// -*- c++ -*-
#ifndef HUGO_LP_SOLVER_WRAPPER_H
#define HUGO_LP_SOLVER_WRAPPER

///\ingroup misc
///\file
///\brief Dijkstra algorithm.

// #include <stdio.h>
#include <stdlib.h>
// #include <stdio>
//#include <stdlib>
#include "glpk.h"

#include <iostream>
#include <vector>
#include <string>
#include <list>
#include <memory>
#include <utility>

//#include <sage_graph.h>
//#include <hugo/list_graph.h>
//#include <hugo/graph_wrapper.h>
#include <hugo/invalid.h>
//#include <bfs_dfs.h>
//#include <stp.h>
//#include <hugo/max_flow.h>
//#include <augmenting_flow.h>
//#include <iter_map.h>

using std::cout;
using std::cin;
using std::endl;

namespace hugo {

  
  /// \addtogroup misc
  /// @{

  /// \brief A partitioned vector with iterable classes.
  ///
  /// This class implements a container in which the data is stored in an 
  /// stl vector, the range is partitioned into sets and each set is 
  /// doubly linked in a list. 
  /// That is, each class is iterable by hugo iterators, and any member of 
  /// the vector can bo moved to an other class.
  template <typename T>
  class IterablePartition {
  protected:
    struct Node {
      T data;
      int prev; //invalid az -1
      int next; 
    };
    std::vector<Node> nodes;
    struct Tip {
      int first;
      int last;
    };
    std::vector<Tip> tips;
  public:
    /// The classes are indexed by integers from \c 0 to \c classNum()-1.
    int classNum() const { return tips.size(); }
    /// This hugo style iterator iterates through a class. 
    class ClassIt;
    /// Constructor. The number of classes is to be given which is fixed 
    /// over the life of the container. 
    /// The partition classes are indexed from 0 to class_num-1. 
    IterablePartition(int class_num) { 
      for (int i=0; i<class_num; ++i) {
	Tip t;
	t.first=t.last=-1;
	tips.push_back(t);
      }
    }
  protected:
    void befuz(ClassIt it, int class_id) {
      if (tips[class_id].first==-1) {
	if (tips[class_id].last==-1) {
	  nodes[it.i].prev=nodes[it.i].next=-1;
	  tips[class_id].first=tips[class_id].last=it.i;
	}
      } else {
	nodes[it.i].prev=tips[class_id].last;
	nodes[it.i].next=-1;
	nodes[tips[class_id].last].next=it.i;
	tips[class_id].last=it.i;
      }
    }
    void kifuz(ClassIt it, int class_id) {
      if (tips[class_id].first==it.i) {
	if (tips[class_id].last==it.i) {
	  tips[class_id].first=tips[class_id].last=-1;
	} else {
	  tips[class_id].first=nodes[it.i].next;
	  nodes[nodes[it.i].next].prev=-1;
	}
      } else {
	if (tips[class_id].last==it.i) {
	  tips[class_id].last=nodes[it.i].prev;
	  nodes[nodes[it.i].prev].next=-1;
	} else {
	  nodes[nodes[it.i].next].prev=nodes[it.i].prev;
	  nodes[nodes[it.i].prev].next=nodes[it.i].next;
	}
      }
    }
  public:
    /// A new element with data \c t is pushed into the vector and into class 
    /// \c class_id.
    ClassIt push_back(const T& t, int class_id) { 
      Node n;
      n.data=t;
      nodes.push_back(n);
      int i=nodes.size()-1;
      befuz(i, class_id);
      return i;
    }
    /// A member is moved to an other class.
    void set(ClassIt it, int old_class_id, int new_class_id) {
      kifuz(it.i, old_class_id);
      befuz(it.i, new_class_id);
    }
    /// Returns the data pointed by \c it.
    T& operator[](ClassIt it) { return nodes[it.i].data; }
    /// Returns the data pointed by \c it.
    const T& operator[](ClassIt it) const { return nodes[it.i].data; }
    ///.
    class ClassIt {
      friend class IterablePartition;
    protected:
      int i;
    public:
      /// Default constructor.
      ClassIt() { }
      /// This constructor constructs an iterator which points
      /// to the member of th container indexed by the integer _i.
      ClassIt(const int& _i) : i(_i) { }
      /// Invalid constructor.
      ClassIt(const Invalid&) : i(-1) { }
    };
    /// First member of class \c class_id.
    ClassIt& first(ClassIt& it, int class_id) const {
      it.i=tips[class_id].first;
      return it;
    }
    /// Next member.
    ClassIt& next(ClassIt& it) const {
      it.i=nodes[it.i].next;
      return it;
    }
    /// True iff the iterator is valid.
    bool valid(const ClassIt& it) const { return it.i!=-1; }
  };
  
  /// \brief Wrappers for LP solvers
  /// 
  /// This class implements a hugo wrapper for glpk.
  /// Later other LP-solvers will be wrapped into hugo.
  /// The aim of this class is to give a general surface to different 
  /// solvers, i.e. it makes possible to write algorithms using LP's, 
  /// in which the solver can be changed to an other one easily.
  class LPSolverWrapper {
  public:

