refactor: improve traffic light queue processing, add graceful intersection shutdown, and remove obsolete event and serialization classes.

main/src/main/java/sd/IntersectionProcess.java

@@ -469,6 +469,12 @@ public class IntersectionProcess {
 
                         // Record arrival for statistics
                         recordVehicleArrival();
+                    } else if (message.getType() == MessageType.SHUTDOWN) {
+                        System.out.println(
+                                "[" + intersectionId + "] Received SHUTDOWN command from " + message.getSourceNode());
+                        running = false;
+                        // Close this specific connection
+                        break;
                     }
 
                 } catch (java.net.SocketTimeoutException e) {
@@ -512,6 +518,9 @@ public class IntersectionProcess {
         System.out.println("\n[" + intersectionId + "] Shutting down...");
         running = false;
 
+        // Send final stats before closing connections
+        sendStatsToDashboard();
+
         // 1. Close ServerSocket first
         if (serverSocket != null && !serverSocket.isClosed()) {
             try {

main/src/main/java/sd/config/SimulationConfig.java

@@ -227,6 +227,16 @@ public class SimulationConfig {
         return Double.parseDouble(properties.getProperty("simulation.duration", "3600.0"));
     }
 
+    /**
+     * Gets the drain time (in virtual seconds) to allow vehicles to exit after
+     * generation stops.
+     * 
+     * @return The drain time.
+     */
+    public double getDrainTime() {
+        return Double.parseDouble(properties.getProperty("simulation.drain.time", "60.0"));
+    }
+
     /**
      * Gets the vehicle arrival model ("POISSON" or "FIXED").
      * 

main/src/main/java/sd/coordinator/CoordinatorProcess.java

@@ -119,11 +119,22 @@ public class CoordinatorProcess {
         nextGenerationTime = vehicleGenerator.getNextArrivalTime(currentTime);
         final double TIME_STEP = 0.1;
 
-        while (running && currentTime < duration) {
+        double drainTime = config.getDrainTime();
+        double totalDuration = duration + drainTime;
+        boolean draining = false;
+
+        while (running && currentTime < totalDuration) {
+            // Only generate vehicles during the main duration
+            if (currentTime < duration) {
                 if (currentTime >= nextGenerationTime) {
                     generateAndSendVehicle();
                     nextGenerationTime = vehicleGenerator.getNextArrivalTime(currentTime);
                 }
+            } else if (!draining) {
+                draining = true;
+                System.out.println("\n[t=" + String.format("%.2f", currentTime)
+                        + "] Generation complete. Entering DRAIN MODE for " + drainTime + "s...");
+            }
 
             try {
                 Thread.sleep((long) (TIME_STEP * 1000));

main/src/main/java/sd/engine/TrafficLightThread.java

@@ -44,14 +44,12 @@ public class TrafficLightThread implements Runnable {
                     light.changeState(TrafficLightState.GREEN);
                     System.out.println("[" + light.getId() + "] State: GREEN");
 
-                    processGreenLightQueue();
+                    // Process queue for the duration of the green light
+                    long greenDurationMs = (long) (light.getGreenTime() * 1000);
+                    processGreenLightQueue(greenDurationMs);
 
-                    if (!running || Thread.currentThread().isInterrupted()) break;
+                    if (!running || Thread.currentThread().isInterrupted())
-                    
+                        break;
-                    // Wait for green duration
-                    Thread.sleep((long) (light.getGreenTime() * 1000));
-                    
-                    if (!running || Thread.currentThread().isInterrupted()) break;
 
                     // --- RED Phase ---
                     light.changeState(TrafficLightState.RED);
@@ -74,22 +72,35 @@ public class TrafficLightThread implements Runnable {
         }
     }
 
-    private void processGreenLightQueue() throws InterruptedException {
+    private void processGreenLightQueue(long greenDurationMs) throws InterruptedException {
-        while (running && !Thread.currentThread().isInterrupted() 
+        long startTime = System.currentTimeMillis();
-               && light.getState() == TrafficLightState.GREEN 
-               && light.getQueueSize() > 0) {
 
