package org.apidesign.apifest08.test;

 import org.apidesign.apifest08.currency.TimeRangeSpecificConvertor;

 import java.text.DateFormat;

 import java.text.ParseException;

 import java.text.SimpleDateFormat;

 import java.util.Currency;

 import java.util.Date;

 import junit.framework.TestCase;

 import org.apidesign.apifest08.currency.ConversionRate;

 import org.apidesign.apifest08.currency.Convertor;

 import org.apidesign.apifest08.currency.Convertor.ConversionResult;

 import org.apidesign.apifest08.currency.MonetaryAmount;

 import org.apidesign.apifest08.currency.TableConvertor;

 import org.apidesign.apifest08.currency.TimeRangeSpecificConvertor.TimeSpecificConversionRequest;

 /** The exchange rates are not always the same. They are changing. However

  * as in order to predict the future, one needs to understand own past. That is

  * why it is important to know the exchange rate as it was at any time during

  * the past.

  * <p>

  * Today's quest is to enhance the convertor API to deal with dates.

  * One shall be able to convert a currency at any date. Each currencies rate shall

  * be associated with a range between two Date objects. In order

  * to keep compatibility with old API that knew nothing about dates, the

  * rates associated then are applicable "for eternity". Any use of existing

  * convert methods that do not accept a Date argument, uses the current

  * System.currentTimeMillis() as default date.

  */

 public class Task4Test extends TestCase {

     public Task4Test(String testName) {

         super(testName);

     }

     @Override

     protected void setUp() throws Exception {

     }

     @Override

     protected void tearDown() throws Exception {

     }

     protected static final Currency CZK = Currency.getInstance( "CZK" );

     protected static final Currency SKK = Currency.getInstance( "SKK" );

     protected static final Currency USD = Currency.getInstance( "USD" );

     // Backward compatibly enhance your existing API to support following

     // usecases:

     //

     /** Takes a convertor with any rates associated and creates new convertor

      * that returns the same values as the old one for time between from to till.

      * Otherwise it returns no results. This is just a helper method that

      * shall call some real one in the API.

      * 

      * @param old existing convertor

      * @param from initial date (inclusive); null means since the Big Bang

      * @param till final date (exclusive); null means until the End of Universe

      * @return new convertor

      */

     public static Convertor limitTo( final Convertor old, final Date from, final Date till ) {

         return new TimeRangeSpecificConvertor( old, from, till );

     }

     private static final DateFormat DATE_FORMAT = new SimpleDateFormat( "yyyy-MM-dd HH:mm Z" );

     protected static Date parseGmtDate( final String string ) {

         final String zonedString = string + " GMT+0:00";

         try {

             return DATE_FORMAT.parse( zonedString );

         } catch ( final ParseException ex ) {

             throw new IllegalArgumentException( "Cannot parse " + zonedString, ex );

         }

     }

     public void testCompositionOfLimitedConvertors() throws Exception {

         final Date d1 = parseGmtDate( "2008-10-01 0:00" );

         final Date d2 = parseGmtDate( "2008-10-02 0:00" );

         final Date d3 = parseGmtDate( "2008-10-03 0:00" );

         final Convertor c = Task2Test.merge(

             limitTo(Task1Test.createCZKtoUSD(), d1, d2),

             limitTo(Task1Test.createSKKtoCZK(), d2, d3)

         );

         // convert $5 to CZK using c:

         final ConversionResult r1 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 5, USD ), CZK ) );

         final MonetaryAmount a1 = r1.getNetAmount();

         // cannot convert as no rate is applicable to current date

         assertNull( a1 );

         // convert $8 to CZK using c:

         final ConversionResult r2 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 8, USD ), CZK ) );

         final MonetaryAmount a2 = r2.getNetAmount();

         // cannot convert as no rate is applicable to current date

         assertNull( a2 );

         // convert 1003CZK to USD using c:

         final ConversionResult r3 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 1003, CZK ), USD ) );

         final MonetaryAmount a3 = r3.getNetAmount();

         // cannot convert as no rate is applicable to current date

         assertNull( a3 );

         // convert 16CZK using c:

         final ConversionResult r4 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 16, CZK ), USD ) );

         final MonetaryAmount a4 = r4.getNetAmount();

         // cannot convert as no rate is applicable to current date

         assertNull( a4 );

         // convert 500SKK to CZK using c:

         final ConversionResult r5 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 500, SKK ), CZK ) );

         final MonetaryAmount a5 = r5.getNetAmount();

         // cannot convert as no rate is applicable to current date

         assertNull( a5 );

