japod@6: package org.apidesign.apifest08.currency;
japod@6: 
japod@33: import java.util.ArrayList;
japod@6: import java.util.Currency;
japod@20: import java.util.Hashtable;
japod@33: import java.util.List;
japod@20: 
japod@20: import org.apidesign.apifest08.currency.exceptions.ConvertorException;
japod@20: import org.apidesign.apifest08.currency.exceptions.InvalidCurrencyException;
japod@20: import org.apidesign.apifest08.currency.exceptions.UnknownConvertorException;
japod@6: 
japod@6: /**
japod@6:  * This is the skeleton class for your API. You need to make it public, so it is accessible to your client code
japod@6:  * (currently in Task1Test.java) file.
japod@6:  * <p>
japod@6:  * Feel free to create additional classes or rename this one, just keep all the API and its implementation in this
japod@6:  * package. Do not spread it outside to other packages.
japod@6:  */
japod@6: public class Convertor {
japod@6: 
japod@20:   private static Hashtable<String, ExchangeRate> exchangeRates;
japod@6: 
japod@33:   private Hashtable<String, ExchangeRate> convertorInstanceExchangeRates; 
japod@20: 
japod@33:   private Convertor(List<Currency> currencies) throws UnknownConvertorException {
japod@33: 	  convertorInstanceExchangeRates = new Hashtable<String, ExchangeRate>();
japod@33: 	  for (Currency currency1 : currencies) {
japod@33: 		for (Currency currency2 : currencies) {
japod@33: 			if(!currency1.getCurrencyCode().equals(currency2.getCurrencyCode())) {
japod@33: 				String key = currency1.getCurrencyCode() + currency2.getCurrencyCode();
japod@33: 				ExchangeRate exchangeRate = exchangeRates.get(key);
japod@33: 				convertorInstanceExchangeRates.put(key, exchangeRate);
japod@33: 			}
japod@33: 		}
japod@33: 	}
japod@20:   }
japod@20: 
japod@20:   /**
japod@20:    * Sets convertor rate for selected currencies.
japod@20:    * @param currency1
japod@20:    *          one of the currencies we want to convert to/from
japod@20:    * @param currency2
japod@20:    *          the other currency
japod@20:    * @param rate
japod@20:    *          exchange rate from currency1 to currency2
japod@20:    * @param unit
japod@20:    *          unit of exchangeRate (USD->CZK - unit=1, you exchange one dollar, SKK->CZK unit=100, exchange rate is for
japod@20:    *          100SKK)
japod@20:    */
japod@20:   public static void setConvertorRates(Currency currency1, Currency currency2, double rate, double unit) {
japod@20:     if (currency1 == null || currency2 == null) {
japod@20:       throw new ConvertorException("None of the currencies should be null!!!");
japod@20:     }
japod@20: 
japod@20:     if (rate <= 0 || unit <= 0) {
japod@20:       throw new ConvertorException("Rate(" + rate + ") and unit(" + unit + ") has to be grater then zero!!!");
japod@20:     }
japod@20: 
japod@20:     if (exchangeRates == null) {
japod@20:       exchangeRates = new Hashtable<String, ExchangeRate>();
japod@20:     }
japod@20: 
japod@20:     String key12 = currency1.getCurrencyCode() + currency2.getCurrencyCode();
japod@20:     String key21 = currency2.getCurrencyCode() + currency1.getCurrencyCode();
japod@20:     double recountedRate = (unit / rate) * unit;
japod@20: 
japod@20:     exchangeRates.put(key12, new ExchangeRate(currency1, currency2, rate, unit));
japod@20:     exchangeRates.put(key21, new ExchangeRate(currency2, currency1, recountedRate, unit));
japod@20: 
japod@6:   }
japod@33:   
japod@33:   /**
japod@33:    * Merge exchange rates of actual convertor with exchange rates from selected 
japod@33:    * convertor. If there are same currencies in both convertors, these from selected
japod@33:    * convertor rewrites these in actual convertor.
japod@33:    * @param convertor convertor to merge with actual one
japod@33:    * @return convertor with merged exchange rates 
japod@33:    */
japod@33:   public Convertor merge(Convertor convertor) {
japod@33: 	  convertorInstanceExchangeRates.putAll(convertor.getInstanceExchangeRates());
japod@33: 	  return this;
japod@33:   }
japod@6: 
japod@6:   /**
japod@6:    * Creates new instance of convertor.
