Add workflow_dispatch trigger to Maven CI

Refactor GitHub Actions workflow for Maven build
Update Maven workflow for JDK setup and packaging
2025-12-08 20:43:32 +00:00 · 2025-11-23 22:12:35 +00:00 · 2025-11-23 22:10:40 +00:00 · 2025-11-23 22:00:49 +00:00 · 2025-11-23 21:53:33 +00:00 · 2025-11-22 22:53:54 +00:00
16 changed files with 53 additions and 3195 deletions
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -1,8 +1,9 @@
 name: Java CI with Maven
 on:
  workflow_dispatch:
  push:
-    branches: [ "main" ]
+    branches: [ "dev", "cleanup" ]
    tags:
      - 'v*.*.*'
  pull_request:
@@ -11,51 +12,88 @@ on:
 jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v4
    - name: Set up JDK 17
      uses: actions/setup-java@v4
      with:
        java-version: '17'
        distribution: 'temurin'
        cache: maven
    - name: Build with Maven
      run: mvn -B package
      working-directory: main
    - name: Upload built JAR
      uses: actions/upload-artifact@v4
      with:
        name: package
        path: main/target/*.jar
    - name: Generate dependency graph
      run: mvn -B -f main/pom.xml com.github.ferstl:depgraph-maven-plugin:4.0.1:graph
    - name: Upload dependency graph artifact
      uses: actions/upload-artifact@v4
      with:
        name: dependency-graph
        path: main/target/**
  build-windows:
    runs-on: windows-latest
    steps:
    - uses: actions/checkout@v4
    - name: Set up JDK 17
      uses: actions/setup-java@v4
      with:
        java-version: '17'
        distribution: 'temurin'
        cache: maven
    - name: Build with Maven (Skip Tests)
      run: mvn -B package -DskipTests
      working-directory: main
    - name: Create JPackage App Image
      shell: pwsh
      run: |
        New-Item -ItemType Directory -Force -Path "dist"
        jpackage --name "DTSS" `
          --input main/target `
          --main-jar main-1.0-SNAPSHOT.jar `
          --dest dist `
          --type app-image `
          --win-console
    - name: Inject java.exe
      shell: pwsh
      run: |
        $javaPath = (Get-Command java).Source
        Copy-Item -Path $javaPath -Destination "dist/DTSS/runtime/bin/"
    - name: Zip Windows Release
      shell: pwsh
      run: |
        Compress-Archive -Path "dist/DTSS" -DestinationPath "dist/DTSS-Windows.zip"
    - name: Upload Windows Artifact
      uses: actions/upload-artifact@v4
      with:
        name: windows-package
        path: dist/DTSS-Windows.zip
  publish-release:
    runs-on: ubuntu-latest
-    needs: [build]
+    needs: [build, build-windows]
    if: startsWith(github.ref, 'refs/tags/')
    permissions:
      contents: write
    steps:
-    - name: Download built JAR
+    - name: Download Linux JAR
      uses: actions/download-artifact@v4
      with:
        name: package
        path: main/target/
-
+    - name: Download Windows Zip
      uses: actions/download-artifact@v4
      with:
        name: windows-package
        path: windows-dist/
    - name: Create GitHub Release
      uses: softprops/action-gh-release@v2
      with:
-        files: main/target/*.jar
+        files: |
          main/target/*.jar
          windows-dist/*.zip
--- a/.gitignore
+++ b/.gitignore
@@ -47,4 +47,3 @@ build/
 # Other
 *.swp
 *.pdf
--- a/Enunciado.pdf
+++ b/Enunciado.pdf
--- a/main/src/main/java/sd/ExitNodeProcess.java
+++ b/main/src/main/java/sd/ExitNodeProcess.java
@@ -1,382 +0,0 @@
 package sd;
 import java.io.IOException;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import sd.config.SimulationConfig;
 import sd.coordinator.SocketClient;
 import sd.model.Message;
 import sd.model.MessageType;
 import sd.model.Vehicle;
 import sd.model.VehicleType;
 import sd.protocol.MessageProtocol;
 import sd.protocol.SocketConnection;
 import sd.serialization.SerializationException;
 /**
 * Processo responsável pelo nó de saída do sistema de simulação de tráfego distribuído.
 * 
 * Este processo representa o ponto final ("S") onde os veículos completam as suas rotas.
 * As suas principais responsabilidades são:
 * - Receber veículos que terminam a sua rota vindos das interseções
 * - Calcular e agregar estatísticas finais dos veículos
 * - Enviar estatísticas periódicas para o dashboard
 * - Gerar relatórios finais ao terminar a simulação
 */
 public class ExitNodeProcess {
    private final SimulationConfig config;
    private ServerSocket serverSocket;
    private final ExecutorService connectionHandlerPool;
    /** Flag para controlar a execução do processo (volatile para visibilidade entre threads) */
    private volatile boolean running;
    /** Counter de veículos que completaram a rota */
    private int totalVehiclesReceived;
    /** Soma dos tempos no sistema de todos os veículos */
    private double totalSystemTime;
    /** Soma dos tempos de espera de todos os veículos */
    private double totalWaitingTime;
    /** Soma dos tempos de travessia de todos os veículos */
    private double totalCrossingTime;
    /** Contagem de veículos por tipo */
    private final Map<VehicleType, Integer> vehicleTypeCount;
    /** Tempo total de espera acumulado por tipo de veículo */
    private final Map<VehicleType, Double> vehicleTypeWaitTime;
    /** Socket para comunicação com o dashboard */
    private SocketClient dashboardClient;
    /**
     * Método para iniciar o processo
     * 
     * @param args Argumentos da linha de comandos. Se fornecido, args[0] deve ser
     *             o caminho para um ficheiro de configuração personalizado.
     */
    public static void main(String[] args) {
        System.out.println("=".repeat(60));
        System.out.println("EXIT NODE PROCESS");
        System.out.println("=".repeat(60));
        try {
            String configFile = args.length > 0 ? args[0] : "src/main/resources/simulation.properties";
            System.out.println("Loading configuration from: " + configFile);
            SimulationConfig config = new SimulationConfig(configFile);
            ExitNodeProcess exitNode = new ExitNodeProcess(config);
            System.out.println("\n" + "=".repeat(60));
            exitNode.initialize();
            System.out.println("\n" + "=".repeat(60));
            exitNode.start();
        } catch (IOException e) {
            System.err.println("Failed to start exit node: " + e.getMessage());
            System.exit(1);
        } catch (Exception e) {
            System.err.println("Exit node error: " + e.getMessage());
            System.exit(1);
        }
    }
    /**
     * Constrói um novo processo de nó de saída.
     * 
     * Inicializa todas as estruturas de dados necessárias para recolher estatísticas
     * e configura o pool de threads para processar as ligações concorrentes.
     * 
     * @param config Configuração da simulação contendo portas e endereços dos serviços
     */
    public ExitNodeProcess(SimulationConfig config) {
        this.config = config;
        this.connectionHandlerPool = Executors.newCachedThreadPool();
        this.running = false;
        this.totalVehiclesReceived = 0;
        this.totalSystemTime = 0.0;
        this.totalWaitingTime = 0.0;
        this.totalCrossingTime = 0.0;
        this.vehicleTypeCount = new HashMap<>();
        this.vehicleTypeWaitTime = new HashMap<>();
        // Inicializa os counters para cada tipo de veículo
        for (VehicleType type : VehicleType.values()) {
            vehicleTypeCount.put(type, 0);
            vehicleTypeWaitTime.put(type, 0.0);
        }
        System.out.println("Exit node initialized");
        System.out.println("  - Exit port: " + config.getExitPort());
        System.out.println("  - Dashboard: " + config.getDashboardHost() + ":" + config.getDashboardPort());
    }
    /**
     * Inicializa o processo de ligação ao dashboard.
     * 
     * Tenta conectar-se ao dashboard. Se a ligação falhar, o processo
     * continua a funcionar normalmente, mas sem enviar estatísticas.
     * 
     */
    public void initialize() {
        System.out.println("Connecting to dashboard...");
        try {
            String host = config.getDashboardHost();
            int port = config.getDashboardPort();
            dashboardClient = new SocketClient("Dashboard", host, port);
            dashboardClient.connect();
            System.out.println("Successfully connected to dashboard");
        } catch (IOException e) {
            System.err.println("WARNING: Failed to connect to dashboard: " + e.getMessage());
            System.err.println("Exit node will continue without dashboard connection");
        }
    }
    /**
     * Inicia o socket e começa a aceitar ligações.
     * 
     * Este é o loop principal do processo que:
     * 1. Cria um socket na porta definida
     * 2. Aguarda pelas ligações das interseções
     * 3. Delega cada ligação a uma thread da pool para processamento assíncrono
     * 
     * @throws IOException Se o socket não puder ser criado ou houver erro na aceitação
     */
    public void start() throws IOException {
        int port = config.getExitPort();
        serverSocket = new ServerSocket(port);
        running = true;
        System.out.println("Exit node started on port " + port);
        System.out.println("Waiting for vehicles...\n");
        while (running) {
            try {
                Socket clientSocket = serverSocket.accept();
                connectionHandlerPool.submit(() -> handleIncomingConnection(clientSocket));
            } catch (IOException e) {
                if (running) {
                    System.err.println("Error accepting connection: " + e.getMessage());
                }
            }
        }
    }
    /**
     * Processa uma ligação recebida de uma interseção.
     * 
     * Mantém a ligação aberta e processa continuamente mensagens do tipo
     * VEHICLE_TRANSFER. Cada mensagem representa um veículo que chegou ao nó de saída.
     * 
     * @param clientSocket Socket da ligação estabelecida com a interseção
     */
    private void handleIncomingConnection(Socket clientSocket) {
        try (SocketConnection connection = new SocketConnection(clientSocket)) {
            System.out.println("New connection accepted from " +
                             clientSocket.getInetAddress().getHostAddress());
            while (running && connection.isConnected()) {
                try {
                    MessageProtocol message = connection.receiveMessage();
                    if (message.getType() == MessageType.VEHICLE_TRANSFER) {
                        Vehicle vehicle = (Vehicle) message.getPayload();
                        processExitingVehicle(vehicle);
                    }
                } catch (ClassNotFoundException e) {
                    System.err.println("Unknown message type received: " + e.getMessage());
                }
            }
        } catch (IOException e) {
            if (running) {
                System.err.println("Connection error: " + e.getMessage());
            }
        }
    }
    /**
     * Processa um veículo que chegou ao nó de saída.
     * 
     * Método sincronizado para garantir thread-safety ao atualizar as estatísticas.
     * Calcula as métricas finais do veículo e atualiza:
     * - Counters globais;
     * - Estatísticas por tipo de veículo;
     * - Faz update ao dashboard a cada 10 veículos.
     * 
     * @param vehicle Veículo que completou a sua rota
     */
    private synchronized void processExitingVehicle(Vehicle vehicle) {
        totalVehiclesReceived++;
        double systemTime = vehicle.getTotalTravelTime(getCurrentTime());
        double waitTime = vehicle.getTotalWaitingTime();
        double crossingTime = vehicle.getTotalCrossingTime();
        totalSystemTime += systemTime;
        totalWaitingTime += waitTime;
        totalCrossingTime += crossingTime;
        VehicleType type = vehicle.getType();
        vehicleTypeCount.put(type, vehicleTypeCount.get(type) + 1);
        vehicleTypeWaitTime.put(type, vehicleTypeWaitTime.get(type) + waitTime);
        System.out.printf("[Exit] Vehicle %s completed (type=%s, system_time=%.2fs, wait=%.2fs)%n",
            vehicle.getId(), vehicle.getType(), systemTime, waitTime);
        if (totalVehiclesReceived % 10 == 0) {
            sendStatsToDashboard();
        }
    }
    /**
     * Obtém o tempo atual da simulação em segundos.
     * 
     * @return Tempo atual em segundos desde "epoch"
     * 
     * "Epoch" é um ponto de referência temporal Unix (1 de janeiro de 1970).
     * Este método retorna os segundos decorridos desde esse momento.
     */
    private double getCurrentTime() {
        return System.currentTimeMillis() / 1000.0;
    }
    /**
     * Envia as estatísticas para o dashboard.
     * 
     * Prepara e envia uma mensagem STATS_UPDATE com:
     * - O total de veículos processados;
     * - A média dos tempos (sistema, espera, travessia);
     * - As contagens e médias por cada tipo de veículo.
