#ifndef TCG_EDGE_H

#define TCG_EDGE_H

// STD includes

#include "assert.h"

namespace tcg

{

template <typename e=""></typename>

struct edge_traits {

	typedef typename E::vertices_const_iterator vertices_const_iterator;

	typedef typename E::vertices_iterator vertices_iterator;

	typedef typename E::faces_const_iterator faces_const_iterator;

	typedef typename E::faces_iterator faces_iterator;

};

//-------------------------------------------------------------------------------

class Edge

{

public:

	typedef const int *vertices_const_iterator;

	typedef int *vertices_iterator;

	typedef const int *faces_const_iterator;

	typedef int *faces_iterator;

protected:

	int m_v[2];

	int m_f[2];

	int m_index;

public:

	Edge() : m_index(-1)

	{

		m_v[0] = -1, m_v[1] = -1;

		m_f[0] = -1, m_f[1] = -1;

	}

	Edge(int v1, int v2) : m_index(-1)

	{

		m_v[0] = v1, m_v[1] = v2;

		m_f[0] = -1, m_f[1] = -1;

	}

	~Edge() {}

	void setIndex(int idx) { m_index = idx; }

	int getIndex() const { return m_index; }

	int vertex(int i) const { return m_v[i]; }

	int verticesCount() const { return m_v[0] < 0 ? 0 : m_v[1] < 0 ? 1 : 2; }

	int otherVertex(int v) const { return m_v[0] == v ? m_v[1] : m_v[0]; }

	void addVertex(int v)

	{

		assert(verticesCount() < 2);

		m_v[verticesCount()] = v;

	}

	void setVertex(int i, int v) { assert(i < verticesCount()), m_v[i] = v; }

	vertices_iterator eraseVertex(vertices_iterator it)

	{

		*std::copy(it + 1, verticesEnd(), it) = -1;

		return it;

	}

	vertices_const_iterator verticesBegin() const { return m_v; }

	vertices_const_iterator verticesEnd() const { return m_v + verticesCount(); }

	vertices_iterator verticesBegin() { return m_v; }

	vertices_iterator verticesEnd() { return m_v + verticesCount(); }

	int face(int i) const { return m_f[i]; }

	int facesCount() const { return m_f[0] < 0 ? 0 : m_f[1] < 0 ? 1 : 2; }

	int otherFace(int f) const { return m_f[0] == f ? m_f[1] : m_f[0]; }

	void addFace(int f)

	{

		assert(facesCount() < 2);

		m_f[facesCount()] = f;

	}

	void setFace(int i, int f) { assert(i < facesCount()), m_f[i] = f; }

	faces_iterator eraseFace(faces_iterator it)

	{

		*std::copy(it + 1, facesEnd(), it) = -1;

		return it;

	}

	faces_const_iterator facesBegin() const { return m_f; }

	faces_const_iterator facesEnd() const { return m_f + facesCount(); }

	faces_iterator facesBegin() { return m_f; }

	faces_iterator facesEnd() { return m_f + facesCount(); }

};

} // namespace tcg

#endif // TCG_EDGE_H