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

public class TempConverterGUI extends JFrame {
    private TempConverter converter;

    public TempConverterGUI() {
        converter = new TempConverter(TempConverter.TEMP_TYPE.Celsius);

        initComponents();
    }




    private void convertButtonActionPerformed(ActionEvent evt) {
        getConvertedTemp();
    }

    private void tempTextFieldMouseClicked(MouseEvent evt) {
        tempTextField.setText("");
    }

    private void tempTextFieldKeyReleased(KeyEvent evt) {
        if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
            getConvertedTemp();
        }
    }

    private void convertButtonKeyReleased(KeyEvent evt) {
        if (evt.getKeyCode() == KeyEvent.VK_ENTER) {
            getConvertedTemp();
        }
    }

    private void tempsComboBoxItemStateChanged(ItemEvent evt) {
        String tempStr = tempsComboBox.getSelectedItem().toString();

        tempTextField.setText("Temperature");
        if (tempStr.equals("Convert Celsius to Fahrenheit")) {
            converter = new TempConverter(TempConverter.TEMP_TYPE.Celsius);
        }
        else if (tempStr.equals("Convert Fahrenheit to Celsius")) {
            converter = new TempConverter(TempConverter.TEMP_TYPE.Fahrenheit);
        }
        else {
            throw new TempConverter.TempTypeDoesntExistException("Temperature type from combo box isn't supported.");
        }

        convertFromLabel.setText(converter.fromTempTypeStr());
        convertToLabel.setText(converter.toTempTypeStr());
        tempTextField.setToolTipText("Enter a temperature in degrees " + converter.fromTempTypeStr());

    }

    private void getConvertedTemp() {
        double fromTemp = 0.0;
        int toTemp = 0;
        boolean validInput = false;

        // Parse degrees Celsius asa double and convert to Fahrenheit.
        try {
            fromTemp = new Scanner(tempTextField.getText()).nextDouble();
            validInput = true;
        }
        catch (java.util.InputMismatchException e) {
            System.out.println("**ERROR**: Entered temperature isn't valid.");
        }
        catch (java.util.NoSuchElementException e) {
            System.out.println("**ERROR**: No temperature entered.");
        }


        if (validInput) {
            toTemp = converter.convertTemp(fromTemp);
            convertToLabel.setText(toTemp + " " + converter.toTempTypeStr());
        }
        else {
            convertToLabel.setText(converter.toTempTypeStr());
        }

        pack();
    }


    /**
     * This method is called from within the constructor to initialize the Netbeans form.
     */
    private void initComponents() {

        convertFromLabel = new JLabel();
        convertToLabel = new JLabel();
        convertButton = new JButton();
        tempTextField = new JTextField();
        tempsComboBox = new JComboBox();

        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setTitle("Temperature Converter");

        convertFromLabel.setLabelFor(convertFromLabel);
        convertFromLabel.setText("Celsius");

        convertToLabel.setText("Fahrenheit");

        convertButton.setText("Convert");
        convertButton.setCursor(new Cursor(Cursor.HAND_CURSOR));
        convertButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                convertButtonActionPerformed(evt);
            }
        });
        convertButton.addKeyListener(new KeyAdapter() {
            public void keyReleased(KeyEvent evt) {
                convertButtonKeyReleased(evt);
            }
        });

        tempTextField.setText("Temperature");
        tempTextField.setToolTipText("Enter a temperature in degrees Celsius");
        tempTextField.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent evt) {
                tempTextFieldMouseClicked(evt);
            }
        });
        tempTextField.addKeyListener(new KeyAdapter() {
            public void keyReleased(KeyEvent evt) {
                tempTextFieldKeyReleased(evt);
            }
        });

        tempsComboBox.setMaximumRowCount(2);
        tempsComboBox.setModel(new DefaultComboBoxModel(new String[] { "Convert Celsius to Fahrenheit", "Convert Fahrenheit to Celsius" }));
        tempsComboBox.addItemListener(new ItemListener() {
            public void itemStateChanged(ItemEvent evt) {
                tempsComboBoxItemStateChanged(evt);
            }
        });

        GroupLayout layout = new GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(convertButton)
                        .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(convertToLabel)
                        .addGap(0, 0, Short.MAX_VALUE))
                    .addGroup(layout.createSequentialGroup()
                        .addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
                            .addGroup(layout.createSequentialGroup()
                                .addComponent(tempTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(convertFromLabel))
                            .addComponent(tempsComboBox, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
                        .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))))
        );

        layout.linkSize(SwingConstants.HORIZONTAL, new Component[] {convertButton, tempTextField});

        layout.setVerticalGroup(
            layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(tempsComboBox, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
                    .addComponent(tempTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
                    .addComponent(convertFromLabel))
                .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
                    .addComponent(convertButton)
                    .addComponent(convertToLabel))
                .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        pack();
    }


    /**
     * @param args Command-line arguments aren't currently supported
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
         */
        try {
            for (UIManager.LookAndFeelInfo info
                    : UIManager.getInstalledLookAndFeels())
            {
                if ("Nimbus".equals(info.getName())) {
                    UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException
                    | UnsupportedLookAndFeelException ex)
        {
            java.util.logging.Logger.getLogger(TempConverterGUI.class.getName())
                                        .log(java.util.logging.Level.SEVERE, null, ex);
        }

        /* Create and display the form */
        EventQueue.invokeLater(() -> {
            new TempConverterGUI().setVisible(true);
        });
    }

    // Variables declaration - do not modify
    private JButton convertButton;
    private JLabel convertFromLabel;
    private JLabel convertToLabel;
    private JTextField tempTextField;
    private JComboBox tempsComboBox;
    // End of variables declaration
}