/** Helper structures for the Collada loader */

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

Copyright (c) 2006-2019, 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,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.

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

#ifndef AI_COLLADAHELPER_H_INC
#define AI_COLLADAHELPER_H_INC

#include <map>
#include <vector>
#include <stdint.h>
#include <assimp/light.h>
#include <assimp/mesh.h>
#include <assimp/material.h>

struct aiMaterial;

namespace Assimp    {
namespace Collada       {

/** Collada file versions which evolved during the years ... */
enum FormatVersion
{
    FV_1_5_n,
    FV_1_4_n,
    FV_1_3_n
};


/** Transformation types that can be applied to a node */
enum TransformType
{
    TF_LOOKAT,
    TF_ROTATE,
    TF_TRANSLATE,
    TF_SCALE,
    TF_SKEW,
    TF_MATRIX
};

/** Different types of input data to a vertex or face */
enum InputType
{
    IT_Invalid,
    IT_Vertex,  // special type for per-index data referring to the <vertices> element carrying the per-vertex data.
    IT_Position,
    IT_Normal,
    IT_Texcoord,
    IT_Color,
    IT_Tangent,
    IT_Bitangent
};

/** Supported controller types */
enum ControllerType
{
    Skin,
    Morph
};

/** Supported morph methods */
enum MorphMethod
{
    Normalized,
    Relative
};

/** Common metadata keys as <Collada, Assimp> */
typedef std::pair<std::string, std::string> MetaKeyPair;
typedef std::vector<MetaKeyPair> MetaKeyPairVector;

// Collada as lower_case (native)
const MetaKeyPairVector &GetColladaAssimpMetaKeys();
// Collada as CamelCase (used by Assimp for consistency)
const MetaKeyPairVector &GetColladaAssimpMetaKeysCamelCase();

/** Convert underscore_separated to CamelCase "authoring_tool" becomes "AuthoringTool" */
void ToCamelCase(std::string &text);

/** Contains all data for one of the different transformation types */
struct Transform
{
    std::string mID;  ///< SID of the transform step, by which anim channels address their target node
    TransformType mType;
    ai_real f[16]; ///< Interpretation of data depends on the type of the transformation
};

/** A collada camera. */
struct Camera
{
    Camera()
        :   mOrtho  (false)
        ,   mHorFov (10e10f)
        ,   mVerFov (10e10f)
        ,   mAspect (10e10f)
        ,   mZNear  (0.1f)
        ,   mZFar   (1000.f)
    {}

    // Name of camera
    std::string mName;

    // True if it is an orthografic camera
    bool mOrtho;

    //! Horizontal field of view in degrees
    ai_real mHorFov;

    //! Vertical field of view in degrees
    ai_real mVerFov;

    //! Screen aspect
    ai_real mAspect;

    //! Near& far z
    ai_real mZNear, mZFar;
};

#define ASSIMP_COLLADA_LIGHT_ANGLE_NOT_SET 1e9f

/** A collada light source. */
struct Light
{
    Light()
        :   mType            (aiLightSource_UNDEFINED)
        ,   mAttConstant     (1.f)
        ,   mAttLinear       (0.f)
        ,   mAttQuadratic    (0.f)
        ,   mFalloffAngle    (180.f)
        ,   mFalloffExponent (0.f)
        ,   mPenumbraAngle   (ASSIMP_COLLADA_LIGHT_ANGLE_NOT_SET)
        ,   mOuterAngle      (ASSIMP_COLLADA_LIGHT_ANGLE_NOT_SET)
        ,   mIntensity       (1.f)
    {}

    //! Type of the light source aiLightSourceType + ambient
    unsigned int mType;

    //! Color of the light
    aiColor3D mColor;

    //! Light attenuation
    ai_real mAttConstant,mAttLinear,mAttQuadratic;

    //! Spot light falloff
    ai_real mFalloffAngle;
    ai_real mFalloffExponent;

    // -----------------------------------------------------
    // FCOLLADA extension from here

    //! ... related stuff from maja and max extensions
    ai_real mPenumbraAngle;
    ai_real mOuterAngle;

    //! Common light intensity
    ai_real mIntensity;
};

/** Short vertex index description */
struct InputSemanticMapEntry
{
    InputSemanticMapEntry()
        :   mSet(0)
        ,   mType(IT_Invalid)
    {}

    //! Index of set, optional
    unsigned int mSet;

    //! Type of referenced vertex input
    InputType mType;
};

/** Table to map from effect to vertex input semantics */
struct SemanticMappingTable
{
    //! Name of material
    std::string mMatName;

    //! List of semantic map commands, grouped by effect semantic name
    std::map<std::string, InputSemanticMapEntry> mMap;

