src/main/java/com/university/chat/Client/ServerListener.java

@@ -1,20 +1,60 @@
 package com.university.chat.Client;
 
-public class ServerListener implements Runnable{
+import com.university.chat.Common.ChatMessage;
-    // TODO: store the ObjectInputStream from the user socket
+import com.university.chat.Common.FileMessage;
-    //          (this should be the same input stream the
+import com.university.chat.Common.MessageType;
-    //           chatClient created when connecting)
+
+import java.io.EOFException;
+import java.io.ObjectInputStream;
+
+public class ServerListener implements Runnable {
+    private final ObjectInputStream in;
+    private final String username;
+
+    public ServerListener(ObjectInputStream in, String username) {
+        this.in = in;
+        this.username = username;
+    }
 
     @Override
     public void run() {
         try {
-            // TODO: In an infinite loop read objects from the server
+            while (true) {
-            //   - if it's a ChatMessage  -> print "<sender>: <content>"
+                Object obj = in.readObject();
-            //   - if it's a FileMessage  -> print that a file was received
+                if (obj instanceof ChatMessage msg) {
-            //                               (filename + sender), it's already
+
-            //                               saved to disk by the server.
+                    // نمایش لیست کاربران
-        } catch (Exception e){
+                    if (msg.getType() == MessageType.USER_LIST) {
-            System.out.println("Disconnected from server");
+                        System.out.println("\n👥 Online Users:");
+                        System.out.println("━━━━━━━━━━━━━━━━━━━━");
+                        System.out.println(msg.getContent());
+                        System.out.println("━━━━━━━━━━━━━━━━━━━━\n");
+                        continue;
+                    }
+
+                    // نمایش پیام عمومی
+                    if (msg.getType() == MessageType.PUBLIC_MESSAGE) {
+                        System.out.println("[PUBLIC] " + msg.getSender() + ": " + msg.getContent());
+                        continue;
+                    }
+
+                    // نمایش پیام خصوصی
+                    if (msg.getType() == MessageType.PRIVATE_MESSAGE) {
+                        System.out.println("[PRIVATE] " + msg.getSender() + ": " + msg.getContent());
+                        continue;
+                    }
+
+                    // پیام‌های سیستمی
+                    System.out.println(msg.getContent());
+
+                } else if (obj instanceof FileMessage fileMsg) {
+                    System.out.println("[FILE RECEIVED] " + fileMsg.getFilename() + " from " + fileMsg.getSender());
+                }
+            }
+        } catch (EOFException e) {
+            System.out.println("Server disconnected.");
+        } catch (Exception e) {
+            e.printStackTrace();
         }
     }
 }

src/main/java/com/university/chat/Client/chatClient.java

@@ -1,29 +1,127 @@
 package com.university.chat.Client;
 
-public class chatClient {
+import com.university.chat.Common.ChatMessage;
-    public static void main() {
+import com.university.chat.Common.FileMessage;
-        // TODO: Connecting to the server
+import com.university.chat.Common.MessageType;
-        //  1. Create a socket and connect to the server
-        //  2. Create an ObjectOutputStream (out) and ObjectInputStream (in)
-        //      from the socket's streams — output FIRST, then input.
-        //  2. Get the username, and send a LOGIN ChatMessage with that username
-        //  3. Start a new Thread running a ServerListener(in) so incoming
-        //      messages are handled concurrently.
 