//   class Row {
//   protected:
//     int i;
//   public:
//     Row() { }
//     Row(const Invalid&) : i(0) { }
//     Row(const int& _i) : i(_i) { }
//     operator int() const { return i; }
//   };
//   class RowIt : public Row {
//   public:
//     RowIt(const Row& row) : Row(row) { }
//   };

//   class Col {
//   protected:
//     int i;
//   public:
//     Col() { }
//     Col(const Invalid&) : i(0) { }
//     Col(const int& _i) : i(_i) { }
//     operator int() const { return i; }
//   };
//   class ColIt : public Col {
//     ColIt(const Col& col) : Col(col) { }
//   };

  public:
    ///.
    LPX* lp;
    ///.
    typedef IterablePartition<int>::ClassIt RowIt;
    ///.
    IterablePartition<int> row_iter_map;
    ///.
    typedef IterablePartition<int>::ClassIt ColIt;
    ///.
    IterablePartition<int> col_iter_map;
    //std::vector<int> row_id_to_lp_row_id;
    //std::vector<int> col_id_to_lp_col_id;
    ///.
    const int VALID_ID;
    ///.
    const int INVALID_ID;

  public:
    ///.
    LPSolverWrapper() : lp(lpx_create_prob()), 
			row_iter_map(2), 
			col_iter_map(2), 
			//row_id_to_lp_row_id(), col_id_to_lp_col_id(), 
			VALID_ID(0), INVALID_ID(1) {
      lpx_set_int_parm(lp, LPX_K_DUAL, 1);
    }
    ///.
    ~LPSolverWrapper() {
      lpx_delete_prob(lp);
    }
    ///.
    void setMinimize() { 
      lpx_set_obj_dir(lp, LPX_MIN);
    }
    ///.
    void setMaximize() { 
      lpx_set_obj_dir(lp, LPX_MAX);
    }
    ///.
    ColIt addCol() {
      int i=lpx_add_cols(lp, 1);  
      ColIt col_it;
      col_iter_map.first(col_it, INVALID_ID);
      if (col_iter_map.valid(col_it)) { //van hasznalhato hely
	col_iter_map.set(col_it, INVALID_ID, VALID_ID);
	col_iter_map[col_it]=i;
	//col_id_to_lp_col_id[col_iter_map[col_it]]=i;
      } else { //a cucc vegere kell inzertalni mert nincs szabad hely
	//col_id_to_lp_col_id.push_back(i);
	//int j=col_id_to_lp_col_id.size()-1;
	col_it=col_iter_map.push_back(i, VALID_ID);
      }
//    edge_index_map.set(e, i);
//    lpx_set_col_bnds(lp, i, LPX_DB, 0.0, 1.0);
//    lpx_set_obj_coef(lp, i, cost[e]);    
      return col_it;
    }
    ///.
    RowIt addRow() {
      int i=lpx_add_rows(lp, 1);  
      RowIt row_it;
      row_iter_map.first(row_it, INVALID_ID);
      if (row_iter_map.valid(row_it)) { //van hasznalhato hely
	row_iter_map.set(row_it, INVALID_ID, VALID_ID);
	row_iter_map[row_it]=i;
      } else { //a cucc vegere kell inzertalni mert nincs szabad hely
	row_it=row_iter_map.push_back(i, VALID_ID);
      }
      return row_it;
    }
    //pair<RowIt, double>-bol kell megadni egy std range-et
    ///.
    template <typename Begin, typename End>
    void setColCoeffs(const ColIt& col_it, 
		      Begin begin, End end) {
      int mem_length=1+lpx_get_num_rows(lp);
      int* indices = new int[mem_length];
      double* doubles = new double[mem_length];
      int length=0;
      for ( ; begin!=end; ++begin) {
	++length;
	indices[length]=row_iter_map[begin->first];
	doubles[length]=begin->second;
      }
      lpx_set_mat_col(lp, col_iter_map[col_it], length, indices, doubles);
      delete [] indices;
      delete [] doubles;
    }
    //pair<ColIt, double>-bol kell megadni egy std range-et
    ///.
    template <typename Begin, typename End>
    void setRowCoeffs(const RowIt& row_it, 
		      Begin begin, End end) {
      int mem_length=1+lpx_get_num_cols(lp);
      int* indices = new int[mem_length];
      double* doubles = new double[mem_length];
      int length=0;
      for ( ; begin!=end; ++begin) {
	++length;
	indices[length]=col_iter_map[begin->first];
	doubles[length]=begin->second;
      }
      lpx_set_mat_row(lp, row_iter_map[row_it], length, indices, doubles);
      delete [] indices;
      delete [] doubles;
    }
    ///.
    void eraseCol(const ColIt& col_it) {
      col_iter_map.set(col_it, VALID_ID, INVALID_ID);
      int cols[2];
      cols[1]=col_iter_map[col_it];
