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

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*/

#ifndef AI_OGRESTRUCTS_H_INC
#define AI_OGRESTRUCTS_H_INC

#ifndef ASSIMP_BUILD_NO_OGRE_IMPORTER

#include <assimp/MemoryIOWrapper.h>
#include <memory>
#include <assimp/mesh.h>
#include <map>
#include <vector>
#include <set>

struct aiNodeAnim;
struct aiAnimation;
struct aiNode;
struct aiMaterial;
struct aiScene;

/** @note Parts of this implementation, for example enums, deserialization constants and logic
    has been copied directly with minor modifications from the MIT licensed Ogre3D code base.
    See more from https://bitbucket.org/sinbad/ogre. */

namespace Assimp
{
namespace Ogre
{

// Forward decl
class Mesh;
class MeshXml;
class SubMesh;
class SubMeshXml;
class Skeleton;

#define OGRE_SAFE_DELETE(p) delete p; p=0;

// Typedefs
typedef Assimp::MemoryIOStream MemoryStream;
typedef std::shared_ptr<MemoryStream> MemoryStreamPtr;
typedef std::map<uint16_t, MemoryStreamPtr> VertexBufferBindings;

// Ogre Vertex Element
class VertexElement
{
public:
    /// Vertex element semantics, used to identify the meaning of vertex buffer contents
    enum Semantic {
        /// Position, 3 reals per vertex
        VES_POSITION = 1,
        /// Blending weights
        VES_BLEND_WEIGHTS = 2,
        /// Blending indices
        VES_BLEND_INDICES = 3,
        /// Normal, 3 reals per vertex
        VES_NORMAL = 4,
        /// Diffuse colours
        VES_DIFFUSE = 5,
        /// Specular colours
        VES_SPECULAR = 6,
        /// Texture coordinates
        VES_TEXTURE_COORDINATES = 7,
        /// Binormal (Y axis if normal is Z)
        VES_BINORMAL = 8,
        /// Tangent (X axis if normal is Z)
        VES_TANGENT = 9,
        /// The  number of VertexElementSemantic elements (note - the first value VES_POSITION is 1)
        VES_COUNT = 9
    };

    /// Vertex element type, used to identify the base types of the vertex contents
    enum Type
    {
        VET_FLOAT1 = 0,
        VET_FLOAT2 = 1,
        VET_FLOAT3 = 2,
        VET_FLOAT4 = 3,
        /// alias to more specific colour type - use the current rendersystem's colour packing
        VET_COLOUR = 4,
        VET_SHORT1 = 5,
        VET_SHORT2 = 6,
        VET_SHORT3 = 7,
        VET_SHORT4 = 8,
        VET_UBYTE4 = 9,
        /// D3D style compact colour
        VET_COLOUR_ARGB = 10,
        /// GL style compact colour
        VET_COLOUR_ABGR = 11,
        VET_DOUBLE1 = 12,
        VET_DOUBLE2 = 13,
        VET_DOUBLE3 = 14,
        VET_DOUBLE4 = 15,
        VET_USHORT1 = 16,
        VET_USHORT2 = 17,
        VET_USHORT3 = 18,
        VET_USHORT4 = 19,
        VET_INT1 = 20,
        VET_INT2 = 21,
        VET_INT3 = 22,
        VET_INT4 = 23,
        VET_UINT1 = 24,
        VET_UINT2 = 25,
        VET_UINT3 = 26,
        VET_UINT4 = 27
    };

    VertexElement();

    /// Size of the vertex element in bytes.
    size_t Size() const;

    /// Count of components in this element, eg. VET_FLOAT3 return 3.
    size_t ComponentCount() const;

    /// Type as string.
    std::string TypeToString();

    /// Semantic as string.
    std::string SemanticToString();

    static size_t TypeSize(Type type);
    static size_t ComponentCount(Type type);
    static std::string TypeToString(Type type);
    static std::string SemanticToString(Semantic semantic);

    uint16_t index;
    uint16_t source;
    uint16_t offset;
    Type type;
    Semantic semantic;
};
typedef std::vector<VertexElement> VertexElementList;

/// Ogre Vertex Bone Assignment
struct VertexBoneAssignment
{
    uint32_t vertexIndex;
    uint16_t boneIndex;
    float weight;
};
typedef std::vector<VertexBoneAssignment> VertexBoneAssignmentList;
typedef std::map<uint32_t, VertexBoneAssignmentList > VertexBoneAssignmentsMap;
typedef std::map<uint16_t, std::vector<aiVertexWeight> > AssimpVertexBoneWeightList;

