Audio::MPD - class to talk to MPD (Music Player Daemon) servers

    use Audio::MPD;

    my $mpd = Audio::MPD->new;
    $mpd->play;
    sleep 10;
    $mpd->next;

    $mpd->collection->all_songs;

    $mpd->playlist->clear;

    my $mpd = Audio::MPD->new( \%opts );

    $mpd->ping;

    my $version = $mpd->version;

    $mpd->kill;

    $mpd->set_password( [$password] );

    $mpd->updatedb( [$path] );

    my @handlers = $mpd->urlhandlers;

    $mpd->volume( [+][-]$volume );

    my @outputs = $mpd->outputs( );

    $mpd->output_enable( $output );

    $mpd->output_disable( $output );

    my $stats = $mpd->stats;

    my $status = $mpd->status;

    my $song = $mpd->current;

    my $song = $mpd->song( [$song] );

    my $song = $mpd->songid( [$songid] );

    $mpd->repeat( [$repeat] );

    $mpd->random( [$random] );

    $mpd->fade( [$seconds] );

    $mpd->play( [$song] );

    $mpd->playid( [$songid] );

    $mpd->pause( [$state] );

    $mpd->stop;

    $mpd->next;

    $mpd->prev;

    $mpd->seek( $time, [$song]);

    $mpd->seekid( $time, $songid );

#
# This file is part of Audio-MPD
#
# This software is copyright (c) 2007 by Jerome Quelin.
#
# This is free software; you can redistribute it and/or modify it under
# the same terms as the Perl 5 programming language system itself.
#
use 5.008;
use warnings;
use strict;

package Audio::MPD;
BEGIN {
  $Audio::MPD::VERSION = '1.111200';
}
# ABSTRACT: class to talk to MPD (Music Player Daemon) servers

use Audio::MPD::Common::Item;
use Audio::MPD::Common::Stats;
use Audio::MPD::Common::Status;
use Audio::MPD::Common::Output;
use Encode;
use IO::Socket;
use Moose;
use MooseX::Has::Sugar;
use MooseX::SemiAffordanceAccessor;

use Audio::MPD::Collection;
use Audio::MPD::Playlist;
use Audio::MPD::Types;



has conntype   => ( ro, isa=>'CONNTYPE', default=>'once'  );
has host       => ( ro, lazy_build );
has password   => ( rw, lazy_build, trigger=>sub { $_[0]->ping } );
has port       => ( ro, lazy_build );

has collection => ( ro, lazy_build, isa=>'Audio::MPD::Collection' );
has playlist   => ( ro, lazy_build, isa=>'Audio::MPD::Playlist'   );
has version    => ( rw );

has _socket    => ( rw, isa=>'IO::Socket::INET' );


#--
# initializer & lazy builders


sub BUILD {
    my $self = shift;

    # create the connection if conntype is set to $REUSE
    $self->_connect_to_mpd_server if $self->conntype eq 'reuse';

    # try to issue a ping to test connection - this can die.
    $self->ping;
}

#
# my ($passwd, $host, $port) = _parse_env_var();
#
# parse MPD_HOST environment variable, and extract its components. the
# canonical format of MPD_HOST is passwd@host:port.
#
sub _parse_env_var {
    return (undef, undef, undef) unless defined $ENV{MPD_HOST};
    return ($1, $2, $3)    if $ENV{MPD_HOST} =~ /^([^@]+)\@([^:@]+):(\d+)$/; # passwd@host:port
    return ($1, $2, undef) if $ENV{MPD_HOST} =~ /^([^@]+)\@([^:@]+)$/;       # passwd@host
    return (undef, $1, $2) if $ENV{MPD_HOST} =~ /^([^:@]+):(\d+)$/;          # host:port
    return (undef, $ENV{MPD_HOST}, undef);
}

sub _build_host     { return ( _parse_env_var() )[1] || 'localhost'; }
sub _build_port     { return $ENV{MPD_PORT}     || ( _parse_env_var() )[2] || 6600; }
sub _build_password { return $ENV{MPD_PASSWORD} || ( _parse_env_var() )[0] || '';   }

sub _build_collection { Audio::MPD::Collection->new( _mpd => $_[0] ); }
sub _build_playlist   { Audio::MPD::Playlist  ->new( _mpd => $_[0] ); }