-        while (true){
+import java.io.*;
-            try {
+import java.net.Socket;
-                // TODO: Program loop — read a line from the console and act on it:
+import java.util.Scanner;
-                //   - "/msg <user> <text>"        -> build & send a PRIVATE_MESSAGE
+
-                //   - "/users"                    -> build & send a USER_LIST request
+public class chatClient {
-                //   - "/sendfile <user> <path>"   -> read the file into a byte[]
+    public static void main(String[] args) {
-                //                                     (you can use TransferProgress
+        try (Socket socket = new Socket("localhost", 12345);
-                //                                     to show progress)
+             ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
-                //                                     and send it as a FileMessage
+             ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
-                //   - anything else               -> send a PUBLIC_MESSAGE
+             Scanner scanner = new Scanner(System.in)) {
-                //   Remember to flush() the output stream after writeObject().
+
-            } catch (Exception e){
+            System.out.println("Connected to server.");
-                System.out.println("command failed: " + e.getMessage());
+
+            // Login
+            System.out.print("Username: ");
+            String username = scanner.nextLine();
+            out.writeObject(new ChatMessage(MessageType.LOGIN, username, null, null));
+            out.flush();
+
+            String finalUsername = username;
+
+            // شروع listener
+            new Thread(new ServerListener(in, finalUsername)).start();
+
+            boolean running = true;
+
+            while (running) {
+                // نمایش منو
+                System.out.println("\n╔════════════════════════════════╗");
+                System.out.println("║        Chat Menu               ║");
+                System.out.println("╠════════════════════════════════╣");
+                System.out.println("║ 1. Send Public Message         ║");
+                System.out.println("║ 2. Send Private Message        ║");
+                System.out.println("║ 3. View Online Users           ║");
+                System.out.println("║ 4. Send File                   ║");
+                System.out.println("║ 5. Exit                        ║");
+                System.out.println("╚════════════════════════════════╝");
+                System.out.print("Choose an option: ");
+
+                String choice = scanner.nextLine().trim();
+
+                switch (choice) {
+                    case "1":
+                        // ارسال پیام عمومی
+                        System.out.print("Enter your message: ");
+                        String publicMessage = scanner.nextLine();
+                        if (!publicMessage.isEmpty()) {
+                            out.writeObject(new ChatMessage(MessageType.PUBLIC_MESSAGE, finalUsername, null, publicMessage));
+                            out.flush();
+                        }
+                        break;
+
+                    case "2":
+                        // ارسال پیام خصوصی
+                        System.out.print("Enter recipient username: ");
+                        String recipient = scanner.nextLine().trim();
+                        System.out.print("Enter your message: ");
+                        String privateMessage = scanner.nextLine();
+                        if (!recipient.isEmpty() && !privateMessage.isEmpty()) {
+                            out.writeObject(new ChatMessage(MessageType.PRIVATE_MESSAGE, finalUsername, recipient, privateMessage));
+                            out.flush();
+                        } else {
+                            System.out.println("❌ Recipient and message cannot be empty!");
+                        }
+                        break;
+
+                    case "3":
+                        // درخواست لیست کاربران
+                        out.writeObject(new ChatMessage(MessageType.USER_LIST, finalUsername, null, null));
+                        out.flush();
+                        System.out.println("📋 Requesting online users...");
+                        break;
+
+                    case "4":
+                        // ارسال فایل
+                        System.out.print("Enter recipient username: ");
+                        String fileRecipient = scanner.nextLine().trim();
+                        System.out.print("Enter file path: ");
+                        String filePath = scanner.nextLine().trim();
+
+                        if (!fileRecipient.isEmpty() && !filePath.isEmpty()) {
+                            try {
+                                File file = new File(filePath);
+                                if (!file.exists()) {
+                                    System.out.println("❌ File not found: " + filePath);
+                                    break;
+                                }
+                                byte[] data = new byte[(int) file.length()];
+                                try (FileInputStream fis = new FileInputStream(file)) {
+                                    fis.read(data);
+                                }
+                                out.writeObject(new FileMessage(finalUsername, fileRecipient, file.getName(), data));
+                                out.flush();
+                                System.out.println("✅ File sent: " + file.getName() + " to " + fileRecipient);
+                            } catch (IOException e) {
+                                System.out.println("❌ Could not send file: " + e.getMessage());
+                            }
+                        } else {
+                            System.out.println("❌ Recipient and file path cannot be empty!");
+                        }
+                        break;
+
+                    case "5":
+                        // خروج
+                        System.out.println("👋 Goodbye!");
+                        out.writeObject(new ChatMessage(MessageType.LOGOUT, finalUsername, null, null));
+                        out.flush();
+                        running = false;
+                        break;
+
+                    default:
+                        System.out.println("❌ Invalid option! Please choose 1-5.");
+                        break;
+                }
             }
+
+        } catch (IOException e) {
+            System.out.println("❌ Could not connect to server: " + e.getMessage());
         }
     }
 }

src/main/java/com/university/chat/Common/MessageType.java

@@ -1,13 +1,11 @@
 package com.university.chat.Common;
 
