#! /usr/bin/env python2.4

'''
=head1 NAME

B<flac2mp3> - transcode FLAC file to MP3 files

=head1 SYNOPSIS

B<flac2mp3> [B<--lame-options> I<lame-options>] [B<-j> I<jobs>] [B<-q>] [B<-v>] I<file> [...]

=head1 DESCRIPTION

B<flac2mp3> transcodes the FLAC files I<file> to MP3 files.  I<file>
may be the kind of FLAC file B<fa-flacd> generates.  That is, it
contains a cue sheet, one TITLE tag per track listed therein, and
ARTIST, ALBUM, and DATE tags.

=head1 OPTIONS

=over 4

=item B<--lame-options> I<lame-options>

Pass I<lame-options> to B<lame>.  This ends up being passed to the
shell, so feel free to take advantage of that.  You'll almost
certainly have to put I<lame-options> in single quotes.

=item B<-j> [B<--jobs>] I<jobs>

Run up to I<jobs> jobs instead of the default 1.

=item B<-q> [B<--quiet>]

Suppress status information.  This option is passed along to B<flac>
and B<lame>.

=item B<-v> [B<--verbose>]

Print diagnostic information.  This option is passed along to B<flac>
and B<lame>.

=back

=head1 AUTHORS

Written by Eric Gillespie <epg@pretzelnet.org>.

=cut

''' #' # python-mode is sucks

import re, sys, traceback
from optparse import OptionParser
from subprocess import Popen, PIPE

import org.diplodocus.jobs
from org.diplodocus import flac, taglib
from org.diplodocus.util import run_or_die

################################################################################
# The child processes

def flac2mp3(fn, title, artist, album, date, track, skip_until, pics=None):
    (title, artist, album, date) = [(x == None and 'unknown') or x
                                    for x in (title, artist, album, date)]
    try:
        (skip_arg, until_arg) = skip_until
    except ValueError:
        skip_arg = until_arg = ''

    if quiet:
        flac_options = '--silent'
    else:
        flac_options = ''

    tmp = []
    global lame_options
    if lame_options != None:
        tmp.append(lame_options)
    else:
        tmp.append('--preset standard');
    quiet and tmp.append('--quiet')
    verbose and tmp.append('--verbose')
    lame_options = ' '.join(tmp)

    outfile = ('%s (%s) %02d %s.mp3' % (artist, album,
                                        track, title)).replace('/', '_')

    # Escape any single quotes ' so we can quote this.
    (fn, title, artist,
     album, date) = [x.replace("'", r"'\''")
                     for x in (fn, title, artist, album, date)]

    quoted_outfile = ('%s (%s) %02d %s.mp3' % (artist, album,
                                               track, title)).replace('/', '_')

    run_or_die(3, "flac %s -cd %s %s '%s' | lame --add-id3v2 %s --tt '%s' --ta '%s' --tl '%s' --ty '%s' --tn %d - '%s'"
               % (flac_options, skip_arg or '', until_arg or '', fn,
                  lame_options, title, artist, album, date, track,
                  quoted_outfile))

    if pics != None:
        taglib.add_apic_frame_to_mp3(outfile, pics)

    return 0

################################################################################
# The master process

def tformat(m, s, c):
    return '%02d:%02d.%02d' % (m, s, c)

def get_decode_args(fn):
    l = []

    p = Popen(['metaflac', '--export-cuesheet-to=-', fn], stdout=PIPE)
    for line in (x.rstrip() for x in p.stdout):
        m = re.search(r'INDEX 01 (\d\d):(\d\d):(\d\d)$', line)
        if m != None:
            l.append(map(int, m.groups()))
    status = p.wait()
    # XXX dataloss!  check status

    args = []
    for i in xrange(len(l)):
        arg = ['--skip=' + tformat(*l[i])]
        try:
            next = l[i + 1]
        except IndexError:
            next = None
        if next != None:
            if next[2] == 0:
                if next[1] == 0:
                    arg.append('--until=' + tformat(next[0] - 1, 59, 74))
                else:
                    arg.append('--until=' + tformat(next[0], next[1] - 1,
                                                    74))
            else:
                arg.append('--until=' + tformat(next[0], next[1],
                                                next[2] - 1))

        args.append(arg)

