#!/usr/bin/perl -w

# Parse a Packages file and store it in an MLDBM file for caching

use strict;
use warnings;

use MLDBM qw(DB_File Storable);
use Fcntl;

my %packages;
my %virtuals;
my %maints;
my $entry = {};
my $lastatt = undef;
my $count=0;
my $spinat=-1;
my @spinner = ( '|', '/', '-', '\\');

unlink($ENV{"HOME"} . "/.packages-dbm");
unlink($ENV{"HOME"} . "/.virtuals-dbm");
unlink($ENV{"HOME"} . "/.maints-dbm");
tie(%packages, "MLDBM", $ENV{"HOME"} . "/.packages-dbm", O_RDWR|O_CREAT, 0640);
tie(%virtuals, "MLDBM", $ENV{"HOME"} . "/.virtuals-dbm", O_RDWR|O_CREAT, 0640);
tie(%maints, "MLDBM", $ENV{"HOME"} . "/.maints-dbm", O_RDWR|O_CREAT, 0640);

$|=1;

print "Reading data... ";

sub handle_provides($) {
	my $ent = shift;
	my $item;

	for $item(split /,/,$ent->{Provides}) {
		my $pack;
		$item =~ s/^\s*//;
		$item =~ s/\s*$//;
		if(!exists $virtuals{$item}) {
			# If this virtual package also exists as a regular
			# package, this will be overwritten. Well, tough, we're
			# not checking that afterwards, anyway
			$pack = {};
			$pack->{Package} = $item;
			$pack->{Provider} = ();
		} else {
			my $pack = $virtuals{$item};
			if(!defined($pack->{Provider})) {
				$pack->{Provider} = ();
			}
		}
		push @{$pack->{Provider}}, $ent->{Package};
		$virtuals{$item} = $pack;
	}
}

while(<ARGV>) {
	chomp;
	if(/^$/) {
		my @val;
		my $dep;
		$count++;
		if($count>$spinat) {
			my $char=shift @spinner;
			if($count) {
				print '';
			}
			print $char;
			push @spinner, $char;
			$spinat+=100;
		}
		$packages{$entry->{Package}} = $entry;
		if(exists $maints{$entry->{Maintainer}}) {
			@val = $maints{$entry->{Maintainer}};
		} else {
			@val = ();
		}
		push @val, $entry->{Package};
		$maints{$entry->{Maintainer}} = \@val;
		if(exists $entry->{Provides}) {
			handle_provides($entry);
		}
		$entry = {};
		$lastatt = undef;
	}
	elsif(/^([^ :]*): (.*)$/) {
		my $name = $1;
		my $val = $2;

		$entry->{$name} = $val;
		$lastatt = \$entry->{$name};
	}
	elsif(/^\s(.*)$/) {
		$lastatt .= "\n$1";
	}
	else {
		die "Encountered unexpected line:\n$_\n";
	}
}

print " done ($count packages). Closing cache... ";
untie %packages;
untie %virtuals;
untie %maints;
print "ready. Have a nice day!\n";