Refuse enemies joining an open talk circle.

RankInvitees already skipped enemies when a circle formed; a later Chat in the same node still joined without checking opinions.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/HSchool.Ai/TalkCircles.cs

@@ -369,6 +369,31 @@ public static class TalkCircles
         BehaviorDef? rules) =>
         Math.Clamp(current + (rules?.TalkLanguageSkillPerHour ?? 0.005f) * hours, skill.Range.Min, skill.Range.Max);
 
+    /// <summary>
+    /// Enemies do not sit in the same circle. RankInvitees only looks at the initiator when
+    /// forming; a later join is a self-invite, so either side already treating the other as an
+    /// enemy is enough to refuse.
+    /// </summary>
+    public static bool JoinerFits(Person joiner, IReadOnlyList<Person> members, BehaviorDef? rules)
+    {
+        foreach (var member in members)
+        {
+            if (member.Id.Equals(joiner.Id, StringComparison.Ordinal))
+            {
+                continue;
+            }
+
+            joiner.Opinions.TryGetValue(member.Id, out var fromJoiner);
+            member.Opinions.TryGetValue(joiner.Id, out var fromMember);
+            if (IsEnemy(fromJoiner, rules) || IsEnemy(fromMember, rules))
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
     /// <summary>Invite priority: friends, classmates, others. Enemies never invited.</summary>
     public static IReadOnlyList<string> RankInvitees(
         Person initiator,

src/HSchool.Simulation/TalkCircleSystem.cs

@@ -147,10 +147,10 @@ internal static class TalkCircleSystem
             return TryStartPhone(school, person, nodeId, action);
         }
 
-        var existing = FindOpenCircle(school, nodeId, actionId);
+        var existing = FindOpenCircle(school, nodeId, actionId, person);
-        if (existing is not null)
+        if (existing is not null && JoinCircle(school, existing, personId, action))
         {
-            return JoinCircle(school, existing, personId, action);
+            return true;
         }
 
         return TryStartGroup(school, person, nodeId, action);
@@ -319,6 +319,14 @@ internal static class TalkCircleSystem
             return false;
         }
 
+        var sitting = circle.Members
+            .Select(id => school.Roster!.People.First(row => row.Id.Equals(id, StringComparison.Ordinal)))
+            .ToArray();
+        if (!TalkCircles.JoinerFits(person, sitting, rules))
+        {
+            return false;
+        }
+
         circle.Members.Add(personId);
         circle.Members.Sort(StringComparer.Ordinal);
         school.TalkCircleByPerson[personId] = circle.Id;
@@ -326,22 +334,28 @@ internal static class TalkCircleSystem
         return true;
     }
 
-    private static ActiveTalkCircle? FindOpenCircle(School school, string nodeId, string actionId)
+    private static ActiveTalkCircle? FindOpenCircle(School school, string nodeId, string actionId, Person joiner)
-    {
-        foreach (var circle in school.TalkCirclesById.Values)
-        {
-            if (circle.NodeId.Equals(nodeId, StringComparison.Ordinal)
-                && circle.ActionId.Equals(actionId, StringComparison.Ordinal)
-                && circle.RemainingMinutes > 0)
     {
         var rules = school.Catalog!.BehaviorRules;
         var max = TalkCircles.MaxSize(actionId, rules, [], school.Catalog);
-                if (circle.Members.Count < max)
+        foreach (var circle in school.TalkCirclesById.Values)
+        {
+            if (!circle.NodeId.Equals(nodeId, StringComparison.Ordinal)
+                || !circle.ActionId.Equals(actionId, StringComparison.Ordinal)
+                || circle.RemainingMinutes <= 0
+                || circle.Members.Count >= max)
+            {
+                continue;
+            }
+
+            var sitting = circle.Members
+                .Select(id => school.Roster!.People.First(row => row.Id.Equals(id, StringComparison.Ordinal)))
+                .ToArray();
+            if (TalkCircles.JoinerFits(joiner, sitting, rules))
             {
                 return circle;
             }
         }
-        }
 
         return null;
     }

tests/HSchool.Ai.Tests/TalkCirclesTests.cs

@@ -206,6 +206,15 @@ public class TalkCirclesTests
         Assert.Equal(2, TalkCircles.AppearanceModifier(ApparelIssue.None));
         Assert.Equal(-2, TalkCircles.AppearanceModifier(ApparelIssue.Formality));
         Assert.Equal(0, TalkCircles.AppearanceModifier(ApparelIssue.Color));
+
+        var (catalog, _, _) = World();
+        var rules = catalog.BehaviorRules!;
+        var topic = catalog.Topics["TopicAppearance"];
+        var from = Person("a", ["RussianLanguage"]);
+        var to = Person("b", ["RussianLanguage"]);
+        var compliment = TalkCircles.OpinionDelta(from, to, topic, 50f, true, TalkActions.Chat, ApparelIssue.None, rules, catalog);
+        var mockery = TalkCircles.OpinionDelta(from, to, topic, 50f, true, TalkActions.Chat, ApparelIssue.Formality, rules, catalog);
+        Assert.True(compliment > mockery);
     }
 
