package cs160.util;

import org.apache.log4j.Logger;

public class Calculator
{
    static final String CLASS_NAME =
        Calculator.class.getName();

    static Logger mainLogger =
        Logger.getLogger(CLASS_NAME);
    static Logger addLogger =
        Logger.getLogger(CLASS_NAME + ".add");
    static Logger subtractLogger =
        Logger.getLogger(CLASS_NAME + ".subtract");

    public double add(double first, double second)
    {
        addLogger.info("Called add");
        addLogger.debug("first=" + first +
                        ", second=" + second);
        return first + second;
    }

    public double subtract(double first, double second)
    {
        subtractLogger.info("Called subtract");
        subtractLogger.debug("first=" + first +
                             ", second=" + second);
        return first - second;
    }

    public static void main(String args[])
    {
        mainLogger.info("Start application.");
        Calculator calc = new Calculator();

        double result = calc.add(40, 30);
        mainLogger.debug("add() returned " + result);

        calc.subtract(40, 30);
        mainLogger.debug("subtract() returned " + result);

        mainLogger.info("End application.");
    }
}