Merge received episode actions (bug 997)

Episode actions are now retrieved from the
server and are merged into gPodder's DB. The
first feed update after this release could
lead to a lot of updates, but further updates
should be faster, as only a few actions will
be processed by the server.

src/gpodder/gui.py

@@ -2459,11 +2459,77 @@ class gPodder(BuilderWidget, dbus.service.Object):
         exporter = opml.Exporter(gpodder.subscription_file)
         return exporter.write(self.channels)
 
+    def find_episode(self, podcast_url, episode_url):
+        """Find an episode given its podcast and episode URL
+
+        The function will return a PodcastEpisode object if
+        the episode is found, or None if it's not found.
+        """
+        for podcast in self.channels:
+            if podcast_url == podcast.url:
+                for episode in podcast.get_all_episodes():
+                    if episode_url == episode.url:
+                        return episode
+
+        return None
+
+    def process_received_episode_actions(self, updated_urls):
+        """Process/merge episode actions from gpodder.net
+
+        This function will merge all changes received from
+        the server to the local database and update the
+        status of the affected episodes as necessary.
+        """
+        indicator = ProgressIndicator(_('Merging episode actions'), \
+                _('Episode actions from gpodder.net are merged.'), \
+                False, self.get_dialog_parent())
+
+        for idx, action in enumerate(self.mygpo_client.get_episode_actions(updated_urls)):
+            if action.action == 'play':
+                episode = self.find_episode(action.podcast_url, \
+                                            action.episode_url)
+
+                if episode is not None:
+                    log('Play action for %s', episode.url, sender=self)
+                    episode.mark(is_played=True)
+
+                    if action.timestamp > episode.current_position_updated:
+                        log('Updating position for %s', episode.url, sender=self)
+                        episode.current_position = action.position
+                        episode.current_position_updated = action.timestamp
+
+                    if action.total:
+                        log('Updating total time for %s', episode.url, sender=self)
+                        episode.total_time = action.total
+
+                    episode.save()
+            elif action.action == 'delete':
+                episode = self.find_episode(action.podcast_url, \
+                                            action.episode_url)
+
+                if episode is not None:
+                    if not episode.was_downloaded(and_exists=True):
+                        # Set the episode to a "deleted" state
+                        log('Marking as deleted: %s', episode.url, sender=self)
+                        episode.delete_from_disk()
+                        episode.save()
+
+            indicator.on_message(N_('%d action processed', '%d actions processed', idx) % idx)
+            gtk.main_iteration(False)
+
+        indicator.on_finished()
+        self.db.commit()
+
+
     def update_feed_cache_finish_callback(self, updated_urls=None, select_url_afterwards=None):
         self.db.commit()
         self.updating_feed_cache = False
 
         self.channels = PodcastChannel.load_from_db(self.db, self.config.download_dir)
+
+        # Process received episode actions for all updated URLs
+        self.process_received_episode_actions(updated_urls)
+
         self.channel_list_changed = True
         self.update_podcast_list_model(select_url=select_url_afterwards)
 

src/gpodder/my.py

@@ -209,6 +209,17 @@ class MygPoClient(object):
         self._store.remove(rewritten_urls)
         return rewritten_urls
 
+    def get_episode_actions(self, updated_urls):
+        for podcast_url in updated_urls:
+            for action in self._store.load(ReceivedEpisodeAction, \
+                    podcast_url=podcast_url):
+                yield action
+
+            # Remove all episode actions belonging to this URL
+            self._store.delete(ReceivedEpisodeAction, \
+                    podcast_url=podcast_url)
+            self._store.commit()
+
     def get_received_actions(self):
         """Returns a list of ReceivedSubscribeAction objects
 
@@ -413,8 +424,6 @@ class MygPoClient(object):
                     action.started, action.position, action.total)
 
         try:
-            save_since = True
-
             # Load the "since" value from the database
             since_o = self._store.get(SinceValue, host=self.host, \
                                                   device_id=self.device_id, \
@@ -426,29 +435,25 @@ class MygPoClient(object):
 
             # Step 1: Download Episode actions
             try:
-                changes = self._client.download_episode_actions(since_o.since, \
-                        device_id=self.device_id)
+                changes = self._client.download_episode_actions(since_o.since)
 
                 received_actions = [convert_from_api(a) for a in changes.actions]
+                log('Received %d episode actions', len(received_actions), \
+                        sender=self)
                 self._store.save(received_actions)
 
                 # Save the "since" value for later use
                 self._store.update(since_o, since=changes.since)
             except Exception, e:
                 log('Exception while polling for episodes.', sender=self, traceback=True)
-                save_since = False
 
             # Step 2: Upload Episode actions
 
             # Convert actions to the mygpoclient format for uploading
             episode_actions = [convert_to_api(a) for a in actions]
 
-            # Upload the episodes and retrieve the new "since" value
-            since = self._client.upload_episode_actions(episode_actions)
-
-            if save_since:
-                # Update the "since" value of the episodes
-                self._store.update(since_o, since=since)
+            # Upload the episode actions
+            self._client.upload_episode_actions(episode_actions)
 
             # Actions have been uploaded to the server - remove them
             self._store.remove(actions)