#!/usr/bin/perl -w
use strict;
use POSIX;
use IO::File;
use Getopt::Long;

our $package='xfonts-traditional';
our $sharedir="/usr/share/$package";
our @rulespath;
our $mode;
our %foundrymap;
our $verbose=0;
our $reportfh;

sub reportloaded {
    return unless $verbose;
    print $reportfh @_,"\n" or die $!;
}

sub loadrules ($) {
    my ($key) = @_;
    our %cache;
    my $fc=$cache{$key};  
    return $fc if $fc;
    foreach my $path (@rulespath) {
	my $script="$path/$key.rules";
	$!=0; $@=''; my $f = do $script;
	if (defined $f) {
	    reportloaded("rules: loaded ",$script);
	    $cache{$key}=$f;
	    return $f;
	}
	die "$! $? $script" unless $! == &ENOENT;
    }
    return $cache{$key}=undef;
}

sub processbdf ($$$) {
    my ($inbdf,$outbdf,$what) = @_;
    my $state='idle';
    my ($foundry,$font);
    my ($w,$h,$xo,$yo,$y,$bitmap,$glyph);
    my $modified=0;
    while (<$inbdf>) {
	if ($state eq 'bitmap' && $y==$h) {
	    $glyph = uc $glyph;
	    $glyph =~ s/\;$//;
	    local ($_) = $glyph;
	    my $key= sprintf "%s,%d,%d,%d,%d", $foundry,$w,$h,$xo,$yo;
	    my $rules= loadrules($key);
	    return (0,'no rules') if !$rules;
	    $rules->();
	    $modified += ($_ ne $glyph);
	    print $outbdf $_,"\n" or die $!
		foreach split /\;/, $_; # /;
	    $state='idle';
	}
	if ($state eq 'bitmap') {
	    m/^([0-9a-fA-F]+)\s+$/ or die $y;
	    length($1) == (($w+7 >> 3) << 1) or die "$1 $w";
	    $glyph .= "$1;";
	    $y++;
	    next;
	}
	if ($state eq 'idle' && m/^FOUNDRY\s+/) {
	    die if defined $foundry;
	    return (0,'foundry syntax') unless m/^FOUNDRY\s+\"(\w+)\"\s+/;
	    $foundry = $foundrymap{lc $1};
	    return (0,'no foundry') unless defined $foundry;
	    $_ = "FOUNDRY \"$foundry\"\n";
	}
	if ($state eq 'idle' && m/^FONT\s+/) {
	    die if defined $font;
	    return 0 unless m/^(FONT\s+)\-(\w+)\-/;
	    $font = $foundrymap{lc $2};
	    return (0,'no foundry') unless defined $font;
	    $_ = "FONT -$font-$'";
	}
	if ($state eq 'idle' && m/^STARTCHAR\s/) {
	    die unless defined $foundry;
	    die unless defined $font;
	    return (0,'foundry != font') unless $foundry eq $font;
	    $state='startchar';
	    $w=undef;
	}
	if ($state eq 'startchar') {
	    if (m/^BBX\s+(\+?\d+)\s+(\+?\d+)\s+([-+]?\d+)\s+([-+]?\d+)\s+$/) {
		($w,$h,$xo,$yo) = ($1,$2,$3,$4);
	    }
	    if (m/^BITMAP\s+$/) {
		die unless defined $w;
		$y=0;
		$glyph='';
		$state='bitmap';
	    }
	}
	print $outbdf $_ or die $!;
    }
    die $! if $inbdf->error;
    die $! if $outbdf->error or !$outbdf->flush;
    die unless $state eq 'idle';
    if ($modified) {
	printf $reportfh "%s: %d glyphs changed\n", $what, $modified
	    or die $!;
    } else {
	printf $reportfh "%s: unchanged - no rules matched\n", $what
	    or die $!;
    }
    return $modified;
}

our (@options)=(
    'R|rules-include=s@' => \@rulespath,
    'share-dir=s' => \$sharedir,
    'verbose|v+' => \$verbose,
    );

sub define_mode ($$) {
    my ($optname,$f) = @_;
    push @options, $optname, sub {
	die "only one mode may be specified\n" if defined $mode;
	$mode=$f;
    };
}

sub loadfoundries () {
    foreach my $path (@rulespath) {
	my $p = "$path/foundries";
	my $f = new IO::File $p;
	if (!$f) {
	    die "$p $!" unless $!==&ENOENT;
	    print $reportfh "foundries: none in $p\n" or die $! if $verbose;
	    next;
	}
	while (<$f>) {
	    s/^\s*//; s/\s+$//;
	    next if m/^\#/;
	    m/^(\w+)\s+(\w+)$/ or die;
	    my $k = lc $1;
	    next if exists $foundrymap{$k};
	    $foundrymap{$k}=$2;
	}
	$f->error and die $!;
	reportloaded('foundries: loaded ',$p);
    }
    die "no foundry maps\n" unless %foundrymap;
}

our $stdin = new IO::File '<&STDIN' or die $!;
our $stdout = new IO::File '>&STDOUT' or die $!;
our $stderr = new IO::File '>&STDERR' or die $!;
$reportfh = $stdout;

define_mode('bdf-filter', sub {
    die "no arguments allowed with --bdf-filter\n" if @ARGV;
    $reportfh = $stderr;
    loadfoundries();
    my $r = processbdf($stdin,$stdout,'stdin');
    if ($r !~ m/^\d/) {
	print STDERR "stdin not processed: $r\n";
	exit 2;
    }
});

Getopt::Long::Configure(qw(bundling));
GetOptions(@options) or exit 127;

push @rulespath, "$sharedir/rules";

die "need a mode\n" unless $mode;

$mode->();

#   70  zcat /usr/share/fonts/X11/misc/6x13.pcf.gz |pcf2bdf >in.bdf
#   71  ./utility <in.bdf >out.bdf
#   83  bdftopcf out.bdf >out.pcf
#   84  gzip out.pcf 
#   85  cp out.pcf.gz /usr/share/fonts/X11/misc/
# really mkfontdir /usr/share/fonts/X11/misc/
# xset fp rehash
# xfontsel