private boolean priorityCommand = false;

    public void start(Stage stage) {
        initDuke("./data/charlie.txt");
        // Step 1. Setting up required components
        ScrollPane scrollPane = new ScrollPane();
        VBox dialogContainer = new VBox();
        scrollPane.setContent(dialogContainer);

        TextField userInput = new TextField();
        Button sendButton = new Button("Send");

        AnchorPane mainLayout = new AnchorPane();
        mainLayout.getChildren().addAll(scrollPane, userInput, sendButton);

        Scene scene = new Scene(mainLayout);
        stage.setScene(scene);
        stage.show();

        stage.setTitle("charlie.ui.Duke");
        stage.setResizable(false);
        stage.setMinHeight(600.0);
        stage.setMinWidth(400.0);

        mainLayout.setPrefSize(400.0, 600.0);

        scrollPane.setPrefSize(385, 535);
        scrollPane.setHbarPolicy(ScrollPane.ScrollBarPolicy.NEVER);
        scrollPane.setVbarPolicy(ScrollPane.ScrollBarPolicy.ALWAYS);

        scrollPane.setVvalue(1.0);
        scrollPane.setFitToWidth(true);

        //You will need to import `javafx.scene.layout.Region` for this.
        dialogContainer.setPrefHeight(Region.USE_COMPUTED_SIZE);

        userInput.setPrefWidth(325.0);

        sendButton.setPrefWidth(55.0);

        AnchorPane.setTopAnchor(scrollPane, 1.0);

        AnchorPane.setBottomAnchor(sendButton, 1.0);
        AnchorPane.setRightAnchor(sendButton, 1.0);

        AnchorPane.setLeftAnchor(userInput , 1.0);
        AnchorPane.setBottomAnchor(userInput, 1.0);

        //Step 3. Add functionality to handle user input.
        sendButton.setOnMouseClicked((event) -> {
            try {
                handleUserInput(userInput, dialogContainer);
            } catch (CharlieException e) {
                System.out.println(e.getMessage());
            }
        });

        userInput.setOnAction((event) -> {
            try {
                handleUserInput(userInput, dialogContainer);
            } catch (CharlieException e) {
                System.out.println(e.getMessage());
            }
        });

        dialogContainer.heightProperty().addListener((observable) -> scrollPane.setVvalue(1.0));
    }

    private void handleUserInput(TextField userInput, VBox dialogContainer) throws CharlieException {

        String input = userInput.getText();
        boolean isAddCommand = input.startsWith("todo") || input.startsWith("deadline")
                || input.startsWith("event");

        if (isAddCommand) {
            dialogContainer.getChildren().addAll(
                    DialogBox.getUserDialog(input, user),
                    DialogBox.getDukeDialog("Assign this task a priority: ", duke)
            );
            setPriority(true,input);
            userInput.clear();
        } else if (this.priorityCommand & this.priorityTaskCommand != null) {
            if (isNumeric(input)) {
                String fullPriorityCommand = this.priorityTaskCommand + " " + input;
                String response = "Assigned the task this priority " + input;
                dialogContainer.getChildren().addAll(
                        DialogBox.getUserDialog(input, user),
                        DialogBox.getDukeDialog(response, duke),
                        DialogBox.getDukeDialog(getResponse(fullPriorityCommand), duke)
                );
                userInput.clear();
                setPriority(false, null);
            } else {
                throw new CharlieException("Priority should be a number");
            }
        } else {
            dialogContainer.getChildren().addAll(
                    DialogBox.getUserDialog(input, user),
                    DialogBox.getDukeDialog(getResponse(input), duke)
            );
            userInput.clear();
        }
    }

    /**
     * Abstract execute method that aims to perform actions for a specific command.
     * Needs to be overridden in sub-classes.
     * @param taskList - task list loaded at the start of the program.
     * @param storage - class responsible for adding and loading tasks from and into the file
     * @throws CharlieException
     */

    /**
     * The parseTaskFromFile method converts a single line of text into a specific Task object
     * (to-Do, Deadline, or Event) based on the line's format, throwing an exception for unrecognized
     * task types
     * @param line line read from the storage file
     * @return the task object
     * @throws IllegalArgumentException
     */

    /**
     * Iteration 1:
     * Creates a label with the specified text and adds it to the dialog container.
     * @param text String containing text to add
     * @return a label with the specified text that has word wrap enabled.
     */