import java.awt.*;
import java.util.Date;

public class pnlCreditCardCost extends Panel {
	private final int intFillH = GridBagConstraints.HORIZONTAL;
	private final int intFillN = GridBagConstraints.NONE;
	private final int intAnchorC = GridBagConstraints.CENTER;
	private final int intAnchorE = GridBagConstraints.EAST;
	private final int intAnchorW = GridBagConstraints.WEST;

	private TextField		txtBalance, txtRate, txtPayment;
	private Label			lblCost, lblTime, lblError;
	private Button			cmdCalc, cmdClear;

	private GridBagConstraints gbc(int gx, int gy, int gw, int gh, int gf, int ga) {
		GridBagConstraints gbcTemp = new GridBagConstraints();
		gbcTemp.weightx = 100;
		gbcTemp.weighty = 100;
		gbcTemp.gridx = gx;
		gbcTemp.gridy = gy;
		gbcTemp.gridwidth = gw;
		gbcTemp.gridheight = gh;
		gbcTemp.fill = gf;
		gbcTemp.anchor = ga;
		return gbcTemp;
	}

	public pnlCreditCardCost(boolean blnStandAlone) {
		super ();

		Label l;
		GridBagLayout gblLocal = null;
		GridBagConstraints gbcLocal = null;

		gblLocal = new GridBagLayout();
		setLayout(gblLocal);

		Font f;
		Panel p;

		f = new Font("TimesRoman", Font.BOLD, 15);
		l = new Label("Please Enter the Following:");
		l.setFont(f);
		gbcLocal = gbc(0, 0, 2, 1, intFillH, intAnchorW);
		gblLocal.setConstraints(l, gbcLocal);
		add(l);

		f = new Font("TimesRoman", Font.PLAIN, 15);

		l = new Label("Credit Card Balance: $", Label.RIGHT);
		l.setFont(f);
		gbcLocal = gbc(0, 1, 1, 1, intFillH, intAnchorE);
		gblLocal.setConstraints(l, gbcLocal);
		add(l);

		txtBalance = new TextField(10);
		txtBalance.setFont(f);
		gbcLocal = gbc(1, 1, 1, 1, intFillH, intAnchorW);
		gblLocal.setConstraints(txtBalance, gbcLocal);
		add(txtBalance);

		l = new Label("Annual Percentage Rate: %", Label.RIGHT);
		l.setFont(f);
		gbcLocal = gbc(0, 2, 1, 1, intFillH, intAnchorE);
		gblLocal.setConstraints(l, gbcLocal);
		add(l);

		txtRate = new TextField(10);
		txtRate.setFont(f);
		gbcLocal = gbc(1, 2, 1, 1, intFillH, intAnchorW);
		gblLocal.setConstraints(txtRate, gbcLocal);
		add(txtRate);

		l = new Label("Minimum Monthly Payment: $", Label.RIGHT);
		gbcLocal = gbc(0, 3, 1, 1, intFillH, intAnchorW);
		gblLocal.setConstraints(l, gbcLocal);
		l.setFont(f);
		add(l);

		txtPayment = new TextField(10);
		txtPayment.setFont(f);
		gbcLocal = gbc(1, 3, 1, 1, intFillH, intAnchorW);
		gblLocal.setConstraints(txtPayment, gbcLocal);
		add(txtPayment);

		f = new Font("TimesRoman", Font.BOLD, 12);

		l = new Label("Please DO NOT use when entering numbers:", Label.CENTER);
		l.setFont(f);
		gbcLocal = gbc(0, 4, 2, 1, intFillH, intAnchorC);
		gblLocal.setConstraints(l, gbcLocal);
		add(l);

		l = new Label("Dollar Signs ($) - Percent Signs (%) - Commas (,)", Label.CENTER);
		l.setFont(f);
		gbcLocal = gbc(0, 5, 2, 1, intFillH, intAnchorC);
		gblLocal.setConstraints(l, gbcLocal);
		add(l);

		p = CommandPanel(blnStandAlone);
		gbcLocal = gbc(0, 6, 2, 1, intFillH, intAnchorC);
		gblLocal.setConstraints(p, gbcLocal);
		add(p);

		f = new Font("TimesRoman", Font.PLAIN, 15);

		lblCost = new Label("", Label.CENTER);
		lblCost.setFont(f);
		gbcLocal = gbc(0, 7, 2, 1, intFillH, intAnchorC);
		gblLocal.setConstraints(lblCost, gbcLocal);
		add(lblCost);

		lblTime = new Label("", Label.CENTER);
		lblTime.setFont(f);
		gbcLocal = gbc(0, 8, 2, 1, intFillH, intAnchorC);
		gblLocal.setConstraints(lblTime, gbcLocal);
		add(lblTime);

		f = new Font("TimesRoman", Font.BOLD, 12);

		lblError = new Label("", Label.CENTER);
		lblError.setFont(f);
		gbcLocal = gbc(0, 9, 2, 1, intFillH, intAnchorC);
		gblLocal.setConstraints(lblError, gbcLocal);
		add(lblError);