#--
# Private methods


#
# $mpd->_connect_to_mpd_server;
#
# This method connects to the mpd server. It can die on several conditions:
#  - if the server cannot be reached,
#  - if it's not an mpd server,
#  - or if the password is incorrect,
#
sub _connect_to_mpd_server {
    my ($self) = @_;

    # try to connect to mpd.
    my $socket = IO::Socket::INET->new(
        PeerAddr => $self->host,
        PeerPort => $self->port,
    )
    or die "Could not create socket: $!\n";

    # parse version information.
    my $line = $socket->getline;
    chomp $line;
    die "Not a mpd server - welcome string was: [$line]\n"
        if $line !~ /^OK MPD (.+)$/;
    $self->set_version($1);

    # send password.
    if ( $self->password ) {
        $socket->print( 'password ' . encode('utf-8', $self->password) . "\n" );
        $line = $socket->getline;
        die $line if $line =~ s/^ACK //;
    }

    # save socket
    $self->_set_socket($socket);
}


#
# my @result = $mpd->_send_command( $command );
#
# This method is central to the module. It is responsible for interacting with
# mpd by sending the $command and reading output - that will be returned as an
# array of chomped lines (status line will not be returned).
#
# This method can die on several conditions:
#  - if the server cannot be reached,
#  - if it's not an mpd server,
#  - if the password is incorrect,
#  - or if the command is an invalid mpd command.
# In the latter case, the mpd error message will be returned.
#
sub _send_command {
    my ($self, $command) = @_;

    $self->_connect_to_mpd_server if $self->conntype eq 'once';
    my $socket = $self->_socket;

    # ok, now we're connected - let's issue the command.
    $socket->print( encode('utf-8', $command) );
    my @output;
    while (defined ( my $line = $socket->getline ) ) {
        chomp $line;
        die $line if $line =~ s/^ACK //; # oops - error.
        last if $line =~ /^OK/;          # end of output.
        push @output, decode('utf-8', $line);
    }

    # close the socket.
    $socket->close if $self->conntype eq 'once';

    return @output;
}


#
# my @items = $mpd->_cooked_command_as_items( $command );
#
# Lots of Audio::MPD methods are using _send_command() and then parse the
# output as a collection of AMC::Item. This method is meant to factorize
# this code, and will parse the raw output of _send_command() in a cooked
# list of items.
#
sub _cooked_command_as_items {
    my ($self, $command) = @_;

    my @lines = $self->_send_command($command);
    my (@items, %param);

    # parse lines in reverse order since "file:" or "directory:" lines
    # come first. therefore, let's first store every other parameter,
    # and the last line will trigger the object creation.
    # of course, since we want to preserve the playlist order, this means
    # that we're going to unshift the objects instead of push.
    foreach my $line (reverse @lines) {
        my ($k,$v) = split /:\s/, $line, 2;
        $param{$k} = $v;
        next unless $k eq 'file' || $k eq 'directory' || $k eq 'playlist'; # last param of item
        unshift @items, Audio::MPD::Common::Item->new(%param);
        %param = ();
    }

    return @items;
}


#
# my %hash = $mpd->_cooked_command_as_kv( $command );
#
# Lots of Audio::MPD methods are using _send_command() and then parse the
# output to get a list of key / value (with the colon ":" acting as separator).
# This method is meant to factorize this code, and will parse the raw output
# of _send_command() in a cooked hash.
#
sub _cooked_command_as_kv {
    my ($self, $command) = @_;
    my %hash =
        map { split(/:\s/, $_, 2) }
        $self->_send_command($command);
    return %hash;
}

#
# my @list = $mpd->_cooked_command_strip_first_field( $command );
#
# Lots of Audio::MPD methods are using _send_command() and then parse the
# output to remove the first field (with the colon ":" acting as separator).
# This method is meant to factorize this code, and will parse the raw output
# of _send_command() in a cooked list of strings.
#
sub _cooked_command_strip_first_field {
    my ($self, $command) = @_;

    my @list =
        map { ( split(/:\s+/, $_, 2) )[1] }
        $self->_send_command($command);
    return @list;
}


