+package App::MPD::Feeder::DB;
+
+use strict;
+use warnings;
+use utf8;
+
+use Log::Any qw($log);
+use Object::Pad;
+use Syntax::Keyword::Try;
+
+class App::MPD::Feeder::DB {
+ has $opt :param;
+ has $db;
+ has $generation;
+
+ method get_option($name) {
+ my $sth = $db->prepare_cached("select $name from options");
+ $sth->execute;
+ my @result = $sth->fetchrow_array;
+ $sth->finish;
+ undef $sth;
+
+ return $result[0];
+ }
+
+ method set_option( $name, $value ) {
+ my $sth = $db->prepare_cached("update options set $name = ?");
+ $sth->execute($value);
+ }
+
+ method start_update {
+ $generation++;
+ $db->begin_work;
+ }
+
+ method finish_update {
+ $self->set_option(generation => $generation);
+ $db->commit;
+ }
+
+ method cancel_update {
+ $generation--;
+ $db->rollback;
+ }
+
+ method store_song($song, $artist, $album) {
+ return unless length($song) and length($artist) and length($album);
+
+ utf8::decode($_) for $song, $artist, $album;
+
+ $db->prepare_cached(
+ <<'SQL')->execute( $song, $artist, $album, $generation );
+INSERT INTO songs(path, artist, album, generation)
+VALUES($1, $2, $3, $4)
+ON CONFLICT ON CONSTRAINT songs_pkey DO
+UPDATE SET artist = $2
+ , album = $3
+ , generation = $4
+SQL
+ $db->prepare_cached(<<'SQL')->execute( $artist, $album, $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, $generation );
+INSERT INTO artists(artist, generation)
+VALUES($1, $2)
+ON CONFLICT ON CONSTRAINT artists_pkey DO
+UPDATE SET generation = $2
+SQL
+ }
+
+ method remove_stale_entries {
+ my $sth =
+ $db->prepare_cached('DELETE FROM songs WHERE generation <> ?');
+ $sth->execute($generation);
+ $log->debug( sprintf( "Deleted %d stale songs", $sth->rows ) );
+
+ $sth = $db->prepare_cached('DELETE FROM albums WHERE generation <> ?');
+ $sth->execute($generation);
+ $log->debug( sprintf( "Deleted %d stale albums", $sth->rows ) );
+
+ $sth =
+ $db->prepare_cached('DELETE FROM artists WHERE generation <> ?');
+ $sth->execute($generation);
+ $log->debug( sprintf( "Deleted %d stale artists", $sth->rows ) );
+ }
+
+ method note_song_qeued($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}, $item->{album} );
+ }
+
+ method find_suitable_songs($num) {
+ my @result;
+ my $sql = <<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 AND al.artist=s.artist
+WHERE (s.last_queued IS NULL OR s.last_queued < CURRENT_TIMESTAMP - (? || ' seconds')::interval)
+ AND (ar.last_queued IS NULL OR ar.last_queued < CURRENT_TIMESTAMP - (? || ' seconds')::interval)
+ AND (al.last_queued IS NULL OR al.last_queued < CURRENT_TIMESTAMP - (? || ' seconds')::interval)
+ AND NOT EXISTS (SELECT 1 FROM unwanted_artists uar WHERE uar.artist = s.artist)
+ AND NOT EXISTS (SELECT 1 FROM unwanted_albums ual WHERE ual.album = s.album)
+ORDER BY random()
+LIMIT ?
