/****************************************************************************
 * Copyright (C) 2009-2015 EPAM Systems
 * 
 * This file is part of Indigo toolkit.
 * 
 * This file may be distributed and/or modified under the terms of the
 * GNU General Public License version 3 as published by the Free Software
 * Foundation and appearing in the file LICENSE.GPL included in the
 * packaging of this file.
 * 
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 ***************************************************************************/

#include "graph/skew_symmetric_network.h"

using namespace indigo;

IMPL_ERROR(SkewSymmetricNetwork, "skew symmetric network");

const Graph& SkewSymmetricNetwork::g() const
{
   return _g;
}

void SkewSymmetricNetwork::clear ()
{
   _g.clear();
   _symmetry.clear();
   _arcs.clear();
   _source = -1;
}

void SkewSymmetricNetwork::setSource (int source)
{
   _source = source;
}

int SkewSymmetricNetwork::getSource () const
{
   return _source;
}

int SkewSymmetricNetwork::addVertex (int *symmetry_vertex)
{
   int v = _g.addVertex();
   int v_sym = _g.addVertex();

   _symmetry.resize(_g.vertexEnd());
   _symmetry[v] = v_sym;
   _symmetry[v_sym] = v;
   if (symmetry_vertex != NULL)
      *symmetry_vertex = v_sym;
   return v;
}

void SkewSymmetricNetwork::removeVertex (int vertex)
{
   int v_sym = getSymmetricVertex(vertex);
   _g.removeVertex(vertex);
   _g.removeVertex(v_sym);
}

int SkewSymmetricNetwork::addArc (int from, int to, int capacity)
{
   int from_sym = getSymmetricVertex(from);
   int to_sym = getSymmetricVertex(to);

   if (_g.haveEdge(from, to))
      throw Error("both directions arcs are not supported");
   if (_g.haveEdge(from_sym, to_sym))
      throw Error("inconsistent skew-symmetric network state");

   int edge = _g.addEdge(from, to);
   int edge_sym = _g.addEdge(to_sym, from_sym);

   _arcs.resize(_g.edgeEnd());
   _arcs[edge].from = from;
   _arcs[edge].to = to;
   _arcs[edge].capacity = capacity;

   _arcs[edge_sym].from = to_sym;
   _arcs[edge_sym].to = from_sym;
   _arcs[edge_sym].capacity = capacity;

   return edge;
}

void SkewSymmetricNetwork::removeArc (int from, int to)
{
   int edge = _g.findEdgeIndex(from, to);
   int edge_sym = getSymmetricArc(edge);

   _g.removeEdge(edge);
   _g.removeEdge(edge_sym);
}

int SkewSymmetricNetwork::getSymmetricVertex (int vertex) const
{
   return _symmetry[vertex];
}

int SkewSymmetricNetwork::getArcType (int edge, int vertex) const
{
   const Arc &arc = _arcs[edge];
   if (arc.from == vertex)
      return ARC_OUT;
   else if (arc.to == vertex)
      return ARC_IN;
   else 
      throw Error("invalid edge passed in getArcType method");
}

int SkewSymmetricNetwork::getArcCapacity (int edge) const
{
   return _arcs[edge].capacity;
}

int SkewSymmetricNetwork::getSymmetricArc (int edge) const
{
   const Arc &arc = _arcs[edge];
   int from_sym = getSymmetricVertex(arc.from);
   int to_sym = getSymmetricVertex(arc.to);
   int edge_sym = _g.findEdgeIndex(from_sym, to_sym);

   return edge_sym;
}

void SkewSymmetricNetwork::setArcCapacity (int edge, int capacity)
{
   if (capacity < 0)
      throw Error("capacity can't be negative");

   int edge_sym = getSymmetricArc(edge);

   _arcs[edge].capacity = capacity;
   _arcs[edge_sym].capacity = capacity;
}