#--
# Public methods

# -- MPD interaction: general commands


sub ping {
    my ($self) = @_;
    $self->_send_command( "ping\n" );
}




# sub version {} # implemented as an accessor.




sub kill {
    my ($self) = @_;
    $self->_send_command("kill\n");
}




# implemented by password trigger (from moose)



sub updatedb {
    my ($self, $path) = @_;
    $path ||= '';
    $self->_send_command("update $path\n");
}



sub urlhandlers {
    my ($self) = @_;
    return $self->_cooked_command_strip_first_field("urlhandlers\n");
}


# -- MPD interaction: handling volume & output


sub volume {
    my ($self, $volume) = @_;

    if ($volume =~ /^(-|\+)(\d+)/ )  {
        my $current = $self->status->volume;
        $volume = $1 eq '+' ? $current + $2 : $current - $2;
    }
    $self->_send_command("setvol $volume\n");
}



sub outputs {
    my ($self) = @_;

    my @lines = $self->_send_command("outputs\n");
    my (@outputs, %param);

    # parse lines in reverse order since "id" lines come first
    foreach my $line (reverse @lines) {
        my ($k,$v) = split /:\s/, $line, 2;
        $k =~ s/^output//;
        $param{$k} = $v;
        next unless $k eq 'id'; # last output param
        unshift @outputs, Audio::MPD::Common::Output->new(%param);
        %param = ();
    }

    return @outputs;
}



sub output_enable {
    my ($self, $output) = @_;
    $self->_send_command("enableoutput $output\n");
}



sub output_disable {
    my ($self, $output) = @_;
    $self->_send_command("disableoutput $output\n");
}



# -- MPD interaction: retrieving info from current state


sub stats {
    my ($self) = @_;
    my %kv = $self->_cooked_command_as_kv( "stats\n" );
    return Audio::MPD::Common::Stats->new(\%kv);
}



sub status {
    my ($self) = @_;
    my %kv = $self->_cooked_command_as_kv( "status\n" );
    my $status = Audio::MPD::Common::Status->new( \%kv );
    return $status;
}



sub current {
    my ($self) = @_;
    my ($item) = $self->_cooked_command_as_items("currentsong\n");
    return $item;
}



sub song {
    my ($self, $song) = @_;
    return $self->current unless defined $song;
    my ($item) = $self->_cooked_command_as_items("playlistinfo $song\n");
    return $item;
}



sub songid {
    my ($self, $songid) = @_;
    return $self->current unless defined $songid;
    my ($item) = $self->_cooked_command_as_items("playlistid $songid\n");
    return $item;
}


# -- MPD interaction: altering settings



sub repeat {
    my ($self, $mode) = @_;

    $mode = not $self->status->repeat
        unless defined $mode; # toggle if no param
    $mode = $mode ? 1 : 0;               # force integer
    $self->_send_command("repeat $mode\n");
}



sub random {
    my ($self, $mode) = @_;

    $mode = not $self->status->random
        unless defined $mode; # toggle if no param
    $mode = $mode ? 1 : 0;               # force integer
    $self->_send_command("random $mode\n");
}



sub fade {
    my ($self, $value) = @_;
    $value ||= 0;
    $self->_send_command("crossfade $value\n");
}


# -- MPD interaction: controlling playback


sub play {
    my ($self, $number) = @_;
    $number = '' unless defined $number;
    $self->_send_command("play $number\n");
}



sub playid {
    my ($self, $number) = @_;
    $number ||= '';
    $self->_send_command("playid $number\n");
}



sub pause {
    my ($self, $state) = @_;
    $state ||= ''; # default is to toggle
    $self->_send_command("pause $state\n");
}



sub stop {
    my ($self) = @_;
    $self->_send_command("stop\n");
}



sub next {
    my ($self) = @_;
    $self->_send_command("next\n");
}



sub prev {
    my($self) = shift;
    $self->_send_command("previous\n");
}



sub seek {
    my ($self, $time, $song) = @_;
    $time ||= 0; $time = int $time;
    $song = $self->status->song if not defined $song; # seek in current song
    $self->_send_command( "seek $song $time\n" );
}



sub seekid {
    my ($self, $time, $song) = @_;
    $time ||= 0; $time = int $time;
    $song = $self->status->songid if not defined $song; # seek in current song
    $self->_send_command( "seekid $song $time\n" );
}


no Moose;
__PACKAGE__->meta->make_immutable;
1;

__END__