Fix PE change-clothes interruption and post-PE mode detection.

Add appropriateness tests for staging PE kit, wearing form before gym, and returning to everyday clothes after the lesson.

src/HSchool.Simulation/ActivitySystem.cs

@@ -166,9 +166,10 @@ internal static class ActivitySystem
         ApparelDresser.RedressPerson(school, person, mode, includeHome: false, todaySubjects: subjects);
     }
 
-    private static bool IsChangeClothes(string actionId) =>
-        actionId.Equals(ApparelActions.ChangeMale, StringComparison.Ordinal)
-        || actionId.Equals(ApparelActions.ChangeFemale, StringComparison.Ordinal);
+    internal static bool IsChangeClothes(string? actionId) =>
+        actionId is not null
+        && (actionId.Equals(ApparelActions.ChangeMale, StringComparison.Ordinal)
+            || actionId.Equals(ApparelActions.ChangeFemale, StringComparison.Ordinal));
 
     private static int Occupied(School school, string nodeId, string thing)
     {

src/HSchool.Simulation/ApparelPresence.cs

@@ -56,12 +56,29 @@ internal static class ApparelPresence
             return ApparelDresser.ModeForLesson(current?.Subject);
         }
 
+        if (slot.Kind == DaySlotKind.Break)
+        {
+            var justEnded = lessons.FirstOrDefault(lesson => lesson.Period == slot.Index);
+            if (justEnded is not null && ApparelDresser.ModeForLesson(justEnded.Subject) == ApparelMode.Pe)
+            {
+                return ApparelMode.Everyday;
+            }
+
             var next = lessons.Where(lesson => lesson.Period > slot.Index).OrderBy(lesson => lesson.Period).FirstOrDefault();
             if (next is not null)
             {
                 return ApparelDresser.ModeForLesson(next.Subject);
             }
 
+            return ApparelMode.Everyday;
+        }
+
+        var nextLesson = lessons.Where(lesson => lesson.Period > slot.Index).OrderBy(lesson => lesson.Period).FirstOrDefault();
+        if (nextLesson is not null)
+        {
+            return ApparelDresser.ModeForLesson(nextLesson.Subject);
+        }
+
         var previous = lessons.Where(lesson => lesson.Period < slot.Index).OrderByDescending(lesson => lesson.Period).FirstOrDefault();
         if (previous is not null && ApparelDresser.ModeForLesson(previous.Subject) == ApparelMode.Pe)
         {

src/HSchool.Simulation/PresenceSystem.cs

@@ -400,15 +400,18 @@ internal static class PresenceSystem
             state,
             (node, thing) => occupied.GetValueOrDefault((node, thing)));
 
+        var changing = activity.IsActive && ActivitySystem.IsChangeClothes(activity.ActionId);
+
         if (decision.WalkTo is not null
             && !decision.WalkTo.Equals(presence.NodeId, StringComparison.Ordinal)
-            && activity.IsActive)
+            && activity.IsActive
+            && !changing)
         {
             activity = PersonActivity.Idle;
         }
 
         intent = decision.Intent;
-        if (decision.WalkTo is not null)
+        if (decision.WalkTo is not null && !changing)
         {
             presence = PresenceStepper.StartWalk(presence, walks, decision.WalkTo, headingHome: false);
         }

tests/HSchool.Simulation.Tests/AppropriatenessSimulationTests.cs

@@ -55,6 +55,51 @@ public class AppropriatenessSimulationTests
             item => item.Location == ItemLocations.Worn && item.Def == "FurCoat");
     }
 
