added Canvas

reverse engineered Spotify Canvas API only available on iOS and Android
displays short looping video for song in place of album when available

_canvas.py

@@ -0,0 +1,57 @@
+import requests
+import random
+from protos.canvas_pb2 import EntityCanvazRequest, EntityCanvazResponse
+
+API_HOST = "https://spclient.wg.spotify.com"
+CANVAS_ROUTE = "/canvaz-cache/v0/canvases"
+TOKEN_ENDPOINT = "https://open.spotify.com/get_access_token?reason=transport"
+TOKEN_RENEW_TIME = 900
+
+TRACK_URI_PREFIX = "spotify:track:"
+OAUTH_SCOPES = "playlist-read"
+
+def get_access_token():
+    try:
+        response = requests.get(TOKEN_ENDPOINT)
+        data = response.json()
+        return data["accessToken"]
+    except Exception as e:
+        raise Exception(e)
+
+
+def get_canvas_for_track(access_token, track_id):
+    canvas_request = EntityCanvazRequest()
+    canvas_request_entities = canvas_request.entities.add()
+    canvas_request_entities.entity_uri = TRACK_URI_PREFIX + track_id
+
+    try:
+        resp = requests.post(
+            API_HOST + CANVAS_ROUTE,
+            headers={
+                "Accept": "application/protobuf",
+                "Content-Type": "application/x-www-form-urlencoded",
+                "Accept-Language": "en",
+                "User-Agent": "Spotify/8.5.49 iOS/Version 13.3.1 (Build 17D50)",
+                "Accept-Encoding": "gzip, deflate, br",
+                "Authorization": "Bearer %s" % access_token
+            },
+            data=canvas_request.SerializeToString(),
+        )
+    except:
+        raise ConnectionError
+
+    canvas_response = EntityCanvazResponse()
+    canvas_response.ParseFromString(resp.content)
+
+    if(len(canvas_response.canvases) == 0):
+        raise AttributeError
+
+    canvas = random.choice(canvas_response.canvases)
+
+    if canvas.url is not None:
+        return canvas.url
+    else:
+        return None
+
+# access_token = get_access_token()
+# print(get_canvas_for_track(access_token, "1kADZJDyRUbmlLxYiqi077"))