// Ogre Vertex Data interface, inherited by the binary and XML implementations.
class IVertexData
{
public:
    IVertexData();

    /// Returns if bone assignments are available.
    bool HasBoneAssignments() const;

    /// Add vertex mapping from old to new index.
    void AddVertexMapping(uint32_t oldIndex, uint32_t newIndex);

    /// Returns re-mapped bone assignments.
    /** @note Uses mappings added via AddVertexMapping. */
    AssimpVertexBoneWeightList AssimpBoneWeights(size_t vertices);

    /// Returns a set of bone indexes that are referenced by bone assignments (weights).
    std::set<uint16_t> ReferencedBonesByWeights() const;

    /// Vertex count.
    uint32_t count;

    /// Bone assignments.
    VertexBoneAssignmentList boneAssignments;

private:
    void BoneAssignmentsForVertex(uint32_t currentIndex, uint32_t newIndex, VertexBoneAssignmentList &dest) const;

    std::map<uint32_t, std::vector<uint32_t> > vertexIndexMapping;
    VertexBoneAssignmentsMap boneAssignmentsMap;
};

// Ogre Vertex Data
class VertexData : public IVertexData
{
public:
    VertexData();
    ~VertexData();

    /// Releases all memory that this data structure owns.
    void Reset();

    /// Get vertex size for @c source.
    uint32_t VertexSize(uint16_t source) const;

    /// Get vertex buffer for @c source.
    MemoryStream *VertexBuffer(uint16_t source);

    /// Get vertex element for @c semantic for @c index.
    VertexElement *GetVertexElement(VertexElement::Semantic semantic, uint16_t index = 0);

    /// Vertex elements.
    VertexElementList vertexElements;

    /// Vertex buffers mapped to bind index.
    VertexBufferBindings vertexBindings;
};

// Ogre Index Data
class IndexData
{
public:
    IndexData();
    ~IndexData();

    /// Releases all memory that this data structure owns.
    void Reset();

    /// Index size in bytes.
    size_t IndexSize() const;

    /// Face size in bytes.
    size_t FaceSize() const;

    /// Index count.
    uint32_t count;

    /// Face count.
    uint32_t faceCount;

    /// If has 32-bit indexes.
    bool is32bit;

    /// Index buffer.
    MemoryStreamPtr buffer;
};

/// Ogre Pose
class Pose
{
public:
    struct Vertex
    {
        uint32_t index;
        aiVector3D offset;
        aiVector3D normal;
    };
    typedef std::map<uint32_t, Vertex> PoseVertexMap;

    Pose() : target(0), hasNormals(false) {}

    /// Name.
    std::string name;

    /// Target.
    uint16_t target;

    /// Does vertices map have normals.
    bool hasNormals;

    /// Vertex offset and normals.
    PoseVertexMap vertices;
};
typedef std::vector<Pose*> PoseList;

/// Ogre Pose Key Frame Ref
struct PoseRef
{
    uint16_t index;
    float influence;
};
typedef std::vector<PoseRef> PoseRefList;

/// Ogre Pose Key Frame
struct PoseKeyFrame
{
    /// Time position in the animation.
    float timePos;

    PoseRefList references;
};
typedef std::vector<PoseKeyFrame> PoseKeyFrameList;

/// Ogre Morph Key Frame
struct MorphKeyFrame
{
    /// Time position in the animation.
    float timePos;

    MemoryStreamPtr buffer;
};
typedef std::vector<MorphKeyFrame> MorphKeyFrameList;

/// Ogre animation key frame
struct TransformKeyFrame
{
    TransformKeyFrame();

    aiMatrix4x4 Transform();

    float timePos;

    aiQuaternion rotation;
    aiVector3D position;
    aiVector3D scale;
};
typedef std::vector<TransformKeyFrame> TransformKeyFrameList;

/// Ogre Animation Track
struct VertexAnimationTrack
{
    enum Type
    {
        /// No animation
        VAT_NONE = 0,
        /// Morph animation is made up of many interpolated snapshot keyframes
        VAT_MORPH = 1,
        /// Pose animation is made up of a single delta pose keyframe
        VAT_POSE = 2,
        /// Keyframe that has its on pos, rot and scale for a time position
        VAT_TRANSFORM = 3
    };

