//imports for the gui
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

/**
 * The main graphical panel used to display conversion components.
 *
 * This is the starting point for the assignment.
 *
 * The variable names have been deliberately made vague and generic, and most comments have been removed.
 *
 * You may want to start by improving the variable names and commenting what the existing code does.
 *
 * @author mdixon
 */
@SuppressWarnings("serial")
public class MainPanel extends JPanel {
//declerations
	//part 7
	private final static String[] list = { "inches/cm","nautical miles/miles",
	"hectares/acres","mph/kph","metres/yards","celsius/fahrenheit","degrees/radians"};
	private JTextField textField;
	private JLabel label;
	private JComboBox<String> combo;

	//part 6 this delcares the countlabel for the gui
	private JLabel countlabel;
	private int count = 0;



	JMenuBar setupMenu() {

		JMenuBar menuBar = new JMenuBar();

		JMenu m1 = new JMenu("File");
		JMenu m2 = new JMenu("Help");

		menuBar.add(m1);
		menuBar.add(m2);
       //part 3 this is the code to add the exit button to the gui and name it
		JMenuItem item1 = new JMenuItem("Exit");
		item1.addActionListener(new ExitListener());
		m1.add(item1);

		//part 1 this part of the code lets you use shortcuts to use the menu quicker
		m1.setMnemonic(KeyEvent.VK_F);
		m2.setMnemonic(KeyEvent.VK_H);

		//part 1 this is too add images
		m1.setIcon(new ImageIcon("img/folder.png"));
		m2.setIcon(new ImageIcon("img/question.png"));

		//part 2 this is the code for the about button to appear on the gui
		JMenuItem about = new JMenuItem("About");
		AboutListener aboutlisten = new AboutListener();
		about.addActionListener(aboutlisten);

		return menuBar;
	}


	MainPanel() {

		ActionListener convertlistner = new ConvertListener();

		combo = new JComboBox<String>(list);
		combo.addActionListener(convertlistner); //convert values when option changed

		JLabel inputLabel = new JLabel("Enter value:");

		JButton convertButton = new JButton("Convert");
		convertButton.addActionListener(convertlistner); // convert values when pressed

		label = new JLabel("---");
		textField = new JTextField(5);

		//part 4 this gives you the power to use the convert button
		textField.addActionListener(convertlistner);

		//part 5 this adds the clear button to the gui to help clear the value
		//and counter when the button is pressed
		JButton clear = new JButton("clear");
		clear.addActionListener(new ClearListener());
		countlabel = new JLabel(Integer.toString(count));

		add(combo);
		add(inputLabel);
		add(textField);
		add(convertButton);
		add(label);
		add(clear);
		add(countlabel);

		setPreferredSize(new Dimension(800, 100));
		setBackground(Color.white);

		// part 11 this adds help for when you hover over different parts of the gui
		// to show you what that part actually does
		combo.setToolTipText("Shows you all the different units to convert");
        convertButton.setToolTipText("This does the conversion");
        clear.setToolTipText("This clears the results and textbox");
        textField.setToolTipText("This is where you enter your value to convert");
	}
	//part 2 this is the code for when it is clicked it shows you this message
	private class AboutListener implements ActionListener {
		public void actionPerformed(ActionEvent event) {
		JOptionPane.showMessageDialog(
		null, "Unit Converter"
		+ "\nAuthor: Jamie Wilkinson"
		+ "\nCopyright: Leeds beckett university"); }}

	//part 5 this is the code that causes the clear action to happen
	private class ClearListener implements ActionListener {
		public void actionPerformed(ActionEvent event) {
		textField.setText(null);
		countlabel.setText(Integer.toString(count = 0)); }}

	//part 3 this is the code of when the exit button is clicked the gui closes
	private class ExitListener implements ActionListener {
		public void actionPerformed(ActionEvent event) {
		System.exit(0); }}


	private class ConvertListener implements ActionListener {

		@Override
		public void actionPerformed(ActionEvent event) {

			String text = textField.getText().trim();

// part 9 this code makes it so that if you do not enter anything into the input boxes
//then a popup will appear telling you about the error
			try {
				double value = Double.parseDouble(text);
				if (text.isEmpty() == false) {

					// the factor applied during the conversion
					double factor = 0;

					// the offset applied during the conversion.
					double offset = 0;

					// Setup the correct factor/offset values depending on required conversion
					switch (combo.getSelectedIndex()) {
//part 7 this is the code for each of the different conversion rates to appear in the gui
					case 0: // inches/cm
						factor = 2.54;
						break;
					case 1: // nautical miles/miles
                        factor = 1.151;
                        break;
                    case 2: // hectares/acres
                        factor = 2.471;
                        break;
                    case 3: // mph/kph
                        factor = 1.609;
                        break;
                    case 4: // metres/yards
                        factor = 1.094;
                        break;
                    case 5: // celsius/fahrenheit
                        factor = 1.8;
                        offset = 32;
                        break;


					}

					double result = factor * value + offset;
					//part 10 this addes the limit to 2 decimal places in the code
					String resultdec=String.format("%.2f", result);
					label.setText(resultdec);
					//part 6 this adds the number to the count label every time it is pressed
					countlabel.setText(Integer.toString(count++));
				}
			} catch(NumberFormatException e) {
			    JOptionPane.showMessageDialog(null, "This input is not valid sorry");
			}
		}
	}

}