+        while (running && !Thread.currentThread().isInterrupted()
+                && light.getState() == TrafficLightState.GREEN) {
+
+            // Check if green time has expired
+            long elapsed = System.currentTimeMillis() - startTime;
+            if (elapsed >= greenDurationMs) {
+                break;
+            }
+
+            if (light.getQueueSize() > 0) {
                 Vehicle vehicle = light.removeVehicle();
 
                 if (vehicle != null) {
                     double crossingTime = getCrossingTimeForVehicle(vehicle);
+                    long crossingTimeMs = (long) (crossingTime * 1000);
 
-                Thread.sleep((long) (crossingTime * 1000));
+                    Thread.sleep(crossingTimeMs);
 
                     vehicle.addCrossingTime(crossingTime);
                     process.getIntersection().incrementVehiclesSent();
                     process.sendVehicleToNextDestination(vehicle);
                 }
+            } else {
+                // Queue is empty, wait briefly for new vehicles or until time expires
+                Thread.sleep(50);
+            }
         }
     }
 

main/src/main/java/sd/model/Event.java

@@ -1,131 +0,0 @@
-package sd.model;
-
-import java.io.Serializable;
-
-/**
- * Represents a single event in the discrete event simulation.
- * * An Event is the fundamental unit of action in the simulation. It contains:
- * - A {@code timestamp} (when the event should occur).
- * - A {@link EventType} (what kind of event it is).
- * - Associated {@code data} (e.g., the {@link Vehicle} or {@link TrafficLight} involved).
- * - An optional {@code location} (e.g., the ID of the {@link Intersection}).
- * * Events are {@link Comparable}, allowing them to be sorted in a
- * {@link java.util.PriorityQueue}. The primary sorting key is the
- * {@code timestamp}. If timestamps are equal, {@code EventType} is used
- * as a tie-breaker to ensure a consistent, deterministic order.
- * * Implements {@link Serializable} so events could (in theory) be sent
- * across a network in a distributed simulation.
- */
-public class Event implements Comparable<Event>, Serializable {
-    private static final long serialVersionUID = 1L;
-    
-    /**
-     * The simulation time (in seconds) when this event is scheduled to occur.
-     */
-    private final double timestamp;
-    
-    /**
-     * The type of event (e.g., VEHICLE_ARRIVAL, TRAFFIC_LIGHT_CHANGE).
-     */
-    private final EventType type;
-    
-    /**
-     * The data payload associated with this event.
-     * This could be a {@link Vehicle}, {@link TrafficLight}, or null.
-     */
-    private final Object data;
-    
-    /**
-     * The ID of the location where the event occurs (e.g., "Cr1").
-     * Can be null if the event is not location-specific (like VEHICLE_GENERATION).
-     */
-    private final String location;
-    
-    /**
-     * Constructs a new Event.
-     *
-     * @param timestamp The simulation time when the event occurs.
-     * @param type The {@link EventType} of the event.
-     * @param data The associated data (e.g., a Vehicle object).
-     * @param location The ID of the location (e.g., an Intersection ID).
-     */
-    public Event(double timestamp, EventType type, Object data, String location) {
-        this.timestamp = timestamp;
-        this.type = type;
-        this.data = data;
-        this.location = location;
-    }
-    
-    /**
-     * Convenience constructor for an Event without a specific location.
-     *
-     * @param timestamp The simulation time when the event occurs.
-     * @param type The {@link EventType} of the event.
-     * @param data The associated data (e.g., a Vehicle object).
-     */
-    public Event(double timestamp, EventType type, Object data) {
-        this(timestamp, type, data, null);
-    }
-    
-    /**
-     * Compares this event to another event for ordering.
-     * * Events are ordered primarily by {@link #timestamp} (ascending).
-     * If timestamps are identical, they are ordered by {@link #type} (alphabetical)
-     * to provide a stable, deterministic tie-breaking mechanism.
-     *
-     * @param other The other Event to compare against.
-     * @return A negative integer if this event comes before {@code other},
-     * zero if they are "equal" in sorting (though this is rare),
-     * or a positive integer if this event comes after {@code other}.
-     */
-    @Override
-    public int compareTo(Event other) {
-        // Primary sort: timestamp (earlier events come first)
-        int cmp = Double.compare(this.timestamp, other.timestamp);
-        if (cmp == 0) {
-            // Tie-breaker: event type (ensures deterministic order)
-            return this.type.compareTo(other.type);
-        }
-        return cmp;
-    }
-    
-    // --- Getters ---
-    
-    /**
-     * @return The simulation time when the event occurs.
-     */
-    public double getTimestamp() {
-        return timestamp;
-    }
-    
-    /**
-     * @return The {@link EventType} of the event.
-     */
-    public EventType getType() {
-        return type;
-    }
-    
-    /**
-     * @return The data payload (e.g., {@link Vehicle}, {@link TrafficLight}).
-     * The caller must cast this to the expected type.
-     */
-    public Object getData() {
-        return data;
-    }
-    
-    /**
-     * @return The location ID (e.g., "Cr1"), or null if not applicable.
-     */
-    public String getLocation() {
-        return location;
-    }
-    
-    /**
-     * @return A string representation of the event for logging.
-     */
-    @Override
-    public String toString() {
-        return String.format("Event{t=%.2f, type=%s, loc=%s}", 
-                           timestamp, type, location);
-    }
-}

