#!/usr/bin/perl -w
#
# Generate symlinks in debian packages, reading debian/links. The
# file contains pairs of files and symlinks.

BEGIN { push @INC, "debian", "/usr/lib/debhelper" }
use Dh_Lib;
init();

foreach $PACKAGE (@{$dh{DOPACKAGES}}) {
	$TMP=tmpdir($PACKAGE);
	$file=pkgfile($PACKAGE,"links");

	undef @links;
	if ($file) {
		@links=filearray($file);
	}

	# Make sure it has pairs of symlinks and destinations. If it
	# doesn't, $#links will be _odd_ (not even, -- it's zero-based).
	if (int($#links/2) eq $#links/2) {
		error("$file lists a link without a destination.");
	}

	if (($PACKAGE eq $dh{FIRSTPACKAGE} || $dh{PARAMS_ALL}) && @ARGV) {
		push @links, @ARGV;
	}

	# Same test as above, including arguments this time.
	if (int($#links/2) eq $#links/2) {
		error("parameters list a link without a destination.");
	}

	# Now I'd prefer to work with a hash.
	%links=@links;

	foreach $src (keys %links) {
		$dest=$links{$src};
				
		# Make sure the directory the link will be in exists.
		$basedir=Dh_Lib::dirname("$TMP/$dest");
		if (! -e $basedir) {
			doit("install","-d",$basedir);
		}
		
		# Policy says that if the link is all within one toplevel
		# directory, it should be relative. If it's between
		# top level directories, leave it absolute.
		@src_dirs=split(m:/+:,$src);
		@dest_dirs=split(m:/+:,$dest);
		if ($src_dirs[0] eq $dest_dirs[0]) {
		    	# Figure out how much of a path $src and $dest
			# share in common.
			for ($x=0; $x<$#src_dirs && $src_dirs[$x] eq $dest_dirs[$x]; $x++) {}

			# Build up the new src.
			$src="";
			for (1..$#dest_dirs - $x) {
				$src.="../";
			}
			# The + 1 is here to include the actual filename.
			for (1..$#src_dirs - $x + 1) {
				$src.=$src_dirs[$_]."/";
			}
			$src=~s:/$::;
		}	
		
		doit("ln","-sf",$src,"$TMP/$dest");
	}
}