/*
Open Asset Import Library (assimp)
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  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
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* Neither the name of the assimp team, nor the names of its
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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*/

/** @file  ACLoader.h
 *  @brief Declaration of the .ac importer class.
 */
#ifndef AI_AC3DLOADER_H_INCLUDED
#define AI_AC3DLOADER_H_INCLUDED

#include <vector>

#include <assimp/BaseImporter.h>
#include <assimp/types.h>

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

namespace Assimp {

// ---------------------------------------------------------------------------
/** AC3D (*.ac) importer class
*/
class AC3DImporter : public BaseImporter {
public:
    AC3DImporter();
    ~AC3DImporter();

    // Represents an AC3D material
    struct Material {
        Material() :
                rgb(0.6f, 0.6f, 0.6f),
                spec(1.f, 1.f, 1.f),
                shin(0.f),
                trans(0.f) {}

        // base color of the material
        aiColor3D rgb;

        // ambient color of the material
        aiColor3D amb;

        // emissive color of the material
        aiColor3D emis;

        // specular color of the material
        aiColor3D spec;

        // shininess exponent
        float shin;

        // transparency. 0 == opaque
        float trans;

        // name of the material. optional.
        std::string name;
    };

    // Represents an AC3D surface
    struct Surface {
        Surface() :
                mat(0),
                flags(0) {}

        unsigned int mat, flags;

        typedef std::pair<unsigned int, aiVector2D> SurfaceEntry;
        std::vector<SurfaceEntry> entries;

        // Type is low nibble of flags
        enum Type : uint8_t {
            Polygon = 0x0,
            ClosedLine = 0x1,
            OpenLine = 0x2,
            TriangleStrip = 0x4, // ACC extension (TORCS and Speed Dreams)

            Mask = 0xf,
        };

        inline uint8_t GetType() const { return (flags & Mask); }
    };

    // Represents an AC3D object
    struct Object {
        Object() :
                type(World),
                name(""),
                children(),
                texture(""),
                texRepeat(1.f, 1.f),
                texOffset(0.0f, 0.0f),
                rotation(),
                translation(),
                vertices(),
                surfaces(),
                numRefs(0),
                subDiv(0),
                crease() {}

        // Type description
        enum Type {
            World = 0x0,
            Poly = 0x1,
            Group = 0x2,
            Light = 0x4
        } type;

        // name of the object
        std::string name;

        // object children
        std::vector<Object> children;

        // texture to be assigned to all surfaces of the object
        std::string texture;

        // texture repat factors (scaling for all coordinates)
        aiVector2D texRepeat, texOffset;

        // rotation matrix
        aiMatrix3x3 rotation;

        // translation vector
        aiVector3D translation;

        // vertices
        std::vector<aiVector3D> vertices;

        // surfaces
        std::vector<Surface> surfaces;

        // number of indices (= num verts in verbose format)
        unsigned int numRefs;

        // number of subdivisions to be performed on the
        // imported data
        unsigned int subDiv;

        // max angle limit for smoothing
        float crease;
    };

public:
    // -------------------------------------------------------------------
    /** Returns whether the class can handle the format of the given file.
     * See BaseImporter::CanRead() for details.
     */
    bool CanRead(const std::string &pFile, IOSystem *pIOHandler,
            bool checkSig) const;

protected:
    // -------------------------------------------------------------------
    /** Return importer meta information.
     * See #BaseImporter::GetInfo for the details */
    const aiImporterDesc *GetInfo() const;

    // -------------------------------------------------------------------
    /** Imports the given file into the given scene structure.
     * See BaseImporter::InternReadFile() for details*/
    void InternReadFile(const std::string &pFile, aiScene *pScene,
            IOSystem *pIOHandler);

    // -------------------------------------------------------------------
    /** Called prior to ReadFile().
    * The function is a request to the importer to update its configuration
    * basing on the Importer's configuration property list.*/
    void SetupProperties(const Importer *pImp);

private:
    // -------------------------------------------------------------------
    /** Get the next line from the file.
     *  @return false if the end of the file was reached*/
    bool GetNextLine();

    // -------------------------------------------------------------------
    /** Load the object section. This method is called recursively to
     *  load subobjects, the method returns after a 'kids 0' was
     *  encountered.
     *  @objects List of output objects*/
    void LoadObjectSection(std::vector<Object> &objects);

    // -------------------------------------------------------------------
    /** Convert all objects into meshes and nodes.
     *  @param object Current object to work on
     *  @param meshes Pointer to the list of output meshes
     *  @param outMaterials List of output materials
     *  @param materials Material list
     *  @param Scenegraph node for the object */
    aiNode *ConvertObjectSection(Object &object,
            std::vector<aiMesh *> &meshes,
            std::vector<aiMaterial *> &outMaterials,
            const std::vector<Material> &materials,
            aiNode *parent = nullptr);

    // -------------------------------------------------------------------
    /** Convert a material
     *  @param object Current object
     *  @param matSrc Source material description
     *  @param matDest Destination material to be filled */
    void ConvertMaterial(const Object &object,
            const Material &matSrc,
            aiMaterial &matDest);

private:
    // points to the next data line
    const char *buffer;

    // Configuration option: if enabled, up to two meshes
    // are generated per material: those faces who have
    // their bf cull flags set are separated.
    bool configSplitBFCull;

    // Configuration switch: subdivision surfaces are only
    // evaluated if the value is true.
    bool configEvalSubdivision;

    // counts how many objects we have in the tree.
    // basing on this information we can find a
    // good estimate how many meshes we'll have in the final scene.
    unsigned int mNumMeshes;

    // current list of light sources
    std::vector<aiLight *> *mLights;

    // name counters
    unsigned int mLightsCounter, mGroupsCounter, mPolysCounter, mWorldsCounter;
};

} // end of namespace Assimp

#endif // AI_AC3DIMPORTER_H_INC