/*	Ferry.java
*	@author: Charles Bell
*
*	Design & implement a class ferry which models a cross-channel ferry. 
*		The class should model the following state:
*			* currentDrive - which can be neutral, forward or reverse.
*			* bowDoors - which can be open or close.
*		*	Methods are:
*			* closeDoors - this closes the bow doors if they are open, otherwise 
*				it displays and error message.
*			* openDoors - this opens the bow doors if they are closed provided the 
*				current drive is in neutralotherwise it displays an error message.
*			* engageDrive - this requires an integer argument (-1 reverse and 1 forward); 
*				if the bow doors are clsed it will engage the selected drive, 
*				otherwise an error message is displayed;
*			* disengageDrive - if neither reverse or forward is engage it will be
*				disengaged, otherwise an error message will be displayed.
*/

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**	Models a cross-channel ferry.
*/
public class Ferry extends JFrame implements ActionListener{
	
	final int NEUTRAL = 0;
	final int FORWARD = 1;
	final int REVERSE = -1;
	private int currentDrive = NEUTRAL;
	
	final int OPEN = 0;
	final int CLOSED = 1;
	private int bowDoors = CLOSED;

	private JLabel driveStatusLabel;
	private JLabel bowdoorStatusLabel;

	public static void main(String[] args){
		Ferry ferry = new Ferry();
		ferry.init();
	}
	
	public void init(){
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		JPanel ferryStatusPanel = new JPanel();
		driveStatusLabel = new JLabel("Neutral");
		bowdoorStatusLabel = new JLabel("Closed");
		ferryStatusPanel.add(new JLabel("Drive Status: "));
		ferryStatusPanel.add(driveStatusLabel);
		ferryStatusPanel.add(new JLabel("Bow Door Status: "));
		ferryStatusPanel.add(bowdoorStatusLabel);
		
		JPanel bowDoorControlPanel = new JPanel();
		JButton openButton = new JButton("Open  Bow Doors");
		JButton closeButton = new JButton("Close Bow Doors");
		JButton exitButton = new JButton("Exit");
		bowDoorControlPanel.add(openButton);
		bowDoorControlPanel.add(closeButton);
		bowDoorControlPanel.add(exitButton);
		openButton.addActionListener(this);
		closeButton.addActionListener(this);
		exitButton.addActionListener(this);
		
		JPanel driveControlPanel = new JPanel();
		JButton reverseButton = new JButton("Reverse");
		JButton neutralButton = new JButton("Neutral");
		JButton forwardButton = new JButton("Forward");
		driveControlPanel.add(reverseButton);
		driveControlPanel.add(neutralButton);
		driveControlPanel.add(forwardButton);
		reverseButton.addActionListener(this);
		neutralButton.addActionListener(this);
		forwardButton.addActionListener(this);
		
		getContentPane().add(ferryStatusPanel, BorderLayout.NORTH);
		getContentPane().add(bowDoorControlPanel, BorderLayout.CENTER);
		getContentPane().add(driveControlPanel, BorderLayout.SOUTH);
		pack();
		setLocationRelativeTo(null);
		show();
	}
	
	/**	Closes the bow doors if they are open, otherwise it displays an error message.
	*/
	public void closeDoors(){
		if (bowDoors == OPEN){
			bowDoors = CLOSED;
		}else{
			JOptionPane.showMessageDialog(this, "The Bow Doors are already closed.", 
				"Error", JOptionPane.ERROR_MESSAGE);
		}
	}

	/**	Opens the bow doors if they are closed provided the current drive is in neutral. 
	 *	Otherwise it displays an error message.
	 */
	public void openDoors(){
		if ((bowDoors == CLOSED) && (currentDrive == NEUTRAL)){
			bowDoors = OPEN;
		}else{
			if (bowDoors == OPEN) {
				JOptionPane.showMessageDialog(this, 
					"The Bow Doors are already open.", 
					"Error", JOptionPane.ERROR_MESSAGE);
			} else if (currentDrive != NEUTRAL) {
				JOptionPane.showMessageDialog(this, 
				"The Cuurent Drive must be in neutral to open the doors.", 
				"Error", JOptionPane.ERROR_MESSAGE);
			}
		}
	}

	/**	Requires an integer argument (-1 reverse and 1 forward); 
	 *	If the bow doors are closed it will engage the selected drive, 
	 * 	otherwise an error message is displayed;
	*/
	public void engageDrive(int request){
		if (bowDoors == CLOSED){
			if (request == -1) currentDrive = REVERSE;
			if (request == 1) currentDrive = FORWARD;
		}else{
			JOptionPane.showMessageDialog(this, 
				"The Bow Doors must be closed to engage the drive.",
				"Error", JOptionPane.ERROR_MESSAGE);
		}			
	}
	
	/**	If neither reverse or forward is engage it will be disengaged, otherwise an error
	 *	message will be displayed.
	 */
	public void disengageDrive(){
		if (currentDrive == REVERSE) {
			currentDrive =NEUTRAL;
		}else if (currentDrive == FORWARD) {
			currentDrive =NEUTRAL;
		}else{
			JOptionPane.showMessageDialog(this, 
				"The Drive was already disengaged.",
				"Error", JOptionPane.ERROR_MESSAGE);
		}			
	}
	
	public void updateStatus(){
		if (currentDrive == REVERSE) driveStatusLabel.setText("Reverse");
		if (currentDrive == FORWARD) driveStatusLabel.setText("Forward");
		if (currentDrive == NEUTRAL) driveStatusLabel.setText("Neutral");
		if (bowDoors == OPEN) bowdoorStatusLabel.setText("Open");
		if (bowDoors == CLOSED) bowdoorStatusLabel.setText("Closed");		
	}
	
	public void actionPerformed(ActionEvent actionEvent){
		String actionCommand = actionEvent.getActionCommand();
		if (actionCommand.compareTo("Open  Bow Doors") == 0){
			openDoors();
		}else if (actionCommand.compareTo("Close Bow Doors") == 0){
			closeDoors();
		}else if (actionCommand.compareTo("Forward") == 0){
			engageDrive(FORWARD);
		}else if (actionCommand.compareTo("Reverse") == 0){
			engageDrive(REVERSE);
		}else if (actionCommand.compareTo("Neutral") == 0){
			disengageDrive();
		}else if (actionCommand.compareTo("Exit") == 0){
			System.exit(0);
		}
		updateStatus();
	}
	
}