#ifndef _Mesh_H__
#define _Mesh_H__

#include <vector>
using namespace std;
#include "Intersectable.h"
#include "Plane3.h"
#include "Matrix4x4.h"
#include "AxisAlignedBox3.h"
#include "Material.h"

struct Triangle3;
class MeshInstance;
class MeshKdTree;

/// default vertex container for Mesh
typedef std::vector<Vector3> VertexContainer;

/// vertex index container
typedef std::vector<short> VertexIndexContainer;


/** Patch used as an element of the mesh */
struct Face {

public:
  Face(): mVertexIndices() {}

  Face(const int a, const int b, const int c):mVertexIndices(3) {
    mVertexIndices[0] = a;
    mVertexIndices[1] = b;
    mVertexIndices[2] = c;
  }

  Face(const int a, const int b, const int c, const int d): 
  mVertexIndices(4) {
    mVertexIndices[0] = a;
    mVertexIndices[1] = b;
    mVertexIndices[2] = c;
    mVertexIndices[3] = d;
  }

  Face(const VertexIndexContainer &vertices):mVertexIndices(vertices.size()) {
	for (int i=0;  i < vertices.size(); i++)
	  mVertexIndices[i] = vertices[i];
  }
  
  /// list of vertex pointers
  VertexIndexContainer mVertexIndices;  
};

/// default patch container for Mesh
typedef std::vector<Face *> FaceContainer;

/** Mesh containing polygonal patches */
class Mesh {

public:

  /// Default constructor
  Mesh():mVertices(), mFaces(), mMaterial(NULL), mKdTree(NULL) {}
  
  /// Constructor with container preallocation
  Mesh(const int vertices,
       const int faces):
    mFaces(),
    mMaterial(NULL),
    mKdTree(NULL),
    mVertices(),
    mIsConvex(false),
    mIsWatertight(false)
  {
    mVertices.reserve(vertices);
    mFaces.reserve(faces);
  }
  
  ~Mesh() {
    for (int i=0; i < mFaces.size(); i++)
      delete mFaces[i];
  }
  

  void Clear() {
	mVertices.clear();
	mFaces.clear();
  }
  
  void IndexVertices();
  
  void AssignRandomMaterial();
  void AddTriangle(const Triangle3 &triangle);
  void AddRectangle(const Rectangle3 &triangle);

  void Cleanup();
  
  bool ValidateFace(const int face);

  void AddFace(Face *face) 
  {
    mFaces.push_back(face);
  }
  
  void Preprocess();

  /** Axis aligned bounding box of the mesh in local mesh coordinates */
  AxisAlignedBox3 mBox;
  
  /** Vertices forming the mesh */
  VertexContainer mVertices;
  
  /** Patches forming the mesh */
  FaceContainer mFaces;
  
  /** Global mesh material */
  Material *mMaterial;
  
  /** true if the mesh is a convex mesh */
  bool mIsConvex;

  /** true if the mesh is a convex mesh */
  bool mIsWatertight;

  MeshKdTree *mKdTree;
  
  int
  CastRay(
					Ray &ray,
					MeshInstance *instance
					);
	
  int
  CastRayToSelectedFaces(
												 Ray &ray,
												 const vector<int> &faces,
												 Intersectable *instance
												 );
	
  int
  CastRayToFace(
								const int faceIndex,
								Ray &ray,
								float &nearestT,
								int &nearestFace,
								Intersectable *instance
								);
	
  
  int
  RayFaceIntersection(const int faceIndex,
											const Ray &ray,
											float &t,
											const float nearestT
											);
  
  Plane3 GetFacePlane(const int faceIndex);

  AxisAlignedBox3 GetFaceBox(const int faceIndex);

  int GetRandomSurfacePoint(Vector3 &point, Vector3 &normal);

  int
  GetRandomVisibleSurfacePoint(Vector3 &point,
							   Vector3 &normal,
							   const Vector3 &viewpoint,
							   const int maxTries
							   );
  
  virtual ostream &Describe(ostream &s) {
	return s<<"Mesh #vertices="<<(int)mVertices.size()<<" #faces="<<(int)mFaces.size();
  }
  
  friend Mesh *CreateBox(const AxisAlignedBox3 &box);
};


class MeshInstance : public Intersectable {
protected:
  Mesh *mMesh;
  
public:
  MeshInstance(Mesh *mesh):Intersectable(), mMesh(mesh)
  {
  }

  int GetRandomSurfacePoint(Vector3 &point, Vector3 &normal);

	int
	GetRandomVisibleSurfacePoint(Vector3 &point,
															 Vector3 &normal,
															 const Vector3 &viewpoint,
															 const int maxTries
															 );


  Mesh *GetMesh() { return mMesh; }

  virtual AxisAlignedBox3 GetBox() {
    return mMesh->mBox;
  }

  virtual int
  CastRay(
	  Ray &ray
	  );

  virtual bool IsConvex() { return mMesh->mIsConvex; }
  virtual bool IsWatertight() { return mMesh->mIsWatertight; }
  virtual float IntersectionComplexity() {  return (float)mMesh->mFaces.size(); }

	virtual int NumberOfFaces() const {  return (int)mMesh->mFaces.size(); }

  virtual int Type() const { return MESH_INSTANCE; }

  virtual int
  CastRay(
	  Ray &ray,
	  const vector<int> &faces
	  );


	virtual ostream &Describe(ostream &s) {
		s<<"MeshInstance Id="<<GetId();
		return mMesh->Describe(s);
	}
	
};


class TransformedMeshInstance : public MeshInstance
{
public:
  TransformedMeshInstance(Mesh *mesh):MeshInstance(mesh)
  {
    mWorldTransform = IdentityMatrix();
  }
  
  virtual AxisAlignedBox3 GetBox() {
    return Transform(mMesh->mBox,
		     mWorldTransform);
  }
  
  virtual int
  CastRay(
	  Ray &ray
	  );

  virtual int Type() const { return TRANSFORMED_MESH_INSTANCE; }

  int GetRandomSurfacePoint(Vector3 &point, Vector3 &normal);

private:
  Matrix4x4 mWorldTransform;
  
};



#endif