     * 
     */
    private void sendStatsToDashboard() {
        if (dashboardClient == null || !dashboardClient.isConnected()) {
            return;
        }
        try {
            Map<String, Object> stats = new HashMap<>();
            stats.put("totalVehicles", totalVehiclesReceived);
            stats.put("avgSystemTime", totalVehiclesReceived > 0 ? totalSystemTime / totalVehiclesReceived : 0.0);
            stats.put("avgWaitingTime", totalVehiclesReceived > 0 ? totalWaitingTime / totalVehiclesReceived : 0.0);
            stats.put("avgCrossingTime", totalVehiclesReceived > 0 ? totalCrossingTime / totalVehiclesReceived : 0.0);
            Map<String, Integer> typeCounts = new HashMap<>();
            Map<String, Double> typeAvgWait = new HashMap<>();
            for (VehicleType type : VehicleType.values()) {
                int count = vehicleTypeCount.get(type);
                typeCounts.put(type.name(), count);
                if (count > 0) {
                    typeAvgWait.put(type.name(), vehicleTypeWaitTime.get(type) / count);
                }
            }
            stats.put("vehicleTypeCounts", typeCounts);
            stats.put("vehicleTypeAvgWait", typeAvgWait);
            Message message = new Message(MessageType.STATS_UPDATE, "ExitNode", "Dashboard", stats);
            dashboardClient.send(message);
            System.out.printf("[Exit] Sent stats to dashboard (total=%d, avg_wait=%.2fs)%n",
                totalVehiclesReceived, totalWaitingTime / totalVehiclesReceived);
        } catch (SerializationException | IOException e) {
            System.err.println("Failed to send stats to dashboard: " + e.getMessage());
        }
    }
    /**
     * Termina o processo
     * 
     * Executa a seguinte sequência:
     *  Imprime as estatísticas finais no terminal;
     *  Envia a última atualização de estatísticas ao dashboard;
     *  Fecha o socket;
     *  Aguarda pela finalização das threads;
     *  Fecha a ligação com o dashboard;
     */
    public void shutdown() {
        System.out.println("\n[Exit] Shutting down...");
        running = false;
        printFinalStatistics();
        sendStatsToDashboard();
        try {
            if (serverSocket != null && !serverSocket.isClosed()) {
                serverSocket.close();
            }
        } catch (IOException e) {
            System.err.println("Error closing server socket: " + e.getMessage());
        }
        connectionHandlerPool.shutdown();
        try {
            if (!connectionHandlerPool.awaitTermination(5, TimeUnit.SECONDS)) {
                connectionHandlerPool.shutdownNow();
            }
        } catch (InterruptedException e) {
            connectionHandlerPool.shutdownNow();
        }
        if (dashboardClient != null) {
            dashboardClient.close();
        }
        System.out.println("[Exit] Shutdown complete.");
        System.out.println("=".repeat(60));
    }
    /**
     * Imprime as estatísticas finais detalhadas no terminal
     * 
     * Gera um relatório com:
     * Total de veículos que completaram a rota;
     * Médias de tempo no sistema, espera e travessia;
     * Distribuição e médias pelo tipo de veículo (BIKE, LIGHT, HEAVY);
     * 
     * Este método é chamado durante o shutdown para fornecer um resumo
     * da simulação antes de terminar o processo.
     */
    private void printFinalStatistics() {
        System.out.println("\n=== EXIT NODE STATISTICS ===");
        System.out.printf("Total Vehicles Completed: %d%n", totalVehiclesReceived);
        if (totalVehiclesReceived > 0) {
            System.out.printf("%nAVERAGE METRICS:%n");
            System.out.printf("  System Time: %.2f seconds%n", totalSystemTime / totalVehiclesReceived);
            System.out.printf("  Waiting Time: %.2f seconds%n", totalWaitingTime / totalVehiclesReceived);
            System.out.printf("  Crossing Time: %.2f seconds%n", totalCrossingTime / totalVehiclesReceived);
        }
        System.out.println("\nVEHICLE TYPE DISTRIBUTION:");
        for (VehicleType type : VehicleType.values()) {
            int count = vehicleTypeCount.get(type);
            if (count > 0) {
                double percentage = (count * 100.0) / totalVehiclesReceived;
                double avgWait = vehicleTypeWaitTime.get(type) / count;
                System.out.printf("  %s: %d (%.1f%%), Avg Wait: %.2fs%n",
                    type, count, percentage, avgWait);
            }
        }
    }
 }
--- a/main/src/main/java/sd/IntersectionProcess.java
+++ b/main/src/main/java/sd/IntersectionProcess.java
@@ -1,557 +0,0 @@
 package sd;
 import java.io.IOException;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 import sd.config.SimulationConfig;
 import sd.model.Intersection;
 import sd.model.MessageType;
 import sd.model.TrafficLight;
 import sd.model.TrafficLightState;
 import sd.model.Vehicle;
 import sd.protocol.MessageProtocol;
 import sd.protocol.SocketConnection;
 /**
 * Main class for an Intersection Process in the distributed traffic simulation.
 * * Each IntersectionProcess runs as an independent Java application (JVM instance)
 * representing one of the five intersections (Cr1-Cr5) in the network.
 */
 public class IntersectionProcess {
    private final String intersectionId;
    private final SimulationConfig config;
    private final Intersection intersection;
    private ServerSocket serverSocket;
    private final Map<String, SocketConnection> outgoingConnections;
    private final ExecutorService connectionHandlerPool;
    private final ExecutorService trafficLightPool;
    private volatile boolean running;   //Quando uma thread escreve um valor volatile, todas as outras
                                        //threads veem a mudança imediatamente.
    // Traffic Light Coordination
    /**
     * Lock to ensure mutual exclusion between traffic lights.
     * Only one traffic light can be green at any given time within this intersection.
     */
    private final Lock trafficCoordinationLock;
    /**
     * Tracks which direction currently has the green light.
     * null means no direction is currently green (all are red).
     */
    private volatile String currentGreenDirection;
    /**
     * Constructs a new IntersectionProcess.
     *
     * @param intersectionId The ID of this intersection (e.g., "Cr1").
     * @param configFilePath Path to the simulation.properties file.
     * @throws IOException If configuration cannot be loaded.
     */
    public IntersectionProcess(String intersectionId, String configFilePath) throws IOException {
        this.intersectionId = intersectionId;
        this.config = new SimulationConfig(configFilePath);
        this.intersection = new Intersection(intersectionId);
        this.outgoingConnections = new HashMap<>();
        this.connectionHandlerPool = Executors.newCachedThreadPool();
        this.trafficLightPool = Executors.newFixedThreadPool(4); // Max 4 directions
        this.running = false;
        this.trafficCoordinationLock = new ReentrantLock();
        this.currentGreenDirection = null;
        System.out.println("=".repeat(60));
        System.out.println("INTERSECTION PROCESS: " + intersectionId);
        System.out.println("=".repeat(60));
    }
    public void initialize() {
        System.out.println("\n[" + intersectionId + "] Initializing intersection...");
        createTrafficLights();
        configureRouting();
        System.out.println("[" + intersectionId + "] Initialization complete.");
    }
    /**
     * Creates traffic lights for this intersection based on its physical connections.
     * Each intersection has different number and directions of traffic lights
     * according to the network topology.
     */
    private void createTrafficLights() {
        System.out.println("\n[" + intersectionId + "] Creating traffic lights...");
        String[] directions = new String[0];
        switch (intersectionId) {
            case "Cr1":
                directions = new String[]{"East", "South"};
                break;
            case "Cr2":
                directions = new String[]{"West", "East", "South"};
                break;
            case "Cr3":
                directions = new String[]{"West", "South"};
                break;
            case "Cr4":
                directions = new String[]{"East"};
                break;
            case "Cr5":
                directions = new String[]{"East"};
                break;
        }
        for (String direction : directions) {
            double greenTime = config.getTrafficLightGreenTime(intersectionId, direction);
            double redTime = config.getTrafficLightRedTime(intersectionId, direction);
            TrafficLight light = new TrafficLight(
                intersectionId + "-" + direction,
                direction,
                greenTime,
                redTime
            );
            intersection.addTrafficLight(light);
            System.out.println("  Created traffic light: " + direction + 
                             " (Green: " + greenTime + "s, Red: " + redTime + "s)");
        }
    }
    private void configureRouting() {
        System.out.println("\n[" + intersectionId + "] Configuring routing...");
        switch (intersectionId) {
            case "Cr1":
                intersection.configureRoute("Cr2", "East");
                intersection.configureRoute("Cr4", "South"); 
                break;
            case "Cr2":
                intersection.configureRoute("Cr1", "West");
                intersection.configureRoute("Cr3", "East");
                intersection.configureRoute("Cr5", "South");
                break;
            case "Cr3":
                intersection.configureRoute("Cr2", "West");
                intersection.configureRoute("S", "South");
                break;
            case "Cr4":
                intersection.configureRoute("Cr5", "East");
                break;
            case "Cr5":
                intersection.configureRoute("S", "East");
                break;
            default:
                System.err.println("  Error: unknown intersection ID: " + intersectionId);
        }
        System.out.println("  Routing configured.");
    }
    /**
     * Starts all traffic light threads.
     */
    private void startTrafficLights() {
        System.out.println("\n[" + intersectionId + "] Starting traffic light threads...");
        for (TrafficLight light : intersection.getTrafficLights()) {
            trafficLightPool.submit(() -> runTrafficLightCycle(light));
            System.out.println("  Started thread for: " + light.getDirection());
        }
    }
    /**
     * The main loop for a traffic light thread.
     * Continuously cycles between green and red states.
     * 
     * only one traffic light can be green at any given time in this intersection.
     *
     * @param light The traffic light to control.
     */
    private void runTrafficLightCycle(TrafficLight light) {
        System.out.println("[" + light.getId() + "] Traffic light thread started.");
        while (running) {
            try {
                // Acquire coordination lock to become green
                trafficCoordinationLock.lock();
                try {
                    // Wait until no other direction is green
                    while (currentGreenDirection != null && running) {
                        trafficCoordinationLock.unlock();
                        Thread.sleep(100); // Brief wait before retrying
                        trafficCoordinationLock.lock();
                    }
                    if (!running) {
                        break; // Exit if shutting down
                    }
                    // Mark this direction as the current green light
                    currentGreenDirection = light.getDirection();
                    light.changeState(TrafficLightState.GREEN);
                    System.out.println("[" + light.getId() + "] State: GREEN");
                } finally {
                    trafficCoordinationLock.unlock();
                }
                // Process vehicles while green
                processGreenLight(light);
                // Wait for green duration
                Thread.sleep((long) (light.getGreenTime() * 1000));
                // Release coordination lock (turn red)
                trafficCoordinationLock.lock();
                try {
                    light.changeState(TrafficLightState.RED);
                    currentGreenDirection = null; // Release exclusive access
                    System.out.println("[" + light.getId() + "] State: RED (RELEASED ACCESS)");
                } finally {
                    trafficCoordinationLock.unlock();
                }
                // Wait for red duration
                Thread.sleep((long) (light.getRedTime() * 1000));
            } catch (InterruptedException e) {
                System.out.println("[" + light.getId() + "] Traffic light thread interrupted.");
                break;
            }
        }
        System.out.println("[" + light.getId() + "] Traffic light thread stopped.");
    }
    /**
     * Processes vehicles when a traffic light is GREEN.
     * Dequeues vehicles and sends them to their next destination.
     *
     * @param light The traffic light that is currently green.
     */
    private void processGreenLight(TrafficLight light) {
        while (light.getState() == TrafficLightState.GREEN && light.getQueueSize() > 0) {
            Vehicle vehicle = light.removeVehicle();
            if (vehicle != null) {
                // Get crossing time based on vehicle type
                double crossingTime = getCrossingTimeForVehicle(vehicle);
                // Simulate crossing time
                try {
                    Thread.sleep((long) (crossingTime * 1000));
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                    break;
                }
                // Update vehicle statistics
                vehicle.addCrossingTime(crossingTime);
                // Update intersection statistics
                intersection.incrementVehiclesSent();
                // Send vehicle to next destination
                sendVehicleToNextDestination(vehicle);
            }
        }
    }
    /**
     * Gets the crossing time for a vehicle based on its type.
     *
     * @param vehicle The vehicle.
     * @return The crossing time in seconds.
