#!/usr/bin/python

"""
This script converts Vorbis OGG and mp3 files to low-bitrate mp3 files.
Requires at least the following Debian packages:
    python, python-pyvorbis, python-eyed3, vorbis-tools
Also required;
    lame, version 3.92 or newer
"""

import sys, os, ogg, ogg.vorbis, eyeD3
import getopt, re

usage = """Usage:
%s [options] <source> [<source>...]"""%(os.path.basename(sys.argv[0]))
help = """
    -h --help       this help
    -n --simple-names   Remove non-alnum chars from filename
    -d --single-directory   Do not create "artist - album" directory

    source      File or directory, directories are searched for ogg
            and mp3 -files.

Found files are converted to 96kbps mp3-files, "-lbr" is appended to the
filename. By default the files are placed in a "artist - album" directory.
"""


def escape(s):
    return s.replace("'", "\\'")

class Config(object):
    def __init__(self, args=[]):
        self.keep_filenames = 1
        self.single_directory = 0
        opts, args=getopt.getopt(sys.argv[1:], "hnd",
            ("help", "simple-names", "single-directory"))
        self.sources=args
        for name, value in opts:
            if name in ("-h", "--help"):
                print usage
                print help
                sys.exit(0)
            elif name in ("-n", "--simple-names"):
                self.keep_filenames=0
            elif name in ("-d", "--single-directory"):
                self.single_directory=1
        if not args:
            print usage
            sys.exit(0)

    def files(self):
        for source in self.sources:
            if os.path.isdir(source):
                for file in self.__subfiles(source):
                    yield file
            elif os.path.isfile(source):
                yield source
            else:
                print>>sys.stderr, "ERROR:"\
                    "'%s' is not a file or a directory."%source

    def __subfiles(self, path):
        for dirpath, dirnames, filenames in os.walk(path):
            for filename in filenames:
                fn=os.path.join(dirpath, filename)
                if os.path.isfile(fn) and\
                        filename[-4:].lower() in (".ogg", ".mp3"):
                    yield fn
                else:
                    print >>sys.stderr, "ERROR: ignoring '%s'"%(filename)

class AudioStream(object):
    def __init__(self, filename):
        self.fn = filename
        if filename[-4:].lower() == ".ogg":
            self.mode="ogg"
            self.get_ogg_tags()
        elif filename[-4:].lower() == ".mp3":
            self.mode="mp3"
            self.get_mp3_tags()
        else:
            raise Exception, "Unknown extension '%s'"%filename[-3:]
        self.lame_opts="--lowpass 14 --preset 96"

    def get_ogg_tags(self):
        stream = ogg.vorbis.VorbisFile(self.fn)
        comments = stream.comment().as_dict()
        self.artist = comments.get("ARTIST", [""])[0].encode("latin_1")
        self.album = comments.get("ALBUM", [""])[0].encode("latin_1")
        self.track = comments.get("TRACKNUMBER", [""])[0].encode("latin_1")
        self.title = comments.get("TITLE", [""])[0].encode("latin_1")

    def get_mp3_tags(self):
        tags = eyeD3.Mp3AudioFile(self.fn).getTag()
        self.artist = tags.getArtist() or "unknown"
        self.album = tags.getAlbum() or "unknown"
        self.track = str(tags.getTrackNum()[0] or "")
        self.title = tags.getTitle() or "unknown"

    def convert(self, target):
        path = os.path.dirname(target)
        if path:
            if not os.path.exists(path):
                os.makedirs(path)
            elif not os.path.isdir(path):
                print >>sys.stderr, "ERROR:"\
                    "'%s' exists and is not a directory"%(path)
            
        if self.mode == "ogg":
            self.convert_ogg(target)
        elif self.mode == "mp3":
            self.convert_mp3(target)
        else:
            raise Exception, "Invalid Mode"
    
    def convert_ogg(self, target):
        tempname = "/tmp/oggconvert-%d.wav"%(os.getpid())
        print "Converting %s to wav"%(os.path.basename(self.fn))
        os.system('ogg123 -q -d wav -f "%s" "%s"'%(
            escape(tempname), escape(self.fn)))
	os.system('lame "%s" %s "%s" --tt "%s" --ta "%s"'%(
            escape(tempname), self.lame_opts,
            escape(target),
            " - ".join(filter(None, (self.track, escape(self.title)))),
            " - ".join(filter(None, (escape(self.artist),
                escape(self.album))))))
        os.remove(tempname)
    
    def convert_mp3(self, target):
            os.system('lame "%s" %s "%s" --tt "%s" --ta "%s"'%(
            escape(self.fn), self.lame_opts,
            escape(target),
            " - ".join(filter(None, (self.track, escape(self.title)))),
            " - ".join(filter(None, (escape(self.artist),
                escape(self.album))))))
    
    def outputname(self, keep_names=1, single_dir=1):
        if single_dir and keep_names:
            return os.path.basename(self.fn)[:-4]+"-lbr.mp3"
        if not keep_names:
            result = re.sub("\W+", "",
                os.path.basename(self.fn[:-4]))+"-lbr.mp3"
        else:
            result = os.path.basename(self.fn)[:-4]+"-lbr.mp3"
        if not single_dir:
            result = "%s - %s%s%s"%(self.artist.replace(os.sep, ""),
                self.album.replace(os.sep, ""), os.sep, result)
        return result


if __name__ == "__main__":
    config = Config(sys.argv[1:])
    for filename in config.files():
        a=AudioStream(filename)
        result=a.outputname(config.keep_filenames,
            config.single_directory)
        a.convert(result)