japod@6: package org.apidesign.apifest08.test;
japod@6: 
japod@6: import java.util.Currency;
japod@6: 
japod@6: import junit.framework.TestCase;
japod@6: 
japod@6: import org.apidesign.apifest08.currency.Convertor;
japod@20: import org.apidesign.apifest08.currency.exceptions.InvalidCurrencyException;
japod@20: import org.apidesign.apifest08.currency.exceptions.UnknownConvertorException;
japod@6: 
japod@6: /**
japod@6:  * Finish the Convertor API, and then write bodies of methods inside of this class to match the given tasks. To fullfil
japod@6:  * your task, use the API define in the <code>org.apidesign.apifest08.currency</code> package. Do not you reflection, or
japod@6:  * other hacks as your code shall run without any runtime permissions.
japod@6:  */
japod@6: public class Task1Test extends TestCase {
japod@6:   public Task1Test(String testName) {
japod@6:     super(testName);
japod@6:   }
japod@6: 
japod@6:   @Override
japod@6:   protected void setUp() throws Exception {
japod@6:   }
japod@6: 
japod@6:   @Override
japod@6:   protected void tearDown() throws Exception {
japod@6:   }
japod@6: 
japod@20:   //
japod@20:   // Imagine that there are three parts of the whole system:
japod@20:   // 1. there is someone who knows the current exchange rate
japod@20:   // 2. there is someone who wants to do the conversion
japod@20:   // 3. there is the API between 1. and 2. which allows them to communicate
japod@20:   // Please design such API
japod@20:   //
japod@20: 
japod@6:   /**
japod@20:    * Create convertor that understands two currencies, CZK and USD. Make 1 USD == 17 CZK. This is a method provided for
japod@20:    * #1 group - e.g. those that know the exchange rate. They somehow need to create the objects from the API and tell
japod@20:    * them the exchange rate. The API itself knows nothing about any rates, before the createCZKtoUSD method is called.
japod@20:    * Creation of the convertor shall not require subclassing of any class or interface on the client side.
japod@6:    * @return prepared convertor ready for converting USD to CZK and CZK to USD
japod@6:    */
japod@6:   public static Convertor createCZKtoUSD() {
japod@20:     // set exchange rates
japod@20:     Convertor.setConvertorRates(Currency.getInstance("USD"), Currency.getInstance("CZK"), 17d, 1d);
japod@20: 
japod@20:     // create new instance
japod@20:     Convertor convertor = null;
japod@20:     try {
japod@20:       convertor = Convertor.getConvertorInstance(Currency.getInstance("USD"), Currency.getInstance("CZK"));
japod@20:     } catch (UnknownConvertorException e) {
japod@20:       e.printStackTrace();
japod@20:     }
japod@20: 
japod@20:     return convertor;
japod@6:   }
japod@6: 
japod@6:   /**
japod@20:    * Create convertor that understands two currencies, CZK and SKK. Make 100 SKK == 80 CZK. Again this is method for the
japod@20:    * #1 group - it knows the exchange rate, and needs to use the API to create objects with the exchange rate. Anyone
japod@20:    * shall be ready to call this method without any other method being called previously. The API itself shall know
japod@20:    * nothing about any rates, before this method is called. Creation of the convertor shall not require subclassing of
japod@20:    * any class or interface on the client side.
japod@6:    * @return prepared convertor ready for converting SKK to CZK and CZK to SKK
japod@6:    */
japod@6:   public static Convertor createSKKtoCZK() {
japod@20:     // set exchange rates
japod@20:     Convertor.setConvertorRates(Currency.getInstance("SKK"), Currency.getInstance("CZK"), 80d, 100d);
japod@20: 
japod@20:     // create new instance
japod@20:     Convertor convertor = null;
japod@20:     try {
japod@20:       convertor = Convertor.getConvertorInstance(Currency.getInstance("SKK"), Currency.getInstance("CZK"));
japod@20:     } catch (UnknownConvertorException e) {
japod@20:       e.printStackTrace();
japod@20:     }
japod@20: 
japod@20:     return convertor;
japod@6:   }
japod@6: 
japod@20:   //
japod@20:   // now the methods for group #2 follow:
japod@20:   // this group knows nothing about exchange rates, but knows how to use
japod@20:   // the API to do conversions. It somehow (by calling one of the factory
japod@20:   // methods) gets objects from the API and uses them to do the conversions.
japod@20:   //
japod@20: 
japod@6:   /**
japod@6:    * Use the convertor from <code>createCZKtoUSD</code> method and do few conversions with it.
