--- /dev/null
+#!/usr/bin/perl
+
+use v5.32;
+
+use Getopt::Long ();
+use Object::Pad;
+use Syntax::Keyword::Try;
+
+class Options {
+ use Time::Duration qw(duration_exact);
+ use Time::Duration::Parse qw(parse_duration);
+ has $target_queue_length :reader = 10;
+ has $mpd_host :reader = undef;
+ has $mpd_port :reader = undef;
+ has $db_path :reader = 'mpd-feeder';
+ has $db_user :reader = undef;
+ has $db_password :reader = undef;
+ has $min_album_interval :reader = parse_duration('5h');
+ has $min_song_interval :reader = parse_duration('13d');
+ has $min_artist_interval :reader = parse_duration('1h 15m');
+ has $verbose :reader = 0;
+ has $single :reader = 0;
+ has $one_shot :reader = 0;
+ has $dump_config :reader = 0;
+
+ method verb($message) {
+ return unless $self->opt->verbose;
+ warn "$message\n";
+ }
+ method dbg($message) {
+ return unless $self->opt->verbose > 1;
+ warn "$message\n";
+ }
+
+ method parse_command_line {
+ Getopt::Long::GetOptions(
+ 'v|verbose+' => \$verbose,
+ 'dump-config!' => \$dump_config,
+ 's|single!' => \$single,
+ 'one-shot!' => \$one_shot,
+ 'tql|target-queue-length=n' => \$target_queue_length,
+ 'mpd-host=s' => \$mpd_host,
+ 'mpd-port=s' => \$mpd_port,
+ 'db-path=s' => \$db_path,
+ 'db-user=s' => \$db_user,
+ 'min-album-interval=s' => sub {
+ $min_album_interval = parse_duration(pop);
+ },
+ 'min-sing-interval=s' => sub {
+ $min_song_interval = parse_duration(pop);
+ },
+ 'min-artist-interval=s' => sub {
+ $min_artist_interval = parse_duration(pop);
+ },
+ ) or exit 1;
+ }
+
+ sub handle_config_option( $ini, $section, $option, $target_ref,
+ $converter = undef )
+ {
+ return undef unless exists $ini->{$section}{$option};
+
+ my $value = $ini->{$section}{$option};
+
+ $value = $converter->($value) if $converter;
+
+ $$target_ref = $value;
+ }
+
+ method dump {
+ say "[mpd-feeder]";
+ say "verbose = $verbose";
+ say "";
+ say "[mpd]";
+ say "host = " . ( $mpd_host // '' );
+ say "port = " . ( $mpd_port // '' );
+ say "target-queue-length = $target_queue_length";
+ say "";
+ say "[queue]";
+ say "target-length = $target_queue_length";
+ say "min-song-interval = " . duration_exact($min_song_interval);
+ say "min-album-interval = " . duration_exact($min_album_interval);
+ say "min-artist-interval = " . duration_exact($min_artist_interval);
+ say "";
+ say "[db]";
+ say "path = " . ( $db_path // '' );
+ say "user = " . ( $db_user // '' );
+ say "password = " . ( $db_password // '' );
+ }
+
+ method parse_config_file($path) {
+ use Config::INI::Reader;
+ my $ini = Config::INI::Reader->read_file($path);
+
+ handle_config_option( $ini => mpd => host => \$mpd_host );
+ handle_config_option( $ini => mpd => port => \$mpd_port );
+
+ handle_config_option( $ini => 'mpd-feeder' => verbose => \$verbose );
+
+ handle_config_option(
+ $ini => queue => 'target-length' => \$target_queue_length );
+ handle_config_option(
+ $ini => queue => 'min-song-interval' => \$min_song_interval,
+ \&parse_duration
+ );
+ handle_config_option(
+ $ini => queue => 'min-album-interval' => \$min_album_interval,
+ \&parse_duration
+ );
+ handle_config_option(
