/*
 * $Revision: 3074 $
 *
 * last checkin:
 *   $Author: chimani $
 *   $Date: 2012-11-29 11:01:06 +0100 (Thu, 29 Nov 2012) $
 ***************************************************************/

/** \file
 * \brief Declaration and implementation of EdgeArray class.
 *
 * \author Carsten Gutwenger
 *
 * \par License:
 * This file is part of the Open Graph Drawing Framework (OGDF).
 *
 * \par
 * Copyright (C)<br>
 * See README.txt in the root directory of the OGDF installation for details.
 *
 * \par
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * Version 2 or 3 as published by the Free Software Foundation;
 * see the file LICENSE.txt included in the packaging of this file
 * for details.
 *
 * \par
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * \par
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 * \see  http://www.gnu.org/copyleft/gpl.html
 ***************************************************************/

#ifdef _MSC_VER
#pragma once
#endif

#ifndef OGDF_EDGE_ARRAY_H
#define OGDF_EDGE_ARRAY_H


#include <ogdf/basic/Graph_d.h>


namespace ogdf {


//! Abstract base class for edge arrays.
/**
 * Defines the interface for event handling used by the Graph class.
 * Use the parameterized class EdgeArray for creating edge arrays.
 */
class EdgeArrayBase {
	/**
	 * Pointer to list element in the list of all registered edge
	 * arrays which references this array.
	 */
	ListIterator<EdgeArrayBase*> m_it;

public:
	const Graph *m_pGraph; //!< The associated graph.

	//! Initializes an edge array not associated with a graph.
	EdgeArrayBase() : m_pGraph(0) { }
	//! Initializes an edge array associated with \a pG.
	EdgeArrayBase(const Graph *pG) : m_pGraph(pG) {
		if(pG) m_it = pG->registerArray(this);
	}

	// destructor, unregisters the array
	virtual ~EdgeArrayBase() {
		if (m_pGraph) m_pGraph->unregisterArray(m_it);
	}

	// event interface used by Graph
	//! Virtual function called when table size has to be enlarged.
	virtual void enlargeTable(int newTableSize) = 0;
	//! Virtual function called when table has to be reinitialized.
	virtual void reinit(int initTableSize) = 0;
	//! Virtual function called when array is disconnected from the graph.
	virtual void disconnect() = 0;

	//! Associates the array with a new graph.
	void reregister(const Graph *pG) {
		if (m_pGraph) m_pGraph->unregisterArray(m_it);
		if ((m_pGraph = pG) != 0) m_it = pG->registerArray(this);
	}
}; // class EdgeArrayBase


//! Dynamic arrays indexed with edges.
/**
 * Edge arrays represent a mapping from edges to data of type \a T.
 * They adjust their table size automatically when the graph grows.
 *
 * @tparam T is the element type.
 */
template<class T> class EdgeArray : private Array<T>, protected EdgeArrayBase {
	T m_x; //!< The default value for array elements.

public:
	//! Constructs an empty edge array associated with no graph.
	EdgeArray() : Array<T>(), EdgeArrayBase() { }
	//! Constructs an edge array associated with \a G.
	EdgeArray(const Graph &G) : Array<T>(G.edgeArrayTableSize()), EdgeArrayBase(&G) { }
	//! Constructs an edge array associated with \a G.
	/**
	 * @param G is the associated graph.
	 * @param x is the default value for all array elements.
	 */
	EdgeArray(const Graph &G, const T &x) :
		Array<T>(0,G.edgeArrayTableSize()-1,x), EdgeArrayBase(&G), m_x(x) { }
	//! Constructs an edge array that is a copy of \a A.
	/**
	 * Associates the array with the same graph as \a A and copies all elements.
	 */
	EdgeArray(const EdgeArray<T> &A) : Array<T>(A), EdgeArrayBase(A.m_pGraph), m_x(A.m_x) { }

	//! Returns true iff the array is associated with a graph.
	bool valid() const { return (Array<T>::low() <= Array<T>::high()); }

	//! Returns a pointer to the associated graph.
	const Graph *graphOf() const {
		return m_pGraph;
	}

	//! Returns a reference to the element with index \a e.
	const T &operator[](edge e) const {
		OGDF_ASSERT(e != 0 && e->graphOf() == m_pGraph)
		return Array<T>::operator [](e->index());
	}

	//! Returns a reference to the element with index \a e.
	T &operator[](edge e) {
		OGDF_ASSERT(e != 0 && e->graphOf() == m_pGraph)
		return Array<T>::operator [](e->index());
	}

	//! Returns a reference to the element with index edge of \a adj.
	const T &operator[](adjEntry adj) const {
		OGDF_ASSERT(adj != 0)
		return Array<T>::operator [](adj->index() >> 1);
	}

	//! Returns a reference to the element with index edge of \a adj.
	T &operator[](adjEntry adj) {
		OGDF_ASSERT(adj != 0)
		return Array<T>::operator [](adj->index() >> 1);
	}

	//! Returns a reference to the element with index \a index.
	/**
	 * \attention Make sure that \a index is a valid index for an edge
	 * in the associated graph!
	 */
	const T &operator[](int index) const {
		return Array<T>::operator [](index);
	}

	//! Returns a reference to the element with index \a index.
	/**
	 * \attention Make sure that \a index is a valid index for an edge
	 * in the associated graph!
	 */
	T &operator[](int index) {
		return Array<T>::operator [](index);
	}

	//! Assignment operator.
	EdgeArray<T> &operator=(const EdgeArray<T> &a) {
		Array<T>::operator =(a);
		m_x = a.m_x;
		reregister(a.m_pGraph);
		return *this;
	}

	//! Reinitializes the array. Associates the array with no graph.
	void init() {
		Array<T>::init(); reregister(0);
	}

	//! Reinitializes the array. Associates the array with \a G.
	void init(const Graph &G) {
		Array<T>::init(G.edgeArrayTableSize()); reregister(&G);
	}

	//! Reinitializes the array. Associates the array with \a G.
	/**
	 * @param G is the associated graph.
	 * @param x is the default value.
	 */
	void init(const Graph &G, const T &x) {
		Array<T>::init(0,G.edgeArrayTableSize()-1, m_x = x); reregister(&G);
	}

	//! Sets all array elements to \a x.
	void fill(const T &x) {
		int high = m_pGraph->maxEdgeIndex();
		if(high >= 0)
			Array<T>::fill(0,high,x);
	}

private:
	virtual void enlargeTable(int newTableSize) {
		Array<T>::resize(newTableSize,m_x);
	}

	virtual void reinit(int initTableSize) {
		Array<T>::init(0,initTableSize-1,m_x);
	}

	virtual void disconnect() {
		Array<T>::init();
		m_pGraph = 0;
	}

	OGDF_NEW_DELETE

}; // class EdgeArray<T>


//! Bucket function for edges.
/**
 * The bucket of an edge is stored in an edge array which is passed
 * by the user at construction; only a pointer is stored to that array.
 */
class OGDF_EXPORT BucketEdgeArray : public BucketFunc<edge>
{
	const EdgeArray<int> *m_pEdgeArray; //!< Pointer to edge array.

public:
	//! Constructs a bucket function.
	/**
	 * @param edgeArray contains the buckets for the edges. May not be deleted
	 *        as long as the bucket function is used.
	 */
	BucketEdgeArray(const EdgeArray<int> &edgeArray) : m_pEdgeArray(&edgeArray) { }

	//! Returns bucket of edge \a e.
	int getBucket(const edge &e) { return (*m_pEdgeArray)[e]; }
};


} // end namespace ogdf
#include <ogdf/basic/Graph.h>

#endif