     */
    private double getCrossingTimeForVehicle(Vehicle vehicle) {
        switch (vehicle.getType()) {
            case BIKE:
                return config.getBikeVehicleCrossingTime();
            case LIGHT:
                return config.getLightVehicleCrossingTime();
            case HEAVY:
                return config.getHeavyVehicleCrossingTime();
            default:
                return config.getLightVehicleCrossingTime();
        }
    }
    /**
     * Sends a vehicle to its next destination via socket connection.
     *
     * @param vehicle The vehicle that has crossed this intersection.
     */
    public void sendVehicleToNextDestination(Vehicle vehicle) {
        String nextDestination = vehicle.getCurrentDestination();
        try {
            // Get or create connection to next destination
            SocketConnection connection = getOrCreateConnection(nextDestination);
            // Create and send message
            MessageProtocol message = new VehicleTransferMessage(
                intersectionId,
                nextDestination,
                vehicle
            );
            connection.sendMessage(message);
            System.out.println("[" + intersectionId + "] Sent vehicle " + vehicle.getId() + 
                             " to " + nextDestination);
            // Note: vehicle route is advanced when it arrives at the next intersection
        } catch (IOException | InterruptedException e) {
            System.err.println("[" + intersectionId + "] Failed to send vehicle " + 
                             vehicle.getId() + " to " + nextDestination + ": " + e.getMessage());
        }
    }
    /**
     * Gets an existing connection to a destination or creates a new one.
     *
     * @param destinationId The ID of the destination node.
     * @return The SocketConnection to that destination.
     * @throws IOException If connection cannot be established.
     * @throws InterruptedException If connection attempt is interrupted.
     */
    private synchronized SocketConnection getOrCreateConnection(String destinationId) 
            throws IOException, InterruptedException {
        if (!outgoingConnections.containsKey(destinationId)) {
            String host = getHostForDestination(destinationId);
            int port = getPortForDestination(destinationId);
            System.out.println("[" + intersectionId + "] Creating connection to " + 
                             destinationId + " at " + host + ":" + port);
            SocketConnection connection = new SocketConnection(host, port);
            outgoingConnections.put(destinationId, connection);
        }
        return outgoingConnections.get(destinationId);
    }
    /**
     * Gets the host address for a destination node from configuration.
     *
     * @param destinationId The destination node ID.
     * @return The host address.
     */
    private String getHostForDestination(String destinationId) {
        if (destinationId.equals("S")) {
            return config.getExitHost();
        } else {
            return config.getIntersectionHost(destinationId);
        }
    }
    /**
     * Gets the port number for a destination node from configuration.
     *
     * @param destinationId The destination node ID.
     * @return The port number.
     */
    private int getPortForDestination(String destinationId) {
        if (destinationId.equals("S")) {
            return config.getExitPort();
        } else {
            return config.getIntersectionPort(destinationId);
        }
    }
    /**
     * Starts the server socket and begins accepting incoming connections.
     * This is the main listening loop of the process.
     *
     * @throws IOException If the server socket cannot be created.
     */
    public void start() throws IOException {
        int port = config.getIntersectionPort(intersectionId);
        serverSocket = new ServerSocket(port);
        running = true;
        System.out.println("\n[" + intersectionId + "] Server started on port " + port);
        // Start traffic light threads when running is true
        startTrafficLights();
        System.out.println("[" + intersectionId + "] Waiting for incoming connections...\n");
        // Main accept loop
        while (running) {
            try {
                Socket clientSocket = serverSocket.accept();
                // Handle each connection in a separate thread
                connectionHandlerPool.submit(() -> handleIncomingConnection(clientSocket));
            } catch (IOException e) {
                if (running) {
                    System.err.println("[" + intersectionId + "] Error accepting connection: " + 
                                     e.getMessage());
                }
            }
        }
    }
    /**
     * Handles an incoming connection from another process.
     * Continuously listens for vehicle transfer messages.
     *
     * @param clientSocket The accepted socket connection.
     */
    private void handleIncomingConnection(Socket clientSocket) {
        try (SocketConnection connection = new SocketConnection(clientSocket)) {
            System.out.println("[" + intersectionId + "] New connection accepted from " +
                             clientSocket.getInetAddress().getHostAddress());
            // Continuously receive messages while connection is active
            while (running && connection.isConnected()) {
                try {
                    MessageProtocol message = connection.receiveMessage();
                    if (message.getType() == MessageType.VEHICLE_TRANSFER) {
                        Vehicle vehicle = (Vehicle) message.getPayload();
                        System.out.println("[" + intersectionId + "] Received vehicle: " + 
                                         vehicle.getId() + " from " + message.getSourceNode());
                        // Add vehicle to appropriate queue
                        intersection.receiveVehicle(vehicle);
                    }
                } catch (ClassNotFoundException e) {
                    System.err.println("[" + intersectionId + "] Unknown message type received: " + 
                                     e.getMessage());
                }
            }
        } catch (IOException e) {
            if (running) {
                System.err.println("[" + intersectionId + "] Connection error: " + e.getMessage());
            }
        }
    }
    /**
     * Stops the intersection process gracefully.
     * Shuts down all threads and closes all connections.
     */
    public void shutdown() {
        System.out.println("\n[" + intersectionId + "] Shutting down...");
        running = false;
        // Close server socket
        try {
            if (serverSocket != null && !serverSocket.isClosed()) {
                serverSocket.close();
            }
        } catch (IOException e) {
            System.err.println("[" + intersectionId + "] Error closing server socket: " + 
                             e.getMessage());
        }
        // Shutdown thread pools
        trafficLightPool.shutdown();
        connectionHandlerPool.shutdown();
        try {
            if (!trafficLightPool.awaitTermination(5, TimeUnit.SECONDS)) {
                trafficLightPool.shutdownNow();
            }
            if (!connectionHandlerPool.awaitTermination(5, TimeUnit.SECONDS)) {
                connectionHandlerPool.shutdownNow();
            }
        } catch (InterruptedException e) {
            trafficLightPool.shutdownNow();
            connectionHandlerPool.shutdownNow();
        }
        // Close all outgoing connections
        for (Map.Entry<String, SocketConnection> entry : outgoingConnections.entrySet()) {
            try {
                entry.getValue().close();
            } catch (IOException e) {
                System.err.println("[" + intersectionId + "] Error closing connection to " + 
                                 entry.getKey() + ": " + e.getMessage());
            }
        }
        System.out.println("[" + intersectionId + "] Shutdown complete.");
        System.out.println("=".repeat(60));
    }
    /**
     * Gets the Intersection object managed by this process.
     * Useful for testing and monitoring.
     * 
     * @return The Intersection object.
     */
    public Intersection getIntersection() {
        return intersection;
    }
    // --- Inner class for Vehicle Transfer Messages ---
    /**
     * Implementation of MessageProtocol for vehicle transfers between processes.
     */
    private static class VehicleTransferMessage implements MessageProtocol {
        private static final long serialVersionUID = 1L;
        private final String sourceNode;
        private final String destinationNode;
        private final Vehicle payload;
        public VehicleTransferMessage(String sourceNode, String destinationNode, Vehicle vehicle) {
            this.sourceNode = sourceNode;
            this.destinationNode = destinationNode;
            this.payload = vehicle;
        }
        @Override
        public MessageType getType() {
            return MessageType.VEHICLE_TRANSFER;
        }
        @Override
        public Object getPayload() {
            return payload;
        }
        @Override
        public String getSourceNode() {
            return sourceNode;
        }
        @Override
        public String getDestinationNode() {
            return destinationNode;
        }
    }
 }
--- a/main/src/main/java/sd/coordinator/CoordinatorProcess.java
+++ b/main/src/main/java/sd/coordinator/CoordinatorProcess.java
@@ -1,204 +0,0 @@
 package sd.coordinator;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 import sd.config.SimulationConfig;
 import sd.model.Message;
 import sd.model.MessageType;
 import sd.model.Vehicle;
 import sd.serialization.SerializationException;
 import sd.util.VehicleGenerator;
 /**
 * Coordinator process responsible for:
 * 1. Vehicle generation (using VehicleGenerator)
 * 2. Distributing vehicles to intersection processes via sockets
 * 3. Managing simulation timing and shutdown
 * 
 * This is the main entry point for the distributed simulation architecture.
 */
 public class CoordinatorProcess {
    private final SimulationConfig config;
    private final VehicleGenerator vehicleGenerator;
    private final Map<String, SocketClient> intersectionClients;
    private double currentTime;
    private int vehicleCounter;
    private boolean running;
    private double nextGenerationTime;
    public static void main(String[] args) {
        System.out.println("=".repeat(60));
        System.out.println("COORDINATOR PROCESS - DISTRIBUTED TRAFFIC SIMULATION");
        System.out.println("=".repeat(60));
        try {
            // 1. Load configuration
            String configFile = args.length > 0 ? args[0] : "src/main/resources/simulation.properties";
            System.out.println("Loading configuration from: " + configFile);
            SimulationConfig config = new SimulationConfig(configFile);
            CoordinatorProcess coordinator = new CoordinatorProcess(config);
            // 2. Connect to intersection processes
            System.out.println("\n" + "=".repeat(60));
            coordinator.initialize();
            // 3. Run the sim
            System.out.println("\n" + "=".repeat(60));
            coordinator.run();
        } catch (IOException e) {
            System.err.println("Failed to load configuration: " + e.getMessage());
            System.exit(1);
        } catch (Exception e) {
            System.err.println("Coordinator error: " + e.getMessage());
            System.exit(1);
        }
    }
    public CoordinatorProcess(SimulationConfig config) {
        this.config = config;
        this.vehicleGenerator = new VehicleGenerator(config);
        this.intersectionClients = new HashMap<>();
        this.currentTime = 0.0;
        this.vehicleCounter = 0;
        this.running = false;
        this.nextGenerationTime = 0.0;
        System.out.println("Coordinator initialized with configuration:");
        System.out.println("  - Simulation duration: " + config.getSimulationDuration() + "s");
        System.out.println("  - Arrival model: " + config.getArrivalModel());
        System.out.println("  - Arrival rate: " + config.getArrivalRate() + " vehicles/s");
    }
    public void initialize() {
        System.out.println("Connecting to intersection processes...");
        String[] intersectionIds = {"Cr1", "Cr2", "Cr3", "Cr4", "Cr5"};
        for (String intersectionId : intersectionIds) {
            try {
                String host = config.getIntersectionHost(intersectionId);
                int port = config.getIntersectionPort(intersectionId);
                SocketClient client = new SocketClient(intersectionId, host, port);
                client.connect();
                intersectionClients.put(intersectionId, client);
            } catch (IOException e) {
                System.err.println("Failed to connect to " + intersectionId + ": " + e.getMessage());
            }
        }
        System.out.println("Successfully connected to " + intersectionClients.size() + " intersection(s)");
        if (intersectionClients.isEmpty()) {
            System.err.println("WARNING: No intersections connected. Simulation cannot proceed.");
        }
    }
    public void run() {
        double duration = config.getSimulationDuration();
        running = true;
        System.out.println("Starting vehicle generation simulation...");
        System.out.println("Duration: " + duration + " seconds");
        System.out.println();
        nextGenerationTime = vehicleGenerator.getNextArrivalTime(currentTime);
        final double TIME_STEP = 0.1;
        while (running && currentTime < duration) {
            if (currentTime >= nextGenerationTime) {
                generateAndSendVehicle();
                nextGenerationTime = vehicleGenerator.getNextArrivalTime(currentTime);
            }            
            currentTime += TIME_STEP;
        }
        System.out.println();
        System.out.println("Simulation complete at t=" + String.format("%.2f", currentTime) + "s");
        System.out.println("Total vehicles generated: " + vehicleCounter);
        shutdown();
    }
    private void generateAndSendVehicle() {
        Vehicle vehicle = vehicleGenerator.generateVehicle("V" + (++vehicleCounter), currentTime);
        System.out.printf("[t=%.2f] Vehicle %s generated (type=%s, route=%s)%n",
            currentTime, vehicle.getId(), vehicle.getType(), vehicle.getRoute());
        if (vehicle.getRoute().isEmpty()) {
            System.err.println("ERROR: Vehicle " + vehicle.getId() + " has empty route!");
            return;
        }
        String entryIntersection = vehicle.getRoute().get(0);
        sendVehicleToIntersection(vehicle, entryIntersection);
    }
    private void sendVehicleToIntersection(Vehicle vehicle, String intersectionId) {
        SocketClient client = intersectionClients.get(intersectionId);
        if (client == null || !client.isConnected()) {
            System.err.println("ERROR: No connection to " + intersectionId + " for vehicle " + vehicle.getId());
            return;
        }
        try {
            Message message = new Message(
                MessageType.VEHICLE_SPAWN,
                "COORDINATOR",
                intersectionId,
                vehicle
            );
            client.send(message);
            System.out.printf("->Sent to %s%n", intersectionId);
        } catch (SerializationException | IOException e) {
            System.err.println("ERROR: Failed to send vehicle " + vehicle.getId() + " to " + intersectionId);
            System.err.println("Reason: " + e.getMessage());
        }
    }
    public void shutdown() {
        System.out.println();
        System.out.println("=".repeat(60));
        System.out.println("Shutting down coordinator...");
        for (Map.Entry<String, SocketClient> entry : intersectionClients.entrySet()) {
            String intersectionId = entry.getKey();
            SocketClient client = entry.getValue();
            try {
                if (client.isConnected()) {
                    Message personalizedShutdown = new Message(
                        MessageType.SHUTDOWN,
                        "COORDINATOR",
                        intersectionId,
                        "Simulation complete"
                    );
                    client.send(personalizedShutdown);
                    System.out.println("Sent shutdown message to " + intersectionId);
                }
            } catch (SerializationException | IOException e) {
                System.err.println("Error sending shutdown to " + intersectionId + ": " + e.getMessage());
            } finally {
                client.close();
            }
        }
        System.out.println("Coordinator shutdown complete");
        System.out.println("=".repeat(60));
    }
    public void stop() {
        System.out.println("\nStop signal received...");
        running = false;
    }
 }
--- a/main/src/main/java/sd/coordinator/SocketClient.java
+++ b/main/src/main/java/sd/coordinator/SocketClient.java
@@ -1,124 +0,0 @@
 package sd.coordinator;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.Socket;
 import sd.model.Message;
 import sd.serialization.MessageSerializer;
 import sd.serialization.SerializationException;
 import sd.serialization.SerializerFactory;
 /**
 * Socket client for communication with a single intersection process.
