/********************************************************************************
* OpenGL-Framework                                                              *
* Copyright (c) 2013 Daniel Chappuis                                            *
*********************************************************************************
*                                                                               *
* This software is provided 'as-is', without any express or implied warranty.   *
* In no event will the authors be held liable for any damages arising from the  *
* use of this software.                                                         *
*                                                                               *
* Permission is granted to anyone to use this software for any purpose,         *
* including commercial applications, and to alter it and redistribute it        *
* freely, subject to the following restrictions:                                *
*                                                                               *
* 1. The origin of this software must not be misrepresented; you must not claim *
*    that you wrote the original software. If you use this software in a        *
*    product, an acknowledgment in the product documentation would be           *
*    appreciated but is not required.                                           *
*                                                                               *
* 2. Altered source versions must be plainly marked as such, and must not be    *
*    misrepresented as being the original software.                             *
*                                                                               *
* 3. This notice may not be removed or altered from any source distribution.    *
*                                                                               *
********************************************************************************/

#ifndef MESH_H
#define MESH_H

// Libraries
#include <string>
#include <vector>
#include <map>
#include "definitions.h"
#include "maths/Vector2.h"
#include "maths/Vector3.h"
#include "maths/Color.h"
#include "Texture2D.h"
#include "Object3D.h"

namespace openglframework {

// Class Mesh
// This class represents a 3D triangular mesh
// object that can be loaded from an OBJ file for instance.
class Mesh : public Object3D {

    protected:

        // -------------------- Attributes -------------------- //

        // A triplet of vertex indices for each triangle
        std::vector<std::vector<unsigned int> > mIndices;

        // Vertices coordinates (local space)
        std::vector<Vector3> mVertices;

        // Normals coordinates
        std::vector<Vector3> mNormals;

        // Tangents coordinates
        std::vector<Vector3> mTangents;

        // Color for each vertex
        std::vector<Color> mColors;

        // UV texture coordinates
        std::vector<Vector2> mUVs;

        // Textures of the mesh (one for each part of the mesh)
        std::map<uint, Texture2D> mTextures;

    public:

        // -------------------- Methods -------------------- //

        // Constructor
        Mesh();

        // Destructor
        virtual ~Mesh();

        // Destroy the mesh
        void destroy();

        // Compute the normals of the mesh
        void calculateNormals();

        // Compute the tangents of the mesh
        void calculateTangents();

        // Calculate the bounding box of the mesh
        void calculateBoundingBox(Vector3& min, Vector3& max) const;

        // Scale of vertices of the mesh using a given factor
        void scaleVertices(float factor);

        // Return the number of triangles
        uint getNbFaces(uint part = 0) const;

        // Return the number of vertices
        uint getNbVertices() const;

        // Return the number of parts in the mesh
        uint getNbParts() const;

        // Return a reference to the vertices
        const std::vector<Vector3>& getVertices() const;

        // Set the vertices of the mesh
        void setVertices(std::vector<Vector3>& vertices);

        // Return a reference to the normals
        const std::vector<Vector3>& getNormals() const;

        // set the normals of the mesh
        void setNormals(std::vector<Vector3>& normals);

        // Return a reference to the UVs
        const std::vector<Vector2>& getUVs() const;

        // Set the UV texture coordinates of the mesh
        void setUVs(std::vector<Vector2>& uvs);

        // Return a reference to the vertex indices
        const std::vector<uint>& getIndices(uint part = 0) const;

        // Set the vertices indices of the mesh
        void setIndices(std::vector<std::vector<uint> >& indices);

        // Return the coordinates of a given vertex
        const Vector3& getVertex(uint i) const;

        // Set the coordinates of a given vertex
        void setVertex(uint i, const Vector3& vertex);

        // Return the coordinates of a given normal
        const Vector3& getNormal(uint i) const;

        // Set the coordinates of a given normal
        void setNormal(uint i, const Vector3& normal);

        // Return the color of a given vertex
        const Color& getVertexColor(uint i) const;

        // Set the color of a given vertex
        void setVertexColor(uint i, const Color& color);

        // Set a color to all the vertices
        void setColorToAllVertices(const Color& color);

        // Return the UV of a given vertex
        const Vector2& getUV(uint i) const;

        // Set the UV of a given vertex
        void setUV(uint i, const Vector2& uv);

        // Return the vertex index of the ith (i=0,1,2) vertex of a given face
        uint getVertexIndexInFace(uint faceIndex, uint i, uint part = 0) const;

        // Return true if the mesh has normals
        bool hasNormals() const;

        // Return true if the mesh has tangents
        bool hasTangents() const;

        // Return true if the mesh has vertex colors
        bool hasColors() const;

        // Return true if the mesh has UV texture coordinates
        bool hasUVTextureCoordinates() const;

        // Return true if the mesh has a texture for a given part of the mesh and if it
        // also have texture coordinates
        bool hasTextureForPart(uint part = 0) const;

        // Return true if the mesh has a texture (and texture coordinates) for at least one
        // part of the mesh
        bool hasTexture() const;

        // Return a pointer to the vertices data
        void* getVerticesPointer();

        // Return a pointer to the normals data
        void* getNormalsPointer();

        // Return a pointer to the colors data
        void* getColorsPointer();

        // Return a pointer to the tangents data
        void* getTangentsPointer();

        // Return a pointer to the UV texture coordinates data
        void* getUVTextureCoordinatesPointer();

        // Return a pointer to the vertex indicies data
        void* getIndicesPointer(uint part = 0);

        // Return a reference to a texture of the mesh
        Texture2D &getTexture(uint part = 0);

        // Set a texture to a part of the mesh
        void setTexture(Texture2D &texture, uint part = 0);
};