      lpx_del_cols(lp, 1, cols);
      col_iter_map[col_it]=0; //glpk specifikus
      ColIt it;
      for (col_iter_map.first(it, VALID_ID); 
	   col_iter_map.valid(it); col_iter_map.next(it)) {
	if (col_iter_map[it]>cols[1]) --col_iter_map[it];
      }
    }
    ///.
    void eraseRow(const RowIt& row_it) {
      row_iter_map.set(row_it, VALID_ID, INVALID_ID);
      int rows[2];
      rows[1]=row_iter_map[row_it];
      lpx_del_rows(lp, 1, rows);
      row_iter_map[row_it]=0; //glpk specifikus
      RowIt it;
      for (row_iter_map.first(it, VALID_ID); 
	   row_iter_map.valid(it); row_iter_map.next(it)) {
	if (row_iter_map[it]>rows[1]) --row_iter_map[it];
      }
    }
    ///.
    void setColBounds(const ColIt& col_it, int bound_type, 
		      double lo, double up) {
      lpx_set_col_bnds(lp, col_iter_map[col_it], bound_type, lo, up);
    }
    ///.
    void setObjCoef(const ColIt& col_it, double obj_coef) { 
      lpx_set_obj_coef(lp, col_iter_map[col_it], obj_coef);
    }
    ///.
    void setRowBounds(const RowIt& row_it, int bound_type, 
		      double lo, double up) {
      lpx_set_row_bnds(lp, row_iter_map[row_it], bound_type, lo, up);
    }
//   void setObjCoef(const RowIt& row_it, double obj_coef) { 
//     lpx_set_obj_coef(lp, row_iter_map[row_it], obj_coef);
//   }
    ///.
    void solveSimplex() { lpx_simplex(lp); }
    ///.
    void solvePrimalSimplex() { lpx_simplex(lp); }
    ///.
    void solveDualSimplex() { lpx_simplex(lp); }
    ///.
    double getPrimal(const ColIt& col_it) {
      return lpx_get_col_prim(lp, col_iter_map[col_it]);
    }
    ///.
    double getObjVal() { return lpx_get_obj_val(lp); }
    ///.
    int rowNum() const { return lpx_get_num_rows(lp); }
    ///.
    int colNum() const { return lpx_get_num_cols(lp); }
    ///.
    int warmUp() { return lpx_warm_up(lp); }
    ///.
    void printWarmUpStatus(int i) {
      switch (i) {
	case LPX_E_OK: cout << "LPX_E_OK" << endl; break;
	case LPX_E_EMPTY: cout << "LPX_E_EMPTY" << endl; break;	
	case LPX_E_BADB: cout << "LPX_E_BADB" << endl; break;
	case LPX_E_SING: cout << "LPX_E_SING" << endl; break;
      }
    }
    ///.
    int getPrimalStatus() { return lpx_get_prim_stat(lp); }
    ///.
    void printPrimalStatus(int i) {
      switch (i) {
	case LPX_P_UNDEF: cout << "LPX_P_UNDEF" << endl; break;
	case LPX_P_FEAS: cout << "LPX_P_FEAS" << endl; break;	
	case LPX_P_INFEAS: cout << "LPX_P_INFEAS" << endl; break;
	case LPX_P_NOFEAS: cout << "LPX_P_NOFEAS" << endl; break;
      }
    }
    ///.
    int getDualStatus() { return lpx_get_dual_stat(lp); }
    ///.
    void printDualStatus(int i) {
      switch (i) {
	case LPX_D_UNDEF: cout << "LPX_D_UNDEF" << endl; break;
	case LPX_D_FEAS: cout << "LPX_D_FEAS" << endl; break;	
	case LPX_D_INFEAS: cout << "LPX_D_INFEAS" << endl; break;
	case LPX_D_NOFEAS: cout << "LPX_D_NOFEAS" << endl; break;
      }
    }
    /// Returns the status of the slack variable assigned to row \c row_it.
    int getRowStat(const RowIt& row_it) { 
      return lpx_get_row_stat(lp, row_iter_map[row_it]); 
    }
    ///.
    void printRowStatus(int i) {
      switch (i) {
	case LPX_BS: cout << "LPX_BS" << endl; break;
	case LPX_NL: cout << "LPX_NL" << endl; break;	
	case LPX_NU: cout << "LPX_NU" << endl; break;
	case LPX_NF: cout << "LPX_NF" << endl; break;
	case LPX_NS: cout << "LPX_NS" << endl; break;
      }
    }
    /// Returns the status of the variable assigned to column \c col_it.
    int getColStat(const ColIt& col_it) { 
      return lpx_get_col_stat(lp, col_iter_map[col_it]); 
    }
    ///.
    void printColStatus(int i) {
      switch (i) {
	case LPX_BS: cout << "LPX_BS" << endl; break;
	case LPX_NL: cout << "LPX_NL" << endl; break;	
	case LPX_NU: cout << "LPX_NU" << endl; break;
	case LPX_NF: cout << "LPX_NF" << endl; break;
	case LPX_NS: cout << "LPX_NS" << endl; break;
      }
    }
  };
  
  /// @}

} //namespace hugo

#endif //HUGO_LP_SOLVER_WRAPPER_H