# -*- perl -*-

sub usage {

    print STDERR "usage: $0 -oOutputFile PARM=value ...\n";

    print STDERR "  where acceptable PARM values are:\n";

    print STDERR "\t", join(' ', @parms), "\n";

    exit(1);

}

%parm = ();

sub run {

    my $arg;

    my $outfile;

    my %allowed_parms = ();

    foreach $arg (@parms) { $allowed_parms{$arg} = 1; }

    foreach $arg (@ARGV) {

	if ($arg =~ /^-o./) {

	    if (defined $outfile) {

		die "$0: Output file specified multiple times\n";

	    }

	    $outfile = substr($arg, 2);

	} else {

	    my @words = split '=', $arg;

	    if ($#words != 1) {

		print STDERR "$0: $arg : #words = $#words\n";

		&usage;

	    }

	    if (!defined $allowed_parms{$words[0]}) {

		print STDERR "$0: Unknown parameter $words[0]\n";

		&usage;

	    }

	    $parm{$words[0]} = $words[1];

	}

    }

    my $p;

    my $subst = "";

    #print "Keys defined: ", join(' ', keys %parm), "\n";

    foreach $p (@parms) {

	if (!defined $parm{$p}) {

	    die "$0: No value supplied for parameter $p\n";

	}

	# XXX More careful quoting of supplied value!

	$subst .= "\t\$a =~ s|<$p>|$parm{$p}|go;\n";

    }

    $subst = "sub do_substitution {\n"

	. "\tmy(\$a) = \@_;\n"

	. $subst

	. "\treturn \$a;\n"

	. "}\n"

	. "1;";

    eval $subst || die;

    if (defined $outfile) {

	open OUTFILE, ">$outfile" || die;

    } else {

	print STDERR "$0: No output file specified.\n";

	&usage;

    }

    print OUTFILE "/*\n";

    print OUTFILE " * This file is generated, please don't edit it.\n";

    print OUTFILE " * script: $0\n";

    print OUTFILE " * args:\n *\t", join("\n *\t", @ARGV), "\n";

    print OUTFILE " * The rest of this file is copied from a template, with\n";

    print OUTFILE " * substitutions.  See the template for copyright info.\n";

    print OUTFILE " */\n";

    while (<DATA>) {

	print OUTFILE &do_substitution($_);

    }

    close OUTFILE;

    exit (0);

}

1;