[gnome-music/wip/mschraal/tageditor: 13/21] grlmusicbrainzwrapper: Initial musicbrainz support

[Marinus Schraal <mschraal src gnome org>]

commit 0287e6f4bcca583aa54d9f9de374449bf1ab1f35
Author: Sumaid Syed <sumaidsyed gmail com>
Date:   Sun Aug 4 23:12:09 2019 +0530

    grlmusicbrainzwrapper: Initial musicbrainz support
    
    Add support for chromparint, acoustid and musicbrainz grilo plugins.
    
    Based on patches by Jean Felder
    
    https://gitlab.gnome.org/GNOME/gnome-music/issues/293

 gnomemusic/coregrilo.py                           |  11 ++
 gnomemusic/grilowrappers/grlmusicbrainzwrapper.py | 165 ++++++++++++++++++++++
 2 files changed, 176 insertions(+)
---
diff --git a/gnomemusic/coregrilo.py b/gnomemusic/coregrilo.py
index f232ca55..dae92585 100644
--- a/gnomemusic/coregrilo.py
+++ b/gnomemusic/coregrilo.py
@@ -29,6 +29,8 @@ from gi.repository import Grl, GLib, GObject
 # from gnomemusic.grilowrappers.grldleynawrapper import GrlDLeynaWrapper
 from gnomemusic.grilowrappers.grlsearchwrapper import GrlSearchWrapper
 from gnomemusic.grilowrappers.grltrackerwrapper import GrlTrackerWrapper
+from gnomemusic.grilowrappers.grlmusicbrainzwrapper import (
+    GrlMusicbrainzWrapper)
 from gnomemusic.trackerwrapper import TrackerState, TrackerWrapper
 
 
@@ -99,6 +101,7 @@ class CoreGrilo(GObject.GObject):
         self._registry.connect('source-removed', self._on_source_removed)
 
         self._registry.load_all_plugins(True)
+        self._musicbrainz = GrlMusicbrainzWrapper(self)
 
     def _on_tracker_available_changed(self, klass, value):
         new_state = self._tracker_wrapper.props.tracker_available
@@ -186,6 +189,14 @@ class CoreGrilo(GObject.GObject):
         for wrapper in self._wrappers.values():
             wrapper.populate_album_disc_songs(media, discnr, callback)
 
+    def get_tags_from_musicbrainz(self, media, callback):
+        """Retrieves the metadata keys of media
+
+        :param Grl.Media media: A Grilo media item
+        :param function callback: Function called after metadata retrieval
+        """
+        return self._musicbrainz.get_song_tags(media, callback)
+
     def _store_metadata(self, source, media, key):
         """Convenience function to store metadata
 