+ $ini => queue => 'min-artist-interval' => \$min_artist_interval,
+ \&parse_duration
+ );
+
+ handle_config_option( $ini => db => path => \$db_path );
+ handle_config_option( $ini => db => user => \$db_user );
+ handle_config_option( $ini => db => password => \$db_password );
+
+ # FIXME: complain about unknown sections/parameters
+ }
+}
+
+class Feeder {
+ has $opt :reader;
+ has $db;
+ has $db_generation;
+ has $mpd;
+
+use constant DEFAULT_CONFIG_FILE => '/etc/mpd-feeder/mpd-feeder.conf';
+
+ ADJUST {
+ $opt = Options->new;
+
+ {
+ my $cfg_file;
+ Getopt::Long::Configure('pass_through');
+ Getopt::Long::GetOptions('cfg|config=s' => \$cfg_file);
+ Getopt::Long::Configure('no_pass_through');
+
+ $cfg_file //= DEFAULT_CONFIG_FILE if -e DEFAULT_CONFIG_FILE;
+
+ $opt->parse_config_file($cfg_file) if $cfg_file;
+ }
+
+ $opt->parse_command_line;
+
+ unless ($opt->dump_config) {
+ $mpd = Net::Async::MPD->new(
+ host => $opt->mpd_host,
+ port => $opt->mpd_port,
+ auto_connect => 1,
+ );
+
+ $self->connect_db;
+ $self->update_db;
+ }
+ }
+
+ method connect_db {
+ return if $db;
+
+ $db = DBI->connect( "dbi:" . $opt->db_path,
+ $opt->db_user, $opt->db_password,
+ { RaiseError => 1, AutoCommit => 1 } );
+
+ $db_generation = $self->db_get_option('generation');
+ }
+
+ method db_get_option($name) {
+ my $sth = $db->prepare_cached("select $name from options");
+ $sth->execute;
+ my @result = $sth->fetchrow_array;
+
+ return $result[0];
+ }
+
+ method db_set_option( $name, $value ) {
+ my $sth = $db->prepare_cached("update options set $name = ?");
+ $sth->execute($value);
+ }
+
+ method db_store_song($song, $artist, $album) {
+ return unless length($song) and length($artist) and length($album);
+
+ $db->prepare_cached(
+ <<'SQL')->execute( $song, $artist, $album, $db_generation );
+INSERT INTO songs(path, artist, album, generation)
+VALUES($1, $2, $3, $3)
+ON CONFLICT ON CONSTRAINT songs_pkey DO
+UPDATE SET artist = $2
+ , album = $3
+ , generation = $4
+SQL
+ $db->prepare_cached(<<'SQL')->execute( $artist, $album, $db_generation );
+INSERT INTO albums(artist, album, generation)
+VALUES($1, $2, $3)
+ON CONFLICT ON CONSTRAINT albums_pkey DO
+UPDATE SET generation = $3
+SQL
+ $db->prepare_cached(<<'SQL')->execute( $artist, $db_generation );
+INSERT INTO artists(artist, generation)
+VALUES($1, $2)
+ON CONFLICT ON CONSTRAINT artists_pkey DO
+UPDATE SET generation = $2
+SQL
+ }
+
+ method db_remove_stale_entries {
+ $db->prepare_cached('DELETE FROM songs WHERE generation <> ?')
+ ->execute($db_generation);
+ $db->prepare_cached('DELETE FROM albums WHERE generation <> ?')
+ ->execute($db_generation);
+ $db->prepare_cached('DELETE FROM artists WHERE generation <> ?')
+ ->execute($db_generation);
+ }
+
+ method db_note_song_qeued($item) {
+ $db->prepare_cached(
+ 'UPDATE songs SET last_queued=current_timestamp WHERE path=?')
+ ->execute( $item->{song} );
+ $db->prepare_cached(
+ 'UPDATE artists SET last_queued=CURRENT_TIMESTAMP WHERE artist=?')
+ ->execute( $item->{artist} );
+ $db->prepare_cached(
+ 'UPDATE albums SET last_queued=CURRENT_TIMESTAMP WHERE artist=? AND album=?'