    VertexAnimationTrack();

    /// Convert to Assimp node animation.
    aiNodeAnim *ConvertToAssimpAnimationNode(Skeleton *skeleton);

    // Animation type.
    Type type;

    /// Vertex data target.
    /**  0 == shared geometry
        >0 == submesh index + 1 */
    uint16_t target;

    /// Only valid for VAT_TRANSFORM.
    std::string boneName;

    /// Only one of these will contain key frames, depending on the type enum.
    PoseKeyFrameList poseKeyFrames;
    MorphKeyFrameList morphKeyFrames;
    TransformKeyFrameList transformKeyFrames;
};
typedef std::vector<VertexAnimationTrack> VertexAnimationTrackList;

/// Ogre Animation
class Animation
{
public:
    explicit Animation(Skeleton *parent);
    explicit Animation(Mesh *parent);

    /// Returns the associated vertex data for a track in this animation.
    /** @note Only valid to call when parent Mesh is set. */
    VertexData *AssociatedVertexData(VertexAnimationTrack *track) const;

    /// Convert to Assimp animation.
    aiAnimation *ConvertToAssimpAnimation();

    /// Parent mesh.
    /** @note Set only when animation is read from a mesh. */
    Mesh *parentMesh;

    /// Parent skeleton.
    /** @note Set only when animation is read from a skeleton. */
    Skeleton *parentSkeleton;

    /// Animation name.
    std::string name;

    /// Base animation name.
    std::string baseName;

    /// Length in seconds.
    float length;

    /// Base animation key time.
    float baseTime;

    /// Animation tracks.
    VertexAnimationTrackList tracks;
};
typedef std::vector<Animation*> AnimationList;

/// Ogre Bone
class Bone
{
public:
    Bone();

    /// Returns if this bone is parented.
    bool IsParented() const;

    /// Parent index as uint16_t. Internally int32_t as -1 means unparented.
    uint16_t ParentId() const;

    /// Add child bone.
    void AddChild(Bone *bone);

    /// Calculates the world matrix for bone and its children.
    void CalculateWorldMatrixAndDefaultPose(Skeleton *skeleton);

    /// Convert to Assimp node (animation nodes).
    aiNode *ConvertToAssimpNode(Skeleton *parent, aiNode *parentNode = 0);

    /// Convert to Assimp bone (mesh bones).
    aiBone *ConvertToAssimpBone(Skeleton *parent, const std::vector<aiVertexWeight> &boneWeights);

    uint16_t id;
    std::string name;

    Bone *parent;
    int32_t parentId;
    std::vector<uint16_t> children;

    aiVector3D position;
    aiQuaternion rotation;
    aiVector3D scale;

    aiMatrix4x4 worldMatrix;
    aiMatrix4x4 defaultPose;
};
typedef std::vector<Bone*> BoneList;

/// Ogre Skeleton
class Skeleton
{
public:
    enum BlendMode
    {
        /// Animations are applied by calculating a weighted average of all animations
        ANIMBLEND_AVERAGE = 0,
        /// Animations are applied by calculating a weighted cumulative total
        ANIMBLEND_CUMULATIVE = 1
    };

    Skeleton();
    ~Skeleton();

    /// Releases all memory that this data structure owns.
    void Reset();

    /// Returns unparented root bones.
    BoneList RootBones() const;

    /// Returns number of unparented root bones.
    size_t NumRootBones() const;

    /// Get bone by name.
    Bone *BoneByName(const std::string &name) const;

    /// Get bone by id.
    Bone *BoneById(uint16_t id) const;

    BoneList bones;
    AnimationList animations;

    /// @todo Take blend mode into account, but where?
    BlendMode blendMode;
};

/// Ogre Sub Mesh interface, inherited by the binary and XML implementations.
class ISubMesh
{
public:
    /// @note Full list of Ogre types, not all of them are supported and exposed to Assimp.
    enum OperationType
    {
        /// A list of points, 1 vertex per point
        OT_POINT_LIST = 1,
        /// A list of lines, 2 vertices per line
        OT_LINE_LIST = 2,
        /// A strip of connected lines, 1 vertex per line plus 1 start vertex
        OT_LINE_STRIP = 3,
        /// A list of triangles, 3 vertices per triangle
        OT_TRIANGLE_LIST = 4,
        /// A strip of triangles, 3 vertices for the first triangle, and 1 per triangle after that
        OT_TRIANGLE_STRIP = 5,
        /// A fan of triangles, 3 vertices for the first triangle, and 1 per triangle after that
        OT_TRIANGLE_FAN = 6
    };

