package org.apidesign.apifest08.test;

 import junit.framework.TestCase;

 import org.apidesign.apifest08.currency.Convertor;

 import org.apidesign.apifest08.currency.ConvertorFactory;

 import org.apidesign.apifest08.currency.CurrencyRate;

 import org.apidesign.apifest08.currency.CurrencyRateFactory;

 /** There are many currencies around the world and many banks manipulate

  * with more than one or two at the same time. As banks are usually the

  * best paying clients, which is true even in case of your Convertor API,

  * it is reasonable to listen to their requests.

  * <p>

  * The quest for today is to enhance your existing convertor API to hold

  * information about many currencies and allow conversions between any of them.

  * Also, as conversion rates for diferent currencies usually arise from various

  * bank departments, there is another important need. There is a need to

  * compose two convertors into one by merging all the information about

  * currencies they know about.

  */

 public class Task2Test extends TestCase {

     public Task2Test(String testName) {

         super(testName);

     }

     @Override

     protected void setUp() throws Exception {

     }

     @Override

     protected void tearDown() throws Exception {

     }

     // As in Task1Test, keep in mind, 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 backward compatibly enhance your existing API to support following

     // usecases:

     //

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

      *  SKK. Make 100 SKK == 75 CZK. This is method for the group of users that

      *  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.

      */

     public static Convertor createTripleConvertor() {

         // Rates: 1USD = 15CZK

         // Rates: 1USD = 20SKK

         // Rates: 75CZK = 100SKK

         CurrencyRate usdCzk = CurrencyRateFactory.getInstance().createCurrencyRate("USD", "CZK", 1, 15);

         CurrencyRate usdSkk = CurrencyRateFactory.getInstance().createCurrencyRate("USD", "SKK", 1, 20);

         CurrencyRate czkSkk = CurrencyRateFactory.getInstance().createCurrencyRate("CZK", "SKK", 75, 100);

         return ConvertorFactory.newInstance().createConvertor(usdCzk, usdSkk, czkSkk);        

     }

     /** Define convertor that understands three currencies. Use it.

      */

     public void testConvertorForUSDandCZKandSKK() throws Exception {

         Convertor c = createTripleConvertor();

         // convert $5 to CZK using c:

         // assertEquals("Result is 75 CZK");

         assertEquals("Result is 75 CZK", 75.0, c.convert("USD", "CZK", 5));

         // convert $5 to SKK using c:

         // assertEquals("Result is 100 SKK");

         assertEquals("Result is 100 SKK", 100.0, c.convert("USD", "SKK", 5));

         // convert 200SKK to CZK using c:

         // assertEquals("Result is 150 CZK");

         assertEquals("Result is 150 CZK", 150.0, c.convert("SKK", "CZK", 200));

         // convert 200SKK to USD using c:

         // assertEquals("Result is 10 USD");

         assertEquals("Result is 10 USD", 10.0, c.convert("SKK", "USD", 200));

     }

     /** Merge all currency rates of convertor 1 with convertor 2.

      * Implement this using your API, preferably this method just delegates

      * into some API method which does the actual work, without requiring

      * API clients to code anything complex.

      */

     public static Convertor merge(Convertor one, Convertor two) {

         return ConvertorFactory.newInstance().mergeConvertors(one,two);

     }

     /** Join the convertors from previous task, Task1Test and show that it

      * can be used to do reasonable conversions.

      */

     public void testConvertorComposition() throws Exception {

         Convertor c = merge(

             Task1Test.createCZKtoUSD(),

             Task1Test.createSKKtoCZK()

         );

         // convert $5 to CZK using c:

         // assertEquals("Result is 85 CZK");

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

         // convert $8 to CZK using c:

         // assertEquals("Result is 136 CZK");

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

         // convert 1003CZK to USD using c:

         // assertEquals("Result is 59 USD");

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

         // 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 using c:

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

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

         //test exceptions

         Convertor one = Task1Test.createCZKtoUSD();

         Convertor two = Task1Test.createSKKtoCZK();

         Convertor three = Task1Test.createSKKtoCZK();

         try {

             ConvertorFactory.newInstance().mergeConvertors(one,two,three);

             fail();

         } catch (IllegalArgumentException e) {

             //ok

         }

         //test exceptions

         try {

             ConvertorFactory.newInstance().mergeConvertors(c, two);

             fail();

         } catch (IllegalArgumentException e) {

             //ok

         }

         //try convertors from version 1

         Convertor v1one = ConvertorFactory.newInstance().createConvertor("CZE", "CZE", 1, 2);        

         assertEquals("CZE->CZE 1:2 10 expects 20", 20.0, v1one.convert("CZE", "CZE", 10));

         try {

             ConvertorFactory.newInstance().mergeConvertors(v1one, two);

             fail();

         } catch (IllegalArgumentException e) {

             //ok

         }

         Convertor v1two = ConvertorFactory.newInstance().createConvertor("EUR", "", 1, 2);

         assertEquals("EUR->'' 1:2 10 expects 20", 20.0, v1two.convert("EUR", "", 10));

         try {

             ConvertorFactory.newInstance().mergeConvertors(v1two, two);

             fail();

         } catch (IllegalArgumentException e) {

             //ok

         }

         Convertor v1three = ConvertorFactory.newInstance().createConvertor("EUR", "", 1, 2);

         assertEquals("''->EUR 1:2 10 expects 5", 5.0, v1three.convert("", "EUR", 10));

         try {

             ConvertorFactory.newInstance().mergeConvertors(v1three, two);

             fail();

         } catch (IllegalArgumentException e) {

             //ok

         }

     }

 }