/*
 * Created on 2004¦~2¤ë2¤é
 *
 * To change the template for this generated file go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import java.text.DecimalFormat;

/**
 * @author dcywchan
 *
 * To change the template for this generated type comment go to
 * Window>Preferences>Java>Code Generation>Code and Comments
 */
public class GUILoanTable extends JFrame implements ActionListener {
	
	Object[][] data;
	Container container;
	JPanel inputPanel,tablePanel;
	JTable table;
	JScrollPane scrollPane;
	TextField 	loanAmountTextField,
			 	annualInterestRateTextField,
			 	monthlyPaymentTextField;
	Button button;
	
	public static void main(String[] args) {
		GUILoanTable application = new GUILoanTable();
		application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	}
	
	public GUILoanTable() {
		super( "GUILoanTable" );
		
		loanAmountTextField = new TextField(10); 	
		annualInterestRateTextField = new TextField(20);
		monthlyPaymentTextField = new TextField(20);
		button = new Button("Calculate");
	
		inputPanel = new JPanel(new GridLayout(1,7));
		tablePanel = new JPanel(new GridLayout(1,0));
		data = new Object[20][6];
		String[] columnNames = {"month",
								"startingBalance", 
								"payment", 
								"middleBalance", 
								"interest", 
								"endingBalance"};
								
		table = new JTable(data, columnNames);
		scrollPane = new JScrollPane(table);
		
		DefaultTableCellRenderer rightAligned = new DefaultTableCellRenderer();
		rightAligned.setHorizontalAlignment(SwingConstants.RIGHT);
		table.getColumn("startingBalance").setCellRenderer(rightAligned);
		table.getColumn("startingBalance").setCellRenderer(rightAligned);
		table.getColumn("payment").setCellRenderer(rightAligned);
		table.getColumn("interest").setCellRenderer(rightAligned);
		table.getColumn("endingBalance").setCellRenderer(rightAligned);

		inputPanel.add(new Label("Loan Amount"));
		inputPanel.add(loanAmountTextField);
		inputPanel.add(new Label("Annual Rate"));
		inputPanel.add(annualInterestRateTextField);
		inputPanel.add(new Label("Monthly Payment"));		
		inputPanel.add(monthlyPaymentTextField);
		inputPanel.add(button);		
		tablePanel.add(scrollPane);
		Container container = getContentPane();
		container.add( tablePanel );   
		container.add( inputPanel, BorderLayout.NORTH);   

		button.addActionListener(this);
		setSize( 600, 300 );
		setVisible( true );
	}

	public void actionPerformed(ActionEvent ae) {
		double loanAmount, annualInterestRate, monthlyPayment;
		int month;
		double startingBalance, payment, middleBalance, interest, endingBalance;
		DecimalFormat decimalformat = new DecimalFormat("0.00");		
			
		loanAmount = Double.parseDouble(loanAmountTextField.getText());
		annualInterestRate = Double.parseDouble(annualInterestRateTextField.getText());
		monthlyPayment = Double.parseDouble(monthlyPaymentTextField.getText());

		month = 1;
		startingBalance = loanAmount;
		payment = monthlyPayment;
		middleBalance = loanAmount - payment;
		interest = middleBalance * annualInterestRate/12/100;
		endingBalance = middleBalance + interest;
		
		
		while (	startingBalance > 0){
			data[month-1][0] = new Integer(month);
			data[month-1][1] = decimalformat.format(startingBalance);
			data[month-1][2] = decimalformat.format(payment);
			data[month-1][3] = decimalformat.format(middleBalance);
			data[month-1][4] = decimalformat.format(interest);
			data[month-1][5] = decimalformat.format(endingBalance);
		
			month++;
			startingBalance = endingBalance;
			payment = (endingBalance > monthlyPayment?monthlyPayment:endingBalance);
			middleBalance =  startingBalance - payment;
			interest = middleBalance * annualInterestRate/12/100;
			endingBalance = middleBalance + interest;
		}
	
		for (int i=--month;i<20;i++) {
			data[i] = new Object[6];
		}
		
		table.repaint();
	}
}