    //! For std::find
    bool operator == (const std::string& s) const {
        return s == mMatName;
    }
};

/** A reference to a mesh inside a node, including materials assigned to the various subgroups.
 * The ID refers to either a mesh or a controller which specifies the mesh
 */
struct MeshInstance
{
    ///< ID of the mesh or controller to be instanced
    std::string mMeshOrController;

    ///< Map of materials by the subgroup ID they're applied to
    std::map<std::string, SemanticMappingTable> mMaterials;
};

/** A reference to a camera inside a node*/
struct CameraInstance
{
     ///< ID of the camera
    std::string mCamera;
};

/** A reference to a light inside a node*/
struct LightInstance
{
     ///< ID of the camera
    std::string mLight;
};

/** A reference to a node inside a node*/
struct NodeInstance
{
     ///< ID of the node
    std::string mNode;
};

/** A node in a scene hierarchy */
struct Node
{
    std::string mName;
    std::string mID;
    std::string mSID;
    Node* mParent;
    std::vector<Node*> mChildren;

    /** Operations in order to calculate the resulting transformation to parent. */
    std::vector<Transform> mTransforms;

    /** Meshes at this node */
    std::vector<MeshInstance> mMeshes;

    /** Lights at this node */
    std::vector<LightInstance> mLights;

    /** Cameras at this node */
    std::vector<CameraInstance> mCameras;

    /** Node instances at this node */
    std::vector<NodeInstance> mNodeInstances;

    /** Root-nodes: Name of primary camera, if any */
    std::string mPrimaryCamera;

    //! Constructor. Begin with a zero parent
    Node()
    : mParent( nullptr ){
        // empty
    }

    //! Destructor: delete all children subsequently
    ~Node() {
        for( std::vector<Node*>::iterator it = mChildren.begin(); it != mChildren.end(); ++it)
            delete *it;
    }
};

/** Data source array: either floats or strings */
struct Data
{
    bool mIsStringArray;
    std::vector<ai_real> mValues;
    std::vector<std::string> mStrings;
};

/** Accessor to a data array */
struct Accessor
{
    size_t mCount;   // in number of objects
    size_t mSize;    // size of an object, in elements (floats or strings, mostly 1)
    size_t mOffset;  // in number of values
    size_t mStride;  // Stride in number of values
    std::vector<std::string> mParams; // names of the data streams in the accessors. Empty string tells to ignore.
    size_t mSubOffset[4]; // Suboffset inside the object for the common 4 elements. For a vector, that's XYZ, for a color RGBA and so on.
                          // For example, SubOffset[0] denotes which of the values inside the object is the vector X component.
    std::string mSource;   // URL of the source array
    mutable const Data* mData; // Pointer to the source array, if resolved. NULL else

    Accessor()
    {
        mCount = 0; mSize = 0; mOffset = 0; mStride = 0; mData = NULL;
        mSubOffset[0] = mSubOffset[1] = mSubOffset[2] = mSubOffset[3] = 0;
    }
};

/** A single face in a mesh */
struct Face
{
    std::vector<size_t> mIndices;
};

/** An input channel for mesh data, referring to a single accessor */
struct InputChannel
{
    InputType mType;      // Type of the data
    size_t mIndex;        // Optional index, if multiple sets of the same data type are given
    size_t mOffset;       // Index offset in the indices array of per-face indices. Don't ask, can't explain that any better.
    std::string mAccessor; // ID of the accessor where to read the actual values from.
    mutable const Accessor* mResolved; // Pointer to the accessor, if resolved. NULL else

    InputChannel() { mType = IT_Invalid; mIndex = 0; mOffset = 0; mResolved = NULL; }
};

/** Subset of a mesh with a certain material */
struct SubMesh
{
    std::string mMaterial; ///< subgroup identifier
    size_t mNumFaces; ///< number of faces in this submesh
};

/** Contains data for a single mesh */
struct Mesh
{
    Mesh()
    {
        for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS;++i)
            mNumUVComponents[i] = 2;
    }

    std::string mName;

    // just to check if there's some sophisticated addressing involved...
    // which we don't support, and therefore should warn about.
    std::string mVertexID;

    // Vertex data addressed by vertex indices
    std::vector<InputChannel> mPerVertexData;

    // actual mesh data, assembled on encounter of a <p> element. Verbose format, not indexed
    std::vector<aiVector3D> mPositions;
    std::vector<aiVector3D> mNormals;
    std::vector<aiVector3D> mTangents;
    std::vector<aiVector3D> mBitangents;
    std::vector<aiVector3D> mTexCoords[AI_MAX_NUMBER_OF_TEXTURECOORDS];
    std::vector<aiColor4D>  mColors[AI_MAX_NUMBER_OF_COLOR_SETS];

    unsigned int mNumUVComponents[AI_MAX_NUMBER_OF_TEXTURECOORDS];

