text: # -*- 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.
  
  """Fetches album art.
  """
  from __future__ import (division, absolute_import, print_function,
                          unicode_literals)
  
  from contextlib import closing
  import os
  import re
  from tempfile import NamedTemporaryFile
  
  import requests
  
  from beets import plugins
  from beets import importer
  from beets import ui
  from beets import util
  from beets import config
  from beets.util.artresizer import ArtResizer
  
  try:
      import itunes
      HAVE_ITUNES = True
  except ImportError:
      HAVE_ITUNES = False
  
  IMAGE_EXTENSIONS = ['png', 'jpg', 'jpeg']
  CONTENT_TYPES = ('image/jpeg', 'image/png')
  DOWNLOAD_EXTENSION = '.jpg'
  
  CANDIDATE_BAD = 0
  CANDIDATE_EXACT = 1
  CANDIDATE_DOWNSCALE = 2
  
  
  def _logged_get(log, *args, **kwargs):
      """Like `requests.get`, but logs the effective URL to the specified
      `log` at the `DEBUG` level.
  
      Use the optional `message` parameter to specify what to log before
      the URL. By default, the string is "getting URL".
  
      Also sets the User-Agent header to indicate beets.
      """
      # Use some arguments with the `send` call but most with the
      # `Request` construction. This is a cheap, magic-filled way to
      # emulate `requests.get` or, more pertinently,
      # `requests.Session.request`.
      req_kwargs = kwargs
      send_kwargs = {}
      for arg in ('stream', 'verify', 'proxies', 'cert', 'timeout'):
          if arg in kwargs:
              send_kwargs[arg] = req_kwargs.pop(arg)
  
      # Our special logging message parameter.
      if 'message' in kwargs:
          message = kwargs.pop('message')
      else:
          message = 'getting URL'
  
      req = requests.Request(b'GET', *args, **req_kwargs)
      with requests.Session() as s:
          s.headers = {b'User-Agent': b'beets'}
          prepped = s.prepare_request(req)
          log.debug('{}: {}', message, prepped.url)
          return s.send(prepped, **send_kwargs)
  
  
  class RequestMixin(object):
      """Adds a Requests wrapper to the class that uses the logger, which
      must be named `self._log`.
      """
  
      def request(self, *args, **kwargs):
          """Like `requests.get`, but uses the logger `self._log`.
  
          See also `_logged_get`.
          """
          return _logged_get(self._log, *args, **kwargs)
  
  
  # ART SOURCES ################################################################
  
  class ArtSource(RequestMixin):
      def __init__(self, log, config):
          self._log = log
          self._config = config
  
      def get(self, album):
          raise NotImplementedError()
  
  
  class CoverArtArchive(ArtSource):
      """Cover Art Archive"""
      URL = 'http://coverartarchive.org/release/{mbid}/front'
      GROUP_URL = 'http://coverartarchive.org/release-group/{mbid}/front'
  
      def get(self, album):
          """Return the Cover Art Archive and Cover Art Archive release group URLs
          using album MusicBrainz release ID and release group ID.
          """
          if album.mb_albumid:
              yield self.URL.format(mbid=album.mb_albumid)
          if album.mb_releasegroupid:
              yield self.GROUP_URL.format(mbid=album.mb_releasegroupid)
  
  
  class Amazon(ArtSource):
      URL = 'http://images.amazon.com/images/P/%s.%02i.LZZZZZZZ.jpg'
      INDICES = (1, 2)
  
      def get(self, album):
          """Generate URLs using Amazon ID (ASIN) string.
          """
          if album.asin:
              for index in self.INDICES:
                  yield self.URL % (album.asin, index)
  
  
  class AlbumArtOrg(ArtSource):
      """AlbumArt.org scraper"""
      URL = 'http://www.albumart.org/index_detail.php'
      PAT = r'href\s*=\s*"([^>"]*)"[^>]*title\s*=\s*"View larger image"'
  
      def get(self, album):
          """Return art URL from AlbumArt.org using album ASIN.
          """
          if not album.asin:
              return
          # Get the page from albumart.org.
          try:
              resp = self.request(self.URL, params={'asin': album.asin})
              self._log.debug(u'scraped art URL: {0}', resp.url)
          except requests.RequestException:
              self._log.debug(u'error scraping art page')
              return
  