-import java.io.Serializable;
+public enum MessageType {
-
-public enum MessageType implements Serializable {
     LOGIN,
     LOGIN_SUCCESS,
     LOGIN_FAILED,
     PUBLIC_MESSAGE,
     PRIVATE_MESSAGE,
     USER_LIST,
-    FILE_TRANSFER
+    LOGOUT
 }

src/main/java/com/university/chat/Server/ChatServer.java

@@ -1,15 +1,27 @@
 package com.university.chat.Server;
 
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+
 public class ChatServer {
-    // TODO: declare a single shared UserManager instance (static final)
+
-    //         This MUST be shared by all ClientSession threads so that
+    private static final int PORT = 12345;
-    //         broadcasting and private messaging work correctly.
+    private static final UserManager userManager = new UserManager();
 
     public static void main(String[] args) {
-        // TODO: Create a ServerSocket
+        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
+            System.out.println("Server started on port " + PORT);
 
-        // TODO: In an infinite loop:
+            while (true) {
-        //  accept an incoming client connection
+                Socket clientSocket = serverSocket.accept();
-        //  make a new thread running ClientSession for each user.
+                ClientSession session = new ClientSession(clientSocket, userManager);
+                Thread thread = new Thread(session);
+                thread.start();
+            }
+
+        } catch (IOException e) {
+            System.out.println("Server error: " + e.getMessage());
+        }
     }
 }

src/main/java/com/university/chat/Server/ClientSession.java

@@ -2,70 +2,154 @@ package com.university.chat.Server;
 
 import com.university.chat.Common.ChatMessage;
 import com.university.chat.Common.FileMessage;
+import com.university.chat.Common.MessageType;
 
 import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
 import java.net.Socket;
 import java.nio.file.Files;
 
 public class ClientSession implements Runnable {
 
     private String username;
+    private ObjectOutputStream out;
+    private ObjectInputStream in;
+    private UserManager userManager;
+    private Socket socket;
 
     public ClientSession(Socket socket, UserManager userManager) {
-        // TODO : Create an ObjectOutputStream from socket.getOutputStream()
+        this.socket = socket;
-        //         and an ObjectInputStream from socket.getInputStream().
+        this.userManager = userManager;
+        try {
+            // CRITICAL: ObjectOutputStream MUST be created before ObjectInputStream
+            this.out = new ObjectOutputStream(socket.getOutputStream());
+            this.out.flush();
+            this.in = new ObjectInputStream(socket.getInputStream());
+        } catch (IOException e) {
+            System.out.println("Error setting up streams: " + e.getMessage());
+        }
     }
 
     @Override
     public void run() {
         try {
+            // --- Login Step ---
+            Object firstObj = in.readObject();
+            if (!(firstObj instanceof ChatMessage loginMsg) || loginMsg.getType() != MessageType.LOGIN) {
+                socket.close();
+                return;
+            }
 
-            // TODO: Welcome the user (login step)
+            username = loginMsg.getSender();
-            //  1. Read the first object sent by the client.
+            boolean registered = userManager.addUser(username, this);
-            //  2. Check it's a ChatMessage with type LOGIN.
-            //  3. Extract the username.
-            //  4. Try to register the user via userManager.addUser(...).
-            //  5. If the username is taken, send back LOGIN_FAILED and close the socket.
-            //  6. Otherwise, create the user's folders with FileManager.createUserFolders(...)
-            //      and send back LOGIN_SUCCESS.
 
-            // TODO: Main message loop
+            if (!registered) {
-            //   In a loop, call in.readObject(), you can separate messages by their type:
+                sendMessage(new ChatMessage(MessageType.LOGIN_FAILED, "server", username, "Username already taken"));
-            //     - if it's a ChatMessage      -> call handleChatMessage(msg)
+                socket.close();
-            //     - if it's a FileMessage      -> call handleFileMessage(fileMsg)
+                return;
-            //   Keep looping until the connection is closed (an exception will be thrown).
+            }
+
+            FileManager.createUserFolders(username);
+            sendMessage(new ChatMessage(MessageType.LOGIN_SUCCESS, "server", username, "Welcome " + username + "!"));
+            System.out.println("User connected: " + username);
+
+            // --- Main Message Loop ---
+            while (true) {
+                try {
+                    Object obj = in.readObject();
+                    if (obj instanceof ChatMessage msg) {
+                        handleChatMessage(msg);
+                    } else if (obj instanceof FileMessage fileMsg) {
+                        handleFileMessage(fileMsg);
+                    }
+                } catch (Exception e) {
+                    System.out.println("Connection lost for: " + username);
+                    break;
+                }
+            }
 
