InitialClient.java

import java.net.Socket;
import java.net.UnknownHostException;
import java.util.List;
import java.util.Arrays;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

/**
 * Project 5 - InitialClient.java
 * 
 * Class that handles initial database interactions with user login.
 *
 * @author Shafer Anthony Hofmann, Qihang Gan, Shreyas Viswanathan, Nathan Pasic
 * Miller, Oliver Long
 * 
 * @version December 7, 2023
 */
public class InitialClient {

    private final String serverErrorMsg = "Error occured when communicating with server";
    private ObjectOutputStream oos;
    private ObjectInputStream ois;

    /**
     * Constructs an InitialClient instance using the output and input streams initialized via the socket
     * 
     * @param oos The object output stream to utilize to send data to the server
     * @param ois The object input stream to utilize to send data to the server
     * @throws IOException
     */
    public InitialClient(ObjectOutputStream oos, ObjectInputStream ois) throws IOException {
        this.oos = oos;
        this.ois = ois;
    }

    public static void main(String[] args) throws UnknownHostException, IOException {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                List<String> validHosts = Arrays.asList("localhost", "192.168.1.183");
                String hostName = JOptionPane.showInputDialog(null, "Enter the host name",
                    "Host name", JOptionPane.QUESTION_MESSAGE);
                if (hostName == null) {
                    JOptionPane.showMessageDialog(null, "Thank you for using the program!", "Thank you", JOptionPane.INFORMATION_MESSAGE);
                    return;
                } else {
                    if (hostName.isBlank() || hostName.isEmpty()) {
                        new ErrorMessageGUI("The host name cannot be blank or empty!");
                        return;
                    } else if (!(validHosts.contains(hostName))) {
                        // The application is run on just one device or the server is run on this device and other clients have to enter the IP of this device to connect
                        new ErrorMessageGUI("Invalid host name!");
                        return;
                    }
                    try {
                        Socket socket = new Socket(hostName, Server.PORT_NUMBER);
                        ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
                        ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
                        oos.flush();
                        InitialClient initialClient = new InitialClient(oos, ois);
                        initialClient.start();
                    } catch (IOException e) {
                        new ErrorMessageGUI("An error occurred when connecting to the server.");
                        return;
                    }
                }
            }
        });
    }

    /**
     * Ground-zero of the application from where execution begins.
     */
    public void start() {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new LoginGUI(InitialClient.this);
            }
        });
    }

    public void resetPassword(String email, String password) {
        try {
            String[] request = {"RESET_PASSWORD", email, password};
            oos.writeObject(request);
            oos.flush();

            String response = (String) ois.readObject();
            if (response.equals("Password reset successfully!")) {
                JOptionPane.showMessageDialog(null, response, "Password Reset", JOptionPane.INFORMATION_MESSAGE);
                new LoginGUI(this);
            } else {
                new ErrorMessageGUI(response);
                new LoginGUI(this);
            }

        } catch (Exception e) {
            new ErrorMessageGUI(serverErrorMsg);
        }
    }

    /**
     * Handles communication with the server for a logging an existing user back into the application
     * 
     * @param email The email the user logged in with
     * @param password The password the user logged in with
     */
    public void attemptLogin(String email, String password) {
        try {
            String[] serverRequest = {"LOGIN", email, password};
            oos.writeObject(serverRequest);
            oos.flush();

            String response = (String) ois.readObject();
            if (response.equals("Customer Connection to Server Established")) {
                new CustomerClient(oos, ois).homepage((String) ois.readObject());
            } else if (response.equals("Seller Connection to Server Established")) {
                new SellerClient(oos, ois).homepage((String) ois.readObject());
            } else {
                new ErrorMessageGUI(response);
                new LoginGUI(this);
            }
        } catch (IOException e) {
            new ErrorMessageGUI(serverErrorMsg);
        } catch (Exception e) {
            new ErrorMessageGUI("Internal Server Communication Error");
        }
    }

    /**
     * Handles communication with the server for creating a new customer account
     * 
     * @param email The email the user provided
     * @param password The password the user provided
     */
    public void attemptCreateNewSellerAccount(String email, String password) {
        try {
            String[] serverRequest = {"CREATE_SELLER", email, password};
            oos.writeObject(serverRequest);
            oos.flush();

            String response = (String) ois.readObject();
            if (response.equals("Seller Connection to Server Established")) {
                new SellerClient(oos, ois).homepage((String) ois.readObject());
            } else {
                new ErrorMessageGUI(response);
                new SignUpGUI(this);
            }
        } catch (IOException e) {
            new ErrorMessageGUI(serverErrorMsg);
        } catch (Exception e) {
            new ErrorMessageGUI("Internal Server Communication Error");
        }
    }

    /**
     * Handles communication with the server for creating a new seller account
     * 
     * @param email The email the user provided
     * @param password The password the user provided
     */
    public void attemptCreateNewCustomerAccount(String email, String password) {
        try {
            String[] serverRequest = {"CREATE_CUSTOMER", email, password};
            oos.writeObject(serverRequest);
            oos.flush();

            String response = (String) ois.readObject();
            if (response.equals("Customer Connection to Server Established")) {
                new CustomerClient(oos, ois).homepage((String) ois.readObject());
            } else {
                new ErrorMessageGUI(response);
                new SignUpGUI(this);
            }
        } catch (IOException e) {
            new ErrorMessageGUI(serverErrorMsg);
        } catch (Exception e) {
            new ErrorMessageGUI("Internal Server Communication Error");
        }
    }
}