          # Search the page for the image URL.
          m = re.search(self.PAT, resp.text)
          if m:
              image_url = m.group(1)
              yield image_url
          else:
              self._log.debug(u'no image found on page')
  
  
  class GoogleImages(ArtSource):
      URL = u'https://www.googleapis.com/customsearch/v1'
  
      def get(self, album):
          """Return art URL from google custom search engine
          given an album title and interpreter.
          """
          if not (album.albumartist and album.album):
              return
          search_string = (album.albumartist + ',' + album.album).encode('utf-8')
          response = self.request(self.URL, params={
              'key': self._config['google_key'].get(),
              'cx': self._config['google_engine'].get(),
              'q': search_string,
              'searchType': 'image'
          })
  
          # Get results using JSON.
          try:
              data = response.json()
          except ValueError:
              self._log.debug(u'google: error loading response: {}'
                              .format(response.text))
              return
  
          if 'error' in data:
              reason = data['error']['errors'][0]['reason']
              self._log.debug(u'google fetchart error: {0}', reason)
              return
  
          if 'items' in data.keys():
              for item in data['items']:
                  yield item['link']
  
  
  class ITunesStore(ArtSource):
      # Art from the iTunes Store.
      def get(self, album):
          """Return art URL from iTunes Store given an album title.
          """
          if not (album.albumartist and album.album):
              return
          search_string = (album.albumartist + ' ' + album.album).encode('utf-8')
          try:
              # Isolate bugs in the iTunes library while searching.
              try:
                  results = itunes.search_album(search_string)
              except Exception as exc:
                  self._log.debug('iTunes search failed: {0}', exc)
                  return
  
              # Get the first match.
              if results:
                  itunes_album = results[0]
              else:
                  self._log.debug('iTunes search for {:r} got no results',
                                  search_string)
                  return
  
              if itunes_album.get_artwork()['100']:
                  small_url = itunes_album.get_artwork()['100']
                  big_url = small_url.replace('100x100', '1200x1200')
                  yield big_url
              else:
                  self._log.debug(u'album has no artwork in iTunes Store')
          except IndexError:
              self._log.debug(u'album not found in iTunes Store')
  
  
  class Wikipedia(ArtSource):
      # Art from Wikipedia (queried through DBpedia)
      DBPEDIA_URL = 'http://dbpedia.org/sparql'
      WIKIPEDIA_URL = 'http://en.wikipedia.org/w/api.php'
      SPARQL_QUERY = '''PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
                   PREFIX dbpprop: <http://dbpedia.org/property/>
                   PREFIX owl: <http://dbpedia.org/ontology/>
                   PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
                   PREFIX foaf: <http://xmlns.com/foaf/0.1/>
  
                   SELECT DISTINCT ?pageId ?coverFilename WHERE {{
                     ?subject owl:wikiPageID ?pageId .
                     ?subject dbpprop:name ?name .
                     ?subject rdfs:label ?label .
                     {{ ?subject dbpprop:artist ?artist }}
                       UNION
                     {{ ?subject owl:artist ?artist }}
                     {{ ?artist foaf:name "{artist}"@en }}
                       UNION
                     {{ ?artist dbpprop:name "{artist}"@en }}
                     ?subject rdf:type <http://dbpedia.org/ontology/Album> .
                     ?subject dbpprop:cover ?coverFilename .
                     FILTER ( regex(?name, "{album}", "i") )
                    }}
                   Limit 1'''
  
      def get(self, album):
          if not (album.albumartist and album.album):
              return
  
          # Find the name of the cover art filename on DBpedia
          cover_filename, page_id = None, None
          dbpedia_response = self.request(
              self.DBPEDIA_URL,
              params={
                  'format': 'application/sparql-results+json',
                  'timeout': 2500,
                  'query': self.SPARQL_QUERY.format(
                      artist=album.albumartist.title(), album=album.album)
              },
              headers={'content-type': 'application/json'},
          )
          try:
              data = dbpedia_response.json()
              results = data['results']['bindings']
              if results:
                  cover_filename = 'File:' + results[0]['coverFilename']['value']
                  page_id = results[0]['pageId']['value']
              else:
                  self._log.debug('wikipedia: album not found on dbpedia')
          except (ValueError, KeyError, IndexError):
              self._log.debug('wikipedia: error scraping dbpedia response: {}',
                              dbpedia_response.text)
  