// Return the number of triangles
inline uint Mesh::getNbFaces(uint part) const {
    return mIndices[part].size() / 3;
}

// Return the number of vertices
inline uint Mesh::getNbVertices() const {
    return mVertices.size();
}

// Return the number of parts in the mesh
inline uint Mesh::getNbParts() const {
    return mIndices.size();
}

// Return a reference to the vertices
inline const std::vector<Vector3>& Mesh::getVertices() const {
    return mVertices;
}

// Set the vertices of the mesh
inline void Mesh::setVertices(std::vector<Vector3>& vertices) {
    mVertices = vertices;
}

// Return a reference to the normals
inline const std::vector<Vector3>& Mesh::getNormals() const {
    return mNormals;
}

// set the normals of the mesh
inline void Mesh::setNormals(std::vector<Vector3>& normals) {
    mNormals = normals;
}

// Return a reference to the UVs
inline const std::vector<Vector2>& Mesh::getUVs() const {
    return mUVs;
}

// Set the UV texture coordinates of the mesh
inline void Mesh::setUVs(std::vector<Vector2>& uvs) {
    mUVs = uvs;
}

// Return a reference to the vertex indices
inline const std::vector<uint>& Mesh::getIndices(uint part) const {
    return mIndices[part];
}

// Set the vertices indices of the mesh
inline void Mesh::setIndices(std::vector<std::vector<uint> >& indices) {
    mIndices = indices;
}

// Return the coordinates of a given vertex
inline const Vector3& Mesh::getVertex(uint i) const {
    assert(i < getNbVertices());
    return mVertices[i];
}

// Set the coordinates of a given vertex
inline void Mesh::setVertex(uint i, const Vector3& vertex) {
    assert(i < getNbVertices());
    mVertices[i] = vertex;
}

// Return the coordinates of a given normal
inline const Vector3& Mesh::getNormal(uint i) const {
    assert(i < getNbVertices());
    return mNormals[i];
}

// Set the coordinates of a given normal
inline void Mesh::setNormal(uint i, const Vector3& normal) {
    assert(i < getNbVertices());
    mNormals[i] = normal;
}

// Return the color of a given vertex
inline const Color& Mesh::getVertexColor(uint i) const {
    assert(i < getNbVertices());
    return mColors[i];
}

// Set the color of a given vertex
inline void Mesh::setVertexColor(uint i, const Color& color) {

    // If the color array does not have the same size as
    // the vertices array
    if (mColors.size() != mVertices.size()) {

        // Create the color array with the same size
        mColors = std::vector<Color>(mVertices.size());
    }

    mColors[i] = color;
}

// Set a color to all the vertices
inline void Mesh::setColorToAllVertices(const Color& color) {

    // If the color array does not have the same size as
    // the vertices array
    if (mColors.size() != mVertices.size()) {

        // Create the color array with the same size
        mColors = std::vector<Color>(mVertices.size());
    }

    for (size_t v=0; v<mVertices.size(); v++) {
        mColors[v] = color;
    }
}

// Return the UV of a given vertex
inline const Vector2& Mesh::getUV(uint i) const {
    assert(i < getNbVertices());
    return mUVs[i];
}

// Set the UV of a given vertex
inline void Mesh::setUV(uint i, const Vector2& uv) {
    assert(i < getNbVertices());
    mUVs[i] = uv;
}

// Return the vertex index of the ith (i=0,1,2) vertex of a given face
inline uint Mesh::getVertexIndexInFace(uint faceIndex, uint i, uint part) const {
    return (mIndices[part])[faceIndex*3 + i];
}

// Return true if the mesh has normals
inline bool Mesh::hasNormals() const {
    return mNormals.size() == mVertices.size();
}

// Return true if the mesh has tangents
inline bool Mesh::hasTangents() const {
    return mTangents.size() == mVertices.size();
}

// Return true if the mesh has vertex colors
inline bool Mesh::hasColors() const {
    return mColors.size() == mVertices.size();
}

// Return true if the mesh has UV texture coordinates
inline bool Mesh::hasUVTextureCoordinates() const {
    return mUVs.size() == mVertices.size();
}

// Return true if the mesh has a texture for a given part of the mesh and if it
// also have texture coordinates
inline bool Mesh::hasTextureForPart(uint part) const {
    return hasUVTextureCoordinates() && mTextures.count(part);
}

// Return true if the mesh has a texture (and texture coordinates) for at least one
// part of the mesh
inline bool Mesh::hasTexture() const {
    return hasUVTextureCoordinates() && (mTextures.size() > 0);
}

// Return a pointer to the vertices data
inline void* Mesh::getVerticesPointer() {
    return &(mVertices[0]);
}

// Return a pointer to the normals data
inline void* Mesh::getNormalsPointer() {
    return &(mNormals[0]);
}

// Return a pointer to the colors data
inline void* Mesh::getColorsPointer() {
    return &(mColors[0]);
}

// Return a pointer to the tangents data
inline void* Mesh::getTangentsPointer() {
    return &(mTangents[0]);
}

// Return a pointer to the UV texture coordinates data
inline void* Mesh::getUVTextureCoordinatesPointer() {
    return &(mUVs[0]);
}

// Return a pointer to the vertex indicies data
inline void* Mesh::getIndicesPointer(uint part) {
    return &(mIndices[part])[0];
}

// Return a reference to a texture of the mesh
inline Texture2D& Mesh::getTexture(uint part) {
    return mTextures[part];
}

// Set a texture to a part of the mesh
inline void Mesh::setTexture(Texture2D& texture, uint part) {
    mTextures[part] = texture;
}

}

#endif