package org.apidesign.apifest08.currency;

 public final class Rate {

     private double rate;

     public Rate(int amountA, int amountB) {

         rate = amountA / (double)amountB;

         if (rate <= 0) {

             throw new IllegalArgumentException("Exchange rate must be positive.");

         }

     }

     public Rate(double amountA, double amountB) {

         rate = amountA / amountB;

         if (rate <= 0) {

             throw new IllegalArgumentException("Exchange rate must be positive.");

         }

     }

     public Rate(double rate) {

         this.rate = rate;

         if (this.rate <= 0) {

             throw new IllegalArgumentException("Exchange rate must be positive.");

         }

     }

     public double convertAtoB(int a) {

         return a / rate;

     }

     public double convertAtoB(double a) {

         return a / rate;

     }

     public double convertBtoA(int b) {

         return b * rate;

     }

     public double convertBtoA(double b) {

         return b * rate;

     }

     @Override

     public boolean equals(Object obj) {

         if (obj == null) {

             return false;

         }

         if (getClass() != obj.getClass()) {

             return false;

         }

         final Rate other = (Rate) obj;

         return true;

     }

     @Override

     public int hashCode() {

         int hash = 5;

         return hash;

     }

     @Override

     public String toString() {

         return ""+rate;

     }

 }