#!perl

my %unit = (
   silver   => 1,
   gold     => 10,
   platina  => 50,
   royalty  => 5000,
); 

my %aliases = (
   platinum => 'platina',
   royalties => 'royalty'
);

sub find_unpaid {
   my ($ob) = @_;

   my @unpaid;
   for ($ob->inv) {
      push @unpaid, $_
         if $_->get_flag (cf::FLAG_UNPAID);

      if ($_->inv) {
         push @unpaid, find_unpaid ($_->inv);
      }
   }
   return @unpaid;
}

sub on_trigger {
   my ($ev, $ob, $who_caused, $who) = @_;
   my $opt = $ev->options;
   return 0 unless $opt =~ m/(\d+),(\d+)/;
   my $val = 0;
   $val += $_->value for find_unpaid ($who);
   warn "PAID $val\n";
   return 0;
}

sub on_drop_on {
   my ($ev, $on, $who, $what) = @_;
   my $name = $what->custom_name;

   if ($what->get_flag (cf::FLAG_UNPAID)) {
      return 0;
   }

   unless ($name =~ m/\d+\s*\S+/) {
      $who->message ("The shopkeeper says: Sorry, i don't recognize '$name' as currency. Please name your item like '10 royalty' or '10 platinum 2 silver'");
      $what->insert_ob_in_ob ($who);
      return 1;
   }

   my $value = 0;
   while ($name =~ s/^\s*(\d+)\s*(\S+)//) {
      if ($aliases{lc $2} or $unit{lc $2}) {
         $value += $1 * ($unit{lc $2} ? $unit{lc $2} : $unit{$aliases{lc $2}});
      } else {
         $what->insert_ob_in_ob ($who);
         $who->message ("The shopkeeper says: I don't know the currency '$2'");
         return 1;
      }
   }

   $what->set_value ($value);
   my $cost = $what->query_cost ($who, cf::F_BUY | cf::F_SHOP);

   if ($cost) {
      my $fact = $value / $cost;
      $what->set_value (cf::ceil ($value * $fact));
   }

   $what->set_flag (cf::FLAG_UNPAID, 1);
   $what->{seller} = $who->name;
   $what->set_custom_name (undef);
   $what->insert_ob_in_map_at ($who->map, $who, cf::INS_BELOW_ORIGINATOR, $who->x, $who->y);
   1;
}