         // convert $5 to CZK using c at 2008-10-01 6:00 GMT:

         final ConversionResult r6 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 5, USD ), CZK, parseGmtDate( "2008-10-01 6:00" ) ) );

         final MonetaryAmount a6 = r6.getNetAmount();

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

         assertNotNull( a6 );

         assertEquals( 85.0, a6.getAmount().doubleValue() );

         assertEquals( CZK, a6.getCurrency() );

         // convert $8 to CZK using c at 2008-10-01 6:00 GMT:

         final ConversionResult r7 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 8, USD ), CZK, parseGmtDate( "2008-10-01 6:00" ) ) );

         final MonetaryAmount a7 = r7.getNetAmount();

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

         assertNotNull( a7 );

         assertEquals( 136.0, a7.getAmount().doubleValue() );

         assertEquals( CZK, a7.getCurrency() );

         // convert 1003CZK to USD using c at 2008-10-01 6:00 GMT:

         final ConversionResult r8 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 1003, CZK ), USD, parseGmtDate( "2008-10-01 6:00" ) ) );

         final MonetaryAmount a8 = r8.getNetAmount();

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

         assertNotNull( a8 );

         assertEquals( 59.0, a8.getAmount().doubleValue() );

         assertEquals( USD, a8.getCurrency() );

         // convert 16CZK using c at 2008-10-02 9:00 GMT:

         final ConversionResult r9 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 16, CZK ), SKK, parseGmtDate( "2008-10-02 9:00" ) ) );

         final MonetaryAmount a9 = r9.getNetAmount();

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

         assertNotNull( a9 );

         assertEquals( 20.0, a9.getAmount().doubleValue() );

         assertEquals( SKK, a9.getCurrency() );

         // convert 500SKK to CZK using c at 2008-10-02 9:00 GMT:

         final ConversionResult r10 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 500, SKK ), CZK, parseGmtDate( "2008-10-02 9:00" ) ) );

         final MonetaryAmount a10 = r10.getNetAmount();

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

         assertNotNull( a10 );

         assertEquals( 400.0, a10.getAmount().doubleValue() );

         assertEquals( CZK, a10.getCurrency() );

         // convert 500SKK to CZK using c at 2008-10-01 6:00 GMT:

         final ConversionResult r11 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 500, SKK ), CZK, parseGmtDate( "2008-10-01 6:00" ) ) );

         final MonetaryAmount a11 = r11.getNetAmount();

         // cannot convert as no rate is applicable to current date

         assertNull( a11 );

     }

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

      *  SKK. Make 100 SKK == 90 CZK.

      *

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

      */

     public static Convertor createSKKtoCZK2() {

         final TableConvertor convertor = new TableConvertor();

         final MonetaryAmount amountInSKK = new MonetaryAmount( 100, SKK );

         final MonetaryAmount amountInCZK = new MonetaryAmount( 90, CZK );

         convertor.putIntoTable( new ConversionRate( amountInSKK, amountInCZK ) );

         convertor.putIntoTable( new ConversionRate( amountInCZK, amountInSKK ) );

         return new ContractImposingDelegatingConvertor( convertor ).test();

     }

     public void testDateConvetorWithTwoDifferentRates() throws Exception {

         final Date d1 = parseGmtDate( "2008-10-01 0:00" );

         final Date d2 = parseGmtDate( "2008-10-02 0:00" );

         final Date d3 = parseGmtDate( "2008-10-03 0:00" );

         final Convertor c = Task2Test.merge(

             limitTo(createSKKtoCZK2(), d1, d2),

             limitTo(Task1Test.createSKKtoCZK(), d2, d3)

         );

         // convert 500SKK to CZK using c at 2008-10-02 9:00 GMT:

         final ConversionResult r1 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 500, SKK ), CZK, parseGmtDate( "2008-10-02 9:00" ) ) );

         final MonetaryAmount a1 = r1.getNetAmount();

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

         assertNotNull( a1 );

         assertEquals( 400.0, a1.getAmount().doubleValue() );

         assertEquals( CZK, a1.getCurrency() );

         // convert 500SKK to CZK using c at 2008-10-01 6:00 GMT:

         final ConversionResult r2 = c.convert( new TimeSpecificConversionRequest( new MonetaryAmount( 500, SKK ), CZK, parseGmtDate( "2008-10-01 6:00" ) ) );

         final MonetaryAmount a2 = r2.getNetAmount();

         // assertEquals("Result is 450 CZK");

         assertNotNull( a2 );

         assertEquals( 450.0, a2.getAmount().doubleValue() );

         assertEquals( CZK, a2.getCurrency() );        

     }

 }