Update timeline to return an active timeline object w/ attributes (#572)

* timeline() now returns ClientTimeline objects

* timeline() creates and returns ClientTimeline objects with associated attributes and caching
* Refactor isPlayingMedia to use the new attributes and fix it's default value

* Clarify docstrings

* Remove default param in timeline call & fix docstring typo

* return empty list if `timelines()` comes back empty

Web clients can occasionally return no timelines if no media has been played on them or if nothing has played for a while, this prevents errors in those cases.

* typo

* Workaround for unresponsive clients

* Use sendCommand rather than timelines() for PTP workaround

* Remove workaround, set timeline's wait default to 1

* set timelines() wait default to 0, document buggy behavior

* Use ClientTimeline.key for consistency

Co-authored-by: jjlawren <jjlawren@users.noreply.github.com>

* cast playQueue's IDs as int

Co-authored-by: jjlawren <jjlawren@users.noreply.github.com>

* Add audio attribs & make casts bool from int where it makes sense.

Co-authored-by: jjlawren <jjlawren@users.noreply.github.com>

plexapi/client.py

@@ -69,6 +69,8 @@ class PlexClient(PlexObject):
         self._proxyThroughServer = False
         self._commandId = 0
         self._last_call = 0
+        self._timeline_cache = []
+        self._timeline_cache_timestamp = 0
         if not any([data is not None, initpath, baseurl, token]):
             self._baseurl = CONFIG.get('auth.client_baseurl', 'http://localhost:32433')
             self._token = logfilter.add_secret(CONFIG.get('auth.client_token'))
@@ -199,7 +201,7 @@ class PlexClient(PlexObject):
             self._last_call = t
         elif t - self._last_call >= 80 and self.product in ('ptp', 'Plex Media Player'):
             self._last_call = t
-            self.timeline(wait=0)
+            self.sendCommand(ClientTimeline.key, wait=0)
 
         params['commandID'] = self._nextCommandId()
         key = '/player/%s%s' % (command, utils.joinArgs(params))
@@ -540,20 +542,68 @@ class PlexClient(PlexObject):
 
     # -------------------
     # Timeline Commands
-    def timeline(self, wait=1):
-        """ Poll the current timeline and return the XML response. """
-        return self.sendCommand('timeline/poll', wait=wait)
+    def timelines(self, wait=0):
+        """Poll the client's timelines, create, and return timeline objects.
+           Some clients may not always respond to timeline requests, believe this
+           to be a Plex bug.
+        """
+        t = time.time()
+        if t - self._timeline_cache_timestamp > 1:
+            self._timeline_cache_timestamp = t
+            timelines = self.sendCommand(ClientTimeline.key, wait=wait) or []
+            self._timeline_cache = [ClientTimeline(self, data) for data in timelines]
 
-    def isPlayingMedia(self, includePaused=False):
+        return self._timeline_cache
+
+    @property
+    def timeline(self):
+        """Returns the active timeline object."""
+        return next((x for x in self.timelines() if x.state != 'stopped'), None)
+
+    def isPlayingMedia(self, includePaused=True):
         """Returns True if any media is currently playing.
 
             Parameters:
                 includePaused (bool): Set True to treat currently paused items
                                       as playing (optional; default True).
         """
-        for mediatype in self.timeline(wait=0):
-            if mediatype.get('state') == 'playing':
-                return True
-            if includePaused and mediatype.get('state') == 'paused':
-                return True
-        return False
+        state = getattr(self.timeline, "state", None)
+        return bool(state == 'playing' or (includePaused and state == 'paused'))
+
+
+class ClientTimeline(PlexObject):
+    """Get the timeline's attributes."""
+
+    key = 'timeline/poll'
+
+    def _loadData(self, data):
+        self._data = data
+        self.address = data.attrib.get('address')
+        self.audioStreamId = utils.cast(int, data.attrib.get('audioStreamId'))
+        self.autoPlay = utils.cast(bool, data.attrib.get('autoPlay'))
+        self.containerKey = data.attrib.get('containerKey')
+        self.controllable = data.attrib.get('controllable')
+        self.duration = utils.cast(int, data.attrib.get('duration'))
+        self.itemType = data.attrib.get('itemType')
+        self.key = data.attrib.get('key')
+        self.location = data.attrib.get('location')
+        self.machineIdentifier = data.attrib.get('machineIdentifier')
+        self.partCount = utils.cast(int, data.attrib.get('partCount'))
+        self.partIndex = utils.cast(int, data.attrib.get('partIndex'))
+        self.playQueueID = utils.cast(int, data.attrib.get('playQueueID'))
+        self.playQueueItemID = utils.cast(int, data.attrib.get('playQueueItemID'))
+        self.playQueueVersion = utils.cast(int, data.attrib.get('playQueueVersion'))
+        self.port = utils.cast(int, data.attrib.get('port'))
+        self.protocol = data.attrib.get('protocol')
+        self.providerIdentifier = data.attrib.get('providerIdentifier')
+        self.ratingKey = utils.cast(int, data.attrib.get('ratingKey'))
+        self.repeat = utils.cast(bool, data.attrib.get('repeat'))
+        self.seekRange = data.attrib.get('seekRange')
+        self.shuffle = utils.cast(bool, data.attrib.get('shuffle'))
+        self.state = data.attrib.get('state')
+        self.subtitleColor = data.attrib.get('subtitleColor')
+        self.subtitlePosition = data.attrib.get('subtitlePosition')
+        self.subtitleSize = utils.cast(int, data.attrib.get('subtitleSize'))
+        self.time = utils.cast(int, data.attrib.get('time'))
+        self.type = data.attrib.get('type')
+        self.volume = utils.cast(int, data.attrib.get('volume'))