 * 
 * Handles a persistent TCP connection to one intersection,
 * providing a simple way to send serialized messages.
 */
 public class SocketClient {
    private final String intersectionId;
    private final String host;
    private final int port;
    private Socket socket;
    private OutputStream outputStream;
    private MessageSerializer serializer;
    /**
     * Creates a new SocketClient for a given intersection.
     *
     * @param intersectionId Intersection ID (ex. "Cr1")
     * @param host Host address (ex. "localhost")
     * @param port Port number
     */
    public SocketClient(String intersectionId, String host, int port) {
        this.intersectionId = intersectionId;
        this.host = host;
        this.port = port;
        this.serializer = SerializerFactory.createDefault();
    }
    /**
     * Connects to the intersection process via TCP.
     * 
     * @throws IOException if the connection cannot be established
     */
    public void connect() throws IOException {
        try {
            socket = new Socket(host, port);
            outputStream = socket.getOutputStream();
            System.out.println("Connected to " + intersectionId + " at " + host + ":" + port);
        } catch (IOException e) {
            System.err.println("Failed to connect to " + intersectionId + " at " + host + ":" + port);
            throw e;
        }
    }
    /**
     * Sends a message to the connected intersection.
     * The message is serialized and written over the socket.
     *
     * @param message The message to send
     * @throws SerializationException if serialization fails
     * @throws IOException if the socket write fails
     */
    public void send(Message message) throws SerializationException, IOException {
        if (socket == null || socket.isClosed()) {
            throw new IOException("Socket is not connected to " + intersectionId);
        }
        try {
            byte[] data = serializer.serialize(message);
            // Prefix with message length (so receiver knows how much to read)
            int length = data.length;
            outputStream.write((length >> 24) & 0xFF);
            outputStream.write((length >> 16) & 0xFF);
            outputStream.write((length >> 8) & 0xFF);
            outputStream.write(length & 0xFF);
            outputStream.write(data);
            outputStream.flush();
        } catch (SerializationException | IOException e) {
            System.err.println("Error sending message to " + intersectionId + ": " + e.getMessage());
            throw e;
        }
    }
    /**
     * Closes the socket connection safely.
     * Calling it multiple times won’t cause issues.
     */
    public void close() {
        try {
            if (outputStream != null) {
                outputStream.close();
            }
            if (socket != null && !socket.isClosed()) {
                socket.close();
                System.out.println("Closed connection to " + intersectionId);
            }
        } catch (IOException e) {
            System.err.println("Error closing connection to " + intersectionId + ": " + e.getMessage());
        }
    }
    /**
     * @return true if connected and socket is open, false otherwise
     */
    public boolean isConnected() {
        return socket != null && socket.isConnected() && !socket.isClosed();
    }
    public String getIntersectionId() {
        return intersectionId;
    }
    @Override
    public String toString() {
        return String.format("SocketClient[intersection=%s, host=%s, port=%d, connected=%s]",
            intersectionId, host, port, isConnected());
    }
 }
--- a/main/src/main/java/sd/engine/TrafficLightThread.java
+++ b/main/src/main/java/sd/engine/TrafficLightThread.java
@@ -1,158 +0,0 @@
 package sd.engine;
 import sd.IntersectionProcess;
 import sd.config.SimulationConfig;
 import sd.model.TrafficLight;
 import sd.model.TrafficLightState;
 import sd.model.Vehicle; 
 /**
 * Implements the control logic for a single TrafficLight
 * as a Runnable task that runs in its own Thread.
 *
 */
 public class TrafficLightThread implements Runnable {
    /**
     * The TrafficLight object (the *model*) that this thread controls.
     * Contains the queue and the state.
     */
    private final TrafficLight light;
    /**
     * The IntersectionProcess (the Process) that "owns" this thread.
     * Used to call methods on the process, such as sendVehicleToNextDestination().
     */
    private final IntersectionProcess process;
    /**
     * The simulation configuration, used to get timings (e.g., crossing time).
     */
    private final SimulationConfig config;
    /**
     * Volatile flag to control the graceful shutdown mechanism.
     * When set to 'false', the 'run()' loop terminates.
     */
    private volatile boolean running;
    /**
     * Constructor for the Traffic Light Thread.
     *
     * @param light The TrafficLight object (model) to be controlled.
     * @param process The parent IntersectionProcess (for callbacks).
     * @param config The simulation configuration (to get timings).
     */
    public TrafficLightThread(TrafficLight light, IntersectionProcess process, SimulationConfig config) {
        this.light = light;
        this.process = process;
        this.config = config;
        this.running = false; // Starts as 'stopped'
    }
    /**
     * The main entry point for the thread.
     * Implements the GREEN/RED cycle logic extracted from IntersectionProcess.
     *
     */
    @Override
    public void run() {
        this.running = true;
        System.out.println("[" + light.getId() + "] Traffic light thread started.");
        try {
            // Main thread loop, continues while 'running' is true
            // This 'running' flag is controlled by the parent IntersectionProcess
            while (running) {
                // --- GREEN Phase ---
                light.changeState(TrafficLightState.GREEN); //
                System.out.println("[" + light.getId() + "] State: GREEN");
                // Process vehicles in the queue
                processGreenLightQueue();
                // Wait for green duration
                Thread.sleep((long) (light.getGreenTime() * 1000)); //
                if (!running) break; // Check flag after sleep
                // --- RED Phase ---
                light.changeState(TrafficLightState.RED); //
                System.out.println("[" + light.getId() + "] State: RED");
                // Wait for red duration
                Thread.sleep((long) (light.getRedTime() * 1000)); //
            }
        } catch (InterruptedException e) {
            // Apanha a InterruptedException (outra forma de parar a thread)
            System.out.println("[" + light.getId() + "] Traffic light thread interrupted.");
            this.running = false; // Garante que o loop termina
        }
        System.out.println("[" + light.getId() + "] Traffic light thread stopped.");
    }
    /**
     * Processes vehicles in the queue while the traffic light is GREEN.
     * Logic extracted from IntersectionProcess.processGreenLight()
     *
     */
    private void processGreenLightQueue() throws InterruptedException {
        //
        while (running && light.getState() == TrafficLightState.GREEN && light.getQueueSize() > 0) {
            Vehicle vehicle = light.removeVehicle(); //
            if (vehicle != null) {
                // 1. Get the crossing time (t_sem)
                double crossingTime = getCrossingTimeForVehicle(vehicle); //
                // 2. Simulate the time the vehicle takes to cross
                Thread.sleep((long) (crossingTime * 1000)); //
                // 3. Update vehicle statistics
                vehicle.addCrossingTime(crossingTime); //
                // 4. Update intersection statistics
                process.getIntersection().incrementVehiclesSent(); //
                // 5. Call the parent Process to send the vehicle
                process.sendVehicleToNextDestination(vehicle); //
            }
        }
    }
    /**
     * Gets the crossing time for a vehicle based on its type.
     * Logic extracted from IntersectionProcess.getCrossingTimeForVehicle()
     *
     *
     * @param vehicle The vehicle.
     * @return The crossing time in seconds.
     */
    private double getCrossingTimeForVehicle(Vehicle vehicle) {
        switch (vehicle.getType()) { //
            case BIKE:
                return config.getBikeVehicleCrossingTime(); //
            case LIGHT:
                return config.getLightVehicleCrossingTime(); //
            case HEAVY:
                return config.getHeavyVehicleCrossingTime(); //
            default:
                return config.getLightVehicleCrossingTime(); //
        }
    }
    /**
     * Requests the thread to stop gracefully (graceful shutdown).
     * Sets the 'running' flag to false. The thread will finish
     * its current sleep cycle and exit the 'run()' loop.
     */
    public void shutdown() {
        this.running = false;
    }
 }
--- a/main/src/main/java/sd/model/Intersection.java
+++ b/main/src/main/java/sd/model/Intersection.java
@@ -104,28 +104,16 @@ public class Intersection {
     * Accepts an incoming vehicle and places it in the correct queue.
     * * This method:
     * 1. Increments the {@link #totalVehiclesReceived} counter.
-     * 2. Advances the vehicle's route (since it just arrived here)
+     * 2. Gets the vehicle's *next* destination (from {@link Vehicle#getCurrentDestination()}).
-     * 3. Gets the vehicle's *next* destination (from {@link Vehicle#getCurrentDestination()}).
+     * 3. Uses the {@link #routing} map to find the correct *direction* for that destination.
-     * 4. Uses the {@link #routing} map to find the correct *direction* for that destination.
+     * 4. Adds the vehicle to the queue of the {@link TrafficLight} for that direction.
     * 5. Adds the vehicle to the queue of the {@link TrafficLight} for that direction.
     *
     * @param vehicle The {@link Vehicle} arriving at the intersection.
     */
    public void receiveVehicle(Vehicle vehicle) {
        totalVehiclesReceived++;
        // Note: Route advancement is handled by SimulationEngine.handleVehicleArrival()
        // before calling this method, so we don't advance here.
        String nextDestination = vehicle.getCurrentDestination();
        // Check if vehicle reached final destination
        if (nextDestination == null) {
            System.out.printf("[%s] Vehicle %s reached final destination%n", 
                this.id, vehicle.getId());
            return;
        }
        String direction = routing.get(nextDestination);
        if (direction != null && trafficLights.containsKey(direction)) {
--- a/main/src/main/java/sd/protocol/MessageProtocol.java
+++ b/main/src/main/java/sd/protocol/MessageProtocol.java
@@ -1,41 +0,0 @@
 package sd.protocol;
 import java.io.Serializable;
 import sd.model.MessageType; // Assuming MessageType is in sd.model or sd.protocol
 /**
 * Interface defining the contract for all messages exchanged in the simulator.
 * Ensures that any message can be identified and routed.
 * * This interface extends Serializable to allow objects that implement it
 * to be sent over Sockets (ObjectOutputStream).
 *
 */
 public interface MessageProtocol extends Serializable {
    /**
     * Returns the type of the message, indicating its purpose.
     * @return The MessageType (e.g., VEHICLE_TRANSFER, STATS_UPDATE).
     */
    MessageType getType();
    /**
     * Returns the data object (payload) that this message carries.
     * The type of object will depend on the MessageType.
     * * - If getType() == VEHICLE_TRANSFER, the payload will be a {@link sd.model.Vehicle} object.
     * - If getType() == STATS_UPDATE, the payload will be a statistics object.
     * * @return The data object (payload), which must also be Serializable.
     */
    Object getPayload();
    /**
     * Returns the ID of the node (Process) that sent this message.
     * @return String (e.g., "Cr1", "Cr5", "S").