    // Faces. Stored are only the number of vertices for each face.
    // 1 == point, 2 == line, 3 == triangle, 4+ == poly
    std::vector<size_t> mFaceSize;

    // Position indices for all faces in the sequence given in mFaceSize -
    // necessary for bone weight assignment
    std::vector<size_t> mFacePosIndices;

    // Submeshes in this mesh, each with a given material
    std::vector<SubMesh> mSubMeshes;
};

/** Which type of primitives the ReadPrimitives() function is going to read */
enum PrimitiveType
{
    Prim_Invalid,
    Prim_Lines,
    Prim_LineStrip,
    Prim_Triangles,
    Prim_TriStrips,
    Prim_TriFans,
    Prim_Polylist,
    Prim_Polygon
};

/** A skeleton controller to deform a mesh with the use of joints */
struct Controller
{
    // controller type
    ControllerType mType;

    // Morphing method if type is Morph
    MorphMethod mMethod;

    // the URL of the mesh deformed by the controller.
    std::string mMeshId;

    // accessor URL of the joint names
    std::string mJointNameSource;

    ///< The bind shape matrix, as array of floats. I'm not sure what this matrix actually describes, but it can't be ignored in all cases
    ai_real mBindShapeMatrix[16];

    // accessor URL of the joint inverse bind matrices
    std::string mJointOffsetMatrixSource;

    // input channel: joint names.
    InputChannel mWeightInputJoints;
    // input channel: joint weights
    InputChannel mWeightInputWeights;

    // Number of weights per vertex.
    std::vector<size_t> mWeightCounts;

    // JointIndex-WeightIndex pairs for all vertices
    std::vector< std::pair<size_t, size_t> > mWeights;

    std::string mMorphTarget;
    std::string mMorphWeight;
};

/** A collada material. Pretty much the only member is a reference to an effect. */
struct Material
{
    std::string mName;
    std::string mEffect;
};

/** Type of the effect param */
enum ParamType
{
    Param_Sampler,
    Param_Surface
};

/** A param for an effect. Might be of several types, but they all just refer to each other, so I summarize them */
struct EffectParam
{
    ParamType mType;
    std::string mReference; // to which other thing the param is referring to.
};

/** Shading type supported by the standard effect spec of Collada */
enum ShadeType
{
    Shade_Invalid,
    Shade_Constant,
    Shade_Lambert,
    Shade_Phong,
    Shade_Blinn
};

/** Represents a texture sampler in collada */
struct Sampler
{
    Sampler()
        :   mWrapU      (true)
        ,   mWrapV      (true)
        ,   mMirrorU    ()
        ,   mMirrorV    ()
        ,   mOp         (aiTextureOp_Multiply)
        ,   mUVId       (UINT_MAX)
        ,   mWeighting  (1.f)
        ,   mMixWithPrevious (1.f)
    {}

    /** Name of image reference
     */
    std::string mName;

    /** Wrap U?
     */
    bool mWrapU;

    /** Wrap V?
     */
    bool mWrapV;

    /** Mirror U?
     */
    bool mMirrorU;

    /** Mirror V?
     */
    bool mMirrorV;

    /** Blend mode
     */
    aiTextureOp mOp;

    /** UV transformation
     */
    aiUVTransform mTransform;

    /** Name of source UV channel
     */
    std::string mUVChannel;

    /** Resolved UV channel index or UINT_MAX if not known
     */
    unsigned int mUVId;

    // OKINO/MAX3D extensions from here
    // -------------------------------------------------------

    /** Weighting factor
     */
    ai_real mWeighting;

    /** Mixing factor from OKINO
     */
    ai_real mMixWithPrevious;
};

/** A collada effect. Can contain about anything according to the Collada spec,
    but we limit our version to a reasonable subset. */
struct Effect
{
    // Shading mode
    ShadeType mShadeType;

    // Colors
    aiColor4D mEmissive, mAmbient, mDiffuse, mSpecular,
        mTransparent, mReflective;

    // Textures
    Sampler mTexEmissive, mTexAmbient, mTexDiffuse, mTexSpecular,
        mTexTransparent, mTexBump, mTexReflective;

    // Scalar factory
    ai_real mShininess, mRefractIndex, mReflectivity;
    ai_real mTransparency;
    bool mHasTransparency;
    bool mRGBTransparency;
    bool mInvertTransparency;

    // local params referring to each other by their SID
    typedef std::map<std::string, Collada::EffectParam> ParamLibrary;
    ParamLibrary mParams;

