#!/usr/bin/perl

use warnings;
use strict;

use IO::Handle;
use IO::File;

my $version= '1.2.6'; # This line modified by Makefile

my %kmap= (optional         => 'suggests',
	   recommended      => 'recommends',
	   class            => 'priority',
	   package_revision => 'revision',
	  );

my @fieldpri= ('Package',
	       'Source',
	       'Version',
	       'Priority',
	       'Section',
	       'Essential',
	       'Maintainer',
	       'Pre-Depends',
	       'Depends',
	       'Recommends',
	       'Suggests',
	       'Conflicts',
	       'Provides',
	       'Replaces',
	       'Enhances',
	       'Architecture',
	       'Filename',
	       'Size',
	       'Installed-Size',
	       'MD5sum',
	       'Description',
	       'Origin',
	       'Bugs'
	      );

# This maps the fields into the proper case
my %field_case;
@field_case{map{lc($_)} @fieldpri} = @fieldpri;

use Getopt::Long qw(:config bundling);

my %options = (help            => 0,
	       udeb            => 0,
	       arch            => undef,
	       multiversion    => 0,
	      );

my $result = GetOptions(\%options,'help|h|?','udeb|u!','arch|a=s','multiversion|m!');

print <<END and exit 1 if not $result or $options{help} or @ARGV < 2;
dpkg-scanpackages [-u] [-a<arch>] [-m] binarypath overridefile [pathprefix] > Packages

 Options:
 --udeb, -u scan for udebs
 --arch, -a architecture to scan for
 --multiversion, -m allow multiple versions of a single package
 --help, -h show this help

END


my $udeb = $options{udeb};
my $arch = $options{arch};

my $ext = $options{udeb} ? 'udeb' : 'deb';
my @find_args;
if ($options{arch}) {
     @find_args = ('(','-name',"*_all.$ext",'-o','-name',"*_${arch}.$ext",')',);
}
else {
     @find_args = ('-name',"*.$ext");
}
push @find_args, '-follow';
my ($binarydir, $override, $pathprefix) = @ARGV;
-d $binarydir or die "Binary dir $binarydir not found\n";
-e $override or die "Override file $override not found\n";

$pathprefix = '' if not defined $pathprefix;

our %vercache;
sub vercmp {
     my ($a,$b)=@_;
     return $vercache{$a}{$b} if exists $vercache{$a}{$b};
     system('dpkg','--compare-versions',$a,'le',$b);
     $vercache{$a}{$b}=$?;
     return $?;
}

my %packages;
my $find_h = new IO::Handle;
open($find_h,'-|','find',"$binarydir/",@find_args,'-print')
     or die "Couldn't open $binarydir for reading: $!\n";
FILE:
    while (<$find_h>) {
	chomp;
	my $fn = $_;
	my $control = `dpkg-deb -I $fn control`;
	if ($control eq "") {
	    warn "Couldn't call dpkg-deb on $fn: $!, skipping package\n";
	    next;
	}
	if ($?) {
	    warn "\`dpkg-deb -I $fn control' exited with $?, skipping package\n";
	    next;
	}
	
	my %tv = ();
	my $temp = $control;
	while ($temp =~ s/^\n*(\S+):[ \t]*(.*(\n[ \t].*)*)\n//) {
	    my ($key,$value)= (lc $1,$2);
	    if (defined($kmap{$key})) { $key= $kmap{$key}; }
	    if (defined($field_case{$key})) { $key= $field_case{$key}; }
	    $value =~ s/\s+$//;
	    $tv{$key}= $value;
	}
	$temp =~ /^\n*$/
	    or die "Unprocessed text from $fn control file; info:\n$control / $temp\n";
	
	defined($tv{'Package'})
	    or die "No Package field in control file of $fn\n";
	my $p= $tv{'Package'}; delete $tv{'Package'};
	
	if (defined($packages{$p}) and not $options{multiversion}) {
	    foreach (@{$packages{$p}}) {
		if (&vercmp($tv{'Version'}, $_->{'Version'})) {
		    print(STDERR " ! Package $p (filename $fn) is repeat but newer version;\n".
			  "   used that one and ignored data from $_->{Filename} !\n")
			|| die $!;
		    $packages{$p} = [];
		} else {
		    print(STDERR " ! Package $p (filename $fn) is repeat;\n".
			  "   ignored that one and using data from $_->{Filename} !\n")
			or die $!;
		    next FILE;
		}
	    }
	}
	print(STDERR " ! Package $p (filename $fn) has Filename field!\n") || die $!
	    if defined($tv{'Filename'});
	