+SQL
+ my @params = (
+ $opt->min_song_interval, $opt->min_artist_interval,
+ $opt->min_album_interval, $num,
+ );
+ my $sth = $db->prepare_cached($sql);
+ $sth->execute(@params);
+ while ( my @row = $sth->fetchrow_array ) {
+ push @result,
+ { song => $row[0], artist => $row[1], album => $row[2] };
+ }
+ undef $sth;
+
+ if (scalar(@result) == $num and $log->is_debug) {
+ $sql =~ s/^SELECT .+$/SELECT COUNT(DISTINCT s.path)/m;
+ $sql =~ s/^ORDER BY .+$//m;
+ $sql =~ s/^LIMIT .+$//m;
+ my $sth = $db->prepare_cached($sql);
+ pop @params;
+ $sth->execute(@params);
+ my $count = ($sth->fetchrow_array)[0];
+ $sth->finish;
+
+ $sth = $db->prepare_cached('SELECT COUNT(*) FROM songs');
+ $sth->execute;
+ my $total = ($sth->fetchrow_array)[0];
+ $sth->finish;
+ $log->debug(
+ sprintf(
+ "Number of songs meeting the criteria: %d out of total %d (%5.2f%%)",
+ $count, $total, 100.0 * $count / $total
+ )
+ );
+
+ $sql = <<SQL;
+SELECT COUNT(*)
+FROM songs s
+WHERE (s.last_queued IS NULL OR s.last_queued < CURRENT_TIMESTAMP - (? || ' seconds')::interval)
+SQL
+ $sth = $db->prepare_cached($sql);
+ $sth->execute($opt->min_song_interval);
+ $count = ($sth->fetchrow_array)[0];
+ $sth->finish;
+
+ $log->debug(
+ sprintf(
+ "Number of songs not queued soon: %d out of total %d (%5.2f%%)",
+ $count, $total, 100.0 * $count / $total
+ )
+ );
+ $sth->finish;
+
+ $sql = <<SQL;
+SELECT COUNT(*)
+FROM artists ar
+WHERE (ar.last_queued IS NULL OR ar.last_queued < CURRENT_TIMESTAMP - (? || ' seconds')::interval)
+SQL
+ $sth = $db->prepare_cached($sql);
+ $sth->execute($opt->min_artist_interval);
+ $count = ($sth->fetchrow_array)[0];
+ $sth->finish;
+
+ $sth = $db->prepare_cached('SELECT COUNT(*) FROM artists');
+ $sth->execute;
+ $total = ($sth->fetchrow_array)[0];
+ $sth->finish;
+ $log->debug(
+ sprintf(
+ "Number of artists not queued soon: %d out of total %d (%5.2f%%)",
+ $count, $total, 100.0 * $count / $total
+ )
+ );
+
+ $sql = <<SQL;
+SELECT COUNT(*)
+FROM albums al
+WHERE (al.last_queued IS NULL OR al.last_queued < CURRENT_TIMESTAMP - (? || ' seconds')::interval)
+SQL
+ $sth = $db->prepare_cached($sql);
+ $sth->execute($opt->min_album_interval);
+ $count = ($sth->fetchrow_array)[0];
+ $sth->finish;
+
+ $sth = $db->prepare_cached('SELECT COUNT(*) FROM albums');
+ $sth->execute;
+ $total = ($sth->fetchrow_array)[0];
+ $sth->finish;
+ $log->debug(
+ sprintf(
+ "Number of albums not queued soon: %d out of total %d (%5.2f%%)",
+ $count, $total, 100.0 * $count / $total
+ )
+ );
+
+ undef $sth;
+ }
+
+ return @result;
+ }
+
+ method add_unwanted_artist($artist) {
+ $self->connect;
+
+ try {
+ $db->do(
+ <<'SQL',
+INSERT INTO unwanted_artists(artist, generation)
+VALUES($1, $2)
+SQL
+ undef, $artist, $generation
+ );
+ return 1;
+ }
+ catch {
+ my $err = $@;
+
+ $log->debug("PostgreSQL error: $err");
+ $log->debug( "SQLSTATE = " . $db->state );
+ return 0 if $db->state eq '23505';
+
+ die $err;
+ }
+ }
+
+ method del_unwanted_artist($artist) {
+ $self->connect;
+
+ return 1 == $db->do(
+ <<'SQL',
+DELETE FROM unwanted_artists
+WHERE artist = $1
+SQL
+ undef, $artist
+ );
+ }
+
+ method connect {
+ return if $db;
+
+ $db = DBI->connect( "dbi:Pg:dbname=" . $opt->db_path,
+ $opt->db_user, $opt->db_password,
+ { RaiseError => 1, PrintError => 0, AutoCommit => 1 } );
+
+ $log->info( "Connected to database " . $opt->db_path );
+ $generation = $self->get_option('generation');
+ $log->debug("DB generation is $generation");
+ }
+
+ method disconnect {
+ return unless $db;
+
+ if ($db->{ActiveKids}) {
+ $log->warn("$db->{ActiveKids} active DB statements");
+ for my $st ( @{ $db->{ChildHandles} } ) {
+ next unless $st->{Active};
+ while(my($k,$v) = each %$st) {
+ $log->debug("$k = ".($v//'<NULL>'));
+ }
+ }
+ }
+
+ $db->disconnect;
+ undef $db;
+ }
+}