[rhythmbox] artsearch: add support for coverartarchive.org

[Jonathan Matthew <jmatthew src gnome org>]

commit e4381e38c35a74deb66611b5f7ad9b6db7719929
Author: Jonathan Matthew <jonathan d14n org>
Date:   Sun Nov 17 22:05:37 2019 +1000

    artsearch: add support for coverartarchive.org
    
    If we have a musicbrainz release ID, or we find one with the album/artist
    search, try to fetch the 'front' image for the release from
    coverartarchive.org.  If this fails, try the Amazon ASID too.
    
    Since we don't know if coverartarchive.org has an image for a release without
    making a http request, we now try to fetch the image and provide that to
    ext-db, rather than giving it the url.

 plugins/artsearch/musicbrainz.py | 44 ++++++++++++++++++++++++++++++++--------
 1 file changed, 36 insertions(+), 8 deletions(-)
---
diff --git a/plugins/artsearch/musicbrainz.py b/plugins/artsearch/musicbrainz.py
index 0f50ea08b..8c422d280 100644
--- a/plugins/artsearch/musicbrainz.py
+++ b/plugins/artsearch/musicbrainz.py
@@ -28,13 +28,16 @@ import xml.dom.minidom as dom
 
 import urllib.parse
 import rb
-from gi.repository import RB
+from gi.repository import RB, GLib
 
 # musicbrainz URLs
 MUSICBRAINZ_RELEASE_URL = "https://musicbrainz.org/ws/2/release/%s?inc=artists";
 MUSICBRAINZ_RELEASE_PREFIX = "http://musicbrainz.org/release/";
 MUSICBRAINZ_RELEASE_SUFFIX = ".html"
 
+# cover art archive
+COVERARTARCHIVE_IMAGE_URL = "https://coverartarchive.org/release/%s/front";
+
 MUSICBRAINZ_SEARCH_QUERY = "artist:\"%s\" AND release:\"%s\""
 MUSICBRAINZ_SEARCH_URL = "https://musicbrainz.org/ws/2/release/?query=%s&limit=1";
 
@@ -46,6 +49,28 @@ AMAZON_IMAGE_URL = "https://images-na.ssl-images-amazon.com/images/P/%s.01.LZZZZ
 
 class MusicBrainzSearch(object):
 
+       def get_image_cb (self, data, args):
+               (storekey, store, urls, callback, cbargs) = args
+               url = urls[0]
+               urls = urls[1:]
+               if data is None:
+                       self.try_image_urls(storekey, store, urls, callback, cbargs)
+                       return
+
+               store.store_raw(storekey, RB.ExtDBSourceType.SEARCH, GLib.Bytes.new_take(data))
+               callback(*cbargs)
+
+       def try_image_urls (self, storekey, store, urls, callback, *args):
+               if len(urls) == 0:
+                       print("no more image urls to try")
+                       callback(*args)
+                       return
+
+               print("%d urls to try, trying %s" % (len(urls), urls[0]))
+               loader = rb.Loader()
+               loader.get_url(urls[0], self.get_image_cb, (storekey, store, urls, callback, args))
+
+
        def get_release_cb (self, data, args):
                (key, store, callback, cbargs) = args
                if data is None:
@@ -56,6 +81,10 @@ class MusicBrainzSearch(object):
                try:
                        parsed = dom.parseString(data)
 
+                       # get release MBID
+                       rel = parsed.getElementsByTagName('release')
+                       mbid = rel[0].attributes['id'].firstChild.data
+
                        storekey = RB.ExtDBKey.create_storage('album', key.get_field('album'))
 
                        # check that there's an artist that isn't 'various artists'
@@ -70,20 +99,19 @@ class MusicBrainzSearch(object):
                                                print("got musicbrainz artist name %s" % artistname)
                                                storekey.add_field('artist', artistname)
 
+                       urls = []
+
+                       # just need an mbid to use coverartarchive
+                       urls.append(COVERARTARCHIVE_IMAGE_URL % mbid)
 
                        # look for an ASIN tag
                        asin_tags = parsed.getElementsByTagName('asin')
                        if len(asin_tags) > 0:
                                asin = asin_tags[0].firstChild.data
+                               urls.append(AMAZON_IMAGE_URL % asin)
 
-                               print("got ASIN %s" % asin)
-                               image_url = AMAZON_IMAGE_URL % asin
-
-                               store.store_uri(storekey, RB.ExtDBSourceType.SEARCH, image_url)
-                       else:
-                               print("no ASIN for this release")
 
-                       callback(*cbargs)
+                       self.try_image_urls(storekey, store, urls, callback, args)
                except Exception as e:
                        print("exception parsing musicbrainz response: %s" % e)
                        callback(*cbargs)