package org.apidesign.apifest08.currency;

import java.math.BigDecimal;

/**

 * Exchange rate value. Contains <code>from</code> and <code>to</code> value.

 * 

 * @author arnostvalicek

 */

public class ExchangeRate {

    private BigDecimal numberFor;

    private BigDecimal numberGet;

    /**

     * Constructor for new exchange rate holding two values - <em>from value</em> and <em>to value</em>

     * @param fromValue Exchange rate <em>from value</em>

     * @param toValue Exchange rate <em>to value</em>

     */

    public  ExchangeRate(BigDecimal fromValue, BigDecimal toValue) {

        this.numberFor = fromValue;

        this.numberGet = toValue;

    }

    /**

     * Create new instance of <code>ExchangeRate</code> based on provided exchange rate, but swapping its

     * <em>from</em> and <em>to</em> value.

     * <p>

     * Provided exchange rate is not chaged, this method returns different instance describing reverted exchange rate.

     * 

     * @param rate Exchange rate which describes rate to be reverted.

     * @return Instance of reverted rate.

     */

    public static ExchangeRate createRevertedRate(ExchangeRate rate) {

        ExchangeRate reverted = new ExchangeRate(rate.getToValue(), rate.getFromValue());

        return reverted;

    }

    @Override

    public String toString() {

        return "for "+numberFor+" recieve "+numberGet+" @"+getClass().getName();

    }

    /**

     * Return exchange rate <em>from</em> value stored in this object.

     * @return Returns <em>from</em> value for this exchange rate.

     */

    public BigDecimal getFromValue() {

        return numberFor;

    }

    /**

     * Return exchange rate <em>to</em> value stored in this object.

     * @return Returns <em>to</em> value for this exchange rate.

     */

    public BigDecimal getToValue() {

        return numberGet;

    }

//    public ExchangeRate createExchangeRate(BigDecimal forValue, BigDecimal getValue) {

//        ExchangeRate rate = new ExchangeRate(forValue, getValue);

//        return rate;

//    }

}