Spotify controller creation (#230)

* Initial Spotify commit

* Add app id to config

* Add token logic and starting session with token

Can't use spotipy's method of getting a token.
Seems there's no scope with enough permissions to start Spotify on CC

* Start spotipy client after app has been launched

* Add spotipy to requirements.txt

Unfortunately the version on PyPi is outdated.
See spotipy-dev/spotipy#211

* Add play_song and play_songs. Only create new token if the session hasn't been started.

* Add context playback mode

* Add docstrings to SpotifyController methods

* Add example on how to use SpotifyController

* Fix PEP8 errors on SpotifyController

* Remove access token logic from Spotify Controller code

This was moved to it's own repo: https://github.com/enriquegh/spotify-webplayer-token

* Fix importing BaseController

This was causing pylint to complain

* Add additional logic when retrieving device id

This will make sure that the device that is being obtained is a Chromecast

* No need for else statements since we are already raising at the beginning

* Poll received messages to know when Spotify is completely started

Instead of sleeping for just 5 seconds, we can check if Spotify responds with `setCredentialsResponse` and then go ahead and grab spotify id.

* Fixed errors for flake8

* Remove external dependencies

The example will now have how to get the access token yourself and how to use spotipy to avoid adding dependencies to pychromecast

* Fix flake8 error

* Fix spotify example

examples/spotify_example.py

@@ -0,0 +1,38 @@
+"""
+Example on how to use the Spotify Controller.
+NOTE: You need to install the spotipy and spotify-token dependencies.
+
+This can be done by running the following:
+pip install spotify-token
+pip install git+https://github.com/plamere/spotipy.git
+"""
+import pychromecast
+from pychromecast.controllers.spotify import SpotifyController
+import spotify_token as st
+import spotipy
+
+chromecasts = pychromecast.get_chromecasts()
+cast = chromecasts[0]
+
+CAST_NAME = "My Chromecast"
+device_id = None
+
+if cast.name == CAST_NAME:
+
+    data = st.start_session("SPOTIFY_USERNAME", "SPOTIFY_PASSWORD")
+    access_token = data[0]
+
+    client = spotipy.Spotify(auth=access_token)
+
+    sp = SpotifyController(access_token)
+    cast.register_handler(sp)
+    sp.launch_app()
+
+    devices_available = client.devices()
+
+    for device in devices_available['devices']:
+        if device['name'] == CAST_NAME and device['type'] == 'CastVideo':
+            device_id = device['id']
+            break
+
+    client.start_playback(device_id=device_id, uris=["spotify:track:3Zwu2K0Qa5sT6teCCHPShP"])

pychromecast/config.py

@@ -10,6 +10,7 @@
 APP_MEDIA_RECEIVER = "CC1AD845"
 APP_PLEX = "06ee44ee-e7e3-4249-83b6-f5d0b6f07f34_1"
 APP_DASHCAST = "84912283"
+APP_SPOTIFY = "CC32E753"
 
 
 def get_possible_app_ids():

pychromecast/controllers/spotify.py

@@ -0,0 +1,52 @@
+"""
+Controller to interface with the DashCast app namespace.
+"""
+import logging
+import time
+
+from . import BaseController
+from ..config import APP_SPOTIFY
+
+logging.basicConfig(level=logging.DEBUG)
+
+APP_NAMESPACE = "urn:x-cast:com.spotify.chromecast.secure.v1"
+TYPE_STATUS = "setCredentials"
+TYPE_RESPONSE_STATUS = 'setCredentialsResponse'
+
+
+# pylint: disable=too-many-instance-attributes
+class SpotifyController(BaseController):
+    """ Controller to interact with Spotify namespace. """
+
+    # pylint: disable=useless-super-delegation
+    # The pylint rule useless-super-delegation doesn't realize
+    # we are setting default values here.
+    def __init__(self, access_token):
+        super(SpotifyController, self).__init__(APP_NAMESPACE, APP_SPOTIFY)
+
+        self.logger = logging.getLogger(__name__)
+        self.session_started = False
+        self.access_token = access_token
+        self.is_launched = False
+    # pylint: enable=useless-super-delegation
+
+    # pylint: disable=unused-argument,no-self-use
+    def receive_message(self, message, data):
+        """ Currently not doing anything with received messages. """
+        if data['type'] == TYPE_RESPONSE_STATUS:
+            self.is_launched = True
+        return True
+
+    def launch_app(self):
+        """ Launch main application """
+
+        def callback():
+            """Callback function"""
+            self.send_message({"type": TYPE_STATUS,
+                               "credentials": self.access_token})
+
+        self.launch(callback_function=callback)
+
+        # Need to wait for Spotify to be launched on Chromecast completely
+        while not self.is_launched:
+            time.sleep(1)

requirements.txt

@@ -1,3 +1,3 @@
 requests>=2.0
 protobuf>=3.0.0
-zeroconf>=0.17.7
+zeroconf>=0.17.7