main/src/main/java/sd/model/EventType.java

@@ -1,45 +0,0 @@
-package sd.model;
-
-/**
- * Enumeration representing all possible event types in the discrete event simulation.
- * These types are used by the {@link sd.engine.SimulationEngine} to determine
- * how to process a given {@link Event}.
- */
-public enum EventType {
-    
-    /**
-     * Fired when a {@link Vehicle} arrives at an {@link Intersection}.
-     * Data: {@link Vehicle}, Location: Intersection ID
-     */
-    VEHICLE_ARRIVAL,
-    
-    /**
-     * Fired when a {@link TrafficLight} is scheduled to change its state.
-     * Data: {@link TrafficLight}, Location: Intersection ID
-     */
-    TRAFFIC_LIGHT_CHANGE,
-    
-    /**
-     * Fired when a {@link Vehicle} begins to cross an {@link Intersection}.
-     * Data: {@link Vehicle}, Location: Intersection ID
-     */
-    CROSSING_START,
-    
-    /**
-     * Fired when a {@link Vehicle} finishes crossing an {@link Intersection}.
-     * Data: {@link Vehicle}, Location: Intersection ID
-     */
-    CROSSING_END,
-    
-    /**
-     * Fired when a new {@link Vehicle} should be created and added to the system.
-     * Data: null, Location: null
-     */
-    VEHICLE_GENERATION,
-    
-    /**
-     * Fired periodically to trigger the printing or sending of simulation statistics.
-     * Data: null, Location: null
-     */
-    STATISTICS_UPDATE
-}

main/src/main/java/sd/model/Vehicle.java

@@ -12,7 +12,7 @@ import java.util.List;
  * - Its complete, pre-determined {@code route} (a list of intersection IDs).
  * - Its current position in the route ({@code currentRouteIndex}).
  * - Metrics for total time spent waiting at red lights and time spent crossing.
- * * This object is passed around the simulation, primarily inside {@link Event}
+ * * This object is passed around the simulation, primarily inside message
  * payloads and stored in {@link TrafficLight} queues.
  * * Implements {@link Serializable} so it can be sent between processes
  * or nodes (e.g., over a socket in a distributed version of the simulation).
@@ -70,7 +70,8 @@ public class Vehicle implements Serializable {
      * @param id        The unique ID for the vehicle.
      * @param type      The {@link VehicleType}.
      * @param entryTime The simulation time when the vehicle is created.
-     * @param route The complete list of destination IDs (e.t., ["Cr1", "Cr2", "S"]).
+     * @param route     The complete list of destination IDs (e.t., ["Cr1", "Cr2",
+     *                  "S"]).
      */
     public Vehicle(String id, VehicleType type, double entryTime, List<String> route) {
         this.id = id;
@@ -151,7 +152,8 @@ public class Vehicle implements Serializable {
     }
 
     /**
-     * @return The current index pointing to the vehicle's destination in its route list.
+     * @return The current index pointing to the vehicle's destination in its route
+     *         list.
      */
     public int getCurrentRouteIndex() {
         return currentRouteIndex;
@@ -212,7 +214,6 @@ public class Vehicle implements Serializable {
     public String toString() {
         return String.format(
                 "Vehicle{id='%s', type=%s, next='%s', route=%s}",
-            id, type, getCurrentDestination(), route
+                id, type, getCurrentDestination(), route);
-        );
     }
 }

