#ifndef MARCI_MAX_FLOW_HH

#define MARCI_MAX_FLOW_HH

#include <algorithm>

#include <marci_property_vector.hh>

#include <marci_bfs.hh>

namespace marci {

  template<typename graph_type, typename T>

  class res_graph_type { 

    typedef typename graph_type::node_iterator node_iterator;

    typedef typename graph_type::each_node_iterator each_node_iterator;

    typedef typename graph_type::sym_edge_iterator old_sym_edge_iterator;

    graph_type& G;

    edge_property_vector<graph_type, T>& flow;

    edge_property_vector<graph_type, T>& capacity;

  public:

    res_graph_type(graph_type& _G, edge_property_vector<graph_type, T>& _flow, edge_property_vector<graph_type, T>& _capacity) : G(_G), flow(_flow), capacity(_capacity) { }

    class edge_iterator {

      friend class res_graph_type<graph_type, T>;

    protected:

      res_graph_type<graph_type, T>* resG;

      old_sym_edge_iterator sym;

    public:

      edge_iterator() { }

      //bool is_free() {  

      //if (resG->G.a_node(sym)==resG->G.tail(sym)) { 

      //  return (resG->flow.get(sym)<resG->capacity.get(sym)); 

      //} else { 

      //  return (resG->flow.get(sym)>0); 

      //}

      //}

      T free() { 

	if (resG->G.a_node(sym)==resG->G.tail(sym)) { 

	  return (resG->capacity.get(sym)-resG->flow.get(sym)); 

	} else { 

	  return (resG->flow.get(sym)); 

	}

      }

      bool valid() { return sym.valid(); }

      void make_invalid() { sym.make_invalid(); }

      void augment(T a) {

	if (resG->G.a_node(sym)==resG->G.tail(sym)) { 

	  resG->flow.put(sym, resG->flow.get(sym)+a);

	} else { 

	  resG->flow.put(sym, resG->flow.get(sym)-a);

	}

      }

    };

    class out_edge_iterator : public edge_iterator {

    public:

      out_edge_iterator() { }

      out_edge_iterator(res_graph_type<graph_type, T>& _resG, const node_iterator& v) { 

      	resG=&_resG;

	sym=resG->G.first_sym_edge(v);

	while( sym.valid() && !(free()>0) ) { ++sym; }

      }

      out_edge_iterator& operator++() { 

	++sym; 

	while( sym.valid() && !(free()>0) ) { ++sym; }

	return *this; 

      }

    };

    out_edge_iterator first_out_edge(const node_iterator& v) {

      return out_edge_iterator(*this, v);

    }

    each_node_iterator first_node() {

      return G.first_node();

    }

    node_iterator tail(const edge_iterator& e) { return G.a_node(e.sym); }

    node_iterator head(const edge_iterator& e) { return G.b_node(e.sym); }

    int id(const node_iterator& v) { return G.id(v); }

    //node_iterator invalid_node() { return G.invalid_node(); }

    //res_edge_it invalid_edge() { res_edge_it n; n.sym=G.invalid_sym_edge(); return n; } 

  };

  template <typename graph_type, typename T>

  struct max_flow_type {

    typedef typename graph_type::node_iterator node_iterator;

    typedef typename graph_type::edge_iterator edge_iterator;

    typedef typename graph_type::each_node_iterator each_node_iterator;

    typedef typename graph_type::out_edge_iterator out_edge_iterator;

    typedef typename graph_type::in_edge_iterator in_edge_iterator;

    graph_type& G;

    node_iterator s;

    node_iterator t;

    edge_property_vector<graph_type, T> flow;

    edge_property_vector<graph_type, T>& capacity;

    max_flow_type(graph_type& _G, node_iterator _s, node_iterator _t, edge_property_vector<graph_type, T>& _capacity) : G(_G), s(_s), t(_t), flow(_G), capacity(_capacity) { 

      for(each_node_iterator i=G.first_node(); i.valid(); ++i) 

	for(out_edge_iterator j=G.first_out_edge(i); j.valid(); ++j) 

	  flow.put(j, 0);

    }

    void run() {

      typedef res_graph_type<graph_type, T> aug_graph_type;

      aug_graph_type res_graph(G, flow, capacity);

      bool augment;

      do {

	augment=false;

	typedef std::queue<aug_graph_type::out_edge_iterator> bfs_queue_type;

	bfs_queue_type bfs_queue;

	bfs_queue.push(res_graph.first_out_edge(s));

	typedef node_property_vector<aug_graph_type, bool> reached_type;

	reached_type reached(res_graph, false);

	reached.put(s, true); 

	bfs_iterator1< aug_graph_type, reached_type > 

	res_bfs(res_graph, bfs_queue, reached);

	typedef node_property_vector<aug_graph_type, aug_graph_type::edge_iterator> pred_type;

	pred_type pred(res_graph);

	aug_graph_type::edge_iterator a; 

	a.make_invalid();

	pred.put(s, a);

	typedef node_property_vector<aug_graph_type, int> free_type;

	free_type free(res_graph);

	//searching for augmenting path

	while ( res_bfs.valid() ) { 

	  //std::cout<<"KULSO ciklus itt jar: "<<G.id(res_graph.tail(res_bfs))<<"->"<<G.id(res_graph.head(res_bfs))<<std::endl;

	  if (res_bfs.newly_reached()) {

	    aug_graph_type::edge_iterator e;

	    e=res_bfs;

	    node_iterator v=res_graph.tail(e);

	    node_iterator w=res_graph.head(e);

	    //std::cout<<G.id(v)<<"->"<<G.id(w)<<", "<<G.id(w)<<" is newly reached";

	    pred.put(w, e);

	    if (pred.get(v).valid()) {

	      free.put(w, std::min(free.get(v), e.free()));

	      //std::cout <<" nem elso csucs: ";

	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";

	    } else {

	      free.put(w, e.free()); 

	      //std::cout <<" elso csucs: ";

	      //std::cout <<"szabad kap eddig: "<< free.get(w) << " ";

	    }

	    //std::cout<<std::endl;

	  }

	  if (res_graph.head(res_bfs)==t) break;

	  ++res_bfs;

	}

	if (reached.get(t)) {

	  augment=true;

	  node_iterator n=t;

	  T augment_value=free.get(t);

	  std::cout<<"augmentation: ";

	  while (pred.get(n).valid()) { 

	    aug_graph_type::edge_iterator e=pred.get(n);

	    e.augment(augment_value); 

	    std::cout<<"("<<res_graph.tail(e)<< "->"<<res_graph.head(e)<<") ";

	    n=res_graph.tail(e);

	  }

	  std::cout<<std::endl;

	}

	std::cout << "actual flow: "<< std::endl;

	for(typename graph_type::each_edge_iterator e=G.first_edge(); e.valid(); ++e) { 

	  std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";

	}

	std::cout<<std::endl;

      } while (augment);

    }

  };

} // namespace marci

#endif //MARCI_MAX_FLOW_HH