(\"Level Of Detail\"), VisibleIf(nameof(SloppyOptimization), true), Limit(0.01f, 1, 0.001f)")
        float LODTargetError = 0.05f;

    public: // Materials

        // If checked, the importer will create materials for model meshes as specified in the file.
        API_FIELD(Attributes="EditorOrder(400), EditorDisplay(\"Materials\"), VisibleIf(nameof(ShowGeometry))")
        bool ImportMaterials = true;
        // If checked, the importer will create the model's materials as instances of a base material.
        API_FIELD(Attributes = "EditorOrder(401), EditorDisplay(\"Materials\"), VisibleIf(nameof(ImportMaterials))")
        bool ImportMaterialsAsInstances = false;
        // The material used as the base material that will be instanced as the imported model's material.
        API_FIELD(Attributes = "EditorOrder(402), EditorDisplay(\"Materials\"), VisibleIf(nameof(ImportMaterialsAsInstances))")
        AssetReference<MaterialBase> InstanceToImportAs;
        // If checked, the importer will import texture files used by the model and any embedded texture resources.
        API_FIELD(Attributes="EditorOrder(410), EditorDisplay(\"Materials\"), VisibleIf(nameof(ShowGeometry))")
        bool ImportTextures = true;
        // If checked, the importer will try to keep the model's current material slots, instead of importing materials from the source file.
        API_FIELD(Attributes="EditorOrder(420), EditorDisplay(\"Materials\", \"Keep Material Slots on Reimport\"), VisibleIf(nameof(ShowGeometry))")
        bool RestoreMaterialsOnReimport = true;

    public: // SDF

        // If checked, enables generation of Signed Distance Field (SDF).
        API_FIELD(Attributes="EditorOrder(1500), EditorDisplay(\"SDF\"), VisibleIf(nameof(ShowModel))")
        bool GenerateSDF = false;
        // Resolution scale for generated Signed Distance Field (SDF) texture. Higher values improve accuracy but increase memory usage and reduce performance.
        API_FIELD(Attributes="EditorOrder(1510), EditorDisplay(\"SDF\"), VisibleIf(nameof(ShowModel)), Limit(0.0001f, 100.0f)")
        float SDFResolution = 1.0f;

    public: // Splitting

        // If checked, the imported mesh/animations are split into separate assets. Used if ObjectIndex is set to -1.
        API_FIELD(Attributes="EditorOrder(2000), EditorDisplay(\"Splitting\")")
        bool SplitObjects = false;
        // The zero-based index for the mesh/animation clip to import. If the source file has more than one mesh/animation it can be used to pick a desired object. Default -1 imports all objects.
        API_FIELD(Attributes="EditorOrder(2010), EditorDisplay(\"Splitting\")")
        int32 ObjectIndex = -1;

    public: // Other

        // If specified, the specified folder will be used as sub-directory name for automatically imported sub assets such as textures and materials. Set to whitespace (single space) to import to the same directory.
        API_FIELD(Attributes="EditorOrder(3030), EditorDisplay(\"Other\")")
        String SubAssetFolder = TEXT("");

        // Runtime data for objects splitting during import (used internally)
        void* SplitContext = nullptr;
        Function<bool(Options& splitOptions, const String& objectName)> OnSplitImport;

    public:
        // [ISerializable]
        void Serialize(SerializeStream& stream, const void* otherObj) override;
        void Deserialize(DeserializeStream& stream, ISerializeModifier* modifier) override;
    };

public:
    /// <summary>
    /// Imports the model source file data.
    /// </summary>
    /// <param name="path">The file path.</param>
    /// <param name="data">The output data.</param>
    /// <param name="options">The import options.</param>
    /// <param name="errorMsg">The error message container.</param>
    /// <returns>True if fails, otherwise false.</returns>
    static bool ImportData(const String& path, ImportedModelData& data, Options& options, String& errorMsg);

    /// <summary>
    /// Imports the model.
    /// </summary>
    /// <param name="path">The file path.</param>
    /// <param name="meshData">The output data.</param>
    /// <param name="options">The import options.</param>
    /// <param name="errorMsg">The error message container.</param>
    /// <param name="autoImportOutput">The output folder for the additional imported data - optional. Used to auto-import textures and material assets.</param>
    /// <returns>True if fails, otherwise false.</returns>
    static bool ImportModel(const String& path, ModelData& meshData, Options& options, String& errorMsg, const String& autoImportOutput = String::Empty);

public:
    static int32 DetectLodIndex(const String& nodeName);
    static bool FindTexture(const String& sourcePath, const String& file, String& path);

    /// <summary>
    /// Gets the local transformations to go from rootIndex to index.
    /// </summary>
    /// <param name="nodes">The nodes containing the local transformations.</param>
    /// <param name="rootIndex">The root index.</param>
    /// <param name="index">The current index.</param>
    /// <returns>The transformation at this index.</returns>
    template<typename Node>
    static Transform CombineTransformsFromNodeIndices(Array<Node>& nodes, int32 rootIndex, int32 index)
    {
        if (index == -1 || index == rootIndex)
            return Transform::Identity;

        auto result = nodes[index].LocalTransform;
        if (index != rootIndex)
        {
            const auto parentTransform = CombineTransformsFromNodeIndices(nodes, rootIndex, nodes[index].ParentIndex);
            result = parentTransform.LocalToWorld(result);
        }

        return result;
    }

private:
    static void CalculateBoneOffsetMatrix(const Array<SkeletonNode>& nodes, Matrix& offsetMatrix, int32 nodeIndex);
#if USE_ASSIMP
    static bool ImportDataAssimp(const char* path, ImportedModelData& data, Options& options, String& errorMsg);
#endif
#if USE_AUTODESK_FBX_SDK
	static bool ImportDataAutodeskFbxSdk(const char* path, ImportedModelData& data, Options& options, String& errorMsg);
#endif
#if USE_OPEN_FBX
    static bool ImportDataOpenFBX(const char* path, ImportedModelData& data, Options& options, String& errorMsg);
#endif
#endif
};

#endif