#!/usr/bin/perl
# UCW Gallery -- Master Program
# (c) 2012 Martin Mares <mj@ucw.cz>

use strict;
use warnings;
use Getopt::Long;

use FindBin;
my $gallery_root = $FindBin::Bin;

my $all;
my $parallel;

sub show_help() {
	print <<AMEN ;
Usage: gal <general-options> <command> <command-options> <args>

General options:
    --all		Run on all galleries in subdirectories
-p, --parallel=<n>	Run in parallel and use <n> processes

Common commands:
scan			Scan directory and obtain originals
gen			Generate web photos from originals
cache			Rebuild thumbnails and other cached info

Other commands:
dump-config		Show configuration settings
dump-meta		Show contents of metadata files
from-gqview		Parse gqview/geeqie collections
AMEN
	exit 0;
}

Getopt::Long::Configure('require_order', 'bundling');
GetOptions(
	"help" => \&show_help,
	"version" => sub {
			print "UCW Gallery 2.0 (c) 2004-2012 Martin Mares <mj\@ucw.cz>\n";
		},
	"all!" => \$all,
	"p|parallel=i" => \$parallel,
) or die "Try `gal help' for more information.\n";
Getopt::Long::Configure('default');

@ARGV or die "Missing subcommand.\n";
my $sub = shift @ARGV;
$sub =~ /^[0-9a-zA-Z-]+$/ or die "Invalid subcommand $sub\n";

if ($sub eq 'help') { show_help(); }

my $sub_path = "$gallery_root/bin/gal-$sub";
-x $sub_path or die "Unknown subcommand $sub\n";

$ENV{"GALLERY_ROOT"} = $gallery_root;
$ENV{"PERL5LIB"} = join(":", $gallery_root . "/lib", $ENV{"PERL5LIB"} // ());

if (!$all) {
	exec $sub_path, @ARGV;
	die "Cannot execute $sub_path: $!\n";
}

### Parallel execution ###

my @dirs = sort map { chomp; s{^\./}{}; s{\/gallery.cf}{}; $_; } `find . -mindepth 2 -name gallery.cf`;
my $done = 0;
my $need = @dirs;
my $logging = $parallel ? 1 : 0;
my $threads = $parallel // 1;

my $running = 0;
my $errors = 0;
my %pid_to_dir = ();

while ($running || @dirs) {
	if ($running == $threads || !@dirs) {
		# Wait for children
		my $pid = wait; die if $pid < 0;
		my $dir = $pid_to_dir{$pid} or die;
		if ($?) {
			print "!! $dir FAILED";
			print " [see $dir/gallery.log]" if $logging;
			$errors++;
		} else {
			print "++ $dir";
			unlink "$dir/gallery.log" if $logging;
		}
		delete $pid_to_dir{$pid};
		$running--;
		$done++;
		print " (done $done/$need)\n";
	} else {
		my $dir = shift @dirs;
		print "<< $dir\n";
		my $pid = fork;
		if (!$pid) {
			if ($logging) {
				close STDOUT;
				open STDOUT, '>', "$dir/gallery.log" or die;
				close STDERR;
				open STDERR, '>&STDOUT';
			}
			chdir $dir or die "Cannot chdir to $dir: $!\n";
			exec $sub_path, @ARGV;
			die "Cannot execute $sub_path: $!\n";
		}
		$pid_to_dir{$pid} = $dir;
		$running++;
	}
}

print "$done jobs, $errors errors.\n";
exit ($errors > 0);