#!/usr/athena/bin/perl
# Play the data on STDIN as an audio file
#
# $Id: sipbmp3-filter,v 1.26 2009/02/20 00:27:17 geofft Exp root $
# $Source: /usr/local/bin/RCS/sipbmp3-filter,v $
#
# TODO
# ----
# Make this structured code. It's a mess.
# Repeat what we just played for EXT files too
# Support HTTP Auth on ogg streams
# License, cleanup and package
#
# Jered Floyd <jered@mit.edu> takes very little credit for this code
# apparently neither does Quentin Smith <quentin@mit.edu>

use Image::ExifTool qw(ImageInfo);
use File::Spec::Functions;
use File::Temp qw{tempdir};
use File::Basename qw(basename);
use LWP::UserAgent;
use Data::Dumper;

my $zephyr_class = "sipb-auto";
my $host = "zsr";

# Configuration
my $config_file = "/etc/sipbmp3-filter-config.pl";
if (-r $config_file) {
    # Inline the configuration file
    local $/;
    my $fh;
    open $fh, $config_file;
    eval <$fh>;
}

my $ua = new LWP::UserAgent;

close(STDERR);
open(STDERR, ">>", "/tmp/sipbmp3.log") or warn "Couldn't open log: $!";

$ENV{"TERM"}="vt100";

print STDERR "STDERR FROM SPOOL FILTER\n";

# set real uid to be effective uid
$< = $>;

# Select the correct output device and set the volume
#system("amixer -q set Headphone 100\% unmute");

# The command line we get from lpd is (no spaces between options and args):
#  -C lpr -C class
#  -A LPRng internal identifier
#  -H originating host
#  -J lpr -J jobname (default: list of files)
#  -L lpr -U username
#  -P logname
#  -Q queuename (lpr -Q)
#  -Z random user-specified options
#  -a printcap af (accounting file name)
#  -d printcap sd entry (spool dir)
#  -e print job data file name (currently being processed)
#  -h print job originiating host (same as -H)
#  -j job number in spool queue
#  -k print job control file name
#  -l printcap pl (page length)
#  -n user name (same as -L)
#  -s printcap sf (status file)
#  -w printcap pw (page width)
#  -x printcap px (page x dimension)
#  -y printcap py (page y dimension)
# accounting file name

printf(STDERR "Got \@ARGV: %s\n", Dumper(\@ARGV));

my %opts;

my @NEWARGV;

foreach my $arg (@ARGV) {
  if ($arg =~ m/^-([a-zA-Z])(.*)$/) {
    $opts{$1} = $2;
  } else {
    push @NEWARGV, @ARGV;
  }
}

@ARGV = @NEWARGV;

printf(STDERR Dumper(\%opts));

# Status messages at start of playback
open(ZEPHYR, '|/usr/athena/bin/zwrite -d -n -c '. $zephyr_class .' -i ' .
  'sipbmp3@'.$host.' -s "SIPB LPR music spooler"');
print(ZEPHYR "$opts{'n'}\@$opts{'H'} is playing:\n");

# For the Now Playing remctl command
open(STATUS, '>', '/var/run/sipbmp3/status') or die("Can't open status file /var/run/sipbmp3/status");

# SIGHUP handler
sub clear_status {
    # Possible race condition if the previous status is still going
    open(STA, '>', '/var/run/sipbmp3/status');
    close(STA);
    open(ZEPH, '|/usr/athena/bin/zwrite -d -n -c '. $zephyr_class .' -i '.
        'sipbmp3@'.$host.' -s "SIPB LPR music spooler"');
    print(ZEPH "Playback aborted.\n");
    close(ZEPH);
    die;
}
$SIG{HUP} = \&clear_status;

# So, the file we're currently processing is "-d/-e".

# Read the metadata information from the file.
my ($filepath) = catfile($opts{'d'}, $opts{'e'});
my ($fileinfo) = ImageInfo($filepath);
my ($magic) = $fileinfo->{FileType};

if ($magic) {
    printf(ZEPHYR "%s file %s\n", $magic, $opts{'J'});
    printf(STATUS "Filetype: %s\n", $magic);
    printf(STATUS "Filename: %s\n", $opts{'J'});
    if (exists $fileinfo->{'Title'}) {
        printf(ZEPHYR "\@b{%s}\n", $fileinfo->{'Title'}) if exists $fileinfo->{'Title'};
        printf(STATUS "Title: %s\n", $fileinfo->{'Title'});
    }
    foreach my $key (qw/Artist Album AlbumArtist/) {
        if (exists $fileinfo->{$key}) {
            printf(ZEPHYR "%s\n", $fileinfo->{$key}) if exists $fileinfo->{$key};
            printf(STATUS "%s: %s\n", $key, $fileinfo->{$key});
        }
    }
    my $tempdir = tempdir();
    $opts{'J'} =~ s/_mp3/.mp3/; #awful hack -- geofft
    my $newpath = $tempdir . '/' . basename($opts{'J'});
    symlink($filepath, $newpath);
    $filepath = $newpath;
}
elsif ($opts{'C'} eq 'Z') {
    $filepath = resolve_external_reference($filepath, \%opts);
    print STDERR "Resolved external reference to $filepath\n";
    printf(ZEPHYR "%s\n", $filepath);
    printf(STATUS "External: %s\n", $filepath);
}
elsif (-T $filepath) {
    split_playlist($filepath, \%opts);
    close(ZEPHYR);
    close(STATUS);
    exit 0;
}

