#!/usr/bin/env perl
use 5.014;
use strict;
use warnings;

use Data::Dump 'pp';
use Font::TTF::Font;
use Getopt::Long;
use Cwd 'abs_path';

our $VERSION = '1.00';

GetOptions(\my %opt,
	'verbose|v!',
);

my ($ttfuri, $outfile) = @ARGV;
$ttfuri or die "usage error\n";

my $fontinc = $ENV{FONTINC} // 'data/font,~/.fonts,/usr/share/fonts/truetype/*';
if (!-e $ttfuri) {
	my $found = (grep {-e} glob "{$fontinc}/$ttfuri")[0] or do {
		warn "font not found: $ttfuri\n";
		exit 1;
	};
	$ttfuri = $found;
}

for ($outfile || ()) {
	open my $output, '>', $_ or die "Cannot write to $outfile: $!\n";
	select $output;
}

{
	my $ttf = Font::TTF::Font->open($ttfuri)
		or die "Cannot open truetype in $ttfuri: $!";

	my $ttfname = ($ttfuri =~ m{([^/.]+) (?:[.]ttf)? \z}msx)[0];
	my $ttfmeta = $ttf->{name}->read;
	my %meta = (
		source   => abs_path($ttfuri) =~ m{(^/usr/.+ | [^/]+) \z}msx,
		name     => $ttfmeta->find_name(4) || $ttfname,
		revision => sprintf('%g', $ttf->{head}->{fontRevision}),
		version  => $ttfmeta->find_name(5) =~ s/\Aversion //ri =~ s/\s+\z//r,
		copyright=> scalar $ttfmeta->find_name(0),
		license  => $ttfmeta->find_name(14) || undef,
		date     => (map {
			$_ && eval {
				require Time::Piece;
				Time::Piece->new($_)->datetime;
			}
		} $ttf->{head}->getdate),
	);
	$meta{abbr} = lc join '', $meta{name} =~ s/ MS$//r =~ m{
		(?!Sans) (?<! [0-9]) ([[:upper:]0-9])
	}gx;

	say "# automatically generated by $0";
	say '+', pp(\%meta), ',';

	my $support = $ttf->{cmap}->find_ms->{val};
	warn scalar keys %$support, " characters read from $ttfname\n"
		if $opt{verbose};
	say pp(sort { $a <=> $b } keys %$support);
}

__END__

=head1 NAME

mkttfinfo - Extract character coverage and metadata in TrueType font

=head1 SYNOPSIS

    mkttfinfo [-v] <font.ttf> [<output.inc.pl>]

=head1 AUTHOR

Mischa POSLAWSKY <perl@shiar.org>

=head1 LICENSE

Licensed under the GNU Affero General Public License version 3.