+    [Fact]
+    public void MorningDress_StagesPeKitForTodaysLesson()
+    {
+        var (school, pupilId) = StaffedPeClass();
+        using (school)
+        {
+            MorningDress.Apply(school);
+            var person = school.Roster!.People.Single(item => item.Id == pupilId);
+            Assert.Contains(
+                person.Items,
+                item => item.Def is "PeShirt" or "PeShorts"
+                    && item.Location is ItemLocations.Locker or ItemLocations.Bag);
+        }
+    }
+
+    [Fact]
+    public void PeBreak_CompletesChangeBeforeLesson()
+    {
+        var (school, pupilId) = StaffedPeClass();
+        using (school)
+        {
+            MorningDress.Apply(school);
+            AdvanceTo(school, new DateTime(2012, 4, 3, 9, 30, 0, DateTimeKind.Utc));
+            var person = school.Roster!.People.Single(item => item.Id == pupilId);
+            Assert.Contains(
+                person.Items,
+                item => item.Location == ItemLocations.Worn && item.Def == "PeShirt");
+        }
+    }
+
+    [Fact]
+    public void AfterPeBreak_ModeExpectsEveryday()
+    {
+        var (school, pupilId) = StaffedPeClass();
+        using (school)
+        {
+            MorningDress.Apply(school);
+            AdvanceTo(school, new DateTime(2012, 4, 3, 10, 12, 0, DateTimeKind.Utc));
+            var person = school.Roster!.People.Single(item => item.Id == pupilId);
+            var schoolClass = school.Roster.Classes.First(row => row.PupilIds.Contains(pupilId));
+            Assert.Equal(ApparelMode.Everyday, ApparelPresence.ModeAt(school, person, schoolClass));
+            Assert.True(ApparelDresser.CurrentIssues(school, person, ApparelMode.Everyday).HasFlag(ApparelIssue.PeForbidden));
+        }
+    }
+
     [Fact]
     public void PeBreak_PupilReachesOwnChangingRoom()
     {
@@ -71,6 +116,38 @@ public class AppropriatenessSimulationTests
         }
     }
 
+    [Fact]
+    public void PeLesson_WearsPeThenReturnsToEveryday()
+    {
+        var (school, pupilId) = StaffedPeClass();
+        using (school)
+        {
+            MorningDress.Apply(school);
+            AdvanceTo(school, new DateTime(2012, 4, 3, 9, 35, 0, DateTimeKind.Utc));
+            var person = school.Roster!.People.Single(item => item.Id == pupilId);
+            Assert.Contains(
+                person.Items,
+                item => item.Location == ItemLocations.Worn && item.Def == "PeShirt");
+            Assert.Contains(
+                person.Items,
+                item => item.Location == ItemLocations.Worn && item.Def == "PeShorts");
+            Assert.DoesNotContain(
+                person.Items,
+                item => item.Location == ItemLocations.Worn
+                    && item.Def is "Shirt" or "TShirt" or "Dress");
+
+            AdvanceTo(school, new DateTime(2012, 4, 3, 10, 25, 0, DateTimeKind.Utc));
+            person = school.Roster.People.Single(item => item.Id == pupilId);
+            Assert.DoesNotContain(
+                person.Items,
+                item => item.Location == ItemLocations.Worn && item.Def == "PeShirt");
+            Assert.Contains(
+                person.Items,
+                item => item.Location == ItemLocations.Worn
+                    && item.Def is "Shirt" or "TShirt" or "Dress" or "Skirt" or "Pants" or "Jeans" or "Trousers");
+        }
+    }
+
     [Fact]
     public void Boy_DoesNotEnterGirlsChangingRoom()
     {
@@ -201,6 +278,7 @@ public class AppropriatenessSimulationTests
             [
                 new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 1),
                 new LessonPlacement(schoolClass.Id, "PhysicalEducation", "t2", "gym-hall", Day: 1, Period: 2),
+                new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 3),
             ],
             []));
         school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);

tests/HSchool.Simulation.Tests/PresenceTests.cs

@@ -68,7 +68,7 @@ public class PresenceTests
     }
 
     [Fact]
-    public void PhysicalEducationAfterAClassroomLesson_ReachesTheGymOnTheBreak()
+    public void PhysicalEducationBeforeLesson_GoesToChangingRoomOnTheBreak()
     {
         var (catalog, map) = Vanilla();
         var walks = WalkGraph.Build(catalog, map);
@@ -78,9 +78,11 @@ public class PresenceTests
         var (school, _, pupilId) = StaffedFirstFloorClass();
         using (school)
         {
-            AdvanceTo(school, new DateTime(2012, 4, 3, 9, 25, 0, DateTimeKind.Utc));
+            AdvanceTo(school, new DateTime(2012, 4, 3, 9, 24, 0, DateTimeKind.Utc));
             var row = school.CapturePresence().Single(item => item.PersonId == pupilId);
-            Assert.Equal("gym-hall", row.NodeId);
+            var person = school.Roster!.People.Single(item => item.Id == pupilId);
+            var room = person.Female ? "girls-changing-room" : "boys-changing-room";
+            Assert.Equal(room, row.NodeId);
             Assert.Empty(row.Path);
         }
     }