#  Copyright (c) 1997-2015
#  Ewgenij Gawrilow, Michael Joswig (Technische Universitaet Berlin, Germany)
#  http://www.polymake.org
#
#  This program is free software; you can redistribute it and/or modify it
#  under the terms of the GNU General Public License as published by the
#  Free Software Foundation; either version 2, or (at your option) any
#  later version: http://www.gnu.org/licenses/gpl.txt.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#-------------------------------------------------------------------------------

REQUIRE polytope::_4ti2.rules

CREDIT 4ti2

# path to circuits
custom $circuits;

CONFIGURE {
    ($circuits=$polytope::groebner) =~ s/groebner$/circuits/;

}

label _4ti2

object Matroid {

   rule _4ti2.circuits : CIRCUITS : VECTORS {
      my $A = $this->VECTORS;
      $this->CIRCUITS = [@{index_matrix(_4ti2Circuits($A))}];
   }
   weight 3.01;

}


# @category Combinatorics
# Calculate the circuits of a set of points given as the rows of a Matrix A.
# The circuits are given as a matrix such that vA=0 for all rows v.
# @param Matrix A Matrix containing the points as rows.
# @return Matrix
user_function _4ti2Circuits(Matrix){
   my($A) = @_;
   my $tempname = new Tempfile;
   open(my $filePipe, ">".$tempname.".mat");
   print $filePipe $A->cols." ".$A->rows."\n";
   print $filePipe dense(transpose(primitive($A)));
   close($filePipe);
   
   if ($Verbose::external) {
      dbg_print( "running 4ti2: $circuits -q $tempname" );
   }
   system("$circuits -q $tempname".(!$DebugLevel && " >/dev/null 2>&1"))
      and die "couldn't run 4ti2: $circuits -q $tempname.mat\n";

   
   open(my $outfile, "<$tempname.cir")
      or die "can't open output file $tempname.cir: $!";
   
   my $dimline = <$outfile>;
   my @circuits=();
	local $_;
   while (<$outfile>) {
       my @vec = split;
       push @circuits, \@vec;
   }
   close $outfile;
   return new SparseMatrix(\@circuits);
}

