#!/usr/bin/perl

# djsync.pl -- Sync's tracks on your Dell DJ with MP3's on your filesystem.
# I can be contacted at dan@daniel.net
#
# Version info:
#
# 0.1 -- Initial working version
# 0.5 -- Bugs fixed, error handeling added

use MP3::Info;

# user defined variables
$djtracklist = "/tmp/djtracks.txt";
$host_mp3_dir = "/stuff/mp3/dj/";     

# program variables
@host_files="";
$host_files_counter=0;
@dj_tracks="";
$dj_tracks_counter=0;

chdir($host_mp3_dir);

get_host_tracks("", 1);
get_dj_tracks();
parse_djtracks();
sync_to_dj();
sync_to_host();
cleanup();

sub get_host_tracks
{
# This loops through the $host_mp3_dir and builds an array of ALL files.  
	my ($directory, $offset) = @_;
	opendir(DIR, $host_mp3_dir . $directory) or die ("Error opening: $!");
	foreach (readdir(DIR)) 
	{
		my $file = $directory . $_;
#		printFile(0, $file, $_, $offset);
		my $full_filename = $host_mp3_dir . $file;

		if ( ! -d $full_filename)
		{
		$host_files[$host_files_counter] = $full_filename;
		$host_files_counter++;
		}

		if ( -d $file && /[A-Za-z]/)      
		{
			get_host_tracks($file . '/' , $offset + 1 );
			next;
		}
	}
}

sub printFile
{
# Called from get_host_tracks()  This function is deprecated and needs to be deleted.
	my ($type, $file, $name, $offset) = @_;
	my $full = $host_mp3_dir . $file;
	if ( ! -d $full)
	{
		$host_files[$host_files_counter] = $full;
		$host_files_counter++;
	}
} 


sub get_dj_tracks
{
# This calls the program 'tracks' to get the track listings off the DJ and stores it 
# in file $djtracklist
	print "Getting DJ Tracks...";
	system("tracks -E >$djtracklist");
	print("\n");
}


sub parse_djtracks
{
# This opens the file from get_dj_tracks and parses the file to get the filename in an
# array.
	local $/="----------------------------------";
	open(INPUT, $djtracklist) or die(print "Could not open $djtracklist: $!\n");

	while(<INPUT>)
	{
		($dj_id) = /ID:\s*(\d*)/;
		($dj_filename) = /FNAME:\s*(.*)/;
        	$dj_tracks[$dj_tracks_counter] = $dj_filename;
		$dj_tracks_counter++;	
	}
	close(INPUT) or die (print "Could not close: $!\n");
}



sub sync_to_dj
{
# sync_to_dj() will get send all tracks on the host to the DJ if they dont exist on the dj
# We do a embedded loop on the dj_tracks and host_files arrays.
	for ($h_counter = 0; $h_counter < @host_files; ++$h_counter)
	{
		$found = 0;
		for ($d_counter = 0; $d_counter < @dj_tracks && $found != 1; ++$d_counter)
		{
			$track_name = substr(@host_files[$h_counter],rindex(@host_files[$h_counter],'/')+1);
#                        print "Comparing $track_name vs @dj_tracks[$d_counter] \n";
			if ($track_name eq @dj_tracks[$d_counter])
			{
			$found = 1;
			}
		}

		if (!$found) 
		{
#			print "The track @host_files[$h_counter] exists on the Host, but not on the DJ.\n";
			$track_info = new MP3::Info @host_files[$h_counter];
			$track_time = int($track_info->{SECS});
			if ($track_time eq 0)
			{
				# If the track time is 0, its not an MP3 file or one stupid song.
# TODO: Put optional logging of skipped files.
				next;
			}			
#				printf "@host_files[$h_counter] info:\nFilename: %s\nCodec: %s\nTitle: %s\nAlbum: %s\nArtist: %s\nGenre: %s\nTrack Num: %s\nYear: %s\nLength: %s\n", 
			               @host_files[$h_counter], "MP3", $track_info->{TITLE}, $track_info->{ALBUM}, $track_info->{ARTIST}, $track_info->{GENRE}, $track_info{TRACKNUM}, $track_info{YEAR}, $track_time;

			# make sure all the ID3 info is set, if not, make it null.  sendtrack needs all input.
			$track_title = $track_info->{TITLE};
			if (!$track_title)
			{
				$track_title="";
			}
			$track_album = $track_info->{ALBUM};
			if (!$track_album)
			{
				$track_album="";
			}
			$track_artist = $track_info->{ARTIST};
			if (!$track_artist)
			{
				$track_artist="";
			}
			$track_genre = $track_info->{GENRE};
			if (!$track_genre)
			{
				$track_genre="";
			}
			$track_tracknum = $track_info->{TRACKNUM};
			if (!$track_tracknum)
			{
				$track_tracknum="";
			}
			$track_year = $track_info->{YEAR};
			if (!$track_year)
			{
				$track_year="";
			}
			print "Sending @host_files[$h_counter] to DJ\n";				
			system("sendtrack \"" . @host_files[$h_counter] . "\" MP3 \"" . $track_title . "\" \"" . $track_album . "\" \"" . $track_artist . "\"  \"" . $track_genre . "\" \"" . $track_tracknum . "\" " . $track_year . "\"\" \"" . $track_time . "\"");
		}
	}
}

sub sync_to_host
{
# sync_to_host() will delete tracks off the DJ if they do not exist on the host
	for ($d_counter = 0; $d_counter < @dj_tracks; ++$d_counter)
	{
		$found = 0;
	       	for ($i = 0; $i < @host_files && $found != 1; ++$i)
	 	{
               		$track_name = substr(@host_files[$i],rindex(@host_files[$i],'/')+1);
#			print "Comparing @dj_tracks[$d_counter] vs $track_name\n";
			if ($track_name eq  @dj_tracks[$d_counter])
			{
				$found = 1;
			}
		}

		if (!$found)
		{
			if (@dj_tracks[$d_counter] eq "")
			{
				next;
			}
#			print "The File @dj_tracks[$d_counter] exists on the DJ, but not on the Host.\n";

# TODO: Put error handeling in getting $dj_id
			($dj_id) = get_dj_trackid(@dj_tracks[$d_counter]);
			print "Deleting @dj_tracks[$d_counter] ($dj_id) off the DJ\n";
			system("deltr $dj_id");
		}
	}
}

sub get_dj_trackid
{
# This gets the trackid of the filename to send to the executable deltr.
# TODO: The same filename can exist on the DJ multiple times.  This code is broke here as it will
# only find the first ID to try and delete.  You will get an error to STDOUT.  Note that running
# djsync multiple times will eventually get rid of the MP3.  Also note that djsync is inherently 
# flawed because it syncs based on unique filenames.  It needs to be changed to sync via ID, but 
# this would involve storing this ID on the host as well (yuck).

	local $/="----------------------------------";
	open(INPUT, $djtracklist) or die(print "Could not open $djtracklist: $!\n");

	$dj_filename_searchstr = $_[0];
	while(<INPUT>)
	{
		($dj_id) = /ID:\s*(\d*)/;
		($dj_filename) = /FNAME:\s*(.*)/;
		if ($dj_filename eq $dj_filename_searchstr)
		{
			return ($dj_id);
		}
	}
	close(INPUT) or die (print "Could not close: $!\n");
}

sub cleanup
{
# clean everything up to exit
	unlink($djtracklist) or die(print "Cannot delete tracklist file: $!\n");
}