core: merge request simulation schedule items with same path offset

core/src/main/kotlin/fr/sncf/osrd/api/api_v2/SimulationScheduleItemsParser.kt

@@ -0,0 +1,53 @@
+package fr.sncf.osrd.api.api_v2
+
+import fr.sncf.osrd.api.api_v2.standalone_sim.SimulationScheduleItem
+import fr.sncf.osrd.utils.units.TimeDelta
+import java.lang.Long.min
+
+/**
+ * Merge consecutive schedule items which are at the same location, i.e. have the same path offset.
+ * Merge rules for a group of schedule items are as follows:
+ * - arrival is the minimum value of all the concerned schedule items, null if they are all null.
+ * - stopFor is the sum of all the stopFor values of all the schedule items, null if they are all
+ *   null.
+ * - onStopSignal is true if at least one schedule item's onStopSignal is true, false otherwise.
+ */
+fun parseRawSimulationScheduleItems(
+    rawSimulationScheduleItems: List<SimulationScheduleItem>
+): List<SimulationScheduleItem> {
+    val simulationScheduleItems = mutableListOf<SimulationScheduleItem>()
+    var i = 0
+    while (i < rawSimulationScheduleItems.size) {
+        val pathOffset = rawSimulationScheduleItems[i].pathOffset
+        var arrival = rawSimulationScheduleItems[i].arrival
+        var stopFor = rawSimulationScheduleItems[i].stopFor
+        var onStopSignal = rawSimulationScheduleItems[i].onStopSignal
+        while (
+            i < rawSimulationScheduleItems.size - 1 &&
+                rawSimulationScheduleItems[i + 1].pathOffset == pathOffset
+        ) {
+            val nextArrival = rawSimulationScheduleItems[i + 1].arrival
+            arrival =
+                when {
+                    nextArrival != null && arrival != null ->
+                        TimeDelta(min(arrival.milliseconds, nextArrival.milliseconds))
+                    nextArrival != null -> nextArrival
+                    else -> arrival
+                }
+            val nextStopFor = rawSimulationScheduleItems[i + 1].stopFor
+            stopFor =
+                when {
+                    nextStopFor != null && stopFor != null -> stopFor + nextStopFor
+                    nextStopFor != null -> nextStopFor
+                    else -> stopFor
+                }
+            onStopSignal = onStopSignal || rawSimulationScheduleItems[i + 1].onStopSignal
+            i++
+        }
+        simulationScheduleItems.add(
+            SimulationScheduleItem(pathOffset, arrival, stopFor, onStopSignal)
+        )
+        i++
+    }
+    return simulationScheduleItems
+}

core/src/main/kotlin/fr/sncf/osrd/api/api_v2/standalone_sim/SimulationEndpoint.kt

@@ -3,6 +3,7 @@ package fr.sncf.osrd.api.api_v2.standalone_sim
 import fr.sncf.osrd.api.ElectricalProfileSetManager
 import fr.sncf.osrd.api.ExceptionHandler
 import fr.sncf.osrd.api.InfraManager
+import fr.sncf.osrd.api.api_v2.parseRawSimulationScheduleItems
 import fr.sncf.osrd.api.pathfinding.makeChunkPath
 import fr.sncf.osrd.reporting.exceptions.OSRDError
 import fr.sncf.osrd.reporting.warnings.DiagnosticRecorderImpl
@@ -65,7 +66,7 @@ class SimulationEndpoint(
                     parsePowerRestrictions(request.powerRestrictions),
                     request.options.useElectricalProfiles,
                     2.0,
-                    request.schedule,
+                    parseRawSimulationScheduleItems(request.schedule),
                     request.initialSpeed,
                     request.margins,
                 )

