Add rain and snow minutes to the morning commute.

Day plans take a precomputed extra; Ai does not know precipitation.

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

src/HSchool.Ai/DayPlan.cs

@@ -10,6 +10,10 @@ public readonly record struct DayPlan(DateOnly Day, DateTime? AppearAt, DateTime
     public bool Comes => AppearAt is not null;
 }
 
+/// <summary>
+/// Day plans. Rain and snow arrive as already-counted extra minutes — this project does not
+/// know precipitation.
+/// </summary>
 public static class DayPlans
 {
     public static DayPlan Build(
@@ -20,7 +24,8 @@ public static class DayPlans
         Timetable? timetable,
         DateTime time,
         int weekDays,
-        int schoolSeed)
+        int schoolSeed,
+        int extraCommuteMinutes = 0)
     {
         ArgumentNullException.ThrowIfNull(catalog);
         ArgumentNullException.ThrowIfNull(walks);
@@ -48,7 +53,7 @@ public static class DayPlans
             travel = 0f;
         }
 
-        var slack = SlackMinutes(catalog, person, schoolSeed, day);
+        var slack = SlackMinutes(catalog, person, schoolSeed, day) + Math.Max(0, extraCommuteMinutes);
         var appear = DateTime.SpecifyKind(utc.Date.Add(firstStart.ToTimeSpan()).AddMinutes(-(travel + slack)), DateTimeKind.Utc);
         var walkHome = DateTime.SpecifyKind(utc.Date.Add(lastEnd.ToTimeSpan()), DateTimeKind.Utc);
         return new DayPlan(day, appear, walkHome, firstRoom);

src/HSchool.Content/PeopleDefValidator.cs

@@ -522,6 +522,12 @@ internal static class PeopleDefValidator
                 $"BehaviorDef '{behavior.DefName}' commute slack must be a non-negative range with min ≤ max.");
         }
 
+        if (behavior.CommuteRainMinutes < 0 || behavior.CommuteSnowMinutes < 0)
+        {
+            throw new ContentLoadException(
+                $"BehaviorDef '{behavior.DefName}' commute rain and snow minutes cannot be negative.");
+        }
+
         if (behavior.DutyLessonWeight < 0f
             || behavior.DutyTravelWeight < 0f
             || behavior.NeedWeightAtZero < 0f

src/HSchool.Content/PeopleDefs.cs

@@ -285,6 +285,15 @@ public sealed class BehaviorDef : Def
 
     public int CommuteSlackMax { get; init; }
 
+    /// <summary>
+    /// Extra minutes on a rainy morning. Added to slack when the street is wet. A pack without
+    /// the field adds nothing so the catalog still loads.
+    /// </summary>
+    public int CommuteRainMinutes { get; init; }
+
+    /// <summary>Same as <see cref="CommuteRainMinutes"/> when the street is snow.</summary>
+    public int CommuteSnowMinutes { get; init; }
+
     /// <summary>A new goal must beat the current one by this much before the person switches.</summary>
     public float SwitchMargin { get; init; }
 

src/HSchool.Server/mods/core/defs/behavior/rules.jsonc

@@ -10,6 +10,9 @@
   // the same seed still arrives at the same minute.
   "commuteSlackMin": 0,
   "commuteSlackMax": 6,
+  // Extra minutes on the road when the street is wet. Snow is slower than rain.
+  "commuteRainMinutes": 3,
+  "commuteSnowMinutes": 6,
   "switchMargin": 0.15,
   // Lesson or posted work. Beats leisure (3) and a need that only just crossed
   // the threshold; a toilet at zero (20) still leaves class.

src/HSchool.Simulation/OutdoorWeather.cs

@@ -1,3 +1,5 @@
+using HSchool.Content;
+
 namespace HSchool.Simulation;
 
 /// <summary>Street precipitation. Below 0 °C the same roll is snow, above it is rain.</summary>
@@ -17,4 +19,23 @@ public readonly record struct OutdoorWeather(float TemperatureC, Precipitation P
         Math.Round(TemperatureC * 10d, MidpointRounding.AwayFromZero),
         short.MinValue,
         short.MaxValue);
+
+    /// <summary>
+    /// Extra commute minutes for today's street. Ai receives this number; it does not see
+    /// precipitation. A pack without the fields adds nothing.
+    /// </summary>
+    public int ExtraCommuteMinutes(BehaviorDef? rules)
+    {
+        if (rules is null)
+        {
+            return 0;
+        }
+
+        return Precipitation switch
+        {
+            Precipitation.Rain => rules.CommuteRainMinutes,
+            Precipitation.Snow => rules.CommuteSnowMinutes,
+            _ => 0,
+        };
+    }
 }

src/HSchool.Simulation/PresenceSystem.cs

@@ -217,7 +217,8 @@ internal static class PresenceSystem
                 school.Timetable,
                 school.Clock.Time,
                 school.SchoolWeekDays,
-                school.PeopleSeed);
+                school.PeopleSeed,
+                school.Weather.ExtraCommuteMinutes(school.Catalog!.BehaviorRules));
         }
 
         school.DecisionQueue.Clear();