#!/usr/local/bin/perl

=head1 NAME

B<fa-encode> - encode WAV files to FLAC

=head1 SYNOPSIS

B<fa-encode> [B<-d> I<artist-directory>] B<input-directory>

I<artist-directory> defaults to the album B<ARTIST> in the tags file; one of
these is required.

TODO:  implement B<-d>

=cut

package epg::flac::archive::encode;

use v5.12;
use warnings;

use FindBin;

require "$FindBin::Bin/tags.p";
epg::flac::archive::tags->import(
    qw[
        read_tags
        mangle_for_file_name
        quote
        two_digits
    ]);

sub main {
    my $input_directory = shift;
    my $fn = "$input_directory/tags";
    open(my $fh, '<', $fn) || die("open($fn): $!");
    my ($album, $tracks) = read_tags($fh);
    if (!defined($album->{ALBUM}) || scalar(@{$album->{ALBUM}}) != 1) {
        die('exactly one ALBUM tag required')
    }
    my $album_tag = $album->{ALBUM}->[0];
    # TODO -d support
    if (!defined($album->{ARTIST}) || scalar(@{$album->{ARTIST}}) != 1) {
        die('exactly one ARTIST tag required')
    }
    my $artist = $album->{ARTIST}->[0];

    my $date;
    if (defined($album->{DATE})) {
        if (scalar(@{$album->{DATE}}) != 1) {
            die('one or zero DATE tags required')
        }
        $date = $album->{DATE}->[0];
    }
    my @discnumber = ();
    if (defined($album->{DISCNUMBER})) {
        if (scalar(@{$album->{DISCNUMBER}}) != 1) {
            die('one or zero DISCNUMBER tags required')
        }
        @discnumber = ($album->{DISCNUMBER}->[0]);
    }

    my $dir = join('/', '..', mangle_for_file_name($artist), mangle_for_file_name($album_tag));

    say('set -ex');
    say('mkdir -p ', quote($dir));
    my $tracknum = 0;
    for my $track (@$tracks) {
        $tracknum++;
        if (!defined($track->{TITLE}) || scalar(@{$track->{TITLE}}) < 1) {
            die("at least one TITLE required for track $tracknum")
        }
        $track->{ALBUM} = $album->{ALBUM};
        $track->{TRACKNUMBER} = [$tracknum];
        if (!defined($track->{ARTIST}) && defined($album->{ARTIST})) {
            $track->{ARTIST} = $album->{ARTIST};
        }
        if (defined($date)) {
            $track->{DATE} = [$date];
        }
        if (@discnumber) {
            $track->{DISCNUMBER} = \@discnumber;
        }
        my $title = join(' ', @{$track->{TITLE}});
        my $tracknum_s = two_digits($tracknum);
        my $fn = join('/',
                      $dir,
                      join('_',
                           (map { two_digits($_) } @discnumber),
                           $tracknum_s,
                           mangle_for_file_name($title) . '.flac',
                      ),
            );
        -e $fn && die("cowardly refusing to clobber $fn");
        my @pictures = ('--picture', quote('3|image/jpeg|||cover.front.jpeg')); # TODO optional
        say(join(' ',
                 'flac -o',
                 quote($fn),
                 '--delete-input-file',
                 '-V',
                 '--no-padding',
                 '--best',
                 @pictures,
                 (map {
                     my $name = $_;
                     map {
                         ('-T', quote($name . '=' . $_))
                     } @{$track->{$_}}
                  } sort(keys(%$track))),
                 "track$tracknum_s.cdda.wav"
            ));
    }
    say('rm tags cover.front.jpeg');

    return 0;
}

if (!caller) {
    exit(main(@ARGV))
}

1;