main/src/main/java/sd/serialization/SerializationExample.java

@@ -1,134 +0,0 @@
-package sd.serialization;
-
-import sd.model.Message;
-import sd.model.MessageType;
-import sd.model.Vehicle;
-import sd.model.VehicleType;
-
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * Demonstration of JSON serialization usage in the traffic simulation system.
- * 
- * This class shows practical examples of how to use JSON (Gson) serialization
- * for network communication between simulation processes.
- */
-public class SerializationExample {
-    
-    public static void main(String[] args) {
-        System.out.println("=== JSON Serialization Example ===\n");
-        
-        // Create a sample vehicle
-        List<String> route = Arrays.asList("Cr1", "Cr2", "Cr5", "S");
-        Vehicle vehicle = new Vehicle("V001", VehicleType.LIGHT, 10.5, route);
-        vehicle.addWaitingTime(2.3);
-        vehicle.addCrossingTime(1.2);
-        
-        // Create a message containing the vehicle
-        Message message = new Message(
-            MessageType.VEHICLE_TRANSFER,
-            "Cr1",
-            "Cr2",
-            vehicle
-        );
-        
-        // ===== JSON Serialization =====
-        demonstrateJsonSerialization(message);
-        
-        // ===== Factory Usage =====
-        demonstrateFactoryUsage(message);
-        
-        // ===== Performance Test =====
-        performanceTest(message);
-    }
-    
-    private static void demonstrateJsonSerialization(Message message) {
-        System.out.println("--- JSON Serialization ---");
-        
-        try {
-            // Create JSON serializer with pretty printing for readability
-            MessageSerializer serializer = new JsonMessageSerializer(true);
-            
-            // Serialize to bytes
-            byte[] data = serializer.serialize(message);
-            
-            // Display the JSON
-            String json = new String(data);
-            System.out.println("Serialized JSON (" + data.length + " bytes):");
-            System.out.println(json);
-            
-            // Deserialize back
-            Message deserialized = serializer.deserialize(data, Message.class);
-            System.out.println("\nDeserialized: " + deserialized);
-            System.out.println("✓ JSON serialization successful\n");
-            
-        } catch (SerializationException e) {
-            System.err.println("❌ JSON serialization failed: " + e.getMessage());
-        }
-    }
-    
-    private static void demonstrateFactoryUsage(Message message) {
-        System.out.println("--- Using SerializerFactory ---");
-        
-        try {
-            // Get default serializer (JSON)
-            MessageSerializer serializer = SerializerFactory.createDefault();
-            System.out.println("Default serializer: " + serializer.getName());
-            
-            // Use it
-            byte[] data = serializer.serialize(message);
-            Message deserialized = serializer.deserialize(data, Message.class);
-            
-            System.out.println("Message type: " + deserialized.getType());
-            System.out.println("From: " + deserialized.getSenderId() + 
-                             " → To: " + deserialized.getDestinationId());
-            System.out.println("✓ Factory usage successful\n");
-            
-        } catch (SerializationException e) {
-            System.err.println("❌ Factory usage failed: " + e.getMessage());
-        }
-    }
-    
-    private static void performanceTest(Message message) {
-        System.out.println("--- Performance Test ---");
-        
-        int iterations = 1000;
-        
-        try {
-            MessageSerializer compactSerializer = new JsonMessageSerializer(false);
-            MessageSerializer prettySerializer = new JsonMessageSerializer(true);
-            
-            // Warm up
-            for (int i = 0; i < 100; i++) {
-                compactSerializer.serialize(message);
-            }
-            
-            // Test compact JSON
-            long compactStart = System.nanoTime();
-            byte[] compactData = null;
-            for (int i = 0; i < iterations; i++) {
-                compactData = compactSerializer.serialize(message);
-            }
-            long compactTime = System.nanoTime() - compactStart;
-            
-            // Test pretty JSON
-            byte[] prettyData = prettySerializer.serialize(message);
-            
-            // Results
-            System.out.println("Iterations: " + iterations);
-            System.out.println("\nJSON Compact:");
-            System.out.println("  Size: " + compactData.length + " bytes");
-            System.out.println("  Time: " + (compactTime / 1_000_000.0) + " ms total");
-            System.out.println("  Avg:  " + (compactTime / iterations / 1_000.0) + " μs/operation");
-            
-            System.out.println("\nJSON Pretty-Print:");
-            System.out.println("  Size: " + prettyData.length + " bytes");
-            System.out.println("  Size increase: " + 
-                String.format("%.1f%%", ((double)prettyData.length / compactData.length - 1) * 100));
-            
-        } catch (SerializationException e) {
-            System.err.println("❌ Performance test failed: " + e.getMessage());
-        }
-    }
-}

