Move common libs to libs/common

libs/common/beetsplug/scrub.py

@@ -0,0 +1,151 @@
+# -*- coding: utf-8 -*-
+# This file is part of beets.
+# Copyright 2016, Adrian Sampson.
+#
+# 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.
+
+"""Cleans extraneous metadata from files' tags via a command or
+automatically whenever tags are written.
+"""
+
+from __future__ import division, absolute_import, print_function
+
+from beets.plugins import BeetsPlugin
+from beets import ui
+from beets import util
+from beets import config
+from beets import mediafile
+import mutagen
+
+_MUTAGEN_FORMATS = {
+    'asf': 'ASF',
+    'apev2': 'APEv2File',
+    'flac': 'FLAC',
+    'id3': 'ID3FileType',
+    'mp3': 'MP3',
+    'mp4': 'MP4',
+    'oggflac': 'OggFLAC',
+    'oggspeex': 'OggSpeex',
+    'oggtheora': 'OggTheora',
+    'oggvorbis': 'OggVorbis',
+    'oggopus': 'OggOpus',
+    'trueaudio': 'TrueAudio',
+    'wavpack': 'WavPack',
+    'monkeysaudio': 'MonkeysAudio',
+    'optimfrog': 'OptimFROG',
+}
+
+
+class ScrubPlugin(BeetsPlugin):
+    """Removes extraneous metadata from files' tags."""
+    def __init__(self):
+        super(ScrubPlugin, self).__init__()
+        self.config.add({
+            'auto': True,
+        })
+
+        if self.config['auto']:
+            self.register_listener("import_task_files", self.import_task_files)
+
+    def commands(self):
+        def scrub_func(lib, opts, args):
+            # Walk through matching files and remove tags.
+            for item in lib.items(ui.decargs(args)):
+                self._log.info(u'scrubbing: {0}',
+                               util.displayable_path(item.path))
+                self._scrub_item(item, opts.write)
+
+        scrub_cmd = ui.Subcommand('scrub', help=u'clean audio tags')
+        scrub_cmd.parser.add_option(
+            u'-W', u'--nowrite', dest='write',
+            action='store_false', default=True,
+            help=u'leave tags empty')
+        scrub_cmd.func = scrub_func
+
+        return [scrub_cmd]
+
+    @staticmethod
+    def _mutagen_classes():
+        """Get a list of file type classes from the Mutagen module.
+        """
+        classes = []
+        for modname, clsname in _MUTAGEN_FORMATS.items():
+            mod = __import__('mutagen.{0}'.format(modname),
+                             fromlist=[clsname])
+            classes.append(getattr(mod, clsname))
+        return classes
+
+    def _scrub(self, path):
+        """Remove all tags from a file.
+        """
+        for cls in self._mutagen_classes():
+            # Try opening the file with this type, but just skip in the
+            # event of any error.
+            try:
+                f = cls(util.syspath(path))
+            except Exception:
+                continue
+            if f.tags is None:
+                continue
+
+            # Remove the tag for this type.
+            try:
+                f.delete()
+            except NotImplementedError:
+                # Some Mutagen metadata subclasses (namely, ASFTag) do not
+                # support .delete(), presumably because it is impossible to
+                # remove them. In this case, we just remove all the tags.
+                for tag in f.keys():
+                    del f[tag]
+                f.save()
+            except (IOError, mutagen.MutagenError) as exc:
+                self._log.error(u'could not scrub {0}: {1}',
+                                util.displayable_path(path), exc)
+
+    def _scrub_item(self, item, restore=True):
+        """Remove tags from an Item's associated file and, if `restore`
+        is enabled, write the database's tags back to the file.
+        """
+        # Get album art if we need to restore it.
+        if restore:
+            try:
+                mf = mediafile.MediaFile(util.syspath(item.path),
+                                         config['id3v23'].get(bool))
+            except mediafile.UnreadableFileError as exc:
+                self._log.error(u'could not open file to scrub: {0}',
+                                exc)
+                return
+            images = mf.images
+
+        # Remove all tags.
+        self._scrub(item.path)
+
+        # Restore tags, if enabled.
+        if restore:
+            self._log.debug(u'writing new tags after scrub')
+            item.try_write()
+            if images:
+                self._log.debug(u'restoring art')
+                try:
+                    mf = mediafile.MediaFile(util.syspath(item.path),
+                                             config['id3v23'].get(bool))
+                    mf.images = images
+                    mf.save()
+                except mediafile.UnreadableFileError as exc:
+                    self._log.error(u'could not write tags: {0}', exc)
+
+    def import_task_files(self, session, task):
+        """Automatically scrub imported files."""
+        for item in task.imported_items():
+            self._log.debug(u'auto-scrubbing {0}',
+                            util.displayable_path(item.path))
+            self._scrub_item(item)