HW-10-Socket-Programming/src/main/java/com/university/chat/Server/ClientSession.java

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.File;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.nio.file.Files;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ClientSession implements Runnable {

    private String username;
    private ObjectOutputStream out = null;
    private ObjectInputStream in = null;
    private final Socket socket;
    private final UserManager userManage;
    private final Lock L = new ReentrantLock();



    public ClientSession(Socket socket, UserManager userManager) {
        this.socket = socket;
        this.userManage = userManager;

        try {
            out = new ObjectOutputStream(socket.getOutputStream());
            in = new ObjectInputStream(socket.getInputStream());
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }

    }

    @Override
    public void run() {
        try {

            ChatMessage loginmsg = (ChatMessage) in.readObject();
            username = loginmsg.getSender();


            if(loginmsg.getType() != MessageType.LOGIN){
                out.writeObject(new ChatMessage(MessageType.LOGIN_FAILED , "server"
                                    , username,"login failed"));
                socket.close();
                return;
            }

            FileManager.createUserFolders(username);

            out.writeObject(new ChatMessage(MessageType.LOGIN_SUCCESS , "server" ,
                    username , "welcome to messanger login succes"));
            System.out.println(username + " connected");

            userManage.addUser(username , this);

            while (true){
                Object inputobj = in.readObject();
                if(inputobj == null){
                    continue;
                }
                if(inputobj instanceof ChatMessage msg){
                    handleChatMessage(msg);
                } else if (inputobj instanceof FileMessage filemsg) {
                    handleFileMessage(filemsg);
                }
            }


        } catch (Exception e) {
            System.out.println("Disconnected: " + username);
            System.out.println(e.getMessage());
        } finally {
            if(username != null) {
                userManage.removeUser(username);
            }
            try {
                socket.close();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }


    private void handleChatMessage(ChatMessage msg) throws IOException {
        switch (msg.getType()) {
            case PUBLIC_MESSAGE -> {
                for(ClientSession cs : userManage.getAllSessions()){
                    if(cs != this){
                        cs.sendMessage(msg);
                    }
                }
            }
            case PRIVATE_MESSAGE -> {
                ClientSession cs = userManage.getUser(msg.getReceiver());
                if (cs != null) {
                    cs.sendMessage(msg);
                }
            }
            case USER_LIST -> {
                ClientSession cs = userManage.getUser(msg.getSender());
                ChatMessage listReply = new ChatMessage(MessageType.USER_LIST, "server",
                        username, userManage.listUsers());

                if (cs != null) {
                    cs.sendMessage(listReply);
                }
            }
        }
    }

    private void handleFileMessage(FileMessage fileMsg) throws IOException {
        // Storing the file
        var sentPath = FileManager.getSentPath(fileMsg.getSender(), fileMsg.getFilename());
        var recvPath = FileManager.getReceivedPath(fileMsg.getReceiver(), fileMsg.getFilename());

        Files.write(sentPath, fileMsg.getData());
        Files.write(recvPath, fileMsg.getData());

        ClientSession cs = userManage.getUser(fileMsg.getReceiver());
        if(cs != null){
            cs.sendMessage(fileMsg);
        }
        System.out.println("Server received file: " + fileMsg.getFilename() + " with size: " + fileMsg.getData().length);

    }



    public void sendMessage(Object object) {
        try {
            L.lock();
            out.writeObject(object);
            out.flush();
        }
        catch (IOException e) {
            System.out.println(e.getMessage());
        }
        finally {
            L.unlock();
        }
    }

}