/**********************************************************************
 * $Id: LineMerger.cpp,v 1.4 2004/12/08 13:54:44 strk Exp $
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.refractions.net
 *
 * Copyright (C) 2001-2002 Vivid Solutions Inc.
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation. 
 * See the COPYING file for more information.
 *
 **********************************************************************/
#include <geos/opLinemerge.h>
#include <geos/util.h>
#include <typeinfo>

namespace geos {

void
LineMerger::add(vector<Geometry*> *geometries)
{
	for(int i=0;i<(int)geometries->size();i++) {
		Geometry *geometry=(*geometries)[i];
		add(geometry);
	}
}

LineMerger::LineMerger()
{
	graph=new LineMergeGraph();
	mergedLineStrings=NULL;
	edgeStrings=NULL;
	factory=NULL;
}

LineMerger::~LineMerger()
{
	delete graph;
//	delete mergedLineStrings;
	if ( edgeStrings )
	{
		for (unsigned int i=0; i<edgeStrings->size(); i++)
			delete (*edgeStrings)[i];
		delete edgeStrings;
	}
}


LMGeometryComponentFilter::LMGeometryComponentFilter(LineMerger *newLm):
	lm(newLm)
{
}

void
LMGeometryComponentFilter::filter_rw(Geometry *geom)
{
	if (typeid(*geom)==typeid(LineString)) {
		lm->add((LineString*)geom);
	}	
}

/**
 * Adds a Geometry to be processed. May be called multiple times.
 * Any dimension of Geometry may be added; the constituent linework will be
 * extracted.
 */  
void
LineMerger::add(Geometry *geometry)
{
	LMGeometryComponentFilter lmgcf(this);
	geometry->apply_rw(&lmgcf);
}

void
LineMerger::add(LineString *lineString)
{
	if (factory==NULL) {
		factory=lineString->getFactory();
	}
	graph->addEdge(lineString);
}

void
LineMerger::merge()
{
	if (mergedLineStrings!=NULL) { 
		return;
	}

	edgeStrings=new vector<EdgeString*>();
	buildEdgeStringsForObviousStartNodes();
	buildEdgeStringsForIsolatedLoops();
	mergedLineStrings=new vector<LineString*>();    
	for (int i=0;i<(int)edgeStrings->size();i++) {
		EdgeString *edgeString=(*edgeStrings)[i];
		mergedLineStrings->push_back(edgeString->toLineString());
	}    
}

void
LineMerger::buildEdgeStringsForObviousStartNodes()
{
	buildEdgeStringsForNonDegree2Nodes();
}

void
LineMerger::buildEdgeStringsForIsolatedLoops()
{
	buildEdgeStringsForUnprocessedNodes();
}  

void
LineMerger::buildEdgeStringsForUnprocessedNodes()
{
	vector<planarNode*> *nodes=graph->getNodes();
	for (int i=0;i<(int)nodes->size();i++) {
		planarNode *node=(*nodes)[i];
		if (!node->isMarked()) { 
			Assert::isTrue(node->getDegree()==2);
			buildEdgeStringsStartingAt(node);
			node->setMarked(true);
		}
	}
	delete nodes;
}

void
LineMerger::buildEdgeStringsForNonDegree2Nodes()
{
	vector<planarNode*> *nodes=graph->getNodes();
	for (int i=0;i<(int)nodes->size();i++) {
		planarNode *node=(*nodes)[i];
		if (node->getDegree()!=2) { 
			buildEdgeStringsStartingAt(node);
			node->setMarked(true);
		}
	}
	delete nodes;
}

void
LineMerger::buildEdgeStringsStartingAt(planarNode *node)
{
	vector<planarDirectedEdge*> *edges=node->getOutEdges()->getEdges();
	for (int i=0;i<(int)edges->size();i++)
	{
		LineMergeDirectedEdge *directedEdge=(LineMergeDirectedEdge*) (*edges)[i];
		if (directedEdge->getEdge()->isMarked()) {
			continue;
		}
		edgeStrings->push_back(buildEdgeStringStartingWith(directedEdge));
	}
}

EdgeString*
LineMerger::buildEdgeStringStartingWith(LineMergeDirectedEdge *start)
{    
	EdgeString *edgeString = new EdgeString(factory);
	LineMergeDirectedEdge *current=start;
	do {
		edgeString->add(current);
		current->getEdge()->setMarked(true);
		current=current->getNext();      
	} while (current!=NULL && current!=start);
	return edgeString;
}

/**
 * Returns the LineStrings built by the merging process.
 */
vector<LineString*>*
LineMerger::getMergedLineStrings()
{
	merge();
	return mergedLineStrings;
}

} // namespace geos

/**********************************************************************
 * $Log: LineMerger.cpp,v $
 * Revision 1.4  2004/12/08 13:54:44  strk
 * gcc warnings checked and fixed, general cleanups.
 *
 * Revision 1.3  2004/10/13 10:03:02  strk
 * Added missing linemerge and polygonize operation.
 * Bug fixes and leaks removal from the newly added modules and
 * planargraph (used by them).
 * Some comments and indentation changes.
 *
 * Revision 1.2  2004/07/02 13:28:28  strk
 * Fixed all #include lines to reflect headers layout change.
 * Added client application build tips in README.
 *
 * Revision 1.1  2004/04/07 06:55:50  ybychkov
 * "operation/linemerge" ported from JTS 1.4
 *
 *
 **********************************************************************/