    # If no cue sheet, stick a dummy in here.
    if len(args) == 0:
        args = [[]]

    return args

# XXX other things should usue this; flac files, for example, should
# get PART as part of the filelname, same as mp3s.
class Tags(object):
    def __init__(self):
        self._tags = {}
    def __len__(self):
        return len(self._tags)
    def get(self, key, track=None):
        key = key.upper()
        try:
            if track == None:
                return self._tags[None][key]
            try:
                return self._tags[track][key]
            except KeyError:
                return self._tags[None][key]
        except KeyError:
            return None
    def gets(self, key, track=None):
        value = self.get(key, track)
        if value == None:
            return None
        return '\n'.join(value)
    def set(self, key, value, track=None):
        if track not in self._tags:
            self._tags[track] = {}
        if key not in self._tags[track]:
            self._tags[track][key] = []
        self._tags[track][key].append(value)

def get_tags(fn):
    '''Return the ARTIST, ALBUM, and DATE tags followed by the TITLE tags
    in the file FN.'''

    tags = Tags()

    p = Popen(['metaflac', '--export-tags-to=-', fn], stdout=PIPE)
    for line in (x.rstrip() for x in p.stdout):
        (tag, value) = line.split('=', 1)

        m = re.search(r'\[([0-9]+)]$', tag)
        if m != None:
            tag = tag[:m.start()]
            track = int(m.group(1))
        else:
            track = None

        tags.set(tag, value, track)
    # XXX dataloss!  check status
    status = p.wait()

    return tags

def find_pics(fn, tags):
    pics = tags.get('__flac2mp3_PICTURE')

    if not isinstance(pics, list):
        pics = flac.get_pictures(fn)
        tags.set('__flac2mp3_PICTURE', pics)

    return pics

def main(argv):
    # Control the exit code for any uncaught exceptions.
    try:
        parser = OptionParser()
        parser.disable_interspersed_args()
        parser.add_option('-X', '--debug', action='store_true', default=False)
        parser.add_option('-j', '--jobs', type='int', default=1)
        parser.add_option('--lame-options')
        parser.add_option('-q', '--quiet', action='store_true', default=False)
        parser.add_option('-v', '--verbose', action='store_true', default=False)
    except:
        traceback.print_exc()
        return 2

    try:
        # Raises SystemExit on invalid options in argv.
        (options, args) = parser.parse_args(argv[1:])
    except Exception, error:
        if isinstance(error, SystemExit):
            return 1
        traceback.print_exc()
        return 2

    try:
        global debug, flac_options, lame_options, quiet, verbose
        debug = options.debug
        lame_options = options.lame_options
        quiet = options.quiet
        verbose = options.verbose

        jobs = []
        for fn in args:
            try:
                args = get_decode_args(fn)

                tags = get_tags(fn)
                album = tags.gets('ALBUM')
                discnum = tags.gets('DISCNUMBER')
                track = tags.gets('TRACKNUMBER')

                # lame doesn't seem to support disc number.
                if discnum != None:
                    album = '%s (disc %s)' % (album, discnum)

                # Stupid hack: only a single-track file should have the
                # TRACKNUMBER tag, so use it if set for the first pass through
                # the loop.  At the end of the loop, we'll set $track for the
                # next run, so this continues to work for multi-track files.
                if track == None:
                    track = 1
                else:
                    track = int(track)

                for i in range(len(tags)):
                    title = tags.gets('TITLE', track)
                    part = tags.gets('PART', track)
                    if part != None:
                        title = '%s - %s' % (title, part)
                    jobs.append([fn, title,
                                 tags.gets('ARTIST', track),
                                 album,
                                 tags.gets('DATE', track),
                                 track, args[i], find_pics(fn, tags)])
                    track = i + 2
            except Exception, error:
                sys.stderr.write(getattr(error, 'msg', ''))
                traceback.print_exc()
                sys.stderr.write('Continuing...\n')

        def getjob(reap):
            try:
                job = jobs.pop(0)
            except IndexError:
                return
            return lambda: flac2mp3(*job)
        org.diplodocus.jobs.run(maxjobs=options.jobs, debug=debug, get_job=getjob)
    except Exception, error:
        if isinstance(error, SystemExit):
            raise
        # check all print_exc and format_exc in fa-flacd.py; i think
        # for some i don't do this msg print check
        sys.stderr.write(getattr(error, 'msg', ''))
        traceback.print_exc()
        return 2

    return 0

if __name__ == '__main__':
    sys.exit(main(sys.argv))