	}

	public boolean action(Event  evt, Object  what) {
		if ( evt.target instanceof Button ) {
			if ( evt.target == cmdCalc ) {
				Calculate();
				validate();
				return true;
			}
			else if ( evt.target == cmdClear ) {
				Clear();
				return true;
			}
		}
		return super.handleEvent(evt);
	}

	private Panel CommandPanel(boolean blnStandAlone) {
		Panel pnlMain = new Panel();
		GridBagLayout gblLocal = new GridBagLayout();
		GridBagConstraints gbcLocal = null;
		Font f = new Font("TimesRoman", Font.PLAIN, 15);

		pnlMain.setLayout(gblLocal);


		cmdCalc = new Button("Calculate");
		cmdCalc.setFont(f);
		gbcLocal = gbc(0, 0, 1, 1, intFillN, intAnchorC);
		gblLocal.setConstraints(cmdCalc, gbcLocal);
		pnlMain.add(cmdCalc);

		cmdClear = new Button("Clear");
		cmdClear.setFont(f);
		gbcLocal = gbc(1, 0, 1, 1, intFillN, intAnchorC);
		gblLocal.setConstraints(cmdClear, gbcLocal);
		pnlMain.add(cmdClear);

		return pnlMain;
	}

	private void Clear() {
		txtBalance.setText("");
		txtRate.setText("");
		txtPayment.setText("");
		lblCost.setText("");
		lblTime.setText("");
		lblError.setText("");
		lblError.setBackground(Color.white);
	}

	private boolean Calculate() {
		String strRetVal = "";
		double dblBalance = 0;
		double dblRate = 0;
		double dblPayment = 0;
		double dblInterest = 0;
		double dblCost = 0;
		int intMonths = 0;
		int intYears = 0;

		clearError();

		strRetVal = "Credit Card Balance";
		if ( (txtBalance.getText() == null) || (txtBalance.getText().length() == 0) ) {
			setFocus(txtBalance);
			setError("Please enter the " + strRetVal);
			return false;
		}
		if ( !verifyString(txtBalance.getText(), strRetVal) ) {
			setFocus(txtBalance);
			return false;
		}
		dblBalance = new Double(txtBalance.getText()).doubleValue();
		if (dblBalance <= 0) {
			setFocus(txtBalance);
			setError("Please enter the " + strRetVal);
			return false;
		}

		strRetVal = "Annual Percentage Rate";
		if ( (txtRate.getText() == null) || (txtRate.getText().length() == 0) ) {
			setFocus(txtRate);
			setError("Please enter the " + strRetVal);
			return false;
		}
		if ( !verifyString(txtRate.getText(), strRetVal) ) {
			setFocus(txtRate);
			return false;
		}
		dblRate = new Double(txtRate.getText()).doubleValue();
		if (dblRate <= 0) {
			setFocus(txtRate);
			setError("Please enter the " + strRetVal);
			return false;
		}
		if (dblRate > 1) {
			dblRate /= 100;
		}
		dblRate /= 12;

		strRetVal = "Minimum Monthly Payment";
		if ( (txtPayment.getText() == null) || (txtPayment.getText().length() == 0) ) {
			setFocus(txtPayment);
			setError("Please enter the " + strRetVal);
			return false;
		}
		if ( !verifyString(txtPayment.getText(), strRetVal) ) {
			setFocus(txtPayment);
			return false;
		}
		dblPayment = new Double(txtPayment.getText()).doubleValue();
		if (dblPayment <= 0) {
			setFocus(txtPayment);
			setError("Please enter the " + strRetVal);
			return false;
		}

		dblCost = dblBalance;
		while ( dblBalance > 0 ) {
			intMonths++;
			if ( dblPayment > dblBalance )
				dblPayment = dblBalance;
			dblBalance -= dblPayment;
			dblInterest = dblBalance * dblRate;
			dblBalance += dblInterest;
			dblCost += dblInterest;
		}
		lblCost.setText("The cost will be $" + toCurrency(dblCost));
		intYears = intMonths / 12;
		intMonths = intMonths % 12;
		lblTime.setText("It will take " + intYears + " years, " + intMonths + " months to pay off");

		return true;
	}

	private String toCurrency(double dblValue) {
		String strRetVal = "";
		String string = "" + dblValue;
		if ( string.indexOf(".") < 0 )
			string += ".";
		string += "000";
		strRetVal = string.substring(string.indexOf("."), string.indexOf(".") + 3);
		string = string.substring(0, string.indexOf("."));
		if ( string.length() > 3 ) {
			strRetVal = string.substring(string.length()-3) + strRetVal;
			string = string.substring(0, string.length()-3);
			while ( string.length() > 3 ) {
				strRetVal = string.substring(string.length()-3) + "," + strRetVal;
				string = string.substring(0, string.length()-3);
			}
			strRetVal = string + "," + strRetVal;
		}
		else {
			strRetVal = string + strRetVal;
		}
		return strRetVal;
	}

	private void setError(String strError) {
		if ( lblError.getBackground() != Color.red ) {
			lblError.setText(strError);
			lblError.setBackground(Color.red);
		}
	}

	private void clearError() {
		lblError.setText("");
		lblError.setBackground(Color.white);
	}

	private boolean verifyString(String string, String label) {
		String strMsg1 = "Error: ";
		String strMsg2 = "";
		String strMsg3 = " Not Permitted";

		for ( int i=0; i<string.length(); i++ ) {
			switch (string.charAt(i)) {
				case '.':
				case '0':
				case '1':
				case '2':
				case '3':
				case '4':
				case '5':
				case '6':
				case '7':
				case '8':
				case '9':
					break;
				case '$':
					strMsg2 = "Dollar Signs ($)";
					break;
				case '%':
					strMsg2 = "Percent Signs (%)";
					break;
				case ',':
					strMsg2 = "Commas (,)";
					break;
				default:
					strMsg2 = "Non-Numeric Character   " + string.substring(i, i+1) + "  ";
					break;
			}
		}

		if ( strMsg2.length() > 0 ) {
			setError(strMsg1 + strMsg2 + strMsg3);
			return false;
		}
		return true;
	}

	private void setFocus(TextField txtField) {
		txtField.requestFocus();
		txtField.selectAll();
	}
}