#!/usr/bin/perl

use strict;
use warnings;

use DB_File;

use lib './lib';

use Deb::Versions;

unless (@ARGV == 2) {
	die "Usage: create_changelogs_map <db_dir> <changelogs_map_file>\n";
}

my ($dbdir, $outfile) = @ARGV;

tie my %src_packages, 'DB_File', "$dbdir/sources_small.db",
    O_RDONLY, 0666, $DB_BTREE
    or die "couldn't tie DB $dbdir/sources_small.db: $!";
tie my %src2bin, 'DB_File', "$dbdir/sources_packages.db",
    O_RDONLY, 0666, $DB_BTREE
    or die "couldn't open $dbdir/sources_packages.db: $!";

open my $out, '>', "$outfile.new"
    or die "couldn't open $outfile.new: $!";

sub get_dir_from_name {
    my $name = shift;

    if ($name =~ /^(lib.)/o) {
	return "$1/$name";
    } else {
	return substr( $name, 0, 1 )."/$name";
    }
}

use Data::Dumper;
my %bin;
while (my ($source, $data) = each %src_packages) {
    my @src = map { [ split(/\s+/) ] } split( /\0/, $data );
    my $newest = (sort( { version_cmp($b->[-1],$a->[-1]) } @src))[0];
    my ($section, $version) = @{$newest}[2,5];
    my $directory = get_dir_from_name($source);
#    warn "src=$source sect=$section v=$version dir=$directory\n";

    my $bin_data = $src2bin{$source};
    unless ($bin_data) {
	warn "no binary data found for $source\n";
	# source packages without binaries have most
	# likely been succeded
	next;
    }

    print $out "$source\tpool/$section/$directory/current/changelog\n";

    my @bin = map { [ split(/\s+/) ] } split( /\0/, $bin_data );
    my %seen;
    foreach (@bin) {
	my ($pkg, $ver) = @{$_}[2,3];
	next if $seen{"$pkg/$ver"}++; # weed out multiple arches/suites faster
	if ($bin{$pkg}
	    && ($bin{$pkg}{source} ne $source)
	    && (version_cmp($bin{$pkg}{version},$ver) > 0)) {
	    warn "ignore $pkg/$ver from $source for ".
		"$pkg/$bin{$pkg}{version} from $bin{$pkg}{source}\n";
	    next;
	} else {
	    $bin{$pkg} = { version => $ver, source => $source,
			   target => "$section/$directory" };
	}
    }
}

while (my ($pkg, $data) = each %bin) {
#    warn "pkg=$pkg v=$data->{version} src=$data->{source} tgt=$data->{target}\n";
    print $out "$pkg\tpool/$data->{target}/current/changelog\n";
}

close $out or warn $!;
rename("$outfile.new", $outfile);