LoginFormController.java

package com.DesktopApplicationClientJava.controllers;

import com.DesktopApplicationClientJava.controllers.utils.Controller;
import com.DesktopApplicationClientJava.entities.Role;
import com.DesktopApplicationClientJava.entities.User;
import com.DesktopApplicationClientJava.utils.FieldError;
import com.DesktopApplicationClientJava.validation.EmailValidator;
import com.DesktopApplicationClientJava.validation.FirstNameValidator;
import com.DesktopApplicationClientJava.validation.LastNameValidator;
import com.DesktopApplicationClientJava.validation.PasswordValidator;
import com.DesktopApplicationClientJava.validation.ThirdNameValidator;
import com.DesktopApplicationClientJava.validation.utils.Validator;
import java.util.UUID;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TextField;

public class LoginFormController extends Controller {
  @FXML private TextField firstNameField;
  @FXML private Label firstNameErrorLabel;
  private FieldError firstNameError;

  @FXML private TextField lastNameField;
  @FXML private Label lastNameErrorLabel;
  private FieldError lastNameError;

  @FXML private TextField thirdNameField;
  @FXML private Label thirdNameErrorLabel;
  private FieldError thirdNameError;

  @FXML private TextField emailField;
  @FXML private Label emailErrorLabel;
  private FieldError emailError;

  @FXML private PasswordField passwordField;
  @FXML private Label passwordErrorLabel;
  private FieldError passwordError;

  @FXML private Button submitButton;

  @FXML
  private void initialize() {
    firstNameError = new FieldError(firstNameErrorLabel);
    lastNameError = new FieldError(lastNameErrorLabel);
    thirdNameError = new FieldError(thirdNameErrorLabel);
    emailError = new FieldError(emailErrorLabel);
    passwordError = new FieldError(passwordErrorLabel);

    emailField.textProperty().addListener((o, a, b) -> emailError.hide());
    passwordField.textProperty().addListener((o, a, b) -> passwordError.hide());
  }

  @FXML
  private void onSubmit(ActionEvent event) {
    if (!isValid()) return;

    User user =
        authenticate(firstNameField.getText(), lastNameField.getText(), emailField.getText());
    if (user == null) return;

    session.setCurrentUser(user);
    navigator.goTo("/fxml/Search.fxml");
  }

  private boolean isValid() {
    return isFirstNameValid()
        & isLastNameValid()
        & isThirdNameValid()
        & isEmailValid()
        & isPasswordValid();
  }

  private boolean isFirstNameValid() {
    return isFieldValid(firstNameField, new FirstNameValidator(), firstNameError);
  }

  private boolean isLastNameValid() {
    return isFieldValid(lastNameField, new LastNameValidator(), lastNameError);
  }

  private boolean isThirdNameValid() {
    return isFieldValid(thirdNameField, new ThirdNameValidator(), thirdNameError);
  }

  private boolean isEmailValid() {
    return isFieldValid(emailField, new EmailValidator(), emailError);
  }

  private boolean isPasswordValid() {
    return isFieldValid(passwordField, new PasswordValidator(), passwordError);
  }

  private boolean isFieldValid(TextField field, Validator validator, FieldError errorLabel) {
    String input = field.getText();
    var error = validator.isValid(input);
    if (error == null) {
      errorLabel.hide();
      return true;
    }
    errorLabel.show(error);
    return false;
  }

  private User authenticate(String firstName, String lastName, String email) {
    return new User(UUID.randomUUID(), email, Role.USER, firstName, lastName, true);
  }
}