Merge pull request #23 from davidalves04/11-convert-intersection-to-standalone-process

Create IntersectionProcess main class

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

@@ -0,0 +1,565 @@
+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.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.
+    
+    /**
+     * 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;
+        
+        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();
+        
+        startTrafficLights();
+        
+        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...");
+        
+        // Define directions based on the actual network topology
+        String[] directions;
+        switch (intersectionId) {
+            case "Cr1":
+                // Cr1: East (to Cr2), South (to Cr4), West (from Cr2)
+                directions = new String[]{"East", "South", "West"};
+                break;
+            case "Cr2":
+                // Cr2: West (to Cr1), East (to Cr3), South (to Cr5)
+                // Plus receiving from Cr1 and Cr3
+                directions = new String[]{"West", "East", "South"};
+                break;
+            case "Cr3":
+                // Cr3: West (to Cr2), East (to S)
+                directions = new String[]{"West", "East"};
+                break;
+            case "Cr4":
+                // Cr4: East (to Cr5), plus pedestrian crossing
+                directions = new String[]{"East"};
+                break;
+            case "Cr5":
+                // Cr5: East (to S), receives from Cr2 and Cr4
+                directions = new String[]{"East"};
+                break;
+            default:
+                // Fallback to all directions
+                directions = new String[]{"North", "South", "East", "West"};
+        }
+        
+        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":
+                // Cr1 connections: → Cr2 (East), → Cr4 (South), ← Cr2 (West)
+                intersection.configureRoute("Cr2", "East");   // Go to Cr2
+                intersection.configureRoute("Cr4", "South");  // Go to Cr4
+                // Routes through other intersections to reach S
+                intersection.configureRoute("S", "East");     // S via Cr2
+                break;
+                
+            case "Cr2":
+                // Cr2 connections: ↔ Cr1 (West/East), ↔ Cr3 (East/West), → Cr5 (South)
+                intersection.configureRoute("Cr1", "West");   // Go to Cr1
+                intersection.configureRoute("Cr3", "East");   // Go to Cr3
+                intersection.configureRoute("Cr5", "South");  // Go to Cr5
+                intersection.configureRoute("S", "South");    // S via Cr5 or direct
+                break;
+                
+            case "Cr3":
+                // Cr3 connections: ← Cr2 (West), → S (South/East)
+                intersection.configureRoute("Cr2", "West");   // Go back to Cr2
+                intersection.configureRoute("S", "East");     // Go to exit S
+                break;
+                
+            case "Cr4":
+                // Cr4 connections: → Cr5 (East)
+                intersection.configureRoute("Cr5", "East");   // Go to Cr5
+                intersection.configureRoute("S", "East");     // S via Cr5
+                break;
+                
+            case "Cr5":
+                // Cr5 connections: → S (East/South)
+                intersection.configureRoute("S", "East");     // Go to exit S
+                // Cr5 might also receive from Cr2 and Cr4 but doesn't route back
+                break;
+                
+            default:
+                System.err.println("  Warning: 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.
+     *
+     * @param light The traffic light to control.
+     */
+    private void runTrafficLightCycle(TrafficLight light) {
+        System.out.println("[" + light.getId() + "] Traffic light thread started.");
+        
+        while (running) {
+            try {
+                // GREEN phase
+                light.changeState(TrafficLightState.GREEN);
+                System.out.println("[" + light.getId() + "] State: GREEN");
+                
+                // Process vehicles while green
+                processGreenLight(light);
+                
+                // Wait for green duration
+                Thread.sleep((long) (light.getGreenTime() * 1000));
+                
+                // 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) {
+                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.
+     */
+    private 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);
+            
+            // Update vehicle's path - advance to next destination in route
+            vehicle.advanceRoute();
+            
+        } 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 if (destinationId.startsWith("Cr")) {
+            return config.getIntersectionHost(destinationId);
+        } else {
+            return config.getDashboardHost();
+        }
+    }
+    
+    /**
+     * 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 if (destinationId.startsWith("Cr")) {
+            return config.getIntersectionPort(destinationId);
+        } else {
+            return config.getDashboardPort();
+        }
+    }
+    
+    /**
+     * 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);
+        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));
+    }
+    
+    /**
+     * Main method to start an intersection process.
+     *
+     * @param args Command-line arguments:
+     *             args[0] - Intersection ID (required, e.g., "Cr1")
+     *             args[1] - Config file path (optional, defaults to "simulation.properties")
+     */
+    public static void main(String[] args) {
+        if (args.length < 1) {
+            System.err.println("Usage: java IntersectionProcess <intersectionId> [configFile]");
+            System.err.println("Example: java IntersectionProcess Cr1");
+            System.exit(1);
+        }
+        
+        String intersectionId = args[0];
+        String configFile = args.length > 1 ? args[1] : "simulation.properties";
+        
+        IntersectionProcess process = null;
+        
+        try {
+            process = new IntersectionProcess(intersectionId, configFile);
+            process.initialize();
+            
+            // Add shutdown hook for graceful termination
+            final IntersectionProcess finalProcess = process;
+            Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+                finalProcess.shutdown();
+            }));
+            
+            // Start the process
+            process.start();
+            
+        } catch (IOException e) {
+            System.err.println("Error starting intersection process: " + e.getMessage());
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+    
+    // --- 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;
+        }
+    }
+}