core/src/main/kotlin/fr/sncf/osrd/api/api_v2/stdcm/STDCMEndpointV2.kt

@@ -6,10 +6,7 @@ import fr.sncf.osrd.api.InfraManager
 import fr.sncf.osrd.api.api_v2.*
 import fr.sncf.osrd.api.api_v2.pathfinding.findWaypointBlocks
 import fr.sncf.osrd.api.api_v2.pathfinding.runPathfindingPostProcessing
-import fr.sncf.osrd.api.api_v2.standalone_sim.MarginValue
-import fr.sncf.osrd.api.api_v2.standalone_sim.SimulationScheduleItem
-import fr.sncf.osrd.api.api_v2.standalone_sim.SimulationSuccess
-import fr.sncf.osrd.api.api_v2.standalone_sim.parseRawRollingStock
+import fr.sncf.osrd.api.api_v2.standalone_sim.*
 import fr.sncf.osrd.conflicts.*
 import fr.sncf.osrd.envelope_sim.allowances.utils.AllowanceValue
 import fr.sncf.osrd.envelope_sim.allowances.utils.AllowanceValue.Percentage
@@ -155,9 +152,11 @@ private fun parseMarginValue(margin: MarginValue): AllowanceValue? {
 private fun parseSimulationScheduleItems(
     trainStops: List<TrainStop>
 ): List<SimulationScheduleItem> {
-    return trainStops.map {
-        SimulationScheduleItem(Offset(it.position.meters), null, it.duration.seconds, true)
-    }
+    return parseRawSimulationScheduleItems(
+        trainStops.map {
+            SimulationScheduleItem(Offset(it.position.meters), null, it.duration.seconds, true)
+        }
+    )
 }
 
 /** Sanity check, we assert that the result is not conflicting with the scheduled timetable */

core/src/test/kotlin/fr/sncf/osrd/standalone_sim/SimulationScheduleItemsParserTests.kt

@@ -0,0 +1,75 @@
+package fr.sncf.osrd.standalone_sim
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings
+import fr.sncf.osrd.api.api_v2.parseRawSimulationScheduleItems
+import fr.sncf.osrd.api.api_v2.standalone_sim.SimulationScheduleItem
+import fr.sncf.osrd.utils.units.Distance
+import fr.sncf.osrd.utils.units.Offset
+import fr.sncf.osrd.utils.units.TimeDelta
+import java.util.stream.Stream
+import org.assertj.core.api.Assertions
+import org.junit.jupiter.api.TestInstance
+import org.junit.jupiter.params.ParameterizedTest
+import org.junit.jupiter.params.provider.Arguments
+import org.junit.jupiter.params.provider.MethodSource
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class SimulationScheduleItemsParserTests {
+
+    @ParameterizedTest
+    @MethodSource("testParseRawSimulationScheduleItemsArgs")
+    fun parserOutputsMinimumArrivalForSamePathOffset(
+        simulationScheduleItems: List<SimulationScheduleItem>,
+        expectedItems: List<SimulationScheduleItem>
+    ) {
+        val mergedItems = parseRawSimulationScheduleItems(simulationScheduleItems)
+        Assertions.assertThat(mergedItems).usingRecursiveComparison().isEqualTo(expectedItems)
+    }
+
+    @SuppressFBWarnings(
+        value = ["UPM_UNCALLED_PRIVATE_METHOD"],
+        justification = "called implicitly by MethodSource"
+    )
+    private fun testParseRawSimulationScheduleItemsArgs(): Stream<Arguments> {
+        return Stream.of(
+            // Parser outputs minimum arrival for same path offset
+            Arguments.of(
+                listOf(
+                    SimulationScheduleItem(Offset(Distance.ZERO), null, null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), TimeDelta(200), null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), TimeDelta(100), null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, null, false),
+                ),
+                listOf(
+                    SimulationScheduleItem(Offset(Distance.ZERO), null, null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), TimeDelta(100), null, false),
+                )
+            ),
+            // Parser outputs sum of stopFor for same path offset
+            Arguments.of(
+                listOf(
+                    SimulationScheduleItem(Offset(Distance.ZERO), null, null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, TimeDelta(25), false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, TimeDelta(75), false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, null, false),
+                ),
+                listOf(
+                    SimulationScheduleItem(Offset(Distance.ZERO), null, null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, TimeDelta(100), false),
+                )
+            ),
+            // Parser outputs true if at least one onStopSignal is true for same path offset
+            Arguments.of(
+                listOf(
+                    SimulationScheduleItem(Offset(Distance.ZERO), null, null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, null, true),
+                ),
+                listOf(
+                    SimulationScheduleItem(Offset(Distance.ZERO), null, null, false),
+                    SimulationScheduleItem(Offset(Distance(1000)), null, null, true),
+                )
+            )
+        )
+    }
+}