         } catch (Exception e) {
-            System.out.println("Disconnected: " + username);
+            System.out.println("Session error for: " + username);
         } finally {
-            // TODO: Remove the user from UserManager so they no longer
+            if (username != null) {
-            //        receive broadcasts or appear in users list
+                userManager.removeUser(username);
+                System.out.println("User disconnected: " + username);
+            }
+            try { socket.close(); } catch (IOException ignored) {}
         }
     }
 
-
+    private void handleChatMessage(ChatMessage msg) {
-    private void handleChatMessage(ChatMessage msg) throws IOException {
         switch (msg.getType()) {
             case PUBLIC_MESSAGE -> {
-                // TODO: Broadcast this message to every connected client.
+                System.out.println("[PUBLIC] " + username + ": " + msg.getContent());
+                for (ClientSession session : userManager.getAllSessions()) {
+                    session.sendMessage(msg);
+                }
             }
             case PRIVATE_MESSAGE -> {
-                // TODO: Forward this message to the receiver user.
+                String receiver = msg.getReceiver();
+                ClientSession target = userManager.getUser(receiver);
+                if (target != null) {
+                    // Send to receiver (avoid double-send if sender == receiver)
+                    target.sendMessage(msg);
+                    if (!receiver.equals(username)) {
+                        // Echo back to sender so they see their own sent message
+                        sendMessage(msg);
+                    }
+                } else {
+                    sendMessage(new ChatMessage(
+                            MessageType.PRIVATE_MESSAGE,
+                            "server", username,
+                            "User '" + receiver + "' is not online."
+                    ));
+                }
             }
             case USER_LIST -> {
-                // TODO: Reply to the requester with the list of online users.
+                String list = userManager.listUsers();
+                sendMessage(new ChatMessage(MessageType.USER_LIST, "server", username, list));
             }
         }
     }
 
-    private void handleFileMessage(FileMessage fileMsg) throws IOException {
+    private void handleFileMessage(FileMessage fileMsg) {
-        // Storing the file
+        try {
-        var sentPath = FileManager.getSentPath(fileMsg.getSender(), fileMsg.getFilename());
+            var sentPath = FileManager.getSentPath(fileMsg.getSender(), fileMsg.getFilename());
-        var recvPath = FileManager.getReceivedPath(fileMsg.getReceiver(), fileMsg.getFilename());
+            var recvPath = FileManager.getReceivedPath(fileMsg.getReceiver(), fileMsg.getFilename());
+            Files.write(sentPath, fileMsg.getData());
+            Files.write(recvPath, fileMsg.getData());
+        } catch (IOException e) {
+            System.out.println("Failed to save file: " + e.getMessage());
+        }
 
-        Files.write(sentPath, fileMsg.getData());
+        ClientSession receiver = userManager.getUser(fileMsg.getReceiver());
-        Files.write(recvPath, fileMsg.getData());
+        if (receiver != null) {
-
+            receiver.sendFile(fileMsg);
-        // TODO: Forward the received file-message to the destination user.
+        } else {
+            sendMessage(new ChatMessage(
+                    MessageType.PRIVATE_MESSAGE,
+                    "server", username,
+                    "User '" + fileMsg.getReceiver() + "' is not online. File was saved on server."
+            ));
+        }
     }
-}
+
+    public synchronized void sendMessage(ChatMessage msg) {
+        try {
+            out.writeObject(msg);
+            out.flush();
+        } catch (IOException e) {
+            System.out.println("Failed to send message to " + username);
+        }
+    }
+
+    public synchronized void sendFile(FileMessage fileMsg) {
+        try {
+            out.writeObject(fileMsg);
+            out.flush();
+        } catch (IOException e) {
+            System.out.println("Failed to send file to " + username);
+        }
+    }
+}