	$tv{'Filename'}= "$pathprefix$fn";
	
	open(C,"md5sum <$fn |") || die "$fn $!";
	chop($_=<C>); close(C); $? and die "\`md5sum < $fn' exited with $?\n";
	/^([0-9a-f]{32})\s*-?\s*$/ or die "Strange text from \`md5sum < $fn': \`$_'\n";
	$tv{'MD5sum'}= $1;
	
	my @stat= stat($fn) or die "Couldn't stat $fn: $!\n";
	$stat[7] or die "$fn is empty\n";
	$tv{'Size'}= $stat[7];
	
	if (defined $tv{Revision} and length($tv{Revision})) {
	    $tv{Version}.= '-'.$tv{Revision};
	    delete $tv{Revision};
	}
	
	push @{$packages{$p}}, {%tv};
    }
close($find_h);

select(STDERR); $= = 1000; select(STDOUT);

sub writelist {
    my $title= shift(@_);
    return unless @_;

    print(STDERR " $title\n") || die $!;
    my $packages= join(' ',sort @_);

format STDERR =
  ^<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
$packages
.
    while (length($packages)) { write(STDERR) || die $!; }
    print(STDERR "\n") || die $!;
}

my (@samemaint,@changedmaint);


my %overridden;
my $override_fh = new IO::File $override,'r'
    or die "Couldn't open override file $override: $!\n";
while (<$override_fh>) {
    s/\#.*//;
    s/\s+$//;
    next unless $_;
    my ($p,$priority,$section,$maintainer)= split(/\s+/,$_,4);
    next unless defined($packages{$p});
    for my $package (@{$packages{$p}}) {
	 if ($maintainer) {
	      if ($maintainer =~ m/(.+?)\s*=\>\s*(.+)/) {
		   my $oldmaint= $1;
		   my $newmaint= $2;
		   my $debmaint= $$package{Maintainer};
		   if (!grep($debmaint eq $_, split(m:\s*//\s*:, $oldmaint))) {
			push(@changedmaint,
			     "  $p (package says $$package{Maintainer}, not $oldmaint)\n");
		   } else {
			$$package{Maintainer}= $newmaint;
		   }
	       } elsif ($$package{Maintainer} eq $maintainer) {
		   push(@samemaint,"  $p ($maintainer)\n");
	       } else {
		   print(STDERR " * Unconditional maintainer override for $p *\n") || die $!;
		   $$package{Maintainer}= $maintainer;
	       }
	  }
	 $$package{Priority}= $priority;
	 $$package{Section}= $section;
    }
    $overridden{$p} = 1;
}
close($override_fh);

my @missingover=();

my $records_written = 0;
for my $p (sort keys %packages) {
    if (not defined($overridden{$p})) {
        push(@missingover,$p);
    }
    for my $package (@{$packages{$p}}) {
	 my $record= "Package: $p\n";
	 for my $key (@fieldpri) {
	      next unless defined $$package{$key};
	      $record .= "$key: $$package{$key}\n";
	 }
	 $record .= "\n";
	 $records_written++;
	 print(STDOUT $record) or die "Failed when writing stdout: $!\n";
    }
}
close(STDOUT) or die "Couldn't close stdout: $!\n";

my @spuriousover= grep(!defined($packages{$_}),sort keys %overridden);

&writelist("** Packages in archive but missing from override file: **",
           @missingover);
if (@changedmaint) {
    print(STDERR
          " ++ Packages in override file with incorrect old maintainer value: ++\n",
          @changedmaint,
          "\n") || die $!;
}
if (@samemaint) {
    print(STDERR
          " -- Packages specifying same maintainer as override file: --\n",
          @samemaint,
          "\n") || die $!;
}
if (@spuriousover) {
    print(STDERR
          " -- Packages in override file but not in archive: --\n",
          @spuriousover,
          "\n") || die $!;
}

print(STDERR " Wrote $records_written entries to output Packages file.\n") || die $!;