          # Ensure we have a filename before attempting to query wikipedia
          if not (cover_filename and page_id):
              return
  
          # DBPedia sometimes provides an incomplete cover_filename, indicated
          # by the filename having a space before the extension, e.g., 'foo .bar'
          # An additional Wikipedia call can help to find the real filename.
          # This may be removed once the DBPedia issue is resolved, see:
          # https://github.com/dbpedia/extraction-framework/issues/396
          if ' .' in cover_filename and \
             '.' not in cover_filename.split(' .')[-1]:
              self._log.debug(
                  'wikipedia: dbpedia provided incomplete cover_filename'
              )
              lpart, rpart = cover_filename.rsplit(' .', 1)
  
              # Query all the images in the page
              wikipedia_response = self.request(
                  self.WIKIPEDIA_URL,
                  params={
                      'format': 'json',
                      'action': 'query',
                      'continue': '',
                      'prop': 'images',
                      'pageids': page_id,
                  },
                  headers={'content-type': 'application/json'},
              )
  
              # Try to see if one of the images on the pages matches our
              # imcomplete cover_filename
              try:
                  data = wikipedia_response.json()
                  results = data['query']['pages'][page_id]['images']
                  for result in results:
                      if re.match(re.escape(lpart) + r'.*?\.' + re.escape(rpart),
                                  result['title']):
                          cover_filename = result['title']
                          break
              except (ValueError, KeyError):
                  self._log.debug(
                      'wikipedia: failed to retrieve a cover_filename'
                  )
                  return
  
          # Find the absolute url of the cover art on Wikipedia
          wikipedia_response = self.request(
              self.WIKIPEDIA_URL,
              params={
                  'format': 'json',
                  'action': 'query',
                  'continue': '',
                  'prop': 'imageinfo',
                  'iiprop': 'url',
                  'titles': cover_filename.encode('utf-8'),
              },
              headers={'content-type': 'application/json'},
          )
  
          try:
              data = wikipedia_response.json()
              results = data['query']['pages']
              for _, result in results.iteritems():
                  image_url = result['imageinfo'][0]['url']
                  yield image_url
          except (ValueError, KeyError, IndexError):
              self._log.debug('wikipedia: error scraping imageinfo')
              return
  
  
  class FileSystem(ArtSource):
      """Art from the filesystem"""
      @staticmethod
      def filename_priority(filename, cover_names):
          """Sort order for image names.
  
          Return indexes of cover names found in the image filename. This
          means that images with lower-numbered and more keywords will have
          higher priority.
          """
          return [idx for (idx, x) in enumerate(cover_names) if x in filename]
  
      def get(self, path, cover_names, cautious):
          """Look for album art files in a specified directory.
          """
          if not os.path.isdir(path):
              return
  
          # Find all files that look like images in the directory.
          images = []
          for fn in os.listdir(path):
              for ext in IMAGE_EXTENSIONS:
                  if fn.lower().endswith(b'.' + ext.encode('utf8')) and \
                     os.path.isfile(os.path.join(path, fn)):
                      images.append(fn)
  
          # Look for "preferred" filenames.
          images = sorted(images,
                          key=lambda x: self.filename_priority(x, cover_names))
          cover_pat = br"(\b|_)({0})(\b|_)".format(b'|'.join(cover_names))
          for fn in images:
              if re.search(cover_pat, os.path.splitext(fn)[0], re.I):
                  self._log.debug(u'using well-named art file {0}',
                                  util.displayable_path(fn))
                  return os.path.join(path, fn)
  
          # Fall back to any image in the folder.
          if images and not cautious:
              self._log.debug(u'using fallback art file {0}',
                              util.displayable_path(images[0]))
              return os.path.join(path, images[0])
  
  
  # Try each source in turn.
  
  SOURCES_ALL = [u'coverart', u'itunes', u'amazon', u'albumart',
                 u'wikipedia', u'google']
  
  ART_SOURCES = {
      u'coverart': CoverArtArchive,
      u'itunes': ITunesStore,
      u'albumart': AlbumArtOrg,
      u'amazon': Amazon,
      u'wikipedia': Wikipedia,
      u'google': GoogleImages,
  }
  