     */
    String getSourceNode();
    /**
     * Returns the ID of the destination node (Process) for this message.
     * @return String (e.g., "Cr2", "DashboardServer").
     */
    String getDestinationNode();
 }
--- a/main/src/main/java/sd/protocol/SocketConnection.java
+++ b/main/src/main/java/sd/protocol/SocketConnection.java
@@ -1,199 +0,0 @@
 package sd.protocol; 
 import java.io.Closeable;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.ConnectException;
 import java.net.Socket;
 import java.net.SocketTimeoutException;
 import java.net.UnknownHostException;
 import java.util.concurrent.TimeUnit;
 import sd.serialization.MessageSerializer;
 import sd.serialization.SerializationException;
 import sd.serialization.SerializerFactory;
 /**
 * Wrapper class that simplifies communication via Sockets.
 * Includes connection retry logic for robustness.
 */
 public class SocketConnection implements Closeable {
    private final Socket socket;
    private final OutputStream outputStream;
    private final InputStream inputStream;
    private final MessageSerializer serializer;
    // --- Configuration for Retry Logic ---
    /** Maximum number of connection attempts. */
    private static final int MAX_RETRIES = 5; 
    /** Delay between retry attempts in milliseconds. */
    private static final long RETRY_DELAY_MS = 1000; 
    /**
     * Constructor for the "Client" (who initiates the connection).
     * Tries to connect to a process that is already listening (Server).
     * Includes retry logic in case of initial connection failure.
     *
     * @param host The host address (e.g., "localhost" from your simulation.properties)
     * @param port The port (e.g., 8001 from your simulation.properties)
     * @throws IOException If connection fails after all retries.
     * @throws UnknownHostException If the host is not found (this error usually doesn't need retry).
     * @throws InterruptedException If the thread is interrupted while waiting between retries.
     */
    public SocketConnection(String host, int port) throws IOException, UnknownHostException, InterruptedException {
        Socket tempSocket = null;
        IOException lastException = null;
        System.out.printf("[SocketConnection] Attempting to connect to %s:%d...%n", host, port);
        // --- Retry Loop ---
        for (int attempt = 1; attempt <= MAX_RETRIES; attempt++) {
            try {
                // Try to establish the connection
                tempSocket = new Socket(host, port);
                // If successful, break out of the retry loop
                System.out.printf("[SocketConnection] Connected successfully on attempt %d.%n", attempt);
                lastException = null; // Clear last error on success
                break;
            } catch (ConnectException | SocketTimeoutException e) {
                // These are common errors indicating the server might not be ready.
                lastException = e;
                System.out.printf("[SocketConnection] Attempt %d/%d failed: %s. Retrying in %d ms...%n",
                        attempt, MAX_RETRIES, e.getMessage(), RETRY_DELAY_MS);
                if (attempt < MAX_RETRIES) {
                    // Wait before the next attempt
                    TimeUnit.MILLISECONDS.sleep(RETRY_DELAY_MS);
                }
            } catch (IOException e) {
                // Other IOExceptions might be more permanent, but we retry anyway.
                 lastException = e;
                 System.out.printf("[SocketConnection] Attempt %d/%d failed with IOException: %s. Retrying in %d ms...%n",
                        attempt, MAX_RETRIES, e.getMessage(), RETRY_DELAY_MS);
                 if (attempt < MAX_RETRIES) {
                     TimeUnit.MILLISECONDS.sleep(RETRY_DELAY_MS);
                 }
            }
        } // --- End of Retry Loop ---
        // If after all retries tempSocket is still null, it means connection failed permanently.
        if (tempSocket == null) {
            System.err.printf("[SocketConnection] Failed to connect to %s:%d after %d attempts.%n", host, port, MAX_RETRIES);
            if (lastException != null) {
                 throw lastException; // Throw the last exception encountered
            } else {
                 // Should not happen if loop ran, but as a fallback
                 throw new IOException("Failed to connect after " + MAX_RETRIES + " attempts, reason unknown.");
            }
        }
        // If connection was successful, assign to final variable and create streams
        this.socket = tempSocket;
        this.outputStream = socket.getOutputStream();
        this.inputStream = socket.getInputStream();
        this.serializer = SerializerFactory.createDefault();
    }
    /**
     * Constructor for the "Server" (who accepts the connection).
     * Receives a Socket that has already been accepted by a ServerSocket.
     * No retry logic needed here as the connection is already established.
     *
     * @param acceptedSocket The Socket returned by serverSocket.accept().
     * @throws IOException If stream creation fails.
     */
    public SocketConnection(Socket acceptedSocket) throws IOException {
        this.socket = acceptedSocket;
        this.outputStream = socket.getOutputStream();
        this.inputStream = socket.getInputStream();
        this.serializer = SerializerFactory.createDefault();
    }
    /**
     * Sends (serializes) a MessageProtocol object over the socket.
     *
     * @param message The "envelope" (which contains the Vehicle) to be sent.
     * @throws IOException If writing to the stream fails or socket is not connected.
     */
    public void sendMessage(MessageProtocol message) throws IOException {
   if (socket == null || !socket.isConnected()) {
            throw new IOException("Socket is not connected");
        }
        try {
            // Serializa para bytes JSON
            byte[] data = serializer.serialize(message);
            // Write 4-byte length prefix
            DataOutputStream dataOut = new DataOutputStream(outputStream);
            dataOut.writeInt(data.length);
            dataOut.write(data);
            dataOut.flush();
        } catch (SerializationException e) {
            throw new IOException("Failed to serialize message", e);
        }
    }
    /**
     * Tries to read (deserialize) a MessageProtocol object from the socket.
     *
     * @return The "envelope" (MessageProtocol) that was received.
     * @throws IOException If the connection is lost, the stream is corrupted, or socket is not connected.
     * @throws ClassNotFoundException If the received object is unknown.
     */
    public MessageProtocol receiveMessage() throws IOException, ClassNotFoundException {
       if (socket == null || !socket.isConnected()) {
            throw new IOException("Socket is not connected");
        }
        try {
            // Lê um prefixo de 4 bytes - indicador de tamanho
            DataInputStream dataIn = new DataInputStream(inputStream);
            int length = dataIn.readInt();
            if (length <= 0 || length > 10_000_000) { // Sanity check (10MB max)
                throw new IOException("Invalid message length: " + length);
            }
            // Ler dados da mensagem
            byte[] data = new byte[length];
            dataIn.readFully(data);
            // Deserialize do JSON
            return serializer.deserialize(data, MessageProtocol.class);
        } catch (SerializationException e) {
            throw new IOException("Failed to deserialize message", e);
        }
    }
    /**
     * Closes the socket and all streams (Input and Output).
     */
    @Override
    public void close() throws IOException {
        if (inputStream != null) inputStream.close();
        if (outputStream != null) outputStream.close();
        if (socket != null) socket.close();
    }
    /**
     * @return true if the socket is still connected and not closed.
     */
    public boolean isConnected() {
        return socket != null && socket.isConnected() && !socket.isClosed();
    }
 }
--- a/main/src/test/java/IntersectionProcessTest.java
+++ b/main/src/test/java/IntersectionProcessTest.java
@@ -1,473 +0,0 @@
 import java.io.IOException;
 import java.io.ObjectOutputStream;
 import java.net.Socket;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Arrays;
 import org.junit.jupiter.api.AfterEach;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.Timeout;
 import org.junit.jupiter.api.io.TempDir;
 import sd.IntersectionProcess;
 import sd.model.MessageType;
 import sd.model.Vehicle;
 import sd.model.VehicleType;
 /**
 * Tests for IntersectionProcess - covers initialization, traffic lights, 
 * vehicle transfer and network stuff
 */
 public class IntersectionProcessTest {
    @TempDir
    Path tempDir;
    private Path configFile;
    private IntersectionProcess intersectionProcess;
    // setup test config before each test
    @BeforeEach
    public void setUp() throws IOException {
        // create temp config file
        configFile = tempDir.resolve("test-simulation.properties");
        String configContent = """
                # Test Simulation Configuration
                # Intersection Network Configuration
                intersection.Cr1.host=localhost
                intersection.Cr1.port=18001
                intersection.Cr2.host=localhost
                intersection.Cr2.port=18002
                intersection.Cr3.host=localhost
                intersection.Cr3.port=18003
                intersection.Cr4.host=localhost
                intersection.Cr4.port=18004
                intersection.Cr5.host=localhost
                intersection.Cr5.port=18005
                # Exit Configuration
                exit.host=localhost
                exit.port=18099
                # Dashboard Configuration
                dashboard.host=localhost
                dashboard.port=18100
                # Traffic Light Timing (seconds)
                trafficLight.Cr1.East.greenTime=5.0
                trafficLight.Cr1.East.redTime=5.0
                trafficLight.Cr1.South.greenTime=5.0
                trafficLight.Cr1.South.redTime=5.0
                trafficLight.Cr1.West.greenTime=5.0
                trafficLight.Cr1.West.redTime=5.0
                trafficLight.Cr2.West.greenTime=4.0
                trafficLight.Cr2.West.redTime=6.0
                trafficLight.Cr2.East.greenTime=4.0
                trafficLight.Cr2.East.redTime=6.0
                trafficLight.Cr2.South.greenTime=4.0
                trafficLight.Cr2.South.redTime=6.0
                trafficLight.Cr3.West.greenTime=3.0
                trafficLight.Cr3.West.redTime=7.0
                trafficLight.Cr3.East.greenTime=3.0
                trafficLight.Cr3.East.redTime=7.0
                trafficLight.Cr4.East.greenTime=6.0
                trafficLight.Cr4.East.redTime=4.0
                trafficLight.Cr5.East.greenTime=5.0
                trafficLight.Cr5.East.redTime=5.0
                # Vehicle Crossing Times (seconds)
                vehicle.bike.crossingTime=2.0
                vehicle.light.crossingTime=3.0
                vehicle.heavy.crossingTime=5.0
                """;
        Files.writeString(configFile, configContent);
    }
    // cleanup after tests
    @AfterEach
    public void tearDown() {
        if (intersectionProcess != null) {
            intersectionProcess.shutdown();
        }
    }
    // ==================== Initialization Tests ====================
    @Test
    public void testConstructor_Success() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        assertNotNull(intersectionProcess);
    }
    @Test
    public void testConstructor_InvalidConfig() {
        Exception exception = assertThrows(IOException.class, () -> {
            new IntersectionProcess("Cr1", "non-existent-config.properties");
        });
        assertNotNull(exception);
    }
    @Test
    public void testInitialize_Cr1() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        assertDoesNotThrow(() -> intersectionProcess.initialize());
    }
    @Test
    public void testInitialize_Cr2() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr2", configFile.toString());
        assertDoesNotThrow(() -> intersectionProcess.initialize());
    }
    @Test
    public void testInitialize_Cr3() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr3", configFile.toString());
        assertDoesNotThrow(() -> intersectionProcess.initialize());
    }
    @Test
    public void testInitialize_Cr4() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr4", configFile.toString());
        assertDoesNotThrow(() -> intersectionProcess.initialize());
    }
    @Test
    public void testInitialize_Cr5() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr5", configFile.toString());
        assertDoesNotThrow(() -> intersectionProcess.initialize());
    }
    // traffic light creation tests
    @Test
    public void testTrafficLightCreation_Cr1_HasCorrectDirections() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        intersectionProcess.initialize();
        // cant access private fields but initialization succeds
        assertNotNull(intersectionProcess);
    }
    @Test
    public void testTrafficLightCreation_Cr3_HasCorrectDirections() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr3", configFile.toString());
        intersectionProcess.initialize();
        // Cr3 has west and south only
        assertNotNull(intersectionProcess);
    }
    @Test
    public void testTrafficLightCreation_Cr4_HasSingleDirection() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr4", configFile.toString());
        intersectionProcess.initialize();
        // Cr4 only has east direction
        assertNotNull(intersectionProcess);
    }
    // server startup tests
    @Test
    @Timeout(5)
    public void testServerStart_BindsToCorrectPort() throws IOException, InterruptedException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        intersectionProcess.initialize();
        // start server in seperate thread
        Thread serverThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) {
                // expected on shutdown
            }
        });
        serverThread.start();
        Thread.sleep(500); // wait for server to start
        // try connecting to check if its running
        try (Socket clientSocket = new Socket("localhost", 18001)) {
            assertTrue(clientSocket.isConnected());
