package org.apidesign.apifest08.test;

import java.math.BigDecimal;

import java.util.Currency;

import junit.framework.TestCase;

import org.apidesign.apifest08.currency.Convertor;

import org.apidesign.apifest08.currency.ConvertorFactory;

import org.apidesign.apifest08.currency.InvalidConversionException;

/** 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 {

    private final static Currency CZK;

    private final static Currency SKK;

    private final static Currency USD;

    static

    {

        CZK = Currency.getInstance("CZK");

        SKK = Currency.getInstance("SKK");

        USD = Currency.getInstance("USD");

    }

    public Task1Test(String testName) {

        super(testName);

    }

    @Override

    protected void setUp() throws Exception {

    }

    @Override

    protected void tearDown() throws Exception {

    }

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

     *  USD. Make 1 USD == 17 CZK.

     *

     * 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.getConvertor("CZK", BigDecimal.valueOf(17.0), "USD", BigDecimal.valueOf(1)));

    }

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

     *  SKK. Make 100 SKK == 80 CZK.

     *

     * 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.getConvertor(Currency.getInstance("SKK"), BigDecimal.valueOf(100), Currency.getInstance("CZK"), BigDecimal.valueOf(80)));

    }

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

     * with it.

     */

    public void testCurrencyCZKUSD() throws Exception {

        Convertor  c = createCZKtoUSD();

        BigDecimal result;

        // convert $5 to CZK using c:

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

        result = c.convert(USD, CZK, BigDecimal.valueOf(5));

        assertEquals(new BigDecimal("85.00"), result);

        // convert $8 to CZK

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

        result = c.convert(USD, CZK, BigDecimal.valueOf(8));

        assertEquals(new BigDecimal("136.00"), result);

        // convert 1003CZK to USD

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

        result = c.convert(CZK, USD, BigDecimal.valueOf(1003));

        assertEquals(new BigDecimal("59.00"), result);

    }

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

     * with it.

     */

    public void testCurrencySKKCZK() throws Exception {

        Convertor c = createSKKtoCZK();

        BigDecimal result;

        // convert 16CZK using c:

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

        result = c.convert(CZK, SKK, BigDecimal.valueOf(16));

        assertEquals(new BigDecimal("20.00"), result);

        // convert 500SKK to CZK

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

        result = c.convert(SKK, CZK, BigDecimal.valueOf(500));

        assertEquals(new BigDecimal("400.00"), result);

   }

    /** 

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

     */

    public void testCannotConvertToSKKwithCZKUSDConvertor() 

        throws Exception 

    {

        Convertor c = createCZKtoUSD();

        try

        {

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

            c.convert(USD, SKK, BigDecimal.valueOf(5));

            fail("cannot use the CZKtoUSD converter to convert to SKK");

        }

        catch(InvalidConversionException ex)

        {       

            assertEquals("cannot convert to: SKK", ex.getMessage());

            assertEquals(SKK, ex.getBadCurrency());

            assertEquals(CZK, ex.getCurrencyA());

            assertEquals(USD, ex.getCurrencyB());

        }

        try

        {

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

            c.convert(SKK, CZK, BigDecimal.valueOf(5));

            fail("cannot use the CZKtoUSD converter to convert from SKK");

        }

        catch(InvalidConversionException ex)

        {            

            assertEquals("cannot convert from: SKK", ex.getMessage());

            assertEquals(SKK, ex.getBadCurrency());

            assertEquals(CZK, ex.getCurrencyA());

            assertEquals(USD, ex.getCurrencyB());

        }

    }

    /** 

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

     */

    public void testCannotConvertToUSDwithSKKCZKConvertor() 

        throws Exception 

    {

        Convertor c = createSKKtoCZK();

        try

        {

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

            c.convert(USD, SKK, BigDecimal.valueOf(5));

            fail("cannot use the CZKtoUSD converter to convert to SKK");

        }

        catch(InvalidConversionException ex)

        {       

            assertEquals("cannot convert from: USD", ex.getMessage());

            assertEquals(USD, ex.getBadCurrency());

            assertEquals(SKK, ex.getCurrencyA());

            assertEquals(CZK, ex.getCurrencyB());

        }

        try

        {

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

            c.convert(CZK, USD, BigDecimal.valueOf(500));

            fail("cannot use the CZKtoUSD converter to convert from SKK");

        }

        catch(InvalidConversionException ex)

        {            

            assertEquals("cannot convert to: USD", ex.getMessage());

            assertEquals(USD, ex.getBadCurrency());

            assertEquals(SKK, ex.getCurrencyA());

            assertEquals(CZK, ex.getCurrencyB());

        }

    }

}