// package chapter9;

/**
 * Title:        Chapter 9, "Object-Oriented Software Development"
 * Description:  Examples for Chapter 9
 * Copyright:    Copyright (c) 2000
 * Company:      Armstrong Atlantic State University
 * @author Y. Daniel Liang
 * @version 1.0
 */

// Rational.java: Define a rational number and its associated
// operations such as add, subtract, multiply, and divide
public class Rational extends Number implements Comparable
{
  // Data fields for numerator and denominator
  private long numerator = 0;
  private long denominator = 1;

  /**Default constructor*/
  public Rational()
  {
    this(0, 1);
  }

  /**Construct a rational with specified numerator and denominator*/
  public Rational(long numerator, long denominator)
  {
    long gcd = gcd(numerator, denominator);
    this.numerator = numerator/gcd;
    this.denominator = denominator/gcd;
  }

  /**Find GCD of two numbers*/
  private long gcd(long n, long d)
  {
    long t1 = Math.abs(n);
    long t2 = Math.abs(d);
    long remainder = t1%t2;

    while (remainder != 0)
    {
      t1 = t2;
      t2 = remainder;
      remainder = t1%t2;
    }

    return t2;
  }

  /**Return numerator*/
  public long getNumerator()
  {
    return numerator;
  }

  /**Return denominator*/
  public long getDenominator()
  {
    return denominator;
  }

  /**Add a rational number to this rational*/
  public Rational add(Rational secondRational)
  {
    long n = numerator*secondRational.getDenominator() +
      denominator*secondRational.getNumerator();
    long d = denominator*secondRational.getDenominator();
    return new Rational(n, d);
  }

  /**Subtract a rational number from this rational*/
  public Rational subtract(Rational secondRational)
  {
    long n = numerator*secondRational.getDenominator()
      - denominator*secondRational.getNumerator();
    long d = denominator*secondRational.getDenominator();
    return new Rational(n, d);
  }

  /**Multiply a rational number to this rational*/
  public Rational multiply(Rational secondRational)
  {
    long n = numerator*secondRational.getNumerator();
    long d = denominator*secondRational.getDenominator();
    return new Rational(n, d);
  }

  /**Divide a rational number from this rational*/
  public Rational divide(Rational secondRational)
  {
    long n = numerator*secondRational.getDenominator();
    long d = denominator*secondRational.numerator;
    return new Rational(n, d);
  }

  /**Override the toString() method*/
  public String toString()
  {
    if (denominator == 1)
      return numerator + "";
    else
      return numerator + "/" + denominator;
  }

  /**Override the equals method*/
  public boolean equals(Object parm1)
  {
    /**@todo: Override this java.lang.Object method*/
    if ((this.subtract((Rational)(parm1))).getNumerator() == 0)
      return true;
    else
      return false;
  }

  /**Override the intValue method*/
  public int intValue()
  {
    /**@todo: implement this java.lang.Number abstract method*/
    return (int)doubleValue();
  }

  /**Override the floatValue method*/
  public float floatValue()
  {
    /**@todo: implement this java.lang.Number abstract method*/
    return (float)doubleValue();
  }

  /**Override the doubleValue method*/
  public double doubleValue()
  {
    /**@todo: implement this java.lang.Number abstract method*/
    return numerator*1.0/denominator;
  }

  /**Override the longValue method*/
  public long longValue()
  {
    /**@todo: implement this java.lang.Number abstract method*/
    return (long)doubleValue();
  }

  /**Override the compareTo method*/
  public int compareTo(Object o)
  {
    /**@todo: Implement this java.lang.Comparable method*/
    if ((this.subtract((Rational)o)).getNumerator() > 0)
      return 1;
    else if ((this.subtract((Rational)o)).getNumerator() < 0)
      return -1;
    else
      return 0;
  }
}