main/src/main/java/sd/util/StatisticsCollector.java

@@ -1,381 +0,0 @@
-package sd.util;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-import sd.config.SimulationConfig;
-import sd.model.Intersection;
-import sd.model.Vehicle;
-import sd.model.VehicleType;
-
-/**
- * Collects, manages, and reports statistics throughout the simulation.
- * * This class acts as the central bookkeeper for simulation metrics. It
- * tracks:
- * - Overall system statistics (total vehicles, completion time, wait time).
- * - Per-vehicle-type statistics (counts, average wait time by type).
- * - Per-intersection statistics (arrivals, departures).
- * * It also maintains "in-flight" data, such as the arrival time of a
- * vehicle at its *current* intersection, which is necessary to
- * calculate waiting time when the vehicle later departs.
- */
-public class StatisticsCollector {
-
-    // --- Vehicle tracking (for in-flight vehicles) ---
-
-    /**
-     * Tracks the simulation time when a vehicle arrives at its *current*
-     * intersection.
-     * This is used later to calculate waiting time (Depart_Time - Arrive_Time).
-     * Key: Vehicle ID (String)
-     * Value: Arrival Time (Double)
-     */
-    private final Map<String, Double> vehicleArrivalTimes;
-
-    /**
-     * Tracks the sequence of intersections a vehicle has visited.
-     * Key: Vehicle ID (String)
-     * Value: List of Intersection IDs (String)
-     */
-    private final Map<String, List<String>> vehicleIntersectionHistory;
-
-    // --- Overall system statistics ---
-
-    /** Total number of vehicles created by the {@link VehicleGenerator}. */
-    private int totalVehiclesGenerated;
-
-    /** Total number of vehicles that have reached their final destination ("S"). */
-    private int totalVehiclesCompleted;
-
-    /**
-     * The sum of all *completed* vehicles' total travel times. Used for averaging.
-     */
-    private double totalSystemTime;
-
-    /**
-     * The sum of all *completed* vehicles' total waiting times. Used for averaging.
-     */
-    private double totalWaitingTime;
-
-    // --- Per-vehicle-type statistics ---
-
-    /**
-     * Tracks the total number of vehicles generated, broken down by type.
-     * Key: {@link VehicleType}
-     * Value: Count (Integer)
-     */
-    private final Map<VehicleType, Integer> vehicleTypeCount;
-
-    /**
-     * Tracks the total waiting time, broken down by vehicle type.
-     * Key: {@link VehicleType}
-     * Value: Total Wait Time (Double)
-     */
-    private final Map<VehicleType, Double> vehicleTypeWaitTime;
-
-    // --- Per-intersection statistics ---
-
-    /**
-     * A map to hold statistics objects for each intersection.
-     * Key: Intersection ID (String)
-     * Value: {@link IntersectionStats} object
-     */
-    private final Map<String, IntersectionStats> intersectionStats;
-
-    /**
-     * Constructs a new StatisticsCollector.
-     * Initializes all maps and counters.
-     *
-     * @param config The {@link SimulationConfig} (not currently used, but
-     *               could be for configuration-dependent stats).
-     */
-    public StatisticsCollector(SimulationConfig config) {
-        this.vehicleArrivalTimes = new HashMap<>();
-        this.vehicleIntersectionHistory = new HashMap<>();
-        this.totalVehiclesGenerated = 0;
-        this.totalVehiclesCompleted = 0;
-        this.totalSystemTime = 0.0;
-        this.totalWaitingTime = 0.0;
-        this.vehicleTypeCount = new HashMap<>();
-        this.vehicleTypeWaitTime = new HashMap<>();
-        this.intersectionStats = new HashMap<>();
-
-        // Initialize vehicle type counters to 0
-        for (VehicleType type : VehicleType.values()) {
-            vehicleTypeCount.put(type, 0);
-            vehicleTypeWaitTime.put(type, 0.0);
-        }
-    }
-
-    /**
-     * Records that a new vehicle has been generated.
-     * This is called by the vehicle generation component
-     * during a {@code VEHICLE_GENERATION} event.
-     *
-     * @param vehicle     The {@link Vehicle} that was just created.
-     * @param currentTime The simulation time of the event.
-     */
-    public void recordVehicleGeneration(Vehicle vehicle, double currentTime) {
-        totalVehiclesGenerated++;
-
-        // Track by vehicle type
-        VehicleType type = vehicle.getType();
-        vehicleTypeCount.put(type, vehicleTypeCount.get(type) + 1);
-
-        // Initialize history tracking for this vehicle
-        vehicleIntersectionHistory.put(vehicle.getId(), new ArrayList<>());
-    }
-
-    /**
-     * Records that a vehicle has arrived at an intersection queue.
-     * This is called by the vehicle generation component
-     * during a {@code VEHICLE_ARRIVAL} event.
-     *
-     * @param vehicle        The {@link Vehicle} that arrived.
-     * @param intersectionId The ID of the intersection it arrived at.
-     * @param currentTime    The simulation time of the arrival.
-     */
