/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2022, assimp team

All rights reserved.

Redistribution and use of this software in source and binary forms,
with or without modification, are permitted provided that the
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------
*/

/** @file  BlenderLoader.h
 *  @brief Declaration of the Blender 3D (*.blend) importer class.
 */
#pragma once
#ifndef INCLUDED_AI_BLEND_LOADER_H
#define INCLUDED_AI_BLEND_LOADER_H

#include <assimp/BaseImporter.h>
#include <assimp/LogAux.h>
#include <memory>

struct aiNode;
struct aiMesh;
struct aiLight;
struct aiCamera;
struct aiMaterial;

namespace Assimp {

// TinyFormatter.h
namespace Formatter {

template <typename T, typename TR, typename A>
class basic_formatter;

typedef class basic_formatter<char, std::char_traits<char>, std::allocator<char>> format;

} // namespace Formatter

// BlenderDNA.h
namespace Blender {
class FileDatabase;
struct ElemBase;
} // namespace Blender

// BlenderScene.h
namespace Blender {
struct Scene;
struct Object;
struct Collection;
struct Mesh;
struct Camera;
struct Lamp;
struct MTex;
struct Image;
struct Material;
} // namespace Blender

// BlenderIntermediate.h
namespace Blender {
struct ConversionData;
template <template <typename, typename> class TCLASS, typename T>
struct TempArray;
} // namespace Blender

// BlenderModifier.h
namespace Blender {
class BlenderModifierShowcase;
class BlenderModifier;
} // namespace Blender

// -------------------------------------------------------------------------------------------
/** Load blenders official binary format. The actual file structure (the `DNA` how they
 *  call it is outsourced to BlenderDNA.cpp/BlenderDNA.h. This class only performs the
 *  conversion from intermediate format to aiScene. */
// -------------------------------------------------------------------------------------------
class BlenderImporter : public BaseImporter, public LogFunctions<BlenderImporter> {
public:
    BlenderImporter();
    ~BlenderImporter() override;
    bool CanRead(const std::string &pFile, IOSystem *pIOHandler, bool checkSig) const override;

protected:
    const aiImporterDesc *GetInfo() const override;
    void SetupProperties(const Importer *pImp) override;
    void InternReadFile(const std::string &pFile, aiScene *pScene, IOSystem *pIOHandler) override;
    void ParseBlendFile(Blender::FileDatabase &out, std::shared_ptr<IOStream> stream);
    void ExtractScene(Blender::Scene &out, const Blender::FileDatabase &file);
    void ParseSubCollection(const Blender::Scene &in, aiNode *root, const std::shared_ptr<Blender::Collection>& collection, Blender::ConversionData &conv_data);
    void ConvertBlendFile(aiScene *out, const Blender::Scene &in, const Blender::FileDatabase &file);

private:
    aiNode *ConvertNode(const Blender::Scene &in,
            const Blender::Object *obj,
            Blender::ConversionData &conv_info,
            const aiMatrix4x4 &parentTransform);

    // --------------------
    void ConvertMesh(const Blender::Scene &in,
            const Blender::Object *obj,
            const Blender::Mesh *mesh,
            Blender::ConversionData &conv_data,
            Blender::TempArray<std::vector, aiMesh> &temp);

    // --------------------
    aiLight *ConvertLight(const Blender::Scene &in,
            const Blender::Object *obj,
            const Blender::Lamp *mesh,
            Blender::ConversionData &conv_data);

    // --------------------
    aiCamera *ConvertCamera(const Blender::Scene &in,
            const Blender::Object *obj,
            const Blender::Camera *mesh,
            Blender::ConversionData &conv_data);

    // --------------------
    void BuildDefaultMaterial(
            Blender::ConversionData &conv_data);

    // --------------------
    void AddBlendParams(
            aiMaterial *result,
            const Blender::Material *source);

    // --------------------
    void BuildMaterials(
            Blender::ConversionData &conv_data);

    // --------------------
    void ResolveTexture(
            aiMaterial *out,
            const Blender::Material *mat,
            const Blender::MTex *tex,
            Blender::ConversionData &conv_data);

    // --------------------
    void ResolveImage(
            aiMaterial *out,
            const Blender::Material *mat,
            const Blender::MTex *tex,
            const Blender::Image *img,
            Blender::ConversionData &conv_data);

    // --------------------
    void AddSentinelTexture(
            aiMaterial *out,
            const Blender::Material *mat,
            const Blender::MTex *tex,
            Blender::ConversionData &conv_data);

    // TODO: Move to a std::variant, once c++17 is supported.
    struct StreamOrError {
        std::shared_ptr<IOStream> stream;
        std::shared_ptr<std::vector<char>> input;
        std::string error;
    };

    // Returns either a stream (and optional input data for the stream) or
    // an error if it can't parse the magic token.
    StreamOrError ParseMagicToken(
            const std::string &pFile,
            IOSystem *pIOHandler) const;

private: // static stuff, mostly logging and error reporting.
    // --------------------
    static void CheckActualType(const Blender::ElemBase *dt,
            const char *check);

    // --------------------
    static void NotSupportedObjectType(const Blender::Object *obj,
            const char *type);

private:
    Blender::BlenderModifierShowcase *modifier_cache;

}; // !class BlenderImporter

} // end of namespace Assimp
#endif // AI_UNREALIMPORTER_H_INC