#printf(STDERR "Job priority %s\n", $opts{'C'}) if $opts{'C'} eq 'Z';
#printf(ZEPHYR "Job priority %s\n", $opts{'C'}) if ($opts{'C'} && ($opts{'C'} ne 'A'));
close(ZEPHYR);
close(STATUS);
play_mplayer_audio($filepath, \%opts);

if ($magic) {
    unlink($newpath);
    rmdir($tempdir);
}

# Play an external stream reference
sub resolve_external_reference {
    # Retrieve those command line opts.
    my ($filepath, $opts) = @_;

    my $format, $uri, $userpass;

    if (<STDIN> =~ /^(\S+)/) {
	$uri=$1;

	my $response = $ua->head($uri);
	
	$contenttype=($response->content_type() or "unknown");
	
	if ($contenttype eq "audio/mpeg") { $format="MP3" }
	elsif ($contenttype eq "application/x-ogg") { $format="OGG" }
	elsif ($contenttype eq "application/ogg") { $format="OGG" }
	elsif ($contenttype eq "audio/x-scpls") { $format="SHOUTCAST" }
	else {
	    print ZEPHYR
		"Unknown Content-Type $contenttype for URI $uri\n";
	}
    } else {
        print ZEPHYR "Couldn't read URI for external reference\n";
	return $filepath;
    }

    if ($format eq "SHOUTCAST") {
	print ZEPHYR "Shoutcast playlist...\n";
	#Don't close ZEPHYR yet, will print the name of the stream if available
	return &get_shoutcast($uri);
    } elsif ($format eq "MP3") {
    } elsif ($format eq "OGG") {
    } else {
      print ZEPHYR "Unrecognized stream format: $format\n";
    }
    return $uri;
}

sub split_playlist {
    my ($file, $opts) = @_;

    my $i = 0;
    
    while (<STDIN>) {
	chomp;
	if (/^([^#]\S+)/) {
	    printf (STDERR "Found line: %s\n", $_);
	    open(LPR, "|-", qw/mit-lpr -Psipbmp3@localhost -CZ/, '-J'.$opts->{J});
	    print LPR $1;
	    close(LPR);
	$i++;
	}
    }
    printf(ZEPHYR "Playlist containing %d valid entries, split into separate jobs.\n", $i);
}

# Process a Shoutcast playlist
# get_shoutcast(URI)
sub get_shoutcast {
  my $uri = shift(@_);
  
  my $response = $ua->get($uri);

  foreach (split("\n", $response->content())) {
      if (/^File\d+=(\S+)/) {
	  push(@uris, $1);
      }
      if (/^Title\d+=(.+)$/) {
	  push(@titles, $1);
      }
  }
  
  # choose a random server
  $server = int(rand scalar(@uris));
  # print the name of the stream if available
  print ZEPHYR "$titles[$server]\n";
  return $uris[$server];
}

sub play_mplayer_audio {
    my ($filepath, $opts) = @_;

    # Prepare to write status:
    open(ZEPHYR, '|/usr/athena/bin/zwrite -d -n -c '.$zephyr_class.' -i ' .
	 'sipbmp3@'.$host.' -s "SIPB LPR music spooler"');
    
    # fork for mpg123
    my $pid = open(MP3STATUS, "-|");
    unless (defined $pid) {
	print ZEPHYR "Couldn't fork: $!\n";
	close(ZEPHYR);
	return;
    }
    
    if ($pid) { #parent
	# Check if there were any errors
	if ($_ = <MP3STATUS>) {
	    print ZEPHYR "Playback completed with the following errors:\n";
	    print ZEPHYR $_;
	    while (<MP3STATUS>) {
		print ZEPHYR $_;
	    }
	} else {
	    print ZEPHYR "Playback completed successfully.\n";
	}
	close(MP3STATUS) || print ZEPHYR "mplayer exited $?\n";
	
	close(ZEPHYR);
        open(STATUS, '>', '/var/run/sipbmp3/status');
        close(STATUS);
    }
  else { # child
      # redirect STDERR to STDOUT
      open STDERR, '>&STDOUT';
      # make sure that mplayer doesn't try to intepret the file as keyboard input
      close(STDIN);
      open(STDIN, "/dev/null");
      #print STDERR Dumper([qw|/usr/bin/mplayer -nolirc -ao alsa -quiet|, $filepath]);
      my @args = (qw|/usr/bin/mplayer -vo null -nolirc -ao alsa -cache 512 -really-quiet|, $filepath);
      #print STDERR "About to exec: ", Dumper([@args]);
      exec(@args) ||
	  die "Couldn't exec";
  }
}

# ID3 comments often have useless crap because tools like iTunes were
# written by drooling idiots
sub filter_comment {
  my $comment = shift(@_);

  if ($comment =~ /^engiTunes_CDDB/) {
    return undef;
  }
  return $comment;
}