#!/usr/bin/perl
# -*- perl -*-

use Foomatic::Defaults;
use Foomatic::DB;
use Cwd;

my ($db) = new Foomatic::DB;

use Getopt::Std;
getopts('ft:j:hd:') || help();
my $force = ($opt_f ? 1 : 0);
my $debug = 0;

# Do the whole world

sub help {
    print STDERR <<EOF;
compile_db [ -f ] [ -t type ] [ -d destdir] [ -j n ] [driver1] [driver2] ...
 -f       force: proceed even if the destination directory exists
 -t type  output file type: ppd or xml
 -j n     n==number of work processes to run at the same time
 -d destdir  put PPD files in this directory
 driver1 driver2 ...  
          only compile the database for these drivers
EOF

    exit 1;
}

help() if ($opt_h);

# Default file type are PPD files
if (!$opt_t) {
    $opt_t = "ppd";
}
my $destdir;
if( $opt_d ){
    $destdir = $destdir;
}

print STDERR "\n";
# Destination directory
my $pwd = cwd;

if (($opt_t eq "ppd") || ($opt_t eq "cups") || ($opt_t eq "ppr")) {
    # Generic PPDs
    $filetype = "ppd";
    $destdir = "$pwd/ppd" if not defined( $destdir );
    $suffix = ".ppd";
    print STDERR "Generating Foomatic PPD files ...\n";
} elsif ($opt_t eq "xml") {
    $filetype = "xml";
    $destdir = "$pwd/combo-xml" if not defined( $destdir );
    $suffix = ".xml";
    print STDERR "Generating Foomatic printer/driver combo XML files ...\n";
} else {
    die "Unknown file type: $opt_t!\n";
}

print STDERR "\nStoring files in directory $destdir.\n";
mkdir $destdir, 0777 or $force or die "\nCannot make destination directory (If the directory already exists and you\nwant to proceed anyway, use the \"-f\" option)!\n";

# Compute the overview
$db->get_overview();

# Which drivers should be processed?
my @driverlist;
if (@ARGV) {
    @driverlist = grep {isdrivervalid($_)} @ARGV;
} else {
    @driverlist = grep {isdrivervalid($_)} $db->get_driverlist();
}

# Subprocess to compute all p/d combinations
my @combos;
if (open COMB, '-|') {
    while(<COMB>) {
	push (@combos, $_);
    }
    close COMB;			# wait for child end
} else {
    my $driver;
    for $driver (@driverlist) {
	my $printer;
	for $printer ($db->get_printers_for_driver($driver)) {
	    # Note this combo...
	    print STDOUT "$printer,$driver\n";
	}
    }
    exit 0;			# end of subprocessing
}

# OK, spawn n manager processes
# create lists to process
$opt_j = 0 if( not defined $opt_j );
$opt_j += 0;
$opt_j = 1 if( not $opt_j or $opt_j < 0 );

my $n = 0;
my $rcombos = [];
my @rcombos;
for( $n = 0; $n < $opt_j; ++$n ){
    $rcombos->[$n] = [];
}
$n = 0;
while( @combos ){
	my $pos = int(rand(scalar(@combos)));
	my $j = $n % $opt_j;
	print "$n: combos " . scalar(@combos) . ", pos $pos, id $j\n" if $debug;
	push( @{$rcombos->[$n % $opt_j]}, splice( @combos, $pos, 1 ) );
	++$n;
}
my (@pids, $pid );
for( $n = 0; $n < $opt_j; ++$n ){
    $pid = fork();
    if( ! defined( $pid ) ){
	warn( "cannot fork child process" );
	break;
    } elsif( ! $pid ){
	    # Child, go on immediately
	@rcombos = @{$rcombos->[$n]};
	    last;
	}
    print "process $pid\n" if $debug;
}
if( $pid ){
	# we wait for the processes
	while( ($pid = wait()) > 0 ){ print "DONE $pid\n" if $debug };
	print "ALL DONE" if $debug;
}

print "Monitor process $$\n";

# Now, the processing loop:
my $combo;
my $pcount=0;
my $fileh=spawn_child();
while($combo=pop(@rcombos)) {
    print "PROCESS $n - $$, $combo" if $debug;;
    print $fileh $combo;
    if ($pcount++ > 25) {
	close $fileh or die "\nError in child...\n";
	$fileh = spawn_child();
	$pcount=0;
    }
}
close $fileh;

print STDERR "Done.\n";

exit (0);

# Form a combo-computing child process to handle a flock of combos
sub spawn_child {
    if (open CHILD, '|-') {
	return \*CHILD;
    } else {
	while ($line=<STDIN>) {

	    my ($printer,$driver) = split(',',$line);
	    chomp $driver;

	    # Determine file name for the output file
	    my $printer = Foomatic::DB::translate_printer_id($printer);
	    my $filename = "$destdir/$printer-$driver$suffix";

	    # Skip on bad file name
	    if ($filename =~ /^\-/) {
		print STDERR "WARNING: $printer with $driver gives a bad PPD file name: $filename\n\n";
		next;
	    }

	    # Skip on non-existing printer XML file (happens if in the
	    # list of supported printers of a driver is a printer
	    # which does not exist in the Foomatic database)
	    next if !defined($db->get_printer($printer));

	    ## Skip entirely if we can
	    #next if (-f $filename);
	    
	    print STDERR "  Worker $$ ...printer $printer, driver $driver\n";
	    
	    # Generate the file ...
	    if ($filetype eq 'xml') {
		@data = $db->get_combo_data_xml($driver, $printer);
	    } else {
		my $possible = $db->getdat($driver, $printer);
		# Do not create a PPD file if the printer/driver combo
		# is not possible or if the renderer command line is
		# empty and no custom PPD file is available
		next if ((!$possible) or 
			 ((!$db->{'dat'}{'cmd'}) and 
			  (!$db->{'dat'}{'ppdfile'})));
		@data = $db->getppd();
	    }
	    open OUTPUT, "> $filename" ||
		die "Cannot write $filename!";
	    print OUTPUT join('', @data);
	    close OUTPUT;
	}

	# No more input!
	exit (0);
    }    
}

sub isdrivervalid {
    my ($driver) = @_;
    # Check whether the driver has a valid command line
    if ($filetype ne 'xml') {
	my $driverentry = $db->get_driver($driver);
	if ($driverentry->{'cmd'}) {return 1;}
	return 0;
    } else {
	return 1;
    }
}