     [Fact]
@@ -219,6 +228,42 @@ public class TalkCirclesTests
         Assert.Equal(50f + rules.TalkSkillPerHour, afterTalkHour);
     }
 
+    [Fact]
+    public void LessonWhisperFactor_CutsWhisper_LeavesOrdinaryChat()
+    {
+        var (catalog, _, _) = World();
+        var rules = catalog.BehaviorRules!;
+        Assert.True(TalkCircles.LessonWhisperFactor(TalkActions.Whisper, rules) < 1f);
+        Assert.Equal(1f, TalkCircles.LessonWhisperFactor(TalkActions.Chat, rules));
+        Assert.Equal(rules.LessonWhisperSkillFactor, TalkCircles.LessonWhisperFactor(TalkActions.Whisper, rules));
+    }
+
+    [Fact]
+    public void Outgoing_RaisesMaxSize_WhenTalkCircleMaxIsBelowHardLimit()
+    {
+        var (catalog, _, _) = World();
+        var rules = new BehaviorDef { DefName = "Rules", TalkCircleMin = 2, TalkCircleMax = 3 };
+        Assert.Equal(3, TalkCircles.MaxSize(TalkActions.Chat, rules, [], catalog));
+        Assert.Equal(4, TalkCircles.MaxSize(TalkActions.Chat, rules, ["Outgoing"], catalog));
+        Assert.Equal(4, TalkCircles.MaxSize(TalkActions.Chat, catalog.BehaviorRules, ["Outgoing"], catalog));
+    }
+
+    [Fact]
+    public void Joiner_IsRejectedWhenEitherSideIsEnemy()
+    {
+        var (catalog, _, _) = World();
+        var rules = catalog.BehaviorRules!;
+        var sitting = Person("a", []) with { Opinions = new Dictionary<string, int>(StringComparer.Ordinal) { ["c"] = 10 } };
+        var friend = Person("b", []) with { Opinions = new Dictionary<string, int>(StringComparer.Ordinal) { ["a"] = 50 } };
+        var enemy = Person("c", []) with { Opinions = new Dictionary<string, int>(StringComparer.Ordinal) { ["a"] = -55 } };
+        Assert.True(TalkCircles.JoinerFits(friend, [sitting], rules));
+        Assert.False(TalkCircles.JoinerFits(enemy, [sitting], rules));
+
+        var hated = Person("d", []) with { Opinions = new Dictionary<string, int>(StringComparer.Ordinal) };
+        var hater = Person("a", []) with { Opinions = new Dictionary<string, int>(StringComparer.Ordinal) { ["d"] = -55 } };
+        Assert.False(TalkCircles.JoinerFits(hated, [hater], rules));
+    }
+
     [Fact]
     public void StudyOnlyPolicy_NeverPicksNonStudyTopic()
     {

tests/HSchool.Simulation.Tests/TalkCircleTests.cs

@@ -52,6 +52,44 @@ public class TalkCircleTests
         }
     }
 
+    [Fact]
+    public void Enemy_StartsNeighborCircle_InsteadOfJoiningFriends()
+    {
+        var (school, pupils) = FivePupilsOnBreak();
+        using (school)
+        {
+            var first = pupils[0];
+            var second = pupils[1];
+            var enemy = pupils[2];
+            var ally = pupils[3];
+            OpinionStore.Set(first, second.Id, 55);
+            OpinionStore.Set(second, first.Id, 55);
+            OpinionStore.Set(enemy, first.Id, -55);
+            OpinionStore.Set(first, enemy.Id, -55);
+            OpinionStore.Set(enemy, second.Id, -55);
+            OpinionStore.Set(second, enemy.Id, -55);
+            OpinionStore.Set(enemy, ally.Id, 55);
+            OpinionStore.Set(ally, enemy.Id, 55);
+
+            PlaceAt(school, first.Id, "corridor-1");
+            PlaceAt(school, second.Id, "corridor-1");
+            Assert.True(school.TryStartAction(first.Id, TalkActions.Chat));
+            var friends = school.TalkCircleOf(first.Id);
+            Assert.NotNull(friends);
+            Assert.DoesNotContain(enemy.Id, friends.MemberIds);
+
+            PlaceAt(school, enemy.Id, "corridor-1");
+            PlaceAt(school, ally.Id, "corridor-1");
+            Assert.True(school.TryStartAction(enemy.Id, TalkActions.Chat));
+            var neighbor = school.TalkCircleOf(enemy.Id);
+            Assert.NotNull(neighbor);
+            Assert.NotEqual(friends.MemberIds, neighbor.MemberIds);
+            Assert.Contains(ally.Id, neighbor.MemberIds);
+            Assert.DoesNotContain(first.Id, neighbor.MemberIds);
+            Assert.Equal(friends.MemberIds, school.TalkCircleOf(first.Id)?.MemberIds);
+        }
+    }
+
     [Fact]
     public void FifthPerson_DoesNotJoinFullCircle()
     {