#include <fstream>

#include <string>

#include "test_tools.h"

#include <hugo/smart_graph.h>

#include <hugo/dimacs.h>

#include <hugo/preflow.h>

#include <hugo/skeletons/graph.h>

#include <hugo/skeletons/maps.h>

using namespace hugo;

void check_Preflow() 

{

  typedef int VType;

  typedef skeleton::StaticGraphSkeleton Graph;

  typedef Graph::Node Node;

  typedef Graph::Edge Edge;

  typedef skeleton::ReadMap<Edge,VType> CapMap;

  typedef skeleton::ReadWriteMap<Edge,VType> FlowMap;

  typedef skeleton::ReadWriteMap<Node,bool> CutMap;

  typedef Preflow<Graph, int, CapMap, FlowMap> PType;

  Graph G;

  Node n;

  CapMap cap;

  FlowMap flow;

  CutMap cut;

  PType preflow_test(G,n,n,cap,flow);

  preflow_test.run();

  preflow_test.flowValue();

  preflow_test.setSource(n);

  preflow_test.setFlow(flow);

  preflow_test.phase1(PType::NO_FLOW);

  preflow_test.minCut(cut);

  preflow_test.phase2();

  preflow_test.setTarget(n);

  preflow_test.setCap(cap);

  preflow_test.minMinCut(cut);

  preflow_test.maxMinCut(cut);

}

int cut_value ( SmartGraph& G, SmartGraph::NodeMap<bool>& cut, 

		SmartGraph::EdgeMap<int>& cap) {

  int c=0;

  for(SmartGraph::EdgeIt e(G); e!=INVALID; ++e) {

    if (cut[G.tail(e)] && !cut[G.head(e)]) c+=cap[e];

  }

  return c;

}

int main() {

  typedef SmartGraph Graph;

  typedef Graph::Node Node;

  typedef Graph::NodeIt NodeIt;

  typedef Graph::EdgeIt EdgeIt;

  typedef Graph::EdgeMap<int> CapMap;

  typedef Graph::EdgeMap<int> FlowMap;

  typedef Graph::NodeMap<bool> CutMap;

  typedef Preflow<Graph, int> PType;

  string f_name;

  if( getenv("srcdir") ) {

    f_name = string(getenv("srcdir")) + "/preflow_graph.inp";

  }

  else {

    f_name = "preflow_graph.inp";

  }

  std::ifstream file(f_name.c_str());

  check(file, "Input file '" << f_name << "' not found.");

  Graph G;

  Node s, t;

  CapMap cap(G);

  readDimacs(file, G, cap, s, t);

  FlowMap flow(G,0);

  PType preflow_test(G, s, t, cap, flow);

  preflow_test.run(PType::ZERO_FLOW);

  CutMap mincut(G,false);

  preflow_test.minCut(mincut); 

  int min_cut_value=cut_value(G,mincut,cap);

  CutMap minmincut(G,false);

  preflow_test.minMinCut(minmincut); 

  int min_min_cut_value=cut_value(G,minmincut,cap);

  CutMap maxmincut(G,false);

  preflow_test.maxMinCut(maxmincut); 

  int max_min_cut_value=cut_value(G,maxmincut,cap);

  check(preflow_test.flowValue() == min_cut_value &&

	min_cut_value == min_min_cut_value &&

	min_min_cut_value == max_min_cut_value,

	"The max flow value is not equal to the three min cut values.");

  int flow_value=preflow_test.flowValue();

  for(EdgeIt e(G); e!=INVALID; ++e) cap[e]=2*cap[e]; 

  preflow_test.setCap(cap);  

  NodeIt tmp_node(G,t);

  ++tmp_node;

  t=tmp_node;

  preflow_test.setTarget(t); //the max flow value remains 2*flow_value

  //warning: ++t must be a valid node. In preflow_graph, it is.

  preflow_test.phase1(PType::PRE_FLOW);

  CutMap mincut1(G,false);

  preflow_test.minCut(mincut1); 

  min_cut_value=cut_value(G,mincut1,cap);

  check(preflow_test.flowValue() == min_cut_value &&

	min_cut_value == 2*flow_value,

	"The max flow value or the min cut value is wrong.");

  preflow_test.phase2();

  CutMap mincut2(G,false);

  preflow_test.minCut(mincut2); 

  min_cut_value=cut_value(G,mincut2,cap);

  CutMap minmincut2(G,false);

  preflow_test.minMinCut(minmincut2); 

  min_min_cut_value=cut_value(G,minmincut2,cap);

  preflow_test.maxMinCut(maxmincut); 

  max_min_cut_value=cut_value(G,maxmincut,cap);

  check(preflow_test.flowValue() == min_cut_value &&

	min_cut_value == min_min_cut_value &&

	min_min_cut_value == max_min_cut_value &&

	min_cut_value == 2*flow_value,

	"The max flow value or the three min cut values were not doubled");

  EdgeIt e(G);

  for( int i=1; i==1000; ++i ) {

    flow[e]=0;

    ++e;

  }

  preflow_test.setFlow(flow); 

  preflow_test.setSource(s);

  preflow_test.run();

  CutMap mincut3(G,false);

  preflow_test.minCut(mincut3); 

  min_cut_value=cut_value(G,mincut3,cap);

  CutMap minmincut3(G,false);

  preflow_test.minMinCut(minmincut3); 

  min_min_cut_value=cut_value(G,minmincut3,cap);

  preflow_test.maxMinCut(maxmincut); 

  max_min_cut_value=cut_value(G,maxmincut,cap);

  check(preflow_test.flowValue() == min_cut_value &&

	min_cut_value == min_min_cut_value &&

	min_min_cut_value == max_min_cut_value,

	"The max flow value or the three min cut values are incorrect.");

}