diff --git a/gnomemusic/grilowrappers/grlmusicbrainzwrapper.py 
b/gnomemusic/grilowrappers/grlmusicbrainzwrapper.py
new file mode 100644
index 00000000..61a67e12
--- /dev/null
+++ b/gnomemusic/grilowrappers/grlmusicbrainzwrapper.py
@@ -0,0 +1,165 @@
+# Copyright 2019 The GNOME Music developers
+#
+# GNOME Music is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# GNOME Music is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with GNOME Music; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# The GNOME Music authors hereby grant permission for non-GPL compatible
+# GStreamer plugins to be used and distributed together with GStreamer
+# and GNOME Music.  This permission is above and beyond the permissions
+# granted by the GPL license by which GNOME Music is covered.  If you
+# modify this code, you may extend this exception to your version of the
+# code, but you are not obligated to do so.  If you do not wish to do so,
+# delete this exception statement from your version.
+
+import logging
+
+from gi.repository import GObject, Grl
+
+logger = logging.getLogger(__name__)
+
+
+class GrlMusicbrainzWrapper(GObject.GObject):
+
+    _acoustid_api_key = "Nb8SVVtH1C"
+
+    _needed_sources = [
+        "grl-chromaprint",
+        "grl-acoustid"
+    ]
+
+    ACOUSTID_METADATA_KEYS = [
+        Grl.METADATA_KEY_ALBUM,
+        Grl.METADATA_KEY_ALBUM_DISC_NUMBER,
+        Grl.METADATA_KEY_ARTIST,
+        Grl.METADATA_KEY_CREATION_DATE,
+        Grl.METADATA_KEY_MB_ARTIST_ID,
+        Grl.METADATA_KEY_MB_RECORDING_ID,
+        Grl.METADATA_KEY_MB_RELEASE_GROUP_ID,
+        Grl.METADATA_KEY_MB_RELEASE_ID,
+        Grl.METADATA_KEY_TITLE,
+        Grl.METADATA_KEY_TRACK_NUMBER
+    ]
+
+    def __repr__(self):
+        return "<GrlMusicbrainzWrapper>"
+
+    def __init__(self, grilo):
+        super().__init__()
+
+        self._grilo = grilo
+        self._grilo.connect("new-resolve-source-found", self._add_new_source)
+        self._grilo.connect("new-query-source-found", self._add_new_source)
+
+        config = Grl.Config.new("grl-lua-factory", "grl-acoustid")
+        config.set_api_key(self._acoustid_api_key)
+        self._grilo._registry.add_config(config)
+
+        self._fingerprint_key = Grl.METADATA_KEY_INVALID
+        self._sources = {}
+
+    def _add_new_source(self, klass, source):
+        source_id = source.get_id()
+        print("Add new source called with id", source_id)
+        if source_id in self._needed_sources:
+            self._sources[source_id] = source
+
+        if source_id == "grl-chromaprint":
+            self._fingerprint_key = self._grilo._registry.lookup_metadata_key(
+                "chromaprint")
+            if self._fingerprint_key == Grl.METADATA_KEY_INVALID:
+                logger.warning("Error, cannot retrieve fingerprint key")
+
+    @GObject.Property(type=bool, default=False)
+    def chromaprint_available(self):
+        return ("grl-chromaprint" in self._sources.keys()
+                and self._fingerprint_key != Grl.METADATA_KEY_INVALID)
+
+    @GObject.Property(type=bool, default=False)
+    def acoustid_available(self):
+        return "grl-acoustid" in self._sources.keys()
+
+    @GObject.Property(type=bool, default=False)
+    def available(self):
+        return (self.props.chromaprint_available
+                and self.props.acoustid_available)
+
+    def _acoustid_resolved(self, source, op_id, media,
+                           count, callback, error=None):
+        if error:
+            logger.warning("Error {}: {}".format(error.domain, error.message))
+            return callback(None, 0)
+
+        return callback(media, count)
+
+    def _get_tags_from_acoustid(self, media, callback):
+        if not self.acoustid_available:
+            callback(None)
+            return
+
+        options = Grl.OperationOptions()
+        options.set_resolution_flags(Grl.ResolutionFlags.NORMAL)
+
+        query = "duration=" + str(media.get_duration())
+        query += "&fingerprint=" + media.get_string(self._fingerprint_key)
+
+        self._sources["grl-acoustid"].query(
+            query, self.ACOUSTID_METADATA_KEYS, options,
+            self._acoustid_resolved, callback)
+
+    def _chromaprint_resolved(
+            self, source, op_id, media, callback, error=None):
+        if error:
+            logger.warning("Error {}: {}".format(error.domain, error.message))
+            callback(None)
+            return
+
+        callback(media)
+
+    def _get_song_chromaprint(self, media, callback):
+        if self._fingerprint_key == Grl.METADATA_KEY_INVALID:
+            callback(None)
+            return
+
+        chromaprint = media.get_string(self._fingerprint_key)
+        if chromaprint is not None:
+            callback(media)
+            return
+
+        if not self.props.chromaprint_available:
+            callback(None)
+
+        options = Grl.OperationOptions()
+        options.set_resolution_flags(Grl.ResolutionFlags.FAST_ONLY
+                                     | Grl.ResolutionFlags.IDLE_RELAY)
+
+        keys = [self._fingerprint_key, Grl.METADATA_KEY_DURATION]
+        self._sources["grl-chromaprint"].resolve(
+            media, keys, options, self._chromaprint_resolved,
+            callback)
+
+    def get_song_tags(self, media, callback):
+        """Retrieves the metadata keys of media
+
+        :param Grl.Media media: A Grilo media item
+        :param function callback: Function called after metadata retrieval
+        """
+        def _fingerprint_finished(media):
+            if (not media
+                    or media.get_string(self._fingerprint_key)) is None:
+                callback(None)
+                return
+            self._grilo.writeback(media, self._fingerprint_key)
+            self._get_tags_from_acoustid(media, callback)
+
+        self._get_song_chromaprint(media, _fingerprint_finished)