feat: vehicle positions and state dismissal

shared/src/commonMain/kotlin/moe/lava/banksia/api/ptv/PtvService.kt

@@ -17,6 +17,7 @@ import moe.lava.banksia.api.ptv.structures.PtvDeparture
 import moe.lava.banksia.api.ptv.structures.PtvDirection
 import moe.lava.banksia.api.ptv.structures.PtvRoute
 import moe.lava.banksia.api.ptv.structures.PtvRouteType
+import moe.lava.banksia.api.ptv.structures.PtvRun
 import moe.lava.banksia.api.ptv.structures.PtvStop
 import moe.lava.banksia.log
 import okio.ByteString.Companion.encodeUtf8
@@ -28,6 +29,9 @@ object Responses {
     @Serializable
     data class PtvRoutesResponse(val routes: List<PtvRoute>)
 
+    @Serializable
+    data class PtvRunsResponse(val runs: List<PtvRun>)
+
     @Serializable
     data class PtvStopResponse(val stop: PtvStop)
     @Serializable
@@ -129,6 +133,20 @@ class PtvService {
         return response.routes
     }
 
+    suspend fun runs(routeId: Int): List<PtvRun> {
+        val response: Responses.PtvRunsResponse = client.get() {
+            url {
+                appendPathSegments(
+                    "runs",
+                    "route",
+                    routeId.toString(),
+                )
+                parameter("expand", "VehiclePosition")
+            }
+        }.body()
+        return response.runs
+    }
+
     suspend fun stopsByRoute(routeId: Int, routeType: PtvRouteType): List<PtvStop> {
         val response: Responses.PtvStopsResponse = client.get("stops") {
             url {

shared/src/commonMain/kotlin/moe/lava/banksia/api/ptv/structures/PtvRun.kt

@@ -1,9 +1,46 @@
 package moe.lava.banksia.api.ptv.structures
 
 import kotlinx.datetime.Instant
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toInstant
+import kotlinx.serialization.KSerializer
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
+// Some datetimes are in local time (no timezone), observed on bus vehicle positions,
+// and some datetimes are in UTC, observed on train vehicle positions. We need to handle
+// both cases.
+private object CustomInstantSerialiser : KSerializer<Instant> {
+    override val descriptor: SerialDescriptor
+        get() = PrimitiveSerialDescriptor(
+            CustomInstantSerialiser::class.qualifiedName!!,
+            PrimitiveKind.STRING,
+        )
+
+    override fun serialize(
+        encoder: Encoder,
+        value: Instant
+    ) {
+        encoder.encodeString(value.toString())
+    }
+
+    override fun deserialize(decoder: Decoder): Instant {
+        val str = decoder.decodeString()
+        return runCatching {
+            Instant.parse(str)
+        }.getOrElse {
+            LocalDateTime.parse(str).toInstant(TimeZone.currentSystemDefault())
+        }
+    }
+}
+
+@Serializable
 data class PtvVehiclePosition(
     val latitude: Double,
     val longitude: Double,
@@ -12,8 +49,14 @@ data class PtvVehiclePosition(
     val direction: String?,
     val bearing: Double?,
     val supplier: String?,
-    @SerialName("datetime_utc") val datetimeUtc: Instant?,
-    @SerialName("expiry_time") val expiryTime: Instant?,
+
+    @Serializable(CustomInstantSerialiser::class)
+    @SerialName("datetime_utc")
+    val datetimeUtc: Instant?,
+
+    @Serializable(CustomInstantSerialiser::class)
+    @SerialName("expiry_time")
+    val expiryTime: Instant?,
 )
 
 @Serializable
@@ -25,4 +68,5 @@ data class PtvRun(
     @SerialName("destination_name") val destinationName: String,
     @SerialName("direction_id") val directionId: Int,
     @SerialName("status") val status: String,
+    @SerialName("vehicle_position") val vehiclePosition: PtvVehiclePosition?,
 )