nzbToMedia/libs/beets/plugins.py
echel0n f7e56b979b Fixes issues #344, #314
Added in code to place single files or groups of files that are not contained in a folder into there own folder or grouped folder based on parsing of the filenames to extract details required to determin correcting folder naming.
2014-04-23 19:50:51 -07:00

359 lines
11 KiB
Python

# This file is part of beets.
# Copyright 2013, 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.
"""Support for beets plugins."""
import logging
import traceback
from collections import defaultdict
import beets
from beets import mediafile
PLUGIN_NAMESPACE = 'beetsplug'
# Plugins using the Last.fm API can share the same API key.
LASTFM_KEY = '2dc3914abf35f0d9c92d97d8f8e42b43'
# Global logger.
log = logging.getLogger('beets')
# Managing the plugins themselves.
class BeetsPlugin(object):
"""The base class for all beets plugins. Plugins provide
functionality by defining a subclass of BeetsPlugin and overriding
the abstract methods defined here.
"""
def __init__(self, name=None):
"""Perform one-time plugin setup.
"""
_add_media_fields(self.item_fields())
self.import_stages = []
self.name = name or self.__module__.split('.')[-1]
self.config = beets.config[self.name]
if not self.template_funcs:
self.template_funcs = {}
if not self.template_fields:
self.template_fields = {}
if not self.album_template_fields:
self.album_template_fields = {}
def commands(self):
"""Should return a list of beets.ui.Subcommand objects for
commands that should be added to beets' CLI.
"""
return ()
def queries(self):
"""Should return a dict mapping prefixes to Query subclasses.
"""
return {}
def track_distance(self, item, info):
"""Should return a Distance object to be added to the
distance for every track comparison.
"""
return beets.autotag.hooks.Distance()
def album_distance(self, items, album_info, mapping):
"""Should return a Distance object to be added to the
distance for every album-level comparison.
"""
return beets.autotag.hooks.Distance()
def candidates(self, items, artist, album, va_likely):
"""Should return a sequence of AlbumInfo objects that match the
album whose items are provided.
"""
return ()
def item_candidates(self, item, artist, title):
"""Should return a sequence of TrackInfo objects that match the
item provided.
"""
return ()
def item_fields(self):
"""Returns field descriptors to be added to the MediaFile class,
in the form of a dictionary whose keys are field names and whose
values are descriptor (e.g., MediaField) instances. The Library
database schema is not (currently) extended.
"""
return {}
def album_for_id(self, album_id):
"""Return an AlbumInfo object or None if no matching release was
found.
"""
return None
def track_for_id(self, track_id):
"""Return a TrackInfo object or None if no matching release was
found.
"""
return None
listeners = None
@classmethod
def register_listener(cls, event, func):
"""Add a function as a listener for the specified event. (An
imperative alternative to the @listen decorator.)
"""
if cls.listeners is None:
cls.listeners = defaultdict(list)
cls.listeners[event].append(func)
@classmethod
def listen(cls, event):
"""Decorator that adds a function as an event handler for the
specified event (as a string). The parameters passed to function
will vary depending on what event occurred.
The function should respond to named parameters.
function(**kwargs) will trap all arguments in a dictionary.
Example:
>>> @MyPlugin.listen("imported")
>>> def importListener(**kwargs):
>>> pass
"""
def helper(func):
if cls.listeners is None:
cls.listeners = defaultdict(list)
cls.listeners[event].append(func)
return func
return helper
template_funcs = None
template_fields = None
album_template_fields = None
@classmethod
def template_func(cls, name):
"""Decorator that registers a path template function. The
function will be invoked as ``%name{}`` from path format
strings.
"""
def helper(func):
if cls.template_funcs is None:
cls.template_funcs = {}
cls.template_funcs[name] = func
return func
return helper
@classmethod
def template_field(cls, name):
"""Decorator that registers a path template field computation.
The value will be referenced as ``$name`` from path format
strings. The function must accept a single parameter, the Item
being formatted.
"""
def helper(func):
if cls.template_fields is None:
cls.template_fields = {}
cls.template_fields[name] = func
return func
return helper
_classes = set()
def load_plugins(names=()):
"""Imports the modules for a sequence of plugin names. Each name
must be the name of a Python module under the "beetsplug" namespace
package in sys.path; the module indicated should contain the
BeetsPlugin subclasses desired.