    // MAX3D extensions
    // ---------------------------------------------------------
    // Double-sided?
    bool mDoubleSided, mWireframe, mFaceted;

    Effect()
        : mShadeType    (Shade_Phong)
        , mEmissive     ( 0, 0, 0, 1)
        , mAmbient      ( 0.1f, 0.1f, 0.1f, 1)
        , mDiffuse      ( 0.6f, 0.6f, 0.6f, 1)
        , mSpecular     ( 0.4f, 0.4f, 0.4f, 1)
        , mTransparent  ( 0, 0, 0, 1)
        , mShininess    (10.0f)
        , mRefractIndex (1.f)
        , mReflectivity (0.f)
        , mTransparency (1.f)
        , mHasTransparency (false)
        , mRGBTransparency(false)
        , mInvertTransparency(false)
        , mDoubleSided  (false)
        , mWireframe    (false)
        , mFaceted      (false)
    {
    }
};

/** An image, meaning texture */
struct Image
{
    std::string mFileName;

    /** Embedded image data */
    std::vector<uint8_t> mImageData;

    /** File format hint of embedded image data */
    std::string mEmbeddedFormat;
};

/** An animation channel. */
struct AnimationChannel
{
    /** URL of the data to animate. Could be about anything, but we support only the
     * "NodeID/TransformID.SubElement" notation
     */
    std::string mTarget;

    /** Source URL of the time values. Collada calls them "input". Meh. */
    std::string mSourceTimes;
    /** Source URL of the value values. Collada calls them "output". */
    std::string mSourceValues;
    /** Source URL of the IN_TANGENT semantic values. */
    std::string mInTanValues;
    /** Source URL of the OUT_TANGENT semantic values. */
    std::string mOutTanValues;
    /** Source URL of the INTERPOLATION semantic values. */
    std::string mInterpolationValues;
};

/** An animation. Container for 0-x animation channels or 0-x animations */
struct Animation
{
    /** Anim name */
    std::string mName;

    /** the animation channels, if any */
    std::vector<AnimationChannel> mChannels;

    /** the sub-animations, if any */
    std::vector<Animation*> mSubAnims;

    /** Destructor */
    ~Animation()
    {
        for( std::vector<Animation*>::iterator it = mSubAnims.begin(); it != mSubAnims.end(); ++it)
            delete *it;
    }

	/** Collect all channels in the animation hierarchy into a single channel list. */
	void CollectChannelsRecursively(std::vector<AnimationChannel> &channels)
	{
		channels.insert(channels.end(), mChannels.begin(), mChannels.end());

		for (std::vector<Animation*>::iterator it = mSubAnims.begin(); it != mSubAnims.end(); ++it)
		{
			Animation *pAnim = (*it);

			pAnim->CollectChannelsRecursively(channels);
		}
	}

	/** Combine all single-channel animations' channel into the same (parent) animation channel list. */
	void CombineSingleChannelAnimations()
	{
		CombineSingleChannelAnimationsRecursively(this);
	}

	void CombineSingleChannelAnimationsRecursively(Animation *pParent)
	{
		for (std::vector<Animation*>::iterator it = pParent->mSubAnims.begin(); it != pParent->mSubAnims.end();)
		{
			Animation *anim = *it;

			CombineSingleChannelAnimationsRecursively(anim);

			if (anim->mChannels.size() == 1)
			{
				pParent->mChannels.push_back(anim->mChannels[0]);

				it = pParent->mSubAnims.erase(it);

				delete anim;
			}
			else
			{
				++it;
			}
		}
	}
};

/** Description of a collada animation channel which has been determined to affect the current node */
struct ChannelEntry
{
    const Collada::AnimationChannel* mChannel; ///> the source channel
    std::string mTargetId;
    std::string mTransformId;   // the ID of the transformation step of the node which is influenced
    size_t mTransformIndex; // Index into the node's transform chain to apply the channel to
    size_t mSubElement; // starting index inside the transform data

    // resolved data references
    const Collada::Accessor* mTimeAccessor; ///> Collada accessor to the time values
    const Collada::Data* mTimeData; ///> Source data array for the time values
    const Collada::Accessor* mValueAccessor; ///> Collada accessor to the key value values
    const Collada::Data* mValueData; ///> Source datat array for the key value values

    ChannelEntry()
      : mChannel()
      , mTransformIndex()
      , mSubElement()
      , mTimeAccessor()
      , mTimeData()
      , mValueAccessor()
      , mValueData()
   {}
};

} // end of namespace Collada
} // end of namespace Assimp

#endif // AI_COLLADAHELPER_H_INC