  # PLUGIN LOGIC ###############################################################
  
  
  class FetchArtPlugin(plugins.BeetsPlugin, RequestMixin):
      def __init__(self):
          super(FetchArtPlugin, self).__init__()
  
          self.config.add({
              'auto': True,
              'minwidth': 0,
              'maxwidth': 0,
              'enforce_ratio': False,
              'remote_priority': False,
              'cautious': False,
              'cover_names': ['cover', 'front', 'art', 'album', 'folder'],
              'sources': ['coverart', 'itunes', 'amazon', 'albumart'],
              'google_key': None,
              'google_engine': u'001442825323518660753:hrh5ch1gjzm',
          })
          self.config['google_key'].redact = True
  
          # Holds paths to downloaded images between fetching them and
          # placing them in the filesystem.
          self.art_paths = {}
  
          self.minwidth = self.config['minwidth'].get(int)
          self.maxwidth = self.config['maxwidth'].get(int)
          self.enforce_ratio = self.config['enforce_ratio'].get(bool)
  
          if self.config['auto']:
              # Enable two import hooks when fetching is enabled.
              self.import_stages = [self.fetch_art]
              self.register_listener('import_task_files', self.assign_art)
  
          available_sources = list(SOURCES_ALL)
          if not HAVE_ITUNES and u'itunes' in available_sources:
              available_sources.remove(u'itunes')
          if not self.config['google_key'].get() and \
                  u'google' in available_sources:
              available_sources.remove(u'google')
          sources_name = plugins.sanitize_choices(
              self.config['sources'].as_str_seq(), available_sources)
          self.sources = [ART_SOURCES[s](self._log, self.config)
                          for s in sources_name]
          self.fs_source = FileSystem(self._log, self.config)
  
      # Asynchronous; after music is added to the library.
      def fetch_art(self, session, task):
          """Find art for the album being imported."""
          if task.is_album:  # Only fetch art for full albums.
              if task.album.artpath and os.path.isfile(task.album.artpath):
                  # Album already has art (probably a re-import); skip it.
                  return
              if task.choice_flag == importer.action.ASIS:
                  # For as-is imports, don't search Web sources for art.
                  local = True
              elif task.choice_flag == importer.action.APPLY:
                  # Search everywhere for art.
                  local = False
              else:
                  # For any other choices (e.g., TRACKS), do nothing.
                  return
  
              path = self.art_for_album(task.album, task.paths, local)
  
              if path:
                  self.art_paths[task] = path
  
      # Synchronous; after music files are put in place.
      def assign_art(self, session, task):
          """Place the discovered art in the filesystem."""
          if task in self.art_paths:
              path = self.art_paths.pop(task)
  
              album = task.album
              src_removed = (config['import']['delete'].get(bool) or
                             config['import']['move'].get(bool))
              album.set_art(path, not src_removed)
              album.store()
              if src_removed:
                  task.prune(path)
  
      # Manual album art fetching.
      def commands(self):
          cmd = ui.Subcommand('fetchart', help='download album art')
          cmd.parser.add_option('-f', '--force', dest='force',
                                action='store_true', default=False,
                                help='re-download art when already present')
  
          def func(lib, opts, args):
              self.batch_fetch_art(lib, lib.albums(ui.decargs(args)), opts.force)
          cmd.func = func
          return [cmd]
  
      # Utilities converted from functions to methods on logging overhaul
  
      def _fetch_image(self, url):
          """Downloads an image from a URL and checks whether it seems to
          actually be an image. If so, returns a path to the downloaded image.
          Otherwise, returns None.
          """
          try:
              with closing(self.request(url, stream=True,
                                        message='downloading image')) as resp:
                  if 'Content-Type' not in resp.headers \
                          or resp.headers['Content-Type'] not in CONTENT_TYPES:
                      self._log.debug(
                          'not a supported image: {}',
                          resp.headers.get('Content-Type') or 'no content type',
                      )
                      return None
  
                  # Generate a temporary file with the correct extension.
                  with NamedTemporaryFile(suffix=DOWNLOAD_EXTENSION,
                                          delete=False) as fh:
                      for chunk in resp.iter_content(chunk_size=1024):
                          fh.write(chunk)
                  self._log.debug(u'downloaded art to: {0}',
                                  util.displayable_path(fh.name))
                  return fh.name
  
          except (IOError, requests.RequestException, TypeError) as exc:
              # Handling TypeError works around a urllib3 bug:
              # https://github.com/shazow/urllib3/issues/556
              self._log.debug('error fetching art: {}', exc)
              return None
  
      def _is_valid_image_candidate(self, candidate):
          """Determine whether the given candidate artwork is valid based on
          its dimensions (width and ratio).
  