        }
        intersectionProcess.shutdown();
        serverThread.join(2000);
    }
    @Test
    @Timeout(5)
    public void testServerStart_MultipleIntersections() throws IOException, InterruptedException {
        // test 2 intersections on diferent ports
        IntersectionProcess cr1 = new IntersectionProcess("Cr1", configFile.toString());
        IntersectionProcess cr2 = new IntersectionProcess("Cr2", configFile.toString());
        cr1.initialize();
        cr2.initialize();
        Thread thread1 = new Thread(() -> {
            try { cr1.start(); } catch (IOException e) { }
        });
        Thread thread2 = new Thread(() -> {
            try { cr2.start(); } catch (IOException e) { }
        });
        thread1.start();
        thread2.start();
        Thread.sleep(500);
        // check both are running
        try (Socket socket1 = new Socket("localhost", 18001);
             Socket socket2 = new Socket("localhost", 18002)) {
            assertTrue(socket1.isConnected());
            assertTrue(socket2.isConnected());
        }
        cr1.shutdown();
        cr2.shutdown();
        thread1.join(2000);
        thread2.join(2000);
    }
    // vehicle transfer tests
    @Test
    @Timeout(10)
    public void testVehicleTransfer_ReceiveVehicle() throws IOException, InterruptedException {
        // setup reciever intersection
        intersectionProcess = new IntersectionProcess("Cr2", configFile.toString());
        intersectionProcess.initialize();
        Thread serverThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) { }
        });
        serverThread.start();
        Thread.sleep(500);
        // create test vehicle
        java.util.List<String> route = Arrays.asList("Cr2", "Cr3", "S");
        Vehicle vehicle = new Vehicle("V001", VehicleType.LIGHT, 0.0, route);
        // send vehicle from Cr1 to Cr2
        try (Socket socket = new Socket("localhost", 18002)) {
            ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
            TestVehicleMessage message = new TestVehicleMessage("Cr1", "Cr2", vehicle);
            out.writeObject(message);
            out.flush();
            Thread.sleep(1000); // wait for procesing
        }
        intersectionProcess.shutdown();
        serverThread.join(2000);
    }
    // routing config tests
    @Test
    public void testRoutingConfiguration_Cr1() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        intersectionProcess.initialize();
        // indirect test - if init works routing should be ok
        assertNotNull(intersectionProcess);
    }
    @Test
    public void testRoutingConfiguration_Cr5() throws IOException {
        intersectionProcess = new IntersectionProcess("Cr5", configFile.toString());
        intersectionProcess.initialize();
        // Cr5 routes to exit
        assertNotNull(intersectionProcess);
    }
    // shutdown tests
    @Test
    @Timeout(5)
    public void testShutdown_GracefulTermination() throws IOException, InterruptedException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        intersectionProcess.initialize();
        Thread serverThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) { }
        });
        serverThread.start();
        Thread.sleep(500);
        // shutdown should be fast
        assertDoesNotThrow(() -> intersectionProcess.shutdown());
        serverThread.join(2000);
    }
    @Test
    @Timeout(5)
    public void testShutdown_ClosesServerSocket() throws IOException, InterruptedException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        intersectionProcess.initialize();
        Thread serverThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) { }
        });
        serverThread.start();
        Thread.sleep(500);
        // verify server running
        try (Socket socket = new Socket("localhost", 18001)) {
            assertTrue(socket.isConnected());
        }
        intersectionProcess.shutdown();
        serverThread.join(2000);
        // after shutdown conection should fail
        Thread.sleep(500);
        Exception exception = assertThrows(IOException.class, () -> {
            Socket socket = new Socket("localhost", 18001);
            socket.close();
        });
        assertNotNull(exception);
    }
    @Test
    @Timeout(5)
    public void testShutdown_StopsTrafficLightThreads() throws IOException, InterruptedException {
        intersectionProcess = new IntersectionProcess("Cr1", configFile.toString());
        intersectionProcess.initialize();
        Thread serverThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) { }
        });
        serverThread.start();
        Thread.sleep(500);
        int threadCountBefore = Thread.activeCount();
        intersectionProcess.shutdown();
        serverThread.join(2000);
        Thread.sleep(500); // wait for threads to die
        // thread count should decrese (traffic light threads stop)
        int threadCountAfter = Thread.activeCount();
        assertTrue(threadCountAfter <= threadCountBefore);
    }
    // integration tests
    @Test
    @Timeout(15)
    public void testIntegration_TwoIntersectionsVehicleTransfer() throws IOException, InterruptedException {
        // setup 2 intersections
        IntersectionProcess cr1 = new IntersectionProcess("Cr1", configFile.toString());
        IntersectionProcess cr2 = new IntersectionProcess("Cr2", configFile.toString());
        cr1.initialize();
        cr2.initialize();
        // start both
        Thread thread1 = new Thread(() -> {
            try { cr1.start(); } catch (IOException e) { }
        });
        Thread thread2 = new Thread(() -> {
            try { cr2.start(); } catch (IOException e) { }
        });
        thread1.start();
        thread2.start();
        Thread.sleep(1000); // wait for servers
        // send vehicle to Cr1 that goes to Cr2
        java.util.List<String> route = Arrays.asList("Cr1", "Cr2", "S");
        Vehicle vehicle = new Vehicle("V001", VehicleType.LIGHT, 0.0, route);
        try (Socket socket = new Socket("localhost", 18001)) {
            ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
            TestVehicleMessage message = new TestVehicleMessage("Entry", "Cr1", vehicle);
            out.writeObject(message);
            out.flush();
            Thread.sleep(2000); // time for processing
        }
        cr1.shutdown();
        cr2.shutdown();
        thread1.join(2000);
        thread2.join(2000);
    }
    @Test
    public void testMain_MissingArguments() {
        // main needs intersection ID as argument
        // cant test System.exit easily in modern java
        assertTrue(true, "Main method expects intersection ID as first argument");
    }
    // helper class for testing vehicle messages
    private static class TestVehicleMessage implements sd.protocol.MessageProtocol {
        private static final long serialVersionUID = 1L;
        private final String sourceNode;
        private final String destinationNode;
        private final Vehicle payload;
        public TestVehicleMessage(String sourceNode, String destinationNode, Vehicle vehicle) {
            this.sourceNode = sourceNode;
            this.destinationNode = destinationNode;
            this.payload = vehicle;
        }
        @Override
        public MessageType getType() {
            return MessageType.VEHICLE_TRANSFER;
        }
        @Override
        public Object getPayload() {
            return payload;
        }
        @Override
        public String getSourceNode() {
            return sourceNode;
        }
        @Override
        public String getDestinationNode() {
            return destinationNode;
        }
    }
 }
--- a/main/src/test/java/sd/ExitNodeProcessTest.java
+++ b/main/src/test/java/sd/ExitNodeProcessTest.java
@@ -1,327 +0,0 @@
 package sd;
 import java.io.IOException;
 import java.net.Socket;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import org.junit.jupiter.api.AfterEach;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.Timeout;
 import org.junit.jupiter.api.io.TempDir;
 import sd.config.SimulationConfig;
 /**
 * Testes unitários para a classe ExitNodeProcess.
 * 
 * Esta classe de testes verifica:
 * - Construção e inicialização do processo
 * - Criação e aceitação de conexões do servidor socket
 * - Gestão do ciclo de vida (start/shutdown)
 * - Processamento concorrente de múltiplas conexões
 * - Impressão de estatísticas finais
 * 
 * Os testes utilizam configurações temporárias e portas dedicadas (19001)
 * para evitar conflitos com outros testes ou processos em execução.
 */
 public class ExitNodeProcessTest {
    @TempDir
    Path tempDir;
    private Path configFile;
    private ExitNodeProcess exitNodeProcess;
    private Thread exitNodeThread;
    /**
     * Configura o ambiente de teste antes de cada teste.
     * Cria um ficheiro de configuração temporário com as definições necessárias.
     */
    @BeforeEach
    public void setUp() throws IOException {
        configFile = tempDir.resolve("test-simulation.properties");
        String configContent = """
                # Test Exit Node Configuration
                # Exit Configuration
                exit.host=localhost
                exit.port=19001
                # Dashboard Configuration (will not be running in tests)
                dashboard.host=localhost
                dashboard.port=19000
                # Vehicle Crossing Times
                vehicle.bike.crossingTime=2.0
                vehicle.light.crossingTime=3.0
                vehicle.heavy.crossingTime=5.0
                # Simulation Duration
                simulation.duration=60.0
                """;
        Files.writeString(configFile, configContent);
    }
    /**
     * Limpa os recursos após cada teste.
     * Garante que o processo e threads são terminados corretamente.
     */
    @AfterEach
    public void tearDown() {
        if (exitNodeProcess != null) {
            exitNodeProcess.shutdown();
        }
        if (exitNodeThread != null && exitNodeThread.isAlive()) {
            exitNodeThread.interrupt();
            try {
                exitNodeThread.join(1000);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }
    }
    /**
     * Testa a construção bem-sucedida do ExitNodeProcess com configuração válida.
     */
    @Test
    public void testConstructor_Success() throws IOException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        assertNotNull(exitNodeProcess);
    }
    /**
     * Testa que uma exceção é lançada quando a configuração é inválida.
     */
    @Test
    public void testConstructor_InvalidConfig() {
        Exception exception = assertThrows(IOException.class, () -> {
            new SimulationConfig("non-existent-config.properties");
        });
        assertNotNull(exception);
    }
    /**
     * Testa a inicialização sem dashboard disponível.
     * Verifica que o processo continua a funcionar mesmo sem conexão ao dashboard.
     */
    @Test
    public void testInitialize_WithoutDashboard() throws IOException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        assertDoesNotThrow(() -> exitNodeProcess.initialize());
    }
    /**
     * Testa que o servidor socket é criado corretamente na porta configurada.
     * Verifica que é possível estabelecer uma conexão ao socket do servidor.
     */
    @Test
    @Timeout(value = 3, unit = TimeUnit.SECONDS)
    public void testStart_ServerSocketCreated() throws IOException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        exitNodeProcess.initialize();
        CountDownLatch latch = new CountDownLatch(1);
        exitNodeThread = new Thread(() -> {
            try {
                latch.countDown();
                exitNodeProcess.start();
            } catch (IOException e) {
                // expected when shutdown
            }
        });
        exitNodeThread.start();
        try {
            assertTrue(latch.await(2, TimeUnit.SECONDS), "Exit node should start within timeout");
            Thread.sleep(100);
            assertDoesNotThrow(() -> {
                try (Socket testSocket = new Socket("localhost", 19001)) {
                    assertTrue(testSocket.isConnected());
                }
            });
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
    /**
     * Testa que o servidor aceita conexões de clientes.
     */
    @Test
    @Timeout(value = 3, unit = TimeUnit.SECONDS)
    public void testStart_AcceptsConnection() throws IOException, InterruptedException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        exitNodeProcess.initialize();
        CountDownLatch latch = new CountDownLatch(1);
        exitNodeThread = new Thread(() -> {
            try {
                latch.countDown();
                exitNodeProcess.start();
            } catch (IOException e) {
                // expected
            }
        });
        exitNodeThread.start();
        assertTrue(latch.await(2, TimeUnit.SECONDS));
        Thread.sleep(200);
        assertDoesNotThrow(() -> {
            try (Socket socket = new Socket("localhost", 19001)) {
                assertTrue(socket.isConnected());
            }
        });
    }
    /**
     * Testa múltiplas inicializações e encerramentos do processo.
     * Verifica que o processo pode ser iniciado e parado múltiplas vezes,
     * permitindo reutilização da porta.
     */
    @Test
    @Timeout(value = 3, unit = TimeUnit.SECONDS)
    public void testMultipleStartStop() throws IOException, InterruptedException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        exitNodeProcess.initialize();
        CountDownLatch latch = new CountDownLatch(1);
        exitNodeThread = new Thread(() -> {
            try {
                latch.countDown();
                exitNodeProcess.start();
            } catch (IOException e) {
                // expected
            }
        });
        exitNodeThread.start();
        assertTrue(latch.await(2, TimeUnit.SECONDS));
        Thread.sleep(100);
        exitNodeProcess.shutdown();
        Thread.sleep(100);
        assertDoesNotThrow(() -> {
            SimulationConfig config2 = new SimulationConfig(configFile.toString());
            ExitNodeProcess exitNode2 = new ExitNodeProcess(config2);
            exitNode2.initialize();
            exitNode2.shutdown();
        });
    }
    /**
     * Testa que o shutdown fecha corretamente o servidor socket.
     * Após o shutdown, novas conexões ao socket devem falhar.
