japod@58: package org.apidesign.apifest08.test;
japod@58: 
japod@58: import java.math.BigDecimal;
japod@58: import org.apidesign.apifest08.currency.ConvertorCurrency;
japod@58: import org.apidesign.apifest08.currency.ExchangeRate;
japod@58: import org.apidesign.apifest08.currency.IExchangeRateEngine;
japod@58: 
japod@58: /** Exchange rate engine which is periodicaly changing echange rate.
japod@58:  *  See <a href="http://wiki.apidesign.org/wiki/APIFest08:Task3">http://wiki.apidesign.org/wiki/APIFest08:Task3</a> for further description.
japod@58:  *
japod@58:  * @author arnostvalicek
japod@58:  */
japod@58: public class BouncingExchangeRateEngine implements IExchangeRateEngine {
japod@58:     
japod@58:     ConvertorCurrency fromCurrency;
japod@58:     BigDecimal fromValue;
japod@58:     ConvertorCurrency toCurrency;
japod@58:     BigDecimal toValueStart;
japod@58:     BigDecimal toValueStop;
japod@58:     BigDecimal step;
japod@58:     
japod@58:     BigDecimal toValue;
japod@58: 
japod@58:     
japod@58:     
japod@58:     
japod@58:     private BouncingExchangeRateEngine(ConvertorCurrency fromCurrency, BigDecimal fromValue, ConvertorCurrency toCurrency, BigDecimal toValueStart, BigDecimal toValueStop, BigDecimal step) {
japod@58:         this.fromCurrency = fromCurrency;
japod@58:         this.fromValue = fromValue;
japod@58:         this.toCurrency = toCurrency;
japod@58:         this.toValueStart = toValueStart;
japod@58:         this.toValueStop = toValueStop;
japod@58:         this.step = step;
japod@58:         this.toValue = toValueStart;
japod@58:     }
japod@58: 
japod@58: 
japod@58:     public static IExchangeRateEngine create(ConvertorCurrency fromCurrency, BigDecimal fromValue, ConvertorCurrency toCurrency, BigDecimal toValueStart, BigDecimal toValueStop, BigDecimal step) {
japod@58:         return new BouncingExchangeRateEngine(fromCurrency, fromValue, toCurrency, toValueStart, toValueStop, step);
japod@58:     }
japod@58: 
japod@58:     public ExchangeRate getExchangeRate(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency) {
japod@58:         if (!fromCurrency.equals(this.fromCurrency)) {
japod@58:             return null;
japod@58:         }
japod@58:         if (!toCurrency.equals(this.toCurrency)) {
japod@58:             return null;
japod@58:         }
japod@58:         
japod@58:         ExchangeRate result = new ExchangeRate(fromValue, toValue);
japod@58:         
japod@58:         toValue = toValue.add(step);
japod@58:         
japod@58: //        if (step.signum()==1 && toValueStop.compareTo(toValue)==0) {
japod@58: //            System.out.println("A");
japod@58: //            toValue=toValueStop;
japod@58: //            step = step.negate();
japod@58: //            BigDecimal x = toValueStart;
japod@58: //            toValueStart=toValueStop;
japod@58: //            toValueStop=x;
japod@58: //        } else if (step.signum()==-1 && toValueStop.compareTo(toValue)==0) {
japod@58: //            System.out.println("B");
japod@58: //            toValue=toValueStop;
japod@58: //            step = step.negate();
japod@58: //            BigDecimal x = toValueStart;
japod@58: //            toValueStart=toValueStop;
japod@58: //            toValueStop=x;
japod@58: //        }
japod@58:         if (toValueStop.compareTo(toValue)==0) {
japod@58:             toValue=toValueStop;
japod@58:             step = step.negate();
japod@58:             BigDecimal x = toValueStart;
japod@58:             toValueStart=toValueStop;
japod@58:             toValueStop=x;
japod@58:         }        
japod@58:         return result;
japod@58:     }
japod@58: 
japod@58: }