          Return `CANDIDATE_BAD` if the file is unusable.
          Return `CANDIDATE_EXACT` if the file is usable as-is.
          Return `CANDIDATE_DOWNSCALE` if the file must be resized.
          """
          if not candidate:
              return CANDIDATE_BAD
  
          if not (self.enforce_ratio or self.minwidth or self.maxwidth):
              return CANDIDATE_EXACT
  
          # get_size returns None if no local imaging backend is available
          size = ArtResizer.shared.get_size(candidate)
          self._log.debug('image size: {}', size)
  
          if not size:
              self._log.warning(u'Could not get size of image (please see '
                                u'documentation for dependencies). '
                                u'The configuration options `minwidth` and '
                                u'`enforce_ratio` may be violated.')
              return CANDIDATE_EXACT
  
          # Check minimum size.
          if self.minwidth and size[0] < self.minwidth:
              self._log.debug('image too small ({} < {})',
                              size[0], self.minwidth)
              return CANDIDATE_BAD
  
          # Check aspect ratio.
          if self.enforce_ratio and size[0] != size[1]:
              self._log.debug('image is not square ({} != {})',
                              size[0], size[1])
              return CANDIDATE_BAD
  
          # Check maximum size.
          if self.maxwidth and size[0] > self.maxwidth:
              self._log.debug('image needs resizing ({} > {})',
                              size[0], self.maxwidth)
              return CANDIDATE_DOWNSCALE
  
          return CANDIDATE_EXACT
  
      def art_for_album(self, album, paths, local_only=False):
          """Given an Album object, returns a path to downloaded art for the
          album (or None if no art is found). If `maxwidth`, then images are
          resized to this maximum pixel size. If `local_only`, then only local
          image files from the filesystem are returned; no network requests
          are made.
          """
          out = None
          check = None
  
          # Local art.
          cover_names = self.config['cover_names'].as_str_seq()
          cover_names = map(util.bytestring_path, cover_names)
          cautious = self.config['cautious'].get(bool)
          if paths:
              for path in paths:
                  candidate = self.fs_source.get(path, cover_names, cautious)
                  check = self._is_valid_image_candidate(candidate)
                  if check:
                      out = candidate
                      self._log.debug('found local image {}', out)
                      break
  
          # Web art sources.
          remote_priority = self.config['remote_priority'].get(bool)
          if not local_only and (remote_priority or not out):
              for url in self._source_urls(album):
                  if self.maxwidth:
                      url = ArtResizer.shared.proxy_url(self.maxwidth, url)
                  candidate = self._fetch_image(url)
                  check = self._is_valid_image_candidate(candidate)
                  if check:
                      out = candidate
                      self._log.debug('using remote image {}', out)
                      break
  
          if self.maxwidth and out and check == CANDIDATE_DOWNSCALE:
              out = ArtResizer.shared.resize(self.maxwidth, out)
  
          return out
  
      def batch_fetch_art(self, lib, albums, force):
          """Fetch album art for each of the albums. This implements the manual
          fetchart CLI command.
          """
          for album in albums:
              if album.artpath and not force and os.path.isfile(album.artpath):
                  message = ui.colorize('text_highlight_minor', 'has album art')
              else:
                  # In ordinary invocations, look for images on the
                  # filesystem. When forcing, however, always go to the Web
                  # sources.
                  local_paths = None if force else [album.path]
  
                  path = self.art_for_album(album, local_paths)
                  if path:
                      album.set_art(path, False)
                      album.store()
                      message = ui.colorize('text_success', 'found album art')
                  else:
                      message = ui.colorize('text_error', 'no art found')
  
              self._log.info(u'{0}: {1}', album, message)
  
      def _source_urls(self, album):
          """Generate possible source URLs for an album's art. The URLs are
          not guaranteed to work so they each need to be attempted in turn.
          This allows the main `art_for_album` function to abort iteration
          through this sequence early to avoid the cost of scraping when not
          necessary.
          """
          source_names = {v: k for k, v in ART_SOURCES.items()}
          for source in self.sources:
              self._log.debug(
                  'trying source {0} for album {1.albumartist} - {1.album}',
                  source_names[type(source)],
                  album,
              )
              urls = source.get(album)
              for url in urls:
                  yield url
  