#!/usr/bin/perl -w

BEGIN {
  unshift @INC, ($::ENV{"BUILD_DIR"} || "/usr/lib/build");
}

use strict;
use Digest::MD5;
use File::Path;
use Getopt::Long;
use Build ':deb';
use Build::Deb;
use Build::Debrepo;

Getopt::Long::Configure("no_ignore_case");

#
# supported urls
#
# distribution:   <baseurl>/<dist>/[components]
# flat repo:      <baseurl>/.

my $cachedir = "/var/cache/build";
my $archpath;

GetOptions('cachedir=s'  => \$cachedir, 'archpath=s' => \$archpath) or exit(1);

if (!$archpath) {
  $archpath = `uname -p` || 'unknown';
  chomp $archpath;
}
my $basearch = $archpath;
$basearch =~ s/:.*//;
$basearch = Build::Deb::basearch($basearch);
my $pkgnum = 0;

for my $url (@ARGV) {
  die("$url: not an remote debian repo\n") unless $url =~ /^(:?ftps?|https?):\/\/([^\/]*)\/?/;
  my $repoid = Digest::MD5::md5_hex($url);
  my $dir = "$cachedir/$repoid";

  my @components;
  my $baseurl = $url;

  if ($url =~ /^(.*\/)\.(\/.*)?$/) {
    # flat repo
    $baseurl = $1;
    @components = ('.');
    $url = defined($2) ? "$1$2" : $1;
    $url .= '/' unless $url =~ /\/$/;
  } else {
    if ($url =~ /([^\/]+)$/) {
      @components = split(/[,+]/, $1);
      $url =~ s/([^\/]+)$//;
    }
    push @components, 'main' unless @components;
    $url .= '/' unless $url =~ /\/$/;
    $baseurl = $url;
    $url =~ s/([^\/]+\/)$/dists\/$1/;
    $baseurl =~ s/([^\/]+\/)$//;
  }

  File::Path::mkpath($dir);
  for my $component (@components) {
    unlink("$dir/Packages.gz");
    if ($component eq '.') {
      system($INC[0]."/download", $dir, "${url}Packages.gz");
      die("Packages.gz missing\n") unless -s "$dir/Packages.gz";
    } else {
      system($INC[0]."/download", $dir, "$url$component/binary-$basearch/Packages.gz");
      die("Packages.gz missing for basearch $basearch, component $component\n") unless -s "$dir/Packages.gz";
    }
    Build::Debrepo::parse("$dir/Packages.gz", sub {
      $pkgnum++;
      $_[0]->{'id'} = "$pkgnum/0/0";
      Build::writedeps(\*STDOUT, $_[0], $baseurl);
    }, 'addselfprovides' => 1);
  }
}