Give each school its own people seed so composition no longer follows create order.

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

src/HSchool.Server/Api/SchoolEndpoints.cs

@@ -55,6 +55,7 @@ internal static class SchoolEndpoints
                 request.Map,
                 request.NameSetId,
                 request.NativeLanguage,
+                request.Seed,
                 NewCompletion<SchoolCreationOutcome>());
             commands.Enqueue(command);
 
@@ -490,12 +491,13 @@ internal sealed record CreateSchoolRequest(
     IReadOnlyList<string>? ModIds,
     MapLayout? Map,
     string? NameSetId,
-    string? NativeLanguage);
+    string? NativeLanguage,
+    int? Seed);
 
-internal sealed record SchoolResponse(int Id, string Name, DateTime GameTime, bool Running, byte SpeedIndex)
+internal sealed record SchoolResponse(int Id, string Name, DateTime GameTime, bool Running, byte SpeedIndex, int Seed)
 {
     public static SchoolResponse From(SchoolState school) =>
-        new(school.Id, school.Name, school.GameTime, school.Running, school.SpeedIndex);
+        new(school.Id, school.Name, school.GameTime, school.Running, school.SpeedIndex, school.Seed);
 }
 
 /// <summary>Everything the main menu needs in one request.</summary>

src/HSchool.Server/Game/GameCommand.cs

@@ -18,6 +18,7 @@ internal abstract record GameCommand
         MapLayout? Map,
         string? NameSetId,
         string? NativeLanguage,
+        int? Seed,
         TaskCompletionSource<SchoolCreationOutcome> Result) : GameCommand;
 
     internal sealed record DeleteSchool(int SchoolId, TaskCompletionSource<bool> Result) : GameCommand;

src/HSchool.Server/Game/GameLoopService.cs

@@ -342,9 +342,10 @@ internal sealed class GameLoopService(
 
             var id = _nextId++;
             store.WriteNextId(_nextId);
-            var nativeLanguage = NativeLanguages.Pick(names, id, command.NativeLanguage, rollIfOmitted: true);
+            var seed = command.Seed ?? Random.Shared.Next();
+            var nativeLanguage = NativeLanguages.Pick(names, seed, command.NativeLanguage, rollIfOmitted: true);
 
-            var worker = SpawnWorker(id, normalized, command.StartDate, running: true, ClockSpeed.DefaultIndex, isNew: true, packIds, command.Map, nameSetId, nativeLanguage);
+            var worker = SpawnWorker(id, normalized, command.StartDate, running: true, ClockSpeed.DefaultIndex, isNew: true, packIds, command.Map, nameSetId, nativeLanguage, seed);
             Track(worker);
             worker.Start();
 
@@ -366,7 +367,7 @@ internal sealed class GameLoopService(
                 throw;
             }
 
-            logger.LogInformation("School {SchoolId} \"{Name}\" created.", id, normalized);
+            logger.LogInformation("School {SchoolId} \"{Name}\" created with seed {Seed}.", id, normalized, seed);
             command.Result.TrySetResult(new SchoolCreationOutcome(worker.Snapshot, SchoolCreationError.None));
         }
         catch (Exception ex)
@@ -513,6 +514,7 @@ internal sealed class GameLoopService(
                 save.Map,
                 save.NameSetId,
                 save.NativeLanguage,
+                createSeed: null,
                 save.Presence);
             worker.Start();
 
@@ -562,6 +564,7 @@ internal sealed class GameLoopService(
         MapLayout? map,
         string? nameSetId,
         string? nativeLanguage,
+        int? createSeed = null,
         IReadOnlyList<PresenceSnapshot>? presence = null) =>
         new(
             id,
@@ -574,6 +577,7 @@ internal sealed class GameLoopService(
             map,
             nameSetId,
             nativeLanguage,
+            createSeed,
             presence,
             _options,
             clients,

src/HSchool.Server/Game/SchoolState.cs

@@ -4,7 +4,7 @@ namespace HSchool.Server.Game;
 /// Immutable copy of a school, safe to hand to request threads. The live <c>School</c> object
 /// never leaves its worker thread.
 /// </summary>
-internal sealed record SchoolState(int Id, string Name, DateTime GameTime, bool Running, byte SpeedIndex);
+internal sealed record SchoolState(int Id, string Name, DateTime GameTime, bool Running, byte SpeedIndex, int Seed);
 
 /// <summary>Everything the main menu needs in one read.</summary>
 internal sealed record SchoolsState(int MaxSchools, IReadOnlyList<SchoolState> Schools);

src/HSchool.Server/Game/SchoolWorker.cs

@@ -34,6 +34,7 @@ internal sealed class SchoolWorker
     private readonly MapLayout? _savedMap;
     private readonly string? _nameSetId;
     private string? _nativeLanguage;
+    private readonly int? _createSeed;
     private readonly IReadOnlyList<PresenceSnapshot>? _savedPresence;
     private readonly Action<int> _onFailed;
 
@@ -67,6 +68,7 @@ internal sealed class SchoolWorker
         MapLayout? savedMap,
         string? nameSetId,
         string? nativeLanguage,
+        int? createSeed,
         IReadOnlyList<PresenceSnapshot>? savedPresence,
         SimulationOptions options,
         ClientRegistry clients,
@@ -86,6 +88,7 @@ internal sealed class SchoolWorker
         _savedMap = savedMap;
         _nameSetId = nameSetId;
         _nativeLanguage = nativeLanguage;
+        _createSeed = createSeed;
         _savedPresence = savedPresence;
         _options = options;
         _clients = clients;
@@ -94,7 +97,7 @@ internal sealed class SchoolWorker
         _mods = mods;
         _onFailed = onFailed;
         _logger = logger;
-        _snapshot = new SchoolState(id, name, time, running, (byte)speedIndex);
+        _snapshot = new SchoolState(id, name, time, running, (byte)speedIndex, createSeed ?? 0);
     }
 
     public int Id => _id;
@@ -577,7 +580,8 @@ internal sealed class SchoolWorker
                 school.Name,
                 school.Clock.Time,
                 school.Clock.IsRunning,
-                (byte)school.Clock.SpeedIndex));
+                (byte)school.Clock.SpeedIndex,
+                school.PeopleSeed));
         Volatile.Write(ref _rosterSnapshot, school.Roster);
         Volatile.Write(ref _applicantSnapshot, school.Applicants);
         Volatile.Write(ref _timetableSnapshot, school.Timetable);
@@ -856,7 +860,12 @@ internal sealed class SchoolWorker
 
         if (_isNew)
         {
-            seed = school.Id;
+            if (_createSeed is not int createSeed)
+            {
+                throw new InvalidOperationException($"School {_id} was created without a people seed.");
+            }
+
+            seed = createSeed;
             native = ResolveNative(catalog, nameSetId, seed, _nativeLanguage, generating: true);
             _nativeLanguage = native;
             roster = RosterGenerator.Generate(catalog, map, seed, nameSetId, school.Clock.Time, native);