package make::utilities;
use Exporter 'import';
use POSIX;
@EXPORT = qw(make_rpath pkgconfig_get_include_dirs pkgconfig_get_lib_dirs translate_functions);

# Parse the output of a *_config program,
# such as pcre_config, take out the -L
# directive and return an rpath for it.

# \033[1;32msrc/Makefile\033[0m

my %already_added = ();

sub make_rpath($;$)
{
	my ($executable, $module) = @_;
	chomp($data = `$executable`);
	my $output = "";
	while ($data =~ /-L(\S+)/)
	{
		$libpath = $1;
		if (!exists $already_added{$libpath})
		{
			print "Adding extra library path to \033[1;32m$module\033[0m ... \033[1;32m$libpath\033[0m\n";
			$already_added{$libpath} = 1;
		}
		$output .= "-Wl,--rpath -Wl,$libpath -L$libpath ";
		$data =~ s/-L(\S+)//;
	}
	return $output;
}

sub extend_pkg_path()
{
	if (!exists $ENV{PKG_CONFIG_PATH})
	{
		$ENV{PKG_CONFIG_PATH} = "/usr/lib/pkgconfig:/usr/local/lib/pkgconfig:/usr/local/libdata/pkgconfig:/usr/X11R6/libdata/pkgconfig";
	}
	else
	{
		$ENV{PKG_CONFIG_PATH} .= ":/usr/local/lib/pkgconfig:/usr/local/libdata/pkgconfig:/usr/X11R6/libdata/pkgconfig";
	}
}

sub pkgconfig_get_include_dirs($$$;$)
{
	my ($packagename, $headername, $defaults, $module) = @_;
	extend_pkg_path();

	print "Locating include directory for package \033[1;32m$packagename\033[0m for module \033[1;32m$module\033[0m... ";

	$ret = `pkg-config --cflags $packagename 2>/dev/null`;
	if ((!defined $ret) || ($ret eq ""))
	{
		$foo = `locate "$headername" | head -n 1`;
		$foo =~ /(.+)\Q$headername\E/;
		if (defined $1)
		{
			$foo = "-I$1";
		}
		else
		{
			$foo = "";
		}
		$ret = "$foo";
	}
	if (($defaults ne "") && (($ret eq "") || (!defined $ret)))
	{
		$ret = "$foo " . $defaults;
	}
	chomp($ret);
	if (($ret eq " ") || (!defined $ret))
	{
		print "\033[1;32mUsing defaults\033[0m\n";
	}
	else
	{
		print "\033[1;32m$ret\033[0m\n";
	}
	return $ret;
}

sub pkgconfig_get_lib_dirs($$$;$)
{
	my ($packagename, $libname, $defaults, $module) = @_;
	extend_pkg_path();

	print "Locating library directory for package \033[1;32m$packagename\033[0m for module \033[1;32m$module\033[0m... ";

	$ret = `pkg-config --libs $packagename 2>/dev/null`;
	if ((!defined $ret) || ($ret eq ""))
	{
		$foo = `locate "$libname" | head -n 1`;
		$foo =~ /(.+)\Q$libname\E/;
		if (defined $1)
		{
			$foo = "-L$1";
		}
		else
		{
			$foo = "";
		}
		$ret = "$foo";
	}

	if (($defaults ne "") && (($ret eq "") || (!defined $ret)))
	{
		$ret = "$foo " . $defaults;
	}
	chomp($ret);
	if (($ret eq " ") || (!defined $ret))
	{
		print "\033[1;32mUsing defaults\033[0m\n";
	}
	else
	{
		print "\033[1;32m$ret\033[0m\n";
	}
	return $ret;
}

# Translate a $CompileFlags etc line and parse out function calls
# to functions within these modules at configure time.
sub translate_functions($$)
{
	my ($line,$module) = @_;

	eval
	{
		$module =~ /modules*\/(.+?)$/;
		$module = $1;

		# This is only a cursory check, just designed to catch casual accidental use of backticks.
		# There are pleanty of ways around it, but its not supposed to be for security, just checking
		# that people are using the new configuration api as theyre supposed to and not just using
		# backticks instead of eval(), being as eval has accountability. People wanting to get around
		# the accountability will do so anyway.
		if (($line =~ /`/) && ($line !~ /eval\(.+?`.+?\)/))
		{
			die "Developers should no longer use backticks in configuration macros. Please use exec() and eval() macros instead. Offending line: $line (In module: $module)";
		}
		while ($line =~ /exec\("(.+?)"\)/)
		{
			print "Executing program for module \033[1;32m$module\033[0m ... \033[1;32m$1\033[0m\n";
			my $replace = `$1`;
			chomp($replace);
			$line =~ s/exec\("(.+?)"\)/$replace/;
		}
		while ($line =~ /eval\("(.+?)"\)/)
		{
			print "Evaluating perl code for module \033[1;32m$module\033[0m ... ";
			my $tmpfile;
			do
			{
				$tmpfile = tmpnam();
			} until sysopen(TF, $tmpfile, O_RDWR|O_CREAT|O_EXCL, 0700);
			print "(Created and executed \033[1;32m$tmpfile\033[0m)\n";
			print TF $1;
			close TF;
			my $replace = `perl $tmpfile`;
			chomp($replace);
			$line =~ s/eval\("(.+?)"\)/$replace/;
		}
		while ($line =~ /pkgconflibs\("(.+?)","(.+?)","(.+?)"\)/)
		{
			my $replace = pkgconfig_get_lib_dirs($1, $2, $3, $module);
			$line =~ s/pkgconflibs\("(.+?)","(.+?)","(.+?)"\)/$replace/;
		}
		while ($line =~ /pkgconflibs\("(.+?)","(.+?)",""\)/)
		{
			my $replace = pkgconfig_get_lib_dirs($1, $2, "", $module);
			$line =~ s/pkgconflibs\("(.+?)","(.+?)",""\)/$replace/;
		}
		while ($line =~ /pkgconfincludes\("(.+?)","(.+?)",""\)/)
		{
			my $replace = pkgconfig_get_include_dirs($1, $2, "", $module);
			$line =~ s/pkgconfincludes\("(.+?)","(.+?)",""\)/$replace/;
		}
		while ($line =~ /pkgconfincludes\("(.+?)","(.+?)","(.+?)"\)/)
		{
			my $replace = pkgconfig_get_include_dirs($1, $2, $3, $module);
			$line =~ s/pkgconfincludes\("(.+?)","(.+?)","(.+?)"\)/$replace/;
		}
		while ($line =~ /rpath\("(.+?)"\)/)
		{
			my $replace = make_rpath($1,$module);
			$line =~ s/rpath\("(.+?)"\)/$replace/;
		}
	};
	if ($@)
	{
		print "\n\nConfiguration failed. The following error occured:\n\n$@\n";
		exit;
	}
	else
	{
		return $line;
	}
}

1;