package org.apidesign.apifest08.currency;

import java.math.BigDecimal;

import java.math.RoundingMode;

import java.util.Currency;

/**

 * Intern implementation of Bidirectional Convertor - this class is only for internal purposes only.

 * This implementation uses BigDecimals to count result value

 * Scale is set by ISO 4217 as default

 *

 * @author Ladislav Vitasek

 */

class CurrencyConvertorImpl extends AbstractCurrencyConvertor {

    protected RoundingMode roundingMode;

    protected int currency1Scale;

    protected int currency2Scale;

    /**

     * Constructor

     * By default it creates convertor with conversion value 1

     *

     * @param currency1       currency for conversion

     * @param currency2       currency for conversion

     * @param provider constants provider

     * @param roundingMode    math rounding mode

     */

    CurrencyConvertorImpl(Currency currency1, Currency currency2, ConversionRatioProvider provider, RoundingMode roundingMode) {

        this(currency1, currency2, provider, roundingMode, currency1.getDefaultFractionDigits(), currency2.getDefaultFractionDigits());

    }

    /**

     * Constructor

     *

     * @param currency1       currency for conversion

     * @param currency2       currency for conversion

     * @param conversionRatioProvider conversion constants provider

     * @param roundingMode    math rounding mode

     * @param conversionRatioProvider constants provider

     * @param currency2Scale

     */

    CurrencyConvertorImpl(Currency currency1, Currency currency2, ConversionRatioProvider conversionRatioProvider, RoundingMode roundingMode, int currency1Scale, int currency2Scale) {

        super(currency1, currency2, conversionRatioProvider);

        this.roundingMode = roundingMode;

        this.currency1Scale = currency1Scale;

        this.currency2Scale = currency2Scale;

    }

    public BigDecimal convertCurrency1ToCurrency2(BigDecimal amountOfMoney) throws CannotConvertException {

        try {

            final BigDecimal result = amountOfMoney.multiply(getConversionRatioProvider().getCurrency1ToCurrency2Constant());

            return result.setScale(getCurrency2Scale(), getRoundingMode());

        } catch (CannotProvideValueException e) {

            throw new CannotConvertException(e);            

        } catch (ArithmeticException e) {

            throw new CannotConvertException(e);

        }

    }

    public BigDecimal convertCurrency2ToCurrency1(BigDecimal amountOfMoney) throws CannotConvertException {

        try {

            final BigDecimal result = amountOfMoney.multiply(getConversionRatioProvider().getCurrency2ToCurrency1Constant());

            return result.setScale(getCurrency1Scale(), getRoundingMode());

        } catch (CannotProvideValueException e) {

            throw new CannotConvertException(e);

        } catch (ArithmeticException e) {

            throw new CannotConvertException(e);

        }

    }

    public String toString() {

        return "CurrencyConvertorImpl{" +

                "currency1=" + getCurrency1() +

                ",currency2=" + getCurrency2() +

                ", roundingMode=" + roundingMode +

                ", currency1Scale=" + currency1Scale +

                ", currency2Scale=" + currency2Scale +

                '}';

    }

    RoundingMode getRoundingMode() {

        return roundingMode;

    }    

    int getCurrency1Scale() {

        return currency1Scale;

    }

    int getCurrency2Scale() {

        return currency2Scale;

    }

    void setRoundingMode(RoundingMode roundingMode) {

        this.roundingMode = roundingMode;

    }

    void setCurrency1Scale(int currency1Scale) {

        this.currency1Scale = currency1Scale;

    }

    void setCurrency2Scale(int currency2Scale) {

        this.currency2Scale = currency2Scale;

    }

}