use strict;
use warnings;
use Text::CSV;

die "usage: $0 SourceFile TargetFile MappingFile\n" if @ARGV < 3;

my $csv = Text::CSV->new({ auto_diag=>1, binary=>1, eol=>"\n" });

my %map;
open my $MAP, '<', $ARGV[2] or die "Can't read $ARGV[2]: $!";
while (my $row = $csv->getline($MAP)) {
   my ($old_cost, $old_act, $new_cost, $new_act) = @$row;
   $map{$old_cost}{$old_act} = [$new_cost, $new_act];
}
close $MAP;

open my $IN, '<', $ARGV[0] or die "Can't read $ARGV[0]: $!";
open my $OUT, '>', $ARGV[1] or die "Can't write $ARGV[1]: $!";
while (my $row = $csv->getline($IN)) {
   if (my $new = $map{$row->[6]}{$row->[7]}) {
      $row->[6] = $new->[0];
      $row->[7] = $new->[1];
   }
   $csv->print($OUT, $row);
}
close $IN;
close $OUT;