    ISubMesh();

    /// SubMesh index.
    unsigned int index;

    /// SubMesh name.
    std::string name;

    /// Material used by this submesh.
    std::string materialRef;

    /// Texture alias information.
    std::string textureAliasName;
    std::string textureAliasRef;

    /// Assimp scene material index used by this submesh.
    /** -1 if no material or material could not be imported. */
    int materialIndex;

    /// If submesh uses shared geometry from parent mesh.
    bool usesSharedVertexData;

    /// Operation type.
    OperationType operationType;
};

/// Ogre SubMesh
class SubMesh : public ISubMesh
{
public:
    SubMesh();
    ~SubMesh();

    /// Releases all memory that this data structure owns.
    /** @note Vertex and index data contains shared ptrs
        that are freed automatically. In practice the ref count
        should be 0 after this reset. */
    void Reset();

    /// Covert to Assimp mesh.
    aiMesh *ConvertToAssimpMesh(Mesh *parent);

    /// Vertex data.
    VertexData *vertexData;

    /// Index data.
    IndexData *indexData;
};
typedef std::vector<SubMesh*> SubMeshList;

/// Ogre Mesh
class Mesh
{
public:
    /// Constructor.
    Mesh();

    /// Destructor.
    ~Mesh();

    /// Releases all memory that this data structure owns.
    void Reset();

    /// Returns number of subMeshes.
    size_t NumSubMeshes() const;

    /// Returns submesh for @c index.
    SubMesh *GetSubMesh( size_t index) const;

    /// Convert mesh to Assimp scene.
    void ConvertToAssimpScene(aiScene* dest);

    /// Mesh has skeletal animations.
    bool hasSkeletalAnimations;

    /// Skeleton reference.
    std::string skeletonRef;

    /// Skeleton.
    Skeleton *skeleton;

    /// Vertex data
    VertexData *sharedVertexData;

    /// Sub meshes.
    SubMeshList subMeshes;

    /// Animations
    AnimationList animations;

    /// Poses
    PoseList poses;
};

/// Ogre XML Vertex Data
class VertexDataXml : public IVertexData
{
public:
    VertexDataXml();

    bool HasPositions() const;
    bool HasNormals() const;
    bool HasTangents() const;
    bool HasUvs() const;
    size_t NumUvs() const;

    std::vector<aiVector3D> positions;
    std::vector<aiVector3D> normals;
    std::vector<aiVector3D> tangents;
    std::vector<std::vector<aiVector3D> > uvs;
};

/// Ogre XML Index Data
class IndexDataXml
{
public:
    IndexDataXml() : faceCount(0) {}

    /// Face count.
    uint32_t faceCount;

    std::vector<aiFace> faces;
};

/// Ogre XML SubMesh
class SubMeshXml : public ISubMesh
{
public:
    SubMeshXml();
    ~SubMeshXml();

    /// Releases all memory that this data structure owns.
    void Reset();

    aiMesh *ConvertToAssimpMesh(MeshXml *parent);

    IndexDataXml *indexData;
    VertexDataXml *vertexData;
};
typedef std::vector<SubMeshXml*> SubMeshXmlList;

/// Ogre XML Mesh
class MeshXml
{
public:
    MeshXml();
    ~MeshXml();

    /// Releases all memory that this data structure owns.
    void Reset();

    /// Returns number of subMeshes.
    size_t NumSubMeshes() const;

    /// Returns submesh for @c index.
    SubMeshXml *GetSubMesh(uint16_t index) const;

    /// Convert mesh to Assimp scene.
    void ConvertToAssimpScene(aiScene* dest);

    /// Skeleton reference.
    std::string skeletonRef;

    /// Skeleton.
    Skeleton *skeleton;

    /// Vertex data
    VertexDataXml *sharedVertexData;

    /// Sub meshes.
    SubMeshXmlList subMeshes;
};

} // Ogre
} // Assimp

#endif // ASSIMP_BUILD_NO_OGRE_IMPORTER
#endif // AI_OGRESTRUCTS_H_INC