+ )->execute( $item->{artist}, $item->{album} );
+ }
+
+ method update_db() {
+ $mpd->send('listallinfo')->on_done(
+ sub {
+ try {
+ $db->begin;
+
+ $db_generation++;
+
+ my ($song, $artist, $album);
+
+ foreach my $row (@_) {
+ chomp($row);
+
+ if ($row =~ s/^file:\s*//) {
+ $self->db_store_song( $song, $artist, $album );
+ $song = $row;
+ $artist = $album = undef;
+ }
+ elsif ( $row =~ s/^Artist:\s*// ) {
+ $artist = $row;
+ }
+ elsif ( $row =~ s/^Album:\s*// ) {
+ $album = $row;
+ }
+ }
+
+ $self->db_store_song($song, $artist, $album);
+
+ $self->db_remove_stale_entries;
+
+ $self->db_set_option( generation => $db_generation );
+
+ $db->commit;
+ }
+ catch {
+ my $err = $@;
+
+ $db_generation--;
+
+ $db->rollback;
+
+ die $err;
+ }
+ }
+ );
+ }
+
+ method db_find_suitable_songs($num) {
+ my @result;
+ my $sth = $self->db->prepare_cached(<<SQL);
+SELECT s.path, s.artist, s.album
+FROM songs s
+JOIN artists ar ON ar.artist=s.artist
+JOIN albums al ON al.album=s.album
+WHERE (s.last_queued IS NULL OR s.last_queued < CURRENT_TIMESTAMP - CAST(? AS float))
+ AND (ar.last_queued IS NULL OR ar.last_queued < CURRENT_TIMESTAMP - CAST(? AS float))
+ AND (al.last_queued IS NULL OR al.last_queued < CURRENT_TIMESTAMP - CAST(? AS float))
+ AND NOT EXISTS (SELECT 1 FROM blacklisted_artists bar WHERE bar.artist = s.artist)
+ AND NOT EXISTS (SELECT 1 FROM blacklisted_albums bal WHERE bal.album = s.album)
+ORDER BY random()
+LIMIT ?
+SQL
+ $sth->execute(
+ $self->opt->min_song_interval / 3600.0 / 24.0,
+ $self->opt->min_artist_interval / 3600.0 / 24.0,
+ $self->opt->min_album_interval / 3600.0 / 24.0,
+ $num,
+ );
+ while ( my @row = $sth->fetchrow_array ) {
+ push @result,
+ { song => $row[0], artist => $row[1], album => $row[2] };
+ }
+
+ return @result;
+ }
+
+ method queue_songs($num = undef) {
+ if (!defined $num) {
+ $mpd->send('playlist')->on_done( sub {
+ my $present = scalar @_;
+
+ $self->queue_songs( $opt->target_queue_length - $present )
+ if $present < $opt->target_queue_length;
+ } );
+ }
+ else {
+ my @list = $self->db_find_suitable_songs($num);
+
+ if (@list < $num) {
+ $mpd->loop->add(
+ IO::Async::Timer::Countdown->new(
+ delay => 15,
+ on_expire => sub { $self->queue_songs($num) },
+ )
+ );
+ }
+ else {
+ $mpd->send( [ map {"add $_->{song}"} @list ] );
+ $self->db_note_song_qeued($_) for @list;
+ }
+ }
+ }
+}
+
+my $feeder = Feeder->new();
+
+$feeder->opt->dump, exit if $feeder->opt->dump_config;
+
+$feeder->queue_songs(1), exit if $feeder->opt->single;
+
+# FIXME: handle blacklist manipulation
+
+$feeder->queue_songs;
+
+exit if $feeder->opt->one_shot;
+
+$feeder->mpd->on(
+ database => sub {
+ $feeder->update_db;
+ }
+);
+
+$feeder->mpd->on(
+ playlist => sub {
+ $feeder->queue_songs;
+ }
+);
+
+$feeder->mpd->idle(qw(database playlist));
+$feeder->mpd->get;