package org.apidesign.apifest08.test;

 import junit.framework.TestCase;

 import org.apidesign.apifest08.currency.Convertor;

 import org.apidesign.apifest08.currency.ConvertorFactory;

 /** Finish the Convertor API, and then write bodies of methods inside

  * of this class to match the given tasks. To fullfil your task, use the

  * API define in the <code>org.apidesign.apifest08.currency</code> package.

  * Do not you reflection, or other hacks as your code

  * shall run without any runtime permissions.

  */

 public class Task1Test extends TestCase {

     public Task1Test(String testName) {

         super(testName);

     }

     @Override

     protected void setUp() throws Exception {

     }

     @Override

     protected void tearDown() throws Exception {

     }

     //

     // Imagine that there are three parts of the whole system:

     // 1. there is someone who knows the current exchange rate

     // 2. there is someone who wants to do the conversion

     // 3. there is the API between 1. and 2. which allows them to communicate

     // Please design such API

     //

     /** Create convertor that understands two currencies, CZK and

      *  USD. Make 1 USD == 17 CZK. This is a method provided for #1 group -

      *  e.g. those that know the exchange rate. They somehow need to create

      *  the objects from the API and tell them the exchange rate. The API itself

      *  knows nothing about any rates, before the createCZKtoUSD method is called.

      *

      * Creation of the convertor shall not require subclassing of any class

      * or interface on the client side.

      *

      * @return prepared convertor ready for converting USD to CZK and CZK to USD

      */

     public static Convertor createCZKtoUSD() {

         return ConvertorFactory.newInstance().createConvertor("CZK", "USD", 17, 1);

     }

     /** Create convertor that understands two currencies, CZK and

      *  SKK. Make 100 SKK == 80 CZK. Again this is method for the #1 group -

      *  it knows the exchange rate, and needs to use the API to create objects

      *  with the exchange rate. Anyone shall be ready to call this method without

      *  any other method being called previously. The API itself shall know

      *  nothing about any rates, before this method is called.

      *

      * Creation of the convertor shall not require subclassing of any class

      * or interface on the client side.

      * 

      * @return prepared convertor ready for converting SKK to CZK and CZK to SKK

      */

     public static Convertor createSKKtoCZK() {

         return ConvertorFactory.newInstance().createConvertor("SKK", "CZK", 100, 80);

     }

     //

     // now the methods for group #2 follow:

     // this group knows nothing about exchange rates, but knows how to use

     // the API to do conversions. It somehow (by calling one of the factory

     // methods) gets objects from the API and uses them to do the conversions.

     //

     /** Use the convertor from <code>createCZKtoUSD</code> method and do few conversions

      * with it.

      */

     public void testCurrencyCZKUSD() throws Exception {

         Convertor c = createCZKtoUSD();        

         // convert $5 to CZK using c:        

         assertEquals("Result is 85 CZK", 85.0, c.convert("USD", "CZK", 5));

         // convert $8 to CZK

         assertEquals("Result is 136 CZK", 136.0, c.convert("USD", "CZK", 8));

         // convert 1003CZK to USD

         assertEquals("Result is 59 CZK", 59.0, c.convert("CZK", "USD", 1003));

     }

     /** Use the convertor from <code>createSKKtoCZK</code> method and do few conversions

      * with it.

      */

     public void testCurrencySKKCZK() throws Exception {

         Convertor c = createSKKtoCZK();

         // convert 16CZK using c:

         // assertEquals("Result is 20 SKK");

         assertEquals("Result is 20 SKK", 20.0, c.convert("CZK", "SKK", 16));

         // convert 500SKK to CZK

         // assertEquals("Result is 400 CZK");

         assertEquals("Result is 400 SKK", 400.0, c.convert("SKK", "CZK", 500));

     }

     /** Verify that the CZK to USD convertor knows nothing about SKK.

      */

     public void testCannotConvertToSKKwithCZKUSDConvertor() throws Exception {

         Convertor c = createCZKtoUSD();

         // convert $5 to SKK, the API shall say this is not possible

         try {

             c.convert("USD", "SKK", 5);

             fail("Converting SKK with CZKUSD convertor is impossible");

         } catch (IllegalArgumentException e){

             //ok

         }

         // convert 500 SKK to CZK, the API shall say this is not possible

         try {

             c.convert("SKK", "CZK", 500);

             fail("Converting SKK with CZKUSD convertor is impossible");

         } catch (IllegalArgumentException e){

             //ok

         }

     }

     /** Verify that the CZK to SKK convertor knows nothing about USD.

      */

     public void testCannotConvertToUSDwithCZKSKKConvertor() throws Exception {

         Convertor c = createSKKtoCZK();

         // convert $5 to SKK, the API shall say this is not possible

         try {

             c.convert("USD", "SKK", 5);

             fail("Converting SKK with SKKCZK convertor is impossible");

         } catch (IllegalArgumentException e){

             //ok

         }

         // convert 500 CZK to USD, the API shall say this is not possible

         try {

             c.convert("CZK", "USD", 500);

             fail("Converting USD with SKKCZK convertor is impossible");

         } catch (IllegalArgumentException e){

             //ok

         }

     }

 }