Feat: Mta Subway translator & and realtime ext 'stop_name' field (#4)

* initial translator & tests for mta subway

* parses date to GMT, adjustments to stop id, removes track

* removes DS_store

* added mtasubway to the registry

* updates tests, handles multiple stops

* added stop name to realtime extension

* remove print statement and unused import

gtfs_realtime_translators/bindings/intersection.proto

@@ -10,6 +10,7 @@ message IntersectionStopTimeUpdate {
   optional string track = 1;
   optional transit_realtime.TripUpdate.StopTimeEvent scheduled_arrival = 2;
   optional transit_realtime.TripUpdate.StopTimeEvent scheduled_departure = 3;
+  optional string stop_name = 4;
 }
 
 extend transit_realtime.TripUpdate {

gtfs_realtime_translators/factories/factories.py

@@ -35,6 +35,7 @@ def create(*args, **kwargs):
         track = kwargs.get('track', None)
         scheduled_arrival = kwargs.get('scheduled_arrival_time', None)
         scheduled_departure = kwargs.get('scheduled_departure_time', None)
+        stop_name = kwargs.get('stop_name', None)
 
         trip_descriptor = gtfs_realtime.TripDescriptor(trip_id=trip_id,
                                                        route_id=route_id)
@@ -49,6 +50,8 @@ def create(*args, **kwargs):
             stop_time_update.Extensions[intersection_gtfs_realtime.intersection_stop_time_update].scheduled_arrival.time = scheduled_arrival
         if scheduled_departure:
             stop_time_update.Extensions[intersection_gtfs_realtime.intersection_stop_time_update].scheduled_departure.time = scheduled_departure
+        if stop_name:
+            stop_time_update.Extensions[intersection_gtfs_realtime.intersection_stop_time_update].stop_name = stop_name
 
         trip_update = gtfs_realtime.TripUpdate(trip=trip_descriptor,
                                                stop_time_update=[stop_time_update])

gtfs_realtime_translators/registry/registry.py

@@ -1,7 +1,7 @@
 import warnings
 
 from gtfs_realtime_translators.translators import LaMetroGtfsRealtimeTranslator, \
-        SeptaRegionalRailTranslator
+        SeptaRegionalRailTranslator, MtaSubwayGtfsRealtimeTranslator
 
 class TranslatorKeyWarning(Warning):
     pass
@@ -10,6 +10,7 @@ class TranslatorRegistry:
     TRANSLATORS = {
         'la-metro': LaMetroGtfsRealtimeTranslator,
         'septa-regional-rail': SeptaRegionalRailTranslator,
+        'mta-subway': MtaSubwayGtfsRealtimeTranslator
     }
 
     @classmethod

gtfs_realtime_translators/translators/__init__.py

@@ -1,2 +1,3 @@
 from .la_metro import LaMetroGtfsRealtimeTranslator
 from .septa_regional_rail import SeptaRegionalRailTranslator
+from .mta_subway import MtaSubwayGtfsRealtimeTranslator

gtfs_realtime_translators/translators/mta_subway.py

@@ -0,0 +1,59 @@
+import pendulum
+
+from gtfs_realtime_translators.factories import TripUpdate, FeedMessage
+
+
+class MtaSubwayGtfsRealtimeTranslator:
+    def __init__(self, data):
+        entities = []
+        for stop in data:
+            for group in stop["groups"]:
+                for idx, arrival in enumerate(group["times"]):
+                    route_id = group['route']['id']
+                    stop_name = stop['stop']['name']
+                    entities.append(self.__make_trip_update(idx, route_id, stop_name, arrival))
+
+        self.feed_message = FeedMessage.create(entities=entities)
+
+    @classmethod
+    def get_stop_id(cls, stop_id):
+        """
+        Stop IDs from MTA Subway  come in the form MTASBY:<stop id>.
+        We must parse the stop_id only.
+        """
+        try:
+            return stop_id.split(':')[1]
+        except Exception:
+            return stop_id
+
+
+    @classmethod
+    def to_gmt_timestamp(cls, timestamp):
+        return int(pendulum.from_timestamp(timestamp).subtract(hours=4).timestamp())
+
+    @classmethod
+    def __make_trip_update(cls, _id, route_id, stop_name, arrival):
+        entity_id = str(_id + 1)
+        arrival_time = cls.to_gmt_timestamp(arrival['serviceDay'] + arrival['realtimeArrival'])
+        departure_time = cls.to_gmt_timestamp(arrival['serviceDay'] + arrival['realtimeDeparture'])
+        trip_id = arrival['tripId']
+        stop_id = cls.get_stop_id(arrival['stopId'])
+
+        ##### Intersection Extensions
+        headsign = arrival['tripHeadsign']
+        scheduled_arrival_time = cls.to_gmt_timestamp(arrival['serviceDay'] + arrival['scheduledArrival'])
+        scheduled_departure_time = cls.to_gmt_timestamp(arrival['serviceDay'] + arrival['scheduledDeparture'])
+        return TripUpdate.create(entity_id=entity_id,
+                                arrival_time=arrival_time,
+                                departure_time=departure_time,
+                                trip_id=trip_id,
+                                route_id=route_id,
+                                stop_id=stop_id,
+                                stop_name=stop_name,
+                                headsign=headsign,
+                                scheduled_arrival_time=scheduled_arrival_time,
+                                scheduled_departure_time=scheduled_departure_time)
+
+
+    def serialize(self):
+        return self.feed_message.SerializeToString()