initial version of the mbsync plugin

this plugin provides a faster way to query new metadata from
musicbrainz. (instead of having to 're-import' the files)
Currently it lacks all forms of documentation and will only work for
album queries. not really tested so far so be careful

beetsplug/mbsync.py

@@ -0,0 +1,100 @@
+# This file is part of beets.
+# Copyright 2013, Jakob Schnitzer.
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+
+"""Update local library from MusicBrainz
+"""
+import logging
+
+from beets.plugins import BeetsPlugin
+from beets import autotag, library, ui, util
+
+log = logging.getLogger('beets')
+
+
+def mbsync_func(lib, opts, args):
+    #album = opts.album
+    album = True
+    move = True
+    pretend = opts.pretend
+    with lib.transaction():
+        # Right now this only works for albums....
+        _, albums = ui.commands._do_query(lib, ui.decargs(args), album)
+
+        for a in albums:
+            if not a.mb_albumid:
+                log.info(u'Skipping album {0}: has no mb_albumid'.format(a.id))
+                continue
+
+            items = list(a.items())
+            for item in items:
+                item.old_data = dict(item.record)
+
+            cur_artist, cur_album, candidates, _ = \
+                autotag.match.tag_album(items, search_id=a.mb_albumid)
+            match = candidates[0]     # There should only be one match!
+            # ui.commands.show_change(cur_artist, cur_album, match)
+            autotag.apply_metadata(match.info, match.mapping)
+
+            for item in items:
+                changes = {}
+                for key in library.ITEM_KEYS_META:
+                    if item.dirty[key]:
+                        changes[key] = item.old_data[key], getattr(item, key)
+                if changes:
+                    # Something changed.
+                    ui.print_obj(item, lib)
+                    for key, (oldval, newval) in changes.iteritems():
+                        ui.commands._showdiff(key, oldval, newval)
+
+                    # If we're just pretending, then don't move or save.
+                    if pretend:
+                        continue
+
+                    # Move the item if it's in the library.
+                    if move and lib.directory in util.ancestry(item.path):
+                        lib.move(item)
+                    lib.store(item)
+
+            if pretend or a.id is None:  # pretend or Singleton
+                continue
+
+            # Update album structure to reflect an item in it.
+            for key in library.ALBUM_KEYS_ITEM:
+                setattr(a, key, getattr(items[0], key))
+
+            # Move album art (and any inconsistent items).
+            if move and lib.directory in util.ancestry(items[0].path):
+                log.debug(u'moving album {0}'.format(a.id))
+                a.move()
+
+
+class MBSyncPlugin(BeetsPlugin):
+    def __init__(self):
+        super(MBSyncPlugin, self).__init__()
+
+    def commands(self):
+        cmd = ui.Subcommand('mbsync',
+                            help='update metadata from musicbrainz')
+        #cmd.parser.add_option('-a', '--album', action='store_true',
+        #                      help='choose albums instead of tracks')
+        cmd.parser.add_option('-p', '--pretend', action='store_true',
+                              help='show all changes but do nothing')
+        cmd.parser.add_option('-M', '--nomove', action='store_false',
+                              default=True, dest='move',
+                              help="don't move files in library")
+        cmd.parser.add_option('-W', '--nowrite', action='store_false',
+                              default=True, dest='move',
+                              help="don't write updated metadata to files")
+        cmd.func = mbsync_func
+        return [cmd]