"""
for name in names:
modname = '%s.%s' % (PLUGIN_NAMESPACE, name)
try:
try:
namespace = __import__(modname, None, None)
except ImportError as exc:
# Again, this is hacky:
if exc.args[0].endswith(' ' + name):
log.warn('** plugin %s not found' % name)
else:
raise
else:
for obj in getattr(namespace, name).__dict__.values():
if isinstance(obj, type) and issubclass(obj, BeetsPlugin) \
and obj != BeetsPlugin and obj not in _classes:
_classes.add(obj)
except:
log.warn('** error loading plugin %s' % name)
log.warn(traceback.format_exc())
_instances = {}
def find_plugins():
"""Returns a list of BeetsPlugin subclass instances from all
currently loaded beets plugins. Loads the default plugin set
first.
"""
load_plugins()
plugins = []
for cls in _classes:
# Only instantiate each plugin class once.
if cls not in _instances:
_instances[cls] = cls()
plugins.append(_instances[cls])
return plugins
# Communication with plugins.
def commands():
"""Returns a list of Subcommand objects from all loaded plugins.
"""
out = []
for plugin in find_plugins():
out += plugin.commands()
return out
def queries():
"""Returns a dict mapping prefix strings to Query subclasses all loaded
plugins.
"""
out = {}
for plugin in find_plugins():
out.update(plugin.queries())
return out
def track_distance(item, info):
"""Gets the track distance calculated by all loaded plugins.
Returns a Distance object.
"""
from beets.autotag.hooks import Distance
dist = Distance()
for plugin in find_plugins():
dist.update(plugin.track_distance(item, info))
return dist
def album_distance(items, album_info, mapping):
"""Returns the album distance calculated by plugins."""
from beets.autotag.hooks import Distance
dist = Distance()
for plugin in find_plugins():
dist.update(plugin.album_distance(items, album_info, mapping))
return dist
def candidates(items, artist, album, va_likely):
"""Gets MusicBrainz candidates for an album from each plugin.
"""
out = []
for plugin in find_plugins():
out.extend(plugin.candidates(items, artist, album, va_likely))
return out
def item_candidates(item, artist, title):
"""Gets MusicBrainz candidates for an item from the plugins.
"""
out = []
for plugin in find_plugins():
out.extend(plugin.item_candidates(item, artist, title))
return out
def album_for_id(album_id):
"""Get AlbumInfo objects for a given ID string.
"""
out = []
for plugin in find_plugins():
res = plugin.album_for_id(album_id)
if res:
out.append(res)
return out
def track_for_id(track_id):
"""Get TrackInfo objects for a given ID string.
"""
out = []
for plugin in find_plugins():
res = plugin.track_for_id(track_id)
if res:
out.append(res)
return out
def template_funcs():
"""Get all the template functions declared by plugins as a
dictionary.
"""
funcs = {}
for plugin in find_plugins():
if plugin.template_funcs:
funcs.update(plugin.template_funcs)
return funcs
def _add_media_fields(fields):
"""Adds a {name: descriptor} dictionary of fields to the MediaFile
class. Called during the plugin initialization.
"""
for key, value in fields.iteritems():
setattr(mediafile.MediaFile, key, value)
def import_stages():
"""Get a list of import stage functions defined by plugins."""
stages = []
for plugin in find_plugins():
if hasattr(plugin, 'import_stages'):
stages += plugin.import_stages
return stages
# New-style (lazy) plugin-provided fields.
def item_field_getters():
"""Get a dictionary mapping field names to unary functions that
compute the field's value.
"""
funcs = {}
for plugin in find_plugins():
if plugin.template_fields:
funcs.update(plugin.template_fields)
return funcs
def album_field_getters():
"""As above, for album fields.
"""
funcs = {}
for plugin in find_plugins():
if plugin.album_template_fields:
funcs.update(plugin.album_template_fields)
return funcs
# Event dispatch.
def event_handlers():
"""Find all event handlers from plugins as a dictionary mapping
event names to sequences of callables.
"""
all_handlers = defaultdict(list)
for plugin in find_plugins():
if plugin.listeners:
for event, handlers in plugin.listeners.items():
all_handlers[event] += handlers
return all_handlers
def send(event, **arguments):
"""Sends an event to all assigned event listeners. Event is the
name of the event to send, all other named arguments go to the
event handler(s).
Returns a list of return values from the handlers.
"""
log.debug('Sending event: %s' % event)
return [handler(**arguments) for handler in event_handlers()[event]]