-    public void recordVehicleArrival(Vehicle vehicle, String intersectionId, double currentTime) {
-        // Store arrival time - this is the "start waiting" time
-        vehicleArrivalTimes.put(vehicle.getId(), currentTime);
-
-        // Track intersection history
-        List<String> history = vehicleIntersectionHistory.get(vehicle.getId());
-        if (history != null) {
-            history.add(intersectionId);
-        }
-
-        // Update per-intersection statistics
-        getOrCreateIntersectionStats(intersectionId).recordArrival();
-    }
-
-    /**
-     * Records that a vehicle has completed its route and exited the system.
-     * This is where final metrics for the vehicle are aggregated.
-     * This is called by the vehicle generation component
-     * when a vehicle reaches destination "S".
-     *
-     * @param vehicle     The {@link Vehicle} that is exiting.
-     * @param currentTime The simulation time of the exit.
-     */
-    public void recordVehicleExit(Vehicle vehicle, double currentTime) {
-        totalVehiclesCompleted++;
-
-        // Calculate and aggregate total system time
-        double systemTime = vehicle.getTotalTravelTime(currentTime);
-        totalSystemTime += systemTime;
-
-        // Aggregate waiting time
-        double waitTime = vehicle.getTotalWaitingTime();
-        totalWaitingTime += waitTime;
-
-        // Aggregate waiting time by vehicle type
-        VehicleType type = vehicle.getType();
-        vehicleTypeWaitTime.put(type, vehicleTypeWaitTime.get(type) + waitTime);
-
-        // Clean up tracking maps to save memory
-        vehicleArrivalTimes.remove(vehicle.getId());
-        vehicleIntersectionHistory.remove(vehicle.getId());
-    }
-
-    /**
-     * Gets the time a vehicle arrived at its *current* intersection.
-     * This is used by the intersection component to calculate
-     * wait time just before the vehicle crosses.
-     *
-     * @param vehicle The {@link Vehicle} to check.
-     * @return The arrival time, or 0.0 if not found.
-     */
-    public double getArrivalTime(Vehicle vehicle) {
-        return vehicleArrivalTimes.getOrDefault(vehicle.getId(), 0.0);
-    }
-
-    /**
-     * Prints a "snapshot" of the current simulation statistics.
-     * This is called periodically by the simulation components
-     * during a {@code STATISTICS_UPDATE} event.
-     *
-     * @param intersections A map of all intersections (to get queue data).
-     * @param currentTime   The current simulation time.
-     */
-    public void printCurrentStatistics(Map<String, Intersection> intersections, double currentTime) {
-        System.out.printf("--- Statistics at t=%.2f ---%n", currentTime);
-        System.out.printf("Vehicles: Generated=%d, Completed=%d, In-System=%d%n",
-                totalVehiclesGenerated,
-                totalVehiclesCompleted,
-                totalVehiclesGenerated - totalVehiclesCompleted);
-
-        if (totalVehiclesCompleted > 0) {
-            System.out.printf("Average System Time (so far): %.2fs%n", totalSystemTime / totalVehiclesCompleted);
-            System.out.printf("Average Waiting Time (so far): %.2fs%n", totalWaitingTime / totalVehiclesCompleted);
-        }
-
-        // Print per-intersection queue sizes
-        System.out.println("\nIntersection Queues:");
-        for (Map.Entry<String, Intersection> entry : intersections.entrySet()) {
-            String id = entry.getKey();
-            Intersection intersection = entry.getValue();
-            System.out.printf("  %s: Queue=%d, Received=%d, Sent=%d%n",
-                    id,
-                    intersection.getTotalQueueSize(),
-                    intersection.getTotalVehiclesReceived(),
-                    intersection.getTotalVehiclesSent());
-        }
-    }
-
-    /**
-     * Prints the final simulation summary statistics at the end of the run.
-     *
-     * @param intersections A map of all intersections.
-     * @param currentTime   The final simulation time.
-     */
-    public void printFinalStatistics(Map<String, Intersection> intersections, double currentTime) {
-        System.out.println("\n=== SIMULATION SUMMARY ===");
-        System.out.printf("Duration: %.2f seconds%n", currentTime);
-        System.out.printf("Total Vehicles Generated: %d%n", totalVehiclesGenerated);
-        System.out.printf("Total Vehicles Completed: %d%n", totalVehiclesCompleted);
-        System.out.printf("Vehicles Still in System: %d%n", totalVehiclesGenerated - totalVehiclesCompleted);
-
-        // Overall averages
-        if (totalVehiclesCompleted > 0) {
-            System.out.printf("%nAVERAGE METRICS (for completed vehicles):%n");
-            System.out.printf("  System Time: %.2f seconds%n", totalSystemTime / totalVehiclesCompleted);
-            System.out.printf("  Waiting Time: %.2f seconds%n", totalWaitingTime / totalVehiclesCompleted);
-            System.out.printf("  Throughput: %.2f vehicles/second%n", totalVehiclesCompleted / currentTime);
