import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;

public class CounterPanel extends JPanel implements ActionListener {
	
	private static final String COMMAND_UP = "up";
	private static final String COMMAND_DOWN = "down";
	private static final String COMMAND_RESET = "reset";
	
	private BasicCounter counter;
	
	private JButton countUpButton;
	private JButton countDownButton;
	private JButton resetButton;
	//private JLabel valueLabel;
	private CounterView counterView;	
	
	public CounterPanel(BasicCounter counter){
		this.counter = counter;
		countUpButton = new JButton("count up");
		countUpButton.setActionCommand(COMMAND_UP);
		countUpButton.addActionListener(this);
		countDownButton = new JButton("count down");
		countDownButton.setActionCommand(COMMAND_DOWN);
		countDownButton.addActionListener(this);
		resetButton = new JButton("reset");
		resetButton.setActionCommand(COMMAND_RESET);
		resetButton.addActionListener(this);
		//valueLabel = new JLabel();
		counterView = new CounterView();
		initGui();
		dumpCounterStatus(counter);
	}
	
	private void initGui () {
		//valueLabel.setHorizontalAlignment(SwingConstants.CENTER);
		//valueLabel.setText(""+counter.getCurrentValue());
		
		counterView.updateView(counter.getCurrentValue());
				
		JPanel controlsPanel = new JPanel(new GridLayout(1,3,5,5));
		controlsPanel.add(countDownButton);
		controlsPanel.add(resetButton);
		controlsPanel.add(countUpButton);
			
		GridBagLayout gridbag = new GridBagLayout();
		GridBagConstraints gc = new GridBagConstraints();
		setLayout(gridbag);

		gc.gridx = 0;
		gc.gridy = 0;
		gc.insets = new Insets(15,0,15,0);
		gridbag.setConstraints(counterView,gc);
		add(counterView);

		gc.gridx = 0;
		gc.gridy = 1;
		gc.insets = new Insets(0,5,5,5);
		gridbag.setConstraints(controlsPanel ,gc);
		add(controlsPanel);
		
		/*gc.gridx = 0;
		gc.gridy = 2;
		gc.insets = new Insets(0,5,5,5);
		gridbag.setConstraints(valueLabel,gc);
		add(valueLabel);*/		
	}
	
	public void actionPerformed(ActionEvent e) {
		
		if (e.getActionCommand()==COMMAND_UP) {
			counter.countUp();
		}
		if (e.getActionCommand()==COMMAND_DOWN){
			counter.countDown();
		}
		if (e.getActionCommand()==COMMAND_RESET) {
			counter.reset();
		}
		//valueLabel.setText(""+counter.getCurrentValue());
		counterView.updateView(counter.getCurrentValue());
		dumpCounterStatus(counter);		
	}
	
	private void dumpCounterStatus (BasicCounter counter) {
		System.out.println("\nCounter status:");
		System.out.println("Current value: " + counter.getCurrentValue());
		if (counter instanceof LimitedCounter) {
			LimitedCounter limetedCounter = (LimitedCounter)counter;
			System.out.println("Maximum value: "  + limetedCounter.getMaximumValue());
			System.out.println("Minimum value: "  + limetedCounter.getMinimumValue());
			System.out.println("Is at maximum: "  + limetedCounter.isAtMaximum());
			System.out.println("Is at minimum: "  + limetedCounter.isAtMinimum());
		}
	}
	
	private static class CounterView extends JPanel {
		
		// for use with negative numbers
		private JLabel[] numbers = new JLabel[4]; 
		private DecimalFormat numberFormat = new DecimalFormat("+,000;-,000");
		
		// for use with positive numbers only
		//private JLabel[] numbers = new JLabel[3];
		//private DecimalFormat numberFormat = new DecimalFormat("000");
		
		public CounterView () {
			setLayout(new FlowLayout(FlowLayout.CENTER,2,0));
			Font font = new Font("Monospace", Font.BOLD, 16);
			for (int i=0; i<numbers.length; i++) {
				numbers[i] = new JLabel();
				numbers[i].setOpaque(true);
				numbers[i].setBackground(Color.BLACK);
				numbers[i].setForeground(Color.WHITE);
				numbers[i].setFont(font);
				add(numbers[i]);
			}
		}
		
		public void updateView (int number) {
			String numberString = numberFormat.format(number);
			numberString = numberString.substring((numberString.length()-4));   // for use with negative numbers
			//numberString = numberString.substring((numberString.length()-3));   // for use with positive numbers only
			//System.out.println(numberString);
			for (int i=0; i<numbers.length;i++) {
				numbers[i].setText(numberString.substring(i,(i+1)));
				//System.out.println(numberString.substring(i,(i+1)));
			}
		}
	}
}