     */
    @Test
    @Timeout(value = 3, unit = TimeUnit.SECONDS)
    public void testShutdown_ClosesServerSocket() throws IOException, InterruptedException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        exitNodeProcess.initialize();
        CountDownLatch startLatch = new CountDownLatch(1);
        exitNodeThread = new Thread(() -> {
            try {
                startLatch.countDown();
                exitNodeProcess.start();
            } catch (IOException e) {
                // expected
            }
        });
        exitNodeThread.start();
        assertTrue(startLatch.await(2, TimeUnit.SECONDS));
        Thread.sleep(200);
        exitNodeProcess.shutdown();
        Thread.sleep(200);
        assertThrows(IOException.class, () -> {
            Socket socket = new Socket("localhost", 19001);
            socket.close();
        });
    }
    /**
     * Testa que as estatísticas finais são impressas corretamente durante o shutdown.
     * Verifica que o método não lança exceções mesmo sem dados processados.
     */
    @Test
    public void testPrintFinalStatistics() throws IOException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        exitNodeProcess.initialize();
        assertDoesNotThrow(() -> exitNodeProcess.shutdown());
    }
    /**
     * Testa o processamento de múltiplas conexões concorrentes.
     * Verifica que o servidor consegue lidar com vários clientes simultaneamente
     * usando o pool de threads.
     */
    @Test
    @Timeout(value = 3, unit = TimeUnit.SECONDS)
    public void testMultipleConcurrentConnections() throws IOException, InterruptedException {
        SimulationConfig config = new SimulationConfig(configFile.toString());
        exitNodeProcess = new ExitNodeProcess(config);
        exitNodeProcess.initialize();
        CountDownLatch latch = new CountDownLatch(1);
        exitNodeThread = new Thread(() -> {
            try {
                latch.countDown();
                exitNodeProcess.start();
            } catch (IOException e) {
                // expected
            }
        });
        exitNodeThread.start();
        assertTrue(latch.await(2, TimeUnit.SECONDS));
        Thread.sleep(200);
        Thread[] clients = new Thread[3];
        for (int i = 0; i < 3; i++) {
            clients[i] = new Thread(() -> {
                try (Socket socket = new Socket("localhost", 19001)) {
                    assertTrue(socket.isConnected());
                    Thread.sleep(100);
                } catch (IOException | InterruptedException e) {
                    // ignore
                }
            });
            clients[i].start();
        }
        for (Thread client : clients) {
            client.join(1000);
        }
    }
 }
--- a/main/src/test/java/sd/TrafficLightCoordinationTest.java
+++ b/main/src/test/java/sd/TrafficLightCoordinationTest.java
@@ -1,206 +0,0 @@
 package sd;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import sd.model.TrafficLight;
 import sd.model.TrafficLightState;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
 import static org.junit.jupiter.api.Assertions.*;
 /**
 * Test class to verify traffic light coordination within an intersection.
 * Ensures that only ONE traffic light can be GREEN at any given time.
 */
 public class TrafficLightCoordinationTest {
    private IntersectionProcess intersectionProcess;
    @BeforeEach
    public void setUp() throws IOException {
        // Create an intersection with multiple traffic lights
        intersectionProcess = new IntersectionProcess("Cr2", "src/main/resources/simulation.properties");
        intersectionProcess.initialize();
    }
    @AfterEach
    public void tearDown() throws InterruptedException {
        if (intersectionProcess != null) {
            intersectionProcess.shutdown();
        }
    }
    /**
     * Test that verifies mutual exclusion between traffic lights.
     * Monitors all traffic lights for 10 seconds and ensures that
     * at most ONE light is GREEN at any point in time.
     */
    @Test
    public void testOnlyOneGreenLightAtATime() throws InterruptedException {
        System.out.println("\n=== Testing Traffic Light Mutual Exclusion ===");
        // Start the intersection
        Thread intersectionThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) {
                e.printStackTrace();
            }
        });
        intersectionThread.start();
        // Monitor traffic lights for violations
        AtomicInteger maxGreenSimultaneously = new AtomicInteger(0);
        AtomicInteger violationCount = new AtomicInteger(0);
        List<String> violations = new ArrayList<>();
        // Monitor for 10 seconds
        long endTime = System.currentTimeMillis() + 10000;
        while (System.currentTimeMillis() < endTime) {
            int greenCount = 0;
            StringBuilder currentState = new StringBuilder("States: ");
            for (TrafficLight light : intersectionProcess.getIntersection().getTrafficLights()) {
                TrafficLightState state = light.getState();
                currentState.append(light.getDirection()).append("=").append(state).append(" ");
                if (state == TrafficLightState.GREEN) {
                    greenCount++;
                }
            }
            // Update maximum simultaneous green lights
            if (greenCount > maxGreenSimultaneously.get()) {
                maxGreenSimultaneously.set(greenCount);
            }
            // Check for violations (more than one green)
            if (greenCount > 1) {
                violationCount.incrementAndGet();
                String violation = String.format("[VIOLATION] %d lights GREEN simultaneously: %s", 
                    greenCount, currentState.toString());
                violations.add(violation);
                System.err.println(violation);
            }
            Thread.sleep(50); // Check every 50ms
        }
        System.out.println("\n=== Test Results ===");
        System.out.println("Maximum simultaneous GREEN lights: " + maxGreenSimultaneously.get());
        System.out.println("Total violations detected: " + violationCount.get());
        if (!violations.isEmpty()) {
            System.err.println("\nViolation details:");
            violations.forEach(System.err::println);
        }
        // Assert that we never had more than one green light
        assertEquals(0, violationCount.get(), 
            "Traffic light coordination violated! Multiple lights were GREEN simultaneously.");
        assertTrue(maxGreenSimultaneously.get() <= 1, 
            "At most ONE light should be GREEN at any time. Found: " + maxGreenSimultaneously.get());
        System.out.println("\n✅ Traffic light coordination working correctly!");
    }
    /**
     * Test that verifies all traffic lights get a chance to be GREEN.
     * Ensures fairness in the coordination mechanism.
     */
    @Test
    public void testAllLightsGetGreenTime() throws InterruptedException {
        System.out.println("\n=== Testing Traffic Light Fairness ===");
        // Start the intersection
        Thread intersectionThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) {
                e.printStackTrace();
            }
        });
        intersectionThread.start();
        // Track which lights have been green
        List<TrafficLight> lights = intersectionProcess.getIntersection().getTrafficLights();
        boolean[] hasBeenGreen = new boolean[lights.size()];
        // Monitor for 15 seconds (enough time for all lights to cycle)
        long endTime = System.currentTimeMillis() + 15000;
        while (System.currentTimeMillis() < endTime) {
            for (int i = 0; i < lights.size(); i++) {
                if (lights.get(i).getState() == TrafficLightState.GREEN) {
                    hasBeenGreen[i] = true;
                    System.out.println("✓ " + lights.get(i).getDirection() + " has been GREEN");
                }
            }
            Thread.sleep(100);
        }
        // Check if all lights got green time
        int greenCount = 0;
        System.out.println("\n=== Fairness Results ===");
        for (int i = 0; i < lights.size(); i++) {
            String status = hasBeenGreen[i] ? "✓ YES" : "✗ NO";
            System.out.println(lights.get(i).getDirection() + " got GREEN time: " + status);
            if (hasBeenGreen[i]) greenCount++;
        }
        assertTrue(greenCount > 0, "At least one light should have been GREEN during the test");
        System.out.println("\n" + greenCount + "/" + lights.size() + " lights were GREEN during test period");
    }
    /**
     * Test that verifies the state transitions are consistent.
     */
    @Test
    public void testStateTransitionsAreConsistent() throws InterruptedException {
        System.out.println("\n=== Testing State Transition Consistency ===");
        Thread intersectionThread = new Thread(() -> {
            try {
                intersectionProcess.start();
            } catch (IOException e) {
                e.printStackTrace();
            }
        });
        intersectionThread.start();
        List<TrafficLight> lights = intersectionProcess.getIntersection().getTrafficLights();
        TrafficLightState[] previousStates = new TrafficLightState[lights.size()];
        // Initialize previous states
        for (int i = 0; i < lights.size(); i++) {
            previousStates[i] = lights.get(i).getState();
        }
        int transitionCount = 0;
        long endTime = System.currentTimeMillis() + 8000;
        while (System.currentTimeMillis() < endTime) {
            for (int i = 0; i < lights.size(); i++) {
                TrafficLightState currentState = lights.get(i).getState();
                if (currentState != previousStates[i]) {
                    transitionCount++;
                    System.out.println(lights.get(i).getDirection() + " transitioned: " + 
                        previousStates[i] + " → " + currentState);
                    previousStates[i] = currentState;
                }
            }
            Thread.sleep(100);
        }
        System.out.println("\nTotal state transitions observed: " + transitionCount);
        assertTrue(transitionCount > 0, "There should be state transitions during the test period");
    }
 }
--- a/main/src/test/java/sd/coordinator/CoordinatorIntegrationTest.java
+++ b/main/src/test/java/sd/coordinator/CoordinatorIntegrationTest.java
@@ -1,302 +0,0 @@
 package sd.coordinator;
 import java.io.DataInputStream;
 import java.io.IOException;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import org.junit.jupiter.api.AfterEach;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.Timeout;
 import sd.model.Message;
 import sd.model.MessageType;
 import sd.model.Vehicle;
 import sd.serialization.MessageSerializer;
 import sd.serialization.SerializerFactory;
 /**
 * Integration tests for the Coordinator-side networking.
 *
 * What we’re checking here:
 *  1. A SocketClient can actually connect to something listening
 *  2. Messages go over the wire and can be deserialized
 *  3. Vehicle payloads survive the trip
 *  4. Shutdown messages can be broadcast to multiple intersections
 *
 * We do this by spinning up a tiny mock intersection server in-process.
 */
 class CoordinatorIntegrationTest {
    private List<MockIntersectionServer> mockServers;
    private static final int BASE_PORT = 9001; // keep clear of real ports
    @BeforeEach
    void setUp() {
        mockServers = new ArrayList<>();
    }
    @AfterEach
    void tearDown() {
        // Stop all mock servers
        for (MockIntersectionServer server : mockServers) {
            server.stop();
        }
        mockServers.clear();
    }
    /**
     * Can the client open a TCP connection to our fake intersection?
     */
    @Test
    @Timeout(5)
    void testSocketClientConnection() throws IOException, InterruptedException {
        MockIntersectionServer server = new MockIntersectionServer("Cr1", BASE_PORT);
        server.start();
        mockServers.add(server);
        // tiny pause to let the server bind
        Thread.sleep(100);
        SocketClient client = new SocketClient("Cr1", "localhost", BASE_PORT);
        client.connect();
        assertTrue(client.isConnected(), "Client should be connected to mock intersection");
        client.close();
    }
    /**
     * End-to-end: send a message, make sure the server actually receives it.
     */
    @Test
    @Timeout(5)
    void testMessageTransmission() throws Exception {
        MockIntersectionServer server = new MockIntersectionServer("Cr1", BASE_PORT);
        server.start();
        mockServers.add(server);
        Thread.sleep(100);
        SocketClient client = new SocketClient("Cr1", "localhost", BASE_PORT);
        client.connect();
        Message testMessage = new Message(
            MessageType.VEHICLE_SPAWN,
            "COORDINATOR",
            "Cr1",
            "Test payload"
        );
        client.send(testMessage);
        // give the server a moment to read and deserialize
        Thread.sleep(200);
        assertFalse(
            server.getReceivedMessages().isEmpty(),
            "Mock server should have received at least one message"
        );
        Message receivedMsg = server.getReceivedMessages().poll();
        assertNotNull(receivedMsg, "Server should have actually received a message");
        assertEquals(MessageType.VEHICLE_SPAWN, receivedMsg.getType(), "Message type should match what we sent");
        assertEquals("COORDINATOR", receivedMsg.getSenderId(), "Sender ID should be preserved");
        assertEquals("Cr1", receivedMsg.getDestinationId(), "Destination ID should be preserved");
        client.close();
    }
    /**
     * Make sure vehicle payloads survive the trip and arrive non-null.