-        }
-
-        // Vehicle type breakdown
-        System.out.println("\nVEHICLE TYPE DISTRIBUTION:");
-        for (VehicleType type : VehicleType.values()) {
-            int count = vehicleTypeCount.get(type);
-            if (count > 0) {
-                double percentage = (count * 100.0) / totalVehiclesGenerated;
-                // Calculate avg wait *only* for this type
-                // This assumes all generated vehicles of this type *completed*
-                // A more accurate way would be to track completed vehicle types
-                double avgWait = vehicleTypeWaitTime.get(type) / count;
-                System.out.printf("  %s: %d (%.1f%%), Avg Wait: %.2fs%n",
-                        type, count, percentage, avgWait);
-            }
-        }
-
-        // Per-intersection statistics
-        System.out.println("\nINTERSECTION STATISTICS:");
-        for (Map.Entry<String, Intersection> entry : intersections.entrySet()) {
-            String id = entry.getKey();
-            Intersection intersection = entry.getValue();
-
-            System.out.printf("  %s:%n", id);
-            System.out.printf("    Vehicles Received: %d%n", intersection.getTotalVehiclesReceived());
-            System.out.printf("    Vehicles Sent: %d%n", intersection.getTotalVehiclesSent());
-            System.out.printf("    Final Queue Size: %d%n", intersection.getTotalQueueSize());
-
-            // Traffic light details
-            intersection.getTrafficLights().forEach(light -> {
-                System.out.printf("      Light %s: State=%s, Queue=%d, Processed=%d%n",
-                        light.getDirection(),
-                        light.getState(),
-                        light.getQueueSize(),
-                        light.getTotalVehiclesProcessed());
-            });
-        }
-
-        // System health indicators
-        System.out.println("\nSYSTEM HEALTH:");
-        int totalQueuedVehicles = intersections.values().stream()
-                .mapToInt(Intersection::getTotalQueueSize)
-                .sum();
-        System.out.printf("  Total Queued Vehicles (at end): %d%n", totalQueuedVehicles);
-
-        if (totalVehiclesGenerated > 0) {
-            double completionRate = (totalVehiclesCompleted * 100.0) / totalVehiclesGenerated;
-            System.out.printf("  Completion Rate: %.1f%%%n", completionRate);
-        }
-    }
-
-    /**
-     * Gets or creates the statistics object for a given intersection.
-     * Uses {@code computeIfAbsent} for efficient, thread-safe-like instantiation.
-     *
-     * @param intersectionId The ID of the intersection.
-     * @return The {@link IntersectionStats} object for that ID.
-     */
-    private IntersectionStats getOrCreateIntersectionStats(String intersectionId) {
-        // If 'intersectionId' is not in the map, create a new IntersectionStats()
-        // and put it in the map, then return it.
-        // Otherwise, just return the one that's already there.
-        return intersectionStats.computeIfAbsent(intersectionId, k -> new IntersectionStats());
-    }
-
-    /**
-     * Inner class to track per-intersection statistics.
-     * This is a simple data holder.
-     */
-    private static class IntersectionStats {
-        private int totalArrivals;
-        private int totalDepartures;
-
-        public IntersectionStats() {
-            this.totalArrivals = 0;
-            this.totalDepartures = 0;
-        }
-
-        public void recordArrival() {
-            totalArrivals++;
-        }
-
-        public int getTotalArrivals() {
-            return totalArrivals;
-        }
-
-        public int getTotalDepartures() {
-            return totalDepartures;
-        }
-    }
-
-    // --- Public Getters for Final Statistics ---
-
-    /**
-     * @return Total vehicles generated during the simulation.
-     */
-    public int getTotalVehiclesGenerated() {
-        return totalVehiclesGenerated;
-    }
-
-    /**
-     * @return Total vehicles that completed their route.
-     */
-    public int getTotalVehiclesCompleted() {
-        return totalVehiclesCompleted;
-    }
-
-    /**
-     * @return The sum of all travel times for *completed* vehicles.
-     */
-    public double getTotalSystemTime() {
-        return totalSystemTime;
-    }
-
-    /**
-     * @return The sum of all waiting times for *completed* vehicles.
-     */
-    public double getTotalWaitingTime() {
-        return totalWaitingTime;
-    }
-
-    /**
-     * @return The average travel time for *completed* vehicles.
-     */
-    public double getAverageSystemTime() {
-        return totalVehiclesCompleted > 0 ? totalSystemTime / totalVehiclesCompleted : 0.0;
-    }
-
-    /**
-     * @return The average waiting time for *completed* vehicles.
-     */
-    public double getAverageWaitingTime() {
-        return totalVehiclesCompleted > 0 ? totalWaitingTime / totalVehiclesCompleted : 0.0;
-    }
-}

