Working

tools/java/LandtrainConstraintAuthHelper.java

@@ -1,8 +1,12 @@
 package zombie.vehicles;
 
+import java.util.ArrayDeque;
+import java.util.ArrayList;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 import zombie.characters.IsoGameCharacter;
+import zombie.characters.IsoPlayer;
 
 /**
  * Resolves the effective driver for constraint auth in chained towing.
@@ -62,4 +66,133 @@ public final class LandtrainConstraintAuthHelper {
     private static boolean isVehicleBeingTowedInLandtrain(BaseVehicle vehicle) {
         return vehicle != null && vehicle.getVehicleTowedBy() != null;
     }
+
+    public static void authorizationChangedLandtrain(BaseVehicle vehicle, IsoGameCharacter character) {
+        if (vehicle == null) {
+            return;
+        }
+
+        if (character != null) {
+            applyAuthorizationAcrossChain(
+                    vehicle, BaseVehicle.Authorization.Local, character.getOnlineID(), false);
+        } else {
+            applyAuthorizationAcrossChain(vehicle, BaseVehicle.Authorization.Server, -1, false);
+        }
+    }
+
+    public static void authorizationClientCollideLandtrain(BaseVehicle vehicle, IsoPlayer driver) {
+        if (vehicle == null || driver == null || vehicle.getDriver() != null) {
+            return;
+        }
+
+        applyAuthorizationAcrossChain(
+                vehicle, BaseVehicle.Authorization.LocalCollide, driver.getOnlineID(), true);
+    }
+
+    public static void authorizationServerCollideLandtrain(
+            BaseVehicle vehicle, short playerID, boolean isCollide) {
+        if (vehicle == null) {
+            return;
+        }
+        if (vehicle.isNetPlayerAuthorization(BaseVehicle.Authorization.Local)) {
+            return;
+        }
+
+        if (isCollide) {
+            applyAuthorizationAcrossChain(
+                    vehicle, BaseVehicle.Authorization.LocalCollide, playerID, false);
+            return;
+        }
+
+        BaseVehicle.Authorization auth =
+                playerID == -1 ? BaseVehicle.Authorization.Server : BaseVehicle.Authorization.Local;
+        applyAuthorizationAcrossChain(vehicle, auth, playerID, false);
+    }
+
+    public static void authorizationServerOnSeatLandtrain(
+            BaseVehicle vehicle, IsoPlayer player, boolean enter) {
+        if (vehicle == null || player == null) {
+            return;
+        }
+
+        BaseVehicle vehicleA = vehicle.getVehicleTowing();
+        BaseVehicle vehicleB = vehicle.getVehicleTowedBy();
+        if (vehicle.isNetPlayerId((short) -1) && enter) {
+            if (vehicleA != null && vehicleA.getDriver() == null) {
+                vehicle.addPointConstraint(
+                        null, vehicleA, vehicle.getTowAttachmentSelf(), vehicleA.getTowAttachmentSelf());
+            } else if (vehicleB != null && vehicleB.getDriver() == null) {
+                vehicle.addPointConstraint(
+                        null, vehicleB, vehicle.getTowAttachmentSelf(), vehicleB.getTowAttachmentSelf());
+            } else {
+                applyAuthorizationAcrossChain(
+                        vehicle, BaseVehicle.Authorization.Local, player.getOnlineID(), false);
+            }
+        } else if (vehicle.isNetPlayerId(player.getOnlineID()) && !enter) {
+            if (vehicleA != null && vehicleA.getDriver() != null) {
+                vehicleA.addPointConstraint(
+                        null, vehicle, vehicleA.getTowAttachmentSelf(), vehicle.getTowAttachmentSelf());
+            } else if (vehicleB != null && vehicleB.getDriver() != null) {
+                vehicleB.addPointConstraint(
+                        null, vehicle, vehicleB.getTowAttachmentSelf(), vehicle.getTowAttachmentSelf());
+            } else {
+                applyAuthorizationAcrossChain(vehicle, BaseVehicle.Authorization.Server, -1, false);
+            }
+        }
+    }
+
+    private static List<BaseVehicle> collectConnectedChain(BaseVehicle start) {
+        ArrayList<BaseVehicle> chain = new ArrayList<>();
+        if (start == null) {
+            return chain;
+        }
+
+        ArrayDeque<BaseVehicle> pending = new ArrayDeque<>();
+        Set<Integer> visitedIds = new HashSet<>();
+        pending.add(start);
+
+        while (!pending.isEmpty()) {
+            BaseVehicle cursor = pending.removeFirst();
+            if (cursor == null) {
+                continue;
+            }
+
+            int id = cursor.getId();
+            if (!visitedIds.add(id)) {
+                continue;
+            }
+
+            chain.add(cursor);
+            BaseVehicle front = cursor.getVehicleTowedBy();
+            BaseVehicle rear = cursor.getVehicleTowing();
+            if (front != null && front != cursor) {
+                pending.add(front);
+            }
+            if (rear != null && rear != cursor) {
+                pending.add(rear);
+            }
+        }
+
+        return chain;
+    }
+
+    private static void applyAuthorizationAcrossChain(
+            BaseVehicle start,
+            BaseVehicle.Authorization authorization,
+            int playerId,
+            boolean refreshSimulation) {
+        long now = System.currentTimeMillis();
+        for (BaseVehicle vehicle : collectConnectedChain(start)) {
+            if (vehicle == null) {
+                continue;
+            }
+            vehicle.setNetPlayerAuthorization(authorization, playerId);
+            if (refreshSimulation) {
+                vehicle.authSimulationTime = now;
+                if (vehicle.interpolation != null) {
+                    vehicle.interpolation.clear();
+                }
+            }
+        }
+    }
 }