/*
 * GraphEdge.hpp
 *
 *  Created on: Feb 25, 2011
 *      Author: heber
 */

#ifndef GRAPHEDGE_HPP_
#define GRAPHEDGE_HPP_

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

/** This class represents all features of a bond as used within graph
 * algorithms.
 */
class GraphEdge
{
public:
  /** Constructor.
   */
  GraphEdge();
  /** Destructor.
   */
  virtual ~GraphEdge();

  enum EdgeType { Undetermined, TreeEdge, BackEdge }; //!< edge type in a graph after Depth-First-Search analysis.
  enum Shading { white, lightgray, darkgray, black };  //!< color in Breadth-First-Search analysis

  bool Cyclic;      //!< flag whether bond is part of a cycle or not, given in DepthFirstSearchAnalysis()
  enum EdgeType Type;//!< whether this is a tree or back edge

  /** Marks vertex as used in DFS.
   * \param color color to mark bond with
   * \return bond::Used, false if bond was already marked used
   */
  bool MarkUsed(const enum Shading color);

  /** Returns whether vertex was used in DFS.
   * \return bond::Used
   */
  enum Shading IsUsed();

  /** Resets used flag in DFS.
   * \return bond::Used
   */
  void ResetUsed();

  /** Returns Shading as a char string.
   * \param color the Shading
   * \return string of the flag
   */
  static std::string getColorName(enum Shading color);

private:
    enum Shading Used;        //!< marker in depth-first search, DepthFirstSearchAnalysis()

};

#endif /* GRAPHEDGE_HPP_ */