main/src/test/java/SimulationTest.java

@@ -6,14 +6,11 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.Test;
 
 import sd.config.SimulationConfig;
-import sd.model.Event;
-import sd.model.EventType;
 import sd.model.Intersection;
 import sd.model.TrafficLight;
 import sd.model.TrafficLightState;
 import sd.model.Vehicle;
 import sd.model.VehicleType;
-import sd.util.StatisticsCollector;
 import sd.util.VehicleGenerator;
 
 /**
@@ -45,16 +42,6 @@ class SimulationTest {
         assertTrue(!vehicle.getRoute().isEmpty());
     }
 
-    @Test
-    void testEventOrdering() {
-        Event e1 = new Event(5.0, EventType.VEHICLE_ARRIVAL, null, "Cr1");
-        Event e2 = new Event(3.0, EventType.VEHICLE_ARRIVAL, null, "Cr2");
-        Event e3 = new Event(7.0, EventType.TRAFFIC_LIGHT_CHANGE, null, "Cr1");
-
-        assertTrue(e2.compareTo(e1) < 0); // e2 should come before e1
-        assertTrue(e1.compareTo(e3) < 0); // e1 should come before e3
-    }
-
     @Test
     void testIntersectionVehicleQueue() {
         Intersection intersection = new Intersection("TestCr");
@@ -92,20 +79,4 @@ class SimulationTest {
     // Removed testSimulationEngineInitialization as SimulationEngine has been
     // removed.
 
-    @Test
-    void testStatisticsCollector() throws IOException {
-        SimulationConfig config = new SimulationConfig("src/main/resources/simulation.properties");
-        StatisticsCollector collector = new StatisticsCollector(config);
-
-        Vehicle v1 = new Vehicle("V1", VehicleType.LIGHT, 0.0,
-                java.util.Arrays.asList("Cr1", "Cr2", "S"));
-
-        collector.recordVehicleGeneration(v1, 0.0);
-        assertEquals(1, collector.getTotalVehiclesGenerated());
-
-        collector.recordVehicleArrival(v1, "Cr1", 1.0);
-
-        collector.recordVehicleExit(v1, 10.0);
-        assertEquals(1, collector.getTotalVehiclesCompleted());
-    }
 }