japod@6:    */
japod@6:   public void testCurrencyCZKUSD() throws Exception {
japod@6:     Convertor c = createCZKtoUSD();
japod@6:     // convert $5 to CZK using c:
japod@20:     double result = c.convert(5, Currency.getInstance("USD"), Currency.getInstance("CZK"));
japod@6:     assertEquals("Result is not 85 CZK", 85.0, result);
japod@6: 
japod@6:     // convert $8 to CZK
japod@20:     result = c.convert(8, Currency.getInstance("USD"), Currency.getInstance("CZK"));
japod@6:     assertEquals("Result is not 136 CZK", 136.0, result);
japod@6: 
japod@6:     // convert 1003CZK to USD
japod@20:     result = c.convert(1003, Currency.getInstance("CZK"), Currency.getInstance("USD"));
japod@6:     assertEquals("Result is not 59 USD", 59.0, result);
japod@6:   }
japod@6: 
japod@6:   /**
japod@6:    * Use the convertor from <code>createSKKtoCZK</code> method and do few conversions with it.
japod@6:    */
japod@6:   public void testCurrencySKKCZK() throws Exception {
japod@6:     Convertor c = createSKKtoCZK();
japod@6: 
japod@6:     // convert 16CZK using c:
japod@20:     double result = c.convert(16, Currency.getInstance("CZK"), Currency.getInstance("SKK"));
japod@6:     assertEquals("Result is not 20 SKK", 20.0, result);
japod@6: 
japod@6:     // convert 500SKK to CZK
japod@20:     result = c.convert(500, Currency.getInstance("SKK"), Currency.getInstance("CZK"));
japod@6:     assertEquals("Result is not 400 CZK", 400.0, result);
japod@6:   }
japod@20: 
japod@20:   /**
japod@20:    * Verify that the CZK to USD convertor knows nothing about SKK.
japod@20:    */
japod@20:   public void testCannotConvertToSKKwithCZKUSDConvertor() throws Exception {
japod@20:     Convertor c = createCZKtoUSD();
japod@20:     boolean exceptionThrown = false;
japod@20: 
japod@20:     // convert $5 to SKK, the API shall say this is not possible
japod@20:     try {
japod@20:       c.convert(5, Currency.getInstance("USD"), Currency.getInstance("SKK"));
japod@20:       exceptionThrown = false;
japod@20:     } catch (InvalidCurrencyException e) {
japod@20:       exceptionThrown = true;
japod@20:     }
japod@20:     assertEquals("It should be impossible to convert to SKK with USD->CZK convertor", true, exceptionThrown);
japod@20: 
japod@20:     // convert 500 SKK to CZK, the API shall say this is not possible
japod@20:     try {
japod@20:       c.convert(500, Currency.getInstance("SKK"), Currency.getInstance("CZK"));
japod@20:       exceptionThrown = false;
japod@20:     } catch (InvalidCurrencyException e) {
japod@20:       exceptionThrown = true;
japod@20:     }
japod@20:     assertEquals("It should be impossible to convert from SKK with USD->CZK convertor", true, exceptionThrown);
japod@20: 
japod@20:   }
japod@20: 
japod@20:   /**
japod@20:    * Verify that the CZK to SKK convertor knows nothing about USD.
japod@20:    */
japod@20:   public void testCannotConvertToSKKwithSKKCZKConvertor() throws Exception {
japod@20:     Convertor c = createSKKtoCZK();
japod@20:     boolean exceptionThrown = false;
japod@20: 
japod@20:     // convert $5 to SKK, the API shall say this is not possible
japod@20:     try {
japod@20:       c.convert(5, Currency.getInstance("USD"), Currency.getInstance("SKK"));
japod@20:       exceptionThrown = false;
japod@20:     } catch (InvalidCurrencyException e) {
japod@20:       exceptionThrown = true;
japod@20:     }
japod@20:     assertEquals("It should be impossible to convert form USD with SKK->CZK convertor", true, exceptionThrown);
japod@20: 
japod@20:     // convert 500 CZK to USD, the API shall say this is not possible
japod@20:     try {
japod@20:       c.convert(500, Currency.getInstance("CZK"), Currency.getInstance("USD"));
japod@20:       exceptionThrown = false;
japod@20:     } catch (InvalidCurrencyException e) {
japod@20:       exceptionThrown = true;
japod@20:     }
japod@20:     assertEquals("It should be impossible to convert to USD with SKK->CZK convertor", true, exceptionThrown);
japod@20:   }
japod@6: }