feat(transport_helper): add arrivalTime for more precision

helpful when vehicles are waiting on-station
should be covered by fallbacks without introducing nullability down the
line

lib/transport_helper.dart

@@ -758,6 +758,7 @@ class Departure {
   String vehicleId;
   String vehicleName;
   String stationId;
+  DateTime arrivalTime;
   DateTime departureTime;
 
   Departure({
@@ -765,6 +766,7 @@ class Departure {
     required this.vehicleId,
     required this.vehicleName,
     required this.stationId,
+    required this.arrivalTime,
     required this.departureTime,
   });
 
@@ -774,6 +776,7 @@ class Departure {
       "vehicle": vehicleId,
       "vehiclename": vehicleName,
       "station": stationId,
+      "arrivaltime": arrivalTime,
       "departuretime": departureTime,
     };
   }
@@ -784,6 +787,7 @@ class Departure {
       vehicleId: map["vehicle"] as String,
       vehicleName: map["vehiclename"] as String,
       stationId: map["station"] as String,
+      arrivalTime: map["arrivaltime"] as DateTime,
       departureTime: map["departuretime"] as DateTime,
     );
   }
@@ -804,11 +808,30 @@ class Departure {
     // } catch (e) {
     //   station.dbUpdate();
     // }
+    DateTime? arrDateTime;
+    DateTime? depDateTime;
+    String? arrivalDate = json["arrDate"];
+    String? arrivalTime = json["arrTime"];
+    if (arrivalDate != null && arrivalTime != null) {
+      arrDateTime = DateTime.parse('${arrivalDate}T$arrivalTime');
+    }
+
+    String? departureDate = json["depDate"] ?? json["date"];
+    String? departureTime = json["depTime"] ?? json["time"];
+    if (departureDate != null && departureTime != null) {
+      depDateTime = DateTime.parse('${departureDate}T$departureTime');
+    }
+
     return Departure(
       vehicleId: vehicle.id,
       vehicleName: vehicle.name,
       stationId: station.id,
-      departureTime: DateTime.parse('${json["date"]}T${json["time"]}'),
+      arrivalTime:
+          arrDateTime ??
+          depDateTime as DateTime, // one of these has to be in the json
+      departureTime:
+          depDateTime ??
+          arrDateTime as DateTime, // one of these has to be in the json
     );
   }