PR-C: Sync transport ridership and cargo counters

CS2MultiplayerMod/Game/Sync/Channels/City/StatisticsStateChannel.cs

@@ -10,17 +10,31 @@ namespace CS2MultiplayerMod.Game.Sync.Channels
 {
     /// <summary>
     /// Replicates the cumulative life-event counters - deaths, births, move-ins,
-    /// move-aways, crime, mail - host -> clients, so both players' statistics panels show
-    /// the same numbers between full-world resyncs.
+    /// move-aways, crime, mail, transport passengers and cargo - host -> clients, so
+    /// both players' statistics panels show the same numbers between full-world resyncs.
     /// Mechanism: the host snapshots each counter's lifetime value and the client feeds it
     /// through the game's own event pipeline, the same path the deathcare/crime systems use,
     /// so the statistics buffers stay internally consistent and serializable.
+    /// Only event-accumulated lifetime totals ride here. Gauges the simulation rewrites
+    /// itself (population, money, happiness, current tourists) are deliberately excluded:
+    /// forcing those through the event queue fights the writer, the same reason the
+    /// population channel was retired.
     /// </summary>
     public sealed class StatisticsStateChannel : IStateChannel
     {
         public const byte Id = 10;
         public byte ChannelId => Id;
 
+        /// <summary>
+        /// Statistic parameter holding the event-accumulated lifetime total. All
+        /// counters synced here are lifetime totals at this parameter, which is why
+        /// the generic delta mechanism applies to every entry unchanged.
+        /// </summary>
+        private const int LifetimeParameter = 0;
+
+        /// <summary>Upper bound for entries in one snapshot (the table holds 20).</summary>
+        private const int MaxEntriesPerSnapshot = 64;
+
         private static readonly StatisticType[] Synced =
         {
             StatisticType.DeathRate,          // "deaths" — cumulative count of citizen deaths
@@ -31,6 +45,23 @@ public sealed class StatisticsStateChannel : IStateChannel
             StatisticType.EscapedArrestCount,
             StatisticType.CollectedMail,
             StatisticType.DeliveredMail,
+            // Transport ridership and cargo: lifetime boarding/load totals shown in the
+            // transport info summaries. Same event-accumulated shape as the counters
+            // above, read at parameter 0 (the total), so the generic delta mechanism
+            // applies unchanged. The payload stays self-describing (count + type +
+            // value), so peers without these entries simply exchange fewer of them.
+            StatisticType.PassengerCountBus,
+            StatisticType.PassengerCountSubway,
+            StatisticType.PassengerCountTram,
+            StatisticType.PassengerCountTrain,
+            StatisticType.PassengerCountTaxi,
+            StatisticType.PassengerCountAirplane,
+            StatisticType.PassengerCountShip,
+            StatisticType.PassengerCountFerry,
+            StatisticType.CargoCountTruck,
+            StatisticType.CargoCountTrain,
+            StatisticType.CargoCountShip,
+            StatisticType.CargoCountAirplane,
         };
 
         private CityStatisticsSystem _stats;
@@ -56,7 +87,7 @@ public bool Capture(EntityManager em, NetworkWriter writer)
                 for (int i = 0; i < Synced.Length; i++)
                 {
                     writer.WriteByte((byte)Synced[i]);
-                    writer.WriteLong(stats.GetStatisticValueLong(Synced[i], 0));
+                    writer.WriteLong(stats.GetStatisticValueLong(Synced[i], LifetimeParameter));
                 }
                 return true;
             }
@@ -71,13 +102,21 @@ public void Apply(EntityManager em, NetworkReader reader)
         {
             CityStatisticsSystem stats = Resolve(em);
             int count = reader.ReadByte();
+            if (count < 0 || count > MaxEntriesPerSnapshot)
+            {
+                WarnOnce("apply", new System.IO.InvalidDataException(
+                    "Implausible statistics entry count: " + count + "."));
+                return;
+            }
             try
             {
                 for (int i = 0; i < count; i++)
                 {
-                    var type = (StatisticType)reader.ReadByte();
+                    byte rawType = reader.ReadByte();
                     long hostValue = reader.ReadLong();
-                    long localValue = stats.GetStatisticValueLong(type, 0);
+                    if (!System.Enum.IsDefined(typeof(StatisticType), (int)rawType)) continue;
+                    var type = (StatisticType)rawType;
+                    long localValue = stats.GetStatisticValueLong(type, LifetimeParameter);
 
                     // Where this counter is headed: the value it will hold once the events already
                     // queued are processed. Once the local value has caught up to that target the
@@ -95,7 +134,7 @@ public void Apply(EntityManager em, NetworkReader reader)
                     queue.Enqueue(new StatisticsEvent
                     {
                         m_Statistic = type,
-                        m_Parameter = 0,
+                        m_Parameter = LifetimeParameter,
                         m_Change = delta,
                     });
                     _inFlightTarget[type] = hostValue;