refactor: optimisation around stoptimes

- moved stoptime related functionality into new core:data:stoptime module
  - will feature all the different realtime stoptime sources to be
      integrated later
- create proper database schema for future migrations
- deduplicate trips into stoppingpatterns, since many trips share the
  exact same stopping pattern
  - stoptimes are now linked to stoppingpatterns instead
  - stoppingpattern ids are generated from a hash composed of all stoptimes
- stoptimes now use deltas for arrival time to save space

core/src/commonMain/kotlin/moe/lava/banksia/core/model/StopTime.kt

@@ -1,14 +1,43 @@
 package moe.lava.banksia.core.model
 
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
 import kotlinx.serialization.Serializable
 
 @Serializable
-data class StopTime(
-    val tripId: String,
+data class StopTime<T: TimeType>(
+    val patternId: Long,
     val stopId: String,
-    val arrivalTime: FutureTime,
-    val departureTime: FutureTime,
-    val headsign: String?,
+    val time: T,
     val pickupType: Int,
     val dropOffType: Int,
+) {
+    typealias Dated = StopTime<TimeType.Dated>
+    typealias Undated = StopTime<TimeType.Undated>
+}
+
+@Serializable
+sealed class TimeType {
+    @Serializable
+    data class Undated(
+        val arrival: FutureTime,
+        val departure: FutureTime,
+    ) : TimeType()
+
+    @Serializable
+    data class Dated(
+        val arrival: LocalDateTime,
+        val departure: LocalDateTime,
+    ) : TimeType()
+}
+
+fun StopTime<TimeType.Undated>.atDate(date: LocalDate) = StopTime(
+    patternId = patternId,
+    stopId = stopId,
+    time = TimeType.Dated(
+        arrival = time.arrival.atDate(date),
+        departure = time.departure.atDate(date),
+    ),
+    pickupType = pickupType,
+    dropOffType = dropOffType,
 )

core/src/commonMain/kotlin/moe/lava/banksia/core/model/StopTimeDated.kt

@@ -1,26 +0,0 @@
-package moe.lava.banksia.core.model
-
-import kotlinx.datetime.LocalDate
-import kotlinx.datetime.LocalDateTime
-import kotlinx.serialization.Serializable
-
-@Serializable
-data class StopTimeDated(
-    val tripId: String,
-    val stopId: String,
-    val arrivalTime: LocalDateTime,
-    val departureTime: LocalDateTime,
-    val headsign: String?,
-    val pickupType: Int,
-    val dropOffType: Int,
-)
-
-fun StopTime.atDate(date: LocalDate) = StopTimeDated(
-    tripId = tripId,
-    stopId = stopId,
-    arrivalTime = arrivalTime.atDate(date),
-    departureTime = departureTime.atDate(date),
-    headsign = headsign,
-    pickupType = pickupType,
-    dropOffType = dropOffType,
-)

core/src/commonMain/kotlin/moe/lava/banksia/core/model/StoppingPattern.kt

@@ -0,0 +1,16 @@
+package moe.lava.banksia.core.model
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class StoppingPattern<T: TimeType>(
+    val id: Long,
+    val routeId: String,
+    val shapeId: String,
+    val headsign: String,
+    val wheelchairAccessible: Boolean,
+    val stoptimes: List<StopTime<T>>,
+) {
+    typealias Dated = StoppingPattern<TimeType.Dated>
+    typealias Undated = StoppingPattern<TimeType.Undated>
+}

core/src/commonMain/kotlin/moe/lava/banksia/core/model/Trip.kt

@@ -3,13 +3,13 @@ package moe.lava.banksia.core.model
 import kotlinx.serialization.Serializable
 
 @Serializable
-data class Trip(
+data class Trip<T: TimeType>(
     val id: String,
-    val routeId: String,
+    val pattern: StoppingPattern<T>,
     val service: Service,
-    val shapeId: String,
-    val tripHeadsign: String,
-    val directionId: String,
+    val directionId: Int,
     val blockId: String?,
-    val wheelchairAccessible: Boolean,
-)
+) {
+    typealias Dated = Trip<TimeType.Dated>
+    typealias Undated = Trip<TimeType.Undated>
+}