#! /usr/bin/python

import sys
from subprocess import Popen, PIPE

from org.diplodocus.util import run_or_die

from flac_archive.tags import Tags

class SubprocessError(Exception):
    def __init__(self, status, command=None, stderr=None):
        if command is None:
            command_msg = None
        else:
            command_msg = ': ' + ' '.join(command)
        if status < 0:
            msg = 'exited due to signal %d%s'
        else:
            msg = 'exit status %d%s'
        Exception.__init__(self, msg % (abs(status), command_msg))
        self.status = status
        self.command = command
        self.stderr = stderr

def get_tags(fn):
    tags = Tags()

    command = ['metaflac', '--no-utf8-convert', '--export-tags-to=-', fn]
    p = Popen(command, stdout=PIPE)
    tags.load(p.stdout)

    status = p.wait()
    if status != 0:
        raise SubprocessError(status, command=command, stderr=p.stderr)

    return tags

def do_read(filenames):
    # Use this mapping of tag names to sets of tag values to detect global tags.
    all_tags = {}
    # Build the collated result in this Tags object.
    coll_tags = Tags()
    # XXX The Tags interface is horrible.  It's gotta be almost 10 years since
    # I wrote it, so not surprising...
    for fn in filenames:
        tags = get_tags(fn)
        track_tags = tags.get('TRACKNUMBER')
        if len(track_tags) != 1:
            raise Exception('bogus TRACKNUMBER %s for %s' % (track_tags, fn))
        track = int(track_tags[0])
        for tag, values in tags._global.iteritems():
            for value in values:
                if tag in all_tags:
                    all_tags[tag].add(value)
                else:
                    all_tags[tag] = set([value])
                coll_tags.set(tag, value, track)
    for tag, values in all_tags.iteritems():
        if len(values) == 1:
            # Only one value for this tag, so add it to global tags.
            coll_tags.set(tag, list(values)[0])
            # And now remove it from each track tags.
            for track, tags in coll_tags._tracks.iteritems():
                del tags[tag]
    print '\n'.join(coll_tags.all())
    return 0

def main(args):
    if len(args) < 3:
        return usage()
    if args[1] == 'read':
        return do_read(args[2:])
    if args[1] == 'write':
        return do_write(args[2:])
    return usage()

def usage():
    return 2

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