#!/bin/sh
exec perl -e '
use File::Find;
use IO::File;

use strict; use warnings;

my $timestamp_file = "headers.timestamp";
my $timestamp;
if (-e $timestamp_file) {
	$timestamp = mtime($timestamp_file);
} else {
	$timestamp = -1;
}

my @files = ();
find(\&wanted, ".");
sub wanted {
	my $b = $File::Find::name;
	$b =~ s,^\./,,;
	push @files, $b;
}
for my $b (@files) {
	if (($b =~ /\.b$/ || $b =~ /\.bb$/) && $b !~ m{(^|/)\.}) {
		my $bh = $b;
		$bh =~ s/$/h/; # .bh or .bbh
		if (mtime($b) > $timestamp || ! -s $bh) {
			my $is_c_plus_plus = $b =~ /\.bb$/ ? 1 : 0;
			# TODO get brace_parser.pl and brace_header so can use as a library
			print "$b -> $bh\n";
			my $bq = quotemeta($b);
			my $headers = `sh -c "< $bq brace_number_lines $bq | b2bh"`; # XXX will not cope with dodgy filenames  # win32
			prod($bh, $headers);
		}
	}
}

# update timestamp
IO::File->new($timestamp_file, "w")->print("not empty!");

sub mtime {
	my ($filename) = @_;
	return (stat($filename))[9];
}

sub slurp {
	my $f = IO::File->new($_[0], "r") or
		die "cannot open file \"$_[0]\" to read: $!";
	return join "", <$f>;
}

sub belch {
	my $f = IO::File->new($_[0], "w") or
		die "cannot open file \"$_[0]\" to write: $!";
	print $f $_[1] or
		die "cannot write to \"$_[0]\": $!";
}

sub prod {
	# used to be called belch_if_changed
	if (! -e $_[0] || slurp($_[0]) ne $_[1]) {
		belch($_[0], $_[1]);
	}
}
' "$@"