     */
    @Test
    @Timeout(5)
    void testVehicleSpawnMessage() throws Exception {
        MockIntersectionServer server = new MockIntersectionServer("Cr1", BASE_PORT);
        server.start();
        mockServers.add(server);
        Thread.sleep(100);
        SocketClient client = new SocketClient("Cr1", "localhost", BASE_PORT);
        client.connect();
        // fake a vehicle like the coordinator would send
        List<String> route = List.of("Cr1", "Cr4", "Cr5", "S");
        Vehicle vehicle = new Vehicle("V1", sd.model.VehicleType.LIGHT, 0.0, route);
        Message spawnMessage = new Message(
            MessageType.VEHICLE_SPAWN,
            "COORDINATOR",
            "Cr1",
            vehicle
        );
        client.send(spawnMessage);
        Thread.sleep(200);
        Message receivedMsg = server.getReceivedMessages().poll();
        assertNotNull(receivedMsg, "Mock server should receive the spawn message");
        assertEquals(MessageType.VEHICLE_SPAWN, receivedMsg.getType(), "Message should be of type VEHICLE_SPAWN");
        assertNotNull(receivedMsg.getPayload(), "Payload should not be null (vehicle must arrive)");
        client.close();
    }
    /**
     * Broadcast shutdown to multiple mock intersections and see if all of them get it.
     */
    @Test
    @Timeout(5)
    void testShutdownMessageBroadcast() throws Exception {
        // Start a couple of fake intersections
        for (int i = 1; i <= 3; i++) {
            MockIntersectionServer server = new MockIntersectionServer("Cr" + i, BASE_PORT + i - 1);
            server.start();
            mockServers.add(server);
        }
        Thread.sleep(200);
        // Connect to all of them
        List<SocketClient> clients = new ArrayList<>();
        for (int i = 1; i <= 3; i++) {
            SocketClient client = new SocketClient("Cr" + i, "localhost", BASE_PORT + i - 1);
            client.connect();
            clients.add(client);
        }
        Message shutdownMessage = new Message(
            MessageType.SHUTDOWN,
            "COORDINATOR",
            "ALL",
            "Simulation complete"
        );
        for (SocketClient client : clients) {
            client.send(shutdownMessage);
        }
        Thread.sleep(200);
        for (MockIntersectionServer server : mockServers) {
            assertFalse(
                server.getReceivedMessages().isEmpty(),
                "Server " + server.getIntersectionId() + " should have received the shutdown message"
            );
            Message msg = server.getReceivedMessages().poll();
            assertEquals(MessageType.SHUTDOWN, msg.getType(), "Server should receive a SHUTDOWN message");
        }
        for (SocketClient client : clients) {
            client.close();
        }
    }
    /**
     * Tiny TCP server that pretends to be an intersection.
     * It:
     *  - listens on a port
     *  - accepts connections
     *  - reads length-prefixed messages
     *  - deserializes them and stores them for the test to inspect
     */
    private static class MockIntersectionServer {
        private final String intersectionId;
        private final int port;
        private ServerSocket serverSocket;
        private Thread serverThread;
        private volatile boolean running;
        private final ConcurrentLinkedQueue<Message> receivedMessages;
        private final MessageSerializer serializer;
        public MockIntersectionServer(String intersectionId, int port) {
            this.intersectionId = intersectionId;
            this.port = port;
            this.receivedMessages = new ConcurrentLinkedQueue<>();
            this.serializer = SerializerFactory.createDefault();
            this.running = false;
        }
        public void start() throws IOException {
            serverSocket = new ServerSocket(port);
            running = true;
            System.out.printf("Mock %s listening on port %d%n", intersectionId, port);
            serverThread = new Thread(() -> {
                try {
                    while (running) {
                        Socket clientSocket = serverSocket.accept();
                        handleClient(clientSocket);
                    }
                } catch (IOException e) {
                    if (running) {
                        System.err.println("Mock " + intersectionId + " server error: " + e.getMessage());
                    }
                }
            }, "mock-" + intersectionId + "-listener");
            serverThread.start();
        }
        private void handleClient(Socket clientSocket) {
            new Thread(() -> {
                try (DataInputStream input = new DataInputStream(clientSocket.getInputStream())) {
                    while (running) {
                        // Read length prefix (4 bytes, big-endian)
                        int length = input.readInt();
                        byte[] data = new byte[length];
                        input.readFully(data);
                        Message message = serializer.deserialize(data, Message.class);
                        receivedMessages.offer(message);
                        System.out.println("Mock " + intersectionId + " received: " + message.getType());
                    }
                } catch (IOException e) {
                    if (running) {
                        System.err.println("Mock " + intersectionId + " client handler error: " + e.getMessage());
                    }
                } catch (Exception e) {
                    System.err.println("Mock " + intersectionId + " deserialization error: " + e.getMessage());
                }
            }, "mock-" + intersectionId + "-client").start();
        }
        public void stop() {
            running = false;
            try {
                if (serverSocket != null && !serverSocket.isClosed()) {
                    serverSocket.close();
                }
                if (serverThread != null) {
                    serverThread.interrupt();
                    serverThread.join(1000);
                }
                System.out.printf("Mock %s stopped%n", intersectionId);
            } catch (IOException | InterruptedException e) {
                System.err.println("Error stopping mock server " + intersectionId + ": " + e.getMessage());
            }
        }
        public ConcurrentLinkedQueue<Message> getReceivedMessages() {
            return receivedMessages;
        }
        public String getIntersectionId() {
            return intersectionId;
        }
    }
 }
--- a/main/src/test/java/sd/coordinator/CoordinatorProcessTest.java
+++ b/main/src/test/java/sd/coordinator/CoordinatorProcessTest.java
@@ -1,194 +0,0 @@
 package sd.coordinator;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import org.junit.jupiter.api.AfterEach;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sd.config.SimulationConfig;
 import sd.model.Vehicle;
 import sd.util.VehicleGenerator;
 /**
 * Tests for the Coordinator/vehicle-generation layer.
 *
 * What we’re checking here:
 *  1. Coordinator can be created with a valid config
 *  2. Vehicle arrival times are monotonic and sane
 *  3. Vehicle IDs are created in the format we expect (V1, V2, ...)
 *  4. Generated vehicles have proper routes (start at CrX, end at S)
 *  5. Config actually has intersection info
 *  6. Duration in config is not something crazy
 */
 class CoordinatorProcessTest {
    private SimulationConfig config;
    private static final String TEST_CONFIG = "src/main/resources/simulation.properties";
    @BeforeEach
    void setUp() throws IOException {
        config = new SimulationConfig(TEST_CONFIG);
    }
    @AfterEach
    void tearDown() {
        config = null;
    }
    /**
     * Basic smoke test: can we build a coordinator with this config?
     */
    @Test
    void testCoordinatorInitialization() {
        CoordinatorProcess coordinator = new CoordinatorProcess(config);
        assertNotNull(coordinator, "Coordinator should be created with a valid config");
    }
    /**
     * Make sure the VehicleGenerator is giving us increasing arrival times,
     * i.e. time doesn’t go backwards and intervals look reasonable.
     */
    @Test
    void testVehicleGenerationTiming() {
        VehicleGenerator generator = new VehicleGenerator(config);
        double currentTime = 0.0;
        List<Double> arrivalTimes = new ArrayList<>();
        // generate a small batch to inspect
        for (int i = 0; i < 10; i++) {
            double nextArrival = generator.getNextArrivalTime(currentTime);
            arrivalTimes.add(nextArrival);
            currentTime = nextArrival;
        }
        // times should strictly increase
        for (int i = 1; i < arrivalTimes.size(); i++) {
            assertTrue(
                arrivalTimes.get(i) > arrivalTimes.get(i - 1),
                "Arrival times must increase — got " + arrivalTimes.get(i - 1) + " then " + arrivalTimes.get(i)
            );
        }
        // and they shouldn't be nonsense
        for (double time : arrivalTimes) {
            assertTrue(time >= 0, "Arrival time should not be negative (got " + time + ")");
            assertTrue(time < 1000, "Arrival time looks suspiciously large: " + time);
        }
    }
    /**
     * We generate V1..V5 manually and make sure the IDs are exactly those.
     */
    @Test
    void testVehicleIdGeneration() {
        VehicleGenerator generator = new VehicleGenerator(config);
        List<Vehicle> vehicles = new ArrayList<>();
        for (int i = 1; i <= 5; i++) {
            Vehicle v = generator.generateVehicle("V" + i, 0.0);
            vehicles.add(v);
            assertEquals("V" + i, v.getId(), "Vehicle ID should be 'V" + i + "' but got " + v.getId());
        }
        // just to be safe, no duplicates in that small set
        long distinctCount = vehicles.stream().map(Vehicle::getId).distinct().count();
        assertEquals(5, distinctCount, "Vehicle IDs in this batch should all be unique");
    }
    /**
     * A generated vehicle should:
     *  - have a non-empty route
     *  - start in a known intersection (Cr1..Cr5)
     *  - end in S (exit)
     */
    @Test
    void testVehicleRouteValidity() {
        VehicleGenerator generator = new VehicleGenerator(config);
        for (int i = 0; i < 20; i++) {
            Vehicle vehicle = generator.generateVehicle("V" + i, 0.0);
            assertNotNull(vehicle.getRoute(), "Vehicle route should not be null");
            assertFalse(vehicle.getRoute().isEmpty(), "Vehicle route should not be empty");
            String firstHop = vehicle.getRoute().get(0);
            assertTrue(
                firstHop.matches("Cr[1-5]"),
                "First hop should be a valid intersection (Cr1..Cr5), got: " + firstHop
            );
            String lastHop = vehicle.getRoute().get(vehicle.getRoute().size() - 1);
            assertEquals("S", lastHop, "Last hop should be exit 'S' but got: " + lastHop);
        }
    }
    /**
     * Whatever is in simulation.properties should give us a sane duration.
     */
    @Test
    void testSimulationDuration() {
        double duration = config.getSimulationDuration();
        assertTrue(duration > 0, "Simulation duration must be positive");
        assertTrue(duration >= 1.0, "Simulation should run at least 1 second (got " + duration + ")");
        assertTrue(duration <= 86400.0, "Simulation should not run more than a day (got " + duration + ")");
    }
    /**
     * Check that the 5 intersections defined in the architecture
     * actually exist in the config and have valid network data.
     */
    @Test
    void testIntersectionConfiguration() {
        String[] intersectionIds = {"Cr1", "Cr2", "Cr3", "Cr4", "Cr5"};
        for (String id : intersectionIds) {
            String host = config.getIntersectionHost(id);
            int port = config.getIntersectionPort(id);
            assertNotNull(host, "Host should not be null for " + id);
            assertFalse(host.isEmpty(), "Host should not be empty for " + id);
            assertTrue(port > 0, "Port should be > 0 for " + id + " (got " + port + ")");
            assertTrue(port < 65536, "Port should be a valid TCP port for " + id + " (got " + port + ")");
        }
    }
    /**
     * Quick sanity check: over a bunch of generated vehicles,
     * we should eventually see the different vehicle types appear.
     *
     * Note: this is probabilistic, so we're not being super strict.
     */
    @Test
    void testVehicleTypeDistribution() {
        VehicleGenerator generator = new VehicleGenerator(config);
        boolean hasBike = false;
        boolean hasLight = false;
        boolean hasHeavy = false;
        // 50 is enough for a "we're probably fine" test
        for (int i = 0; i < 50; i++) {
            Vehicle vehicle = generator.generateVehicle("V" + i, 0.0);
            switch (vehicle.getType()) {
                case BIKE -> hasBike = true;
                case LIGHT -> hasLight = true;
                case HEAVY -> hasHeavy = true;
            }
        }
        // at least one of them should have shown up — if not, RNG is cursed
        assertTrue(
            hasBike || hasLight || hasHeavy,
            "Expected to see at least one vehicle type after 50 generations"
        );
    }
 }
Author	SHA1	Message	Date
Leandro Afonso	043ba7d185	Add workflow_dispatch trigger to Maven CI	2025-11-23 22:12:35 +00:00
Leandro Afonso	25f2876c34	Refactor GitHub Actions workflow for Maven build	2025-11-23 22:10:40 +00:00
Leandro Afonso	7cbecc4fab	Update Maven workflow for JDK setup and packaging	2025-11-23 22:00:49 +00:00
Leandro Afonso	72db59415f	Add Windows build job to Maven workflow	2025-11-23 21:53:33 +00:00
Leandro Afonso	60b4f0c2b6	Add 'cleanup' branch to Maven CI workflow	2025-11-22 22:53:54 +00:00
Leandro Afonso	81f842e2bb	Change CI branch from 'main' to 'dev'	2025-11-19 20:54:47 +00:00
David Alves	108d2e544c	Enunciado uploaded	2025-10-27 18:02:24 +00:00