#!/usr/bin/perl
# Simple pkg-config implementation in perl
# jelmer@samba.org, November 2006

use strict;
use Getopt::Long;

my @dirs = split(/:/, $ENV{PKG_CONFIG_PATH});

my $opt_help = 0;
my $opt_libs = 0;
my $opt_cflags = 0;
my $opt_static = 0;

my $result = GetOptions (
	    'help|h|?' => \$opt_help, 
		'static' => \$opt_static,
		'libs' => \$opt_libs,
		'cflags' => \$opt_cflags
	    );

if (not $result) {
	exit(1);
}

if ($opt_help) {
	print "pkg-config replacement in perl\n";
	print "Copyright (C) 2006 Jelmer Vernooij <jelmer\@samba.org>\n";
	print "\n";
	print "Usage: pkg-config [OPTIONS] PACKAGE...\n";
	print " --help			Print this help message\n";
	print " --static		Print flags for static libraries\n";
	print " --libs			Print linker flags\n";
	print " --cflags		Print C compiler flags\n";
	print "\n";
	exit(0);
}

sub find_path($)
{
	my $name = shift;
	foreach my $dir (@dirs) {
		if (-f "$dir/$name-uninstalled.pc") {
			return "$dir/$name-uninstalled.pc";
		}
	} 
	foreach my $dir (@dirs) {
		if (-f "$dir/$name.pc" ) {
			return "$dir/$name.pc";
		}
	}
	die("No such package `$name'");
}

sub ReplaceVars($$)
{
	my ($expr, $vars) = @_;

	$_ = $expr;

	while (/(.*)\${([^}]+)}(.*)/) {
		$_ = "$1$vars->{$2}$3";
	}

	return $_;
}

sub Parse($)
{
	my $name = shift;
	my $path = find_path($name);
	my %variables = ();
	my %fields = ();
	my $lineno = 0;
	open(IN, "<$path") or die("Unable to open $path: $!");
	foreach (<IN>) {
		$lineno+=1;
		next if (/^#.*/);
		if (/^([A-Za-z.]+): (.*)$/) {
			$fields{$1} = ReplaceVars($2, \%variables);
		} elsif (/^([A-Za-z_]+)=(.*)$/) {
			$variables{$1} = ReplaceVars($2, \%variables);
		} elsif (/^[ \t]*$/) {
		} else {
			warn("$path:$lineno: parse error");
		}
	}
	close(IN);
	return \%fields;
}

sub Cflags($)
{
	my $name = shift;
	my $fields = Parse($name);
	my @cflags = split(/ /, $fields->{Cflags});
	foreach (split(/[, ]/, $fields->{Requires})) {
		push (@cflags, Cflags($_));
	}
	return @cflags;
}

sub Libs($)
{
	my $name = shift;
	my $fields = Parse($name);
	my @libs = split(/ /, $fields->{Libs});
	foreach (split(/[, ]/, $fields->{Requires})) {
		push (@libs, Libs($_));
	}
	if ($opt_static) {
		foreach (split(/[ ,]/, $fields->{"Requires.private"})) {
			push (@libs, Libs($_));
		}
	}
	return @libs;
}

my @out = ();

foreach my $pkg (@ARGV) 
{
	push (@out, Libs($pkg)) if ($opt_libs);
	push (@out, Cflags($pkg)) if ($opt_cflags);
}

if ($#out >= 0) {
	print join(' ', @out) . "\n";
}

exit 0;