japod@6:    * @param currency1
japod@6:    *          one of the currencies we want to convert to/from
japod@6:    * @param currency2
japod@6:    *          the other currency
japod@6:    * @return new instance of convertor
japod@20:    * @throws UnknownConvertorException
japod@20:    *           thrown if convertor for selected currencies has not been defined
japod@6:    */
japod@33:   public static Convertor getConvertorInstance(Currency... currencies) throws UnknownConvertorException {
japod@33:    	List<Currency> currencyList = new ArrayList<Currency>();
japod@33:    	
japod@33:    	if(currencies.length < 2) {
japod@33:    		throw new ConvertorException("To get convertor instance, you have to select at least two currencies!!!");
japod@33:    	}
japod@33: 
japod@33:    	for (Currency currency1 : currencies) {
japod@33:    		for (Currency currency2 : currencies) {
japod@33:    	   		if(currency1 == null || currency2 == null) {
japod@33:    	   			throw new ConvertorException("None of the currencies should be null!!!");
japod@33:    	   		}
japod@33:    	   		
japod@33:    			if(!currency1.getCurrencyCode().equals(currency2.getCurrencyCode())) {
japod@33:    				String key12 = currency1.getCurrencyCode() + currency2.getCurrencyCode();
japod@33:    				String key21 = currency2.getCurrencyCode() + currency1.getCurrencyCode();
japod@33:    				if (!(exchangeRates.containsKey(key12) && exchangeRates.containsKey(key21))) {
japod@33:    					throw new UnknownConvertorException("Selected convertor (" + currency1.getCurrencyCode() + "<->"
japod@33:    		    			+ currency2.getCurrencyCode() + ") has not defined exchange rates!!!");
japod@33:    				}
japod@33:    			}
japod@33: 		}
japod@33:    		
japod@33:    		currencyList.add(currency1);
japod@33: 	}
japod@33:     
japod@33:     return new Convertor(currencyList);
japod@6:   }
japod@6: 
japod@6:   /**
japod@6:    * Converts selected amout of selected currency to other currency of this convertor instance.
japod@6:    * @param amount
japod@6:    *          amount to convert
japod@20:    * @param originalCurrency
japod@6:    *          currency of this amount
japod@20:    * @param newCurrency
japod@20:    *          currency to which we want convert
japod@6:    * @return converted amount
japod@20:    * @throws InvalidCurrencyException
japod@20:    *           while one or both currencies doesn't fit for this convertor
japod@6:    */
japod@20:   public double convert(double amount, Currency originalCurrency, Currency newCurrency) throws InvalidCurrencyException {
japod@20:     ExchangeRate actualyUsedExchangeRate = null;
japod@6: 
japod@20:     if (originalCurrency == null) {
japod@20:       throw new ConvertorException("Original currency is null!!!");
japod@6:     }
japod@6: 
japod@20:     if (newCurrency == null) {
japod@20:       throw new ConvertorException("Destination currency is null!!!");
japod@6:     }
japod@6: 
japod@20:     actualyUsedExchangeRate = getExchangeRate(originalCurrency, newCurrency);
japod@20: 
japod@20:     return countResult(actualyUsedExchangeRate, amount);
japod@6:   }
japod@6: 
japod@20:   private double countResult(ExchangeRate actualyUsedExchangeRate, double amount) {
japod@20:     return amount * actualyUsedExchangeRate.getRate() / actualyUsedExchangeRate.getUnit();
japod@6:   }
japod@6: 
japod@6:   /**
japod@6:    * Decides the direction of conversion and returns instance of actual exchange rate.
japod@6:    * @param actualCurrency
japod@6:    *          actual currency we want to convert
japod@6:    * @return actual exchange rate of this convertor for selected currency
japod@6:    */
japod@20:   private ExchangeRate getExchangeRate(Currency originalCurrency, Currency newCurrency) throws InvalidCurrencyException {
japod@20:     ExchangeRate actualyUsedExchangeRate = null;
japod@33:     
japod@33:     String key = originalCurrency.getCurrencyCode() + newCurrency.getCurrencyCode();
japod@6: 
japod@33:     if(convertorInstanceExchangeRates.containsKey(key)) {
japod@33:       actualyUsedExchangeRate = convertorInstanceExchangeRates.get(key);
japod@20:     } else {
japod@33:       throw new InvalidCurrencyException("This convertor could not be used for converting selected currencies (" + originalCurrency.getCurrencyCode() + "->"
japod@20:           + newCurrency.getCurrencyCode() + ") !!!");
japod@6:     }
japod@6: 
japod@20:     return actualyUsedExchangeRate;
japod@6:   }
japod@33:   
japod@33:   /**
japod@33:    * Returns exchange rates for actual instance of convertor.
japod@33:    * @return exchange rates for actual instance of convertor
japod@33:    */
japod@33:   Hashtable<String, ExchangeRate> getInstanceExchangeRates() {
japod@33: 	  return convertorInstanceExchangeRates;
japod@6:   }
japod@33:   
japod@6: }