/*
** Java currency library package.
** Copyright (c) 1999 by Bruno Antunes
**
** This program is free software.
**
** You may redistribute it and/or modify it under the terms of the GNU
** General Public License as published by the Free Software Foundation.
** Version 2 of the license should be included with this distribution in
** the file LICENSE, as well as License.html. If the license is not
** included	with this distribution, you may find a copy at the FSF web
** site at 'www.gnu.org' or 'www.fsf.org', or you may write to the
** Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.
**
** THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY OF ANY KIND,
** NOT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY. THE AUTHOR
** OF THIS SOFTWARE, ASSUMES _NO_ RESPONSIBILITY FOR ANY
** CONSEQUENCE RESULTING FROM THE USE, MODIFICATION, OR
** REDISTRIBUTION OF THIS SOFTWARE.
**
*/
package org.gjt.currency;

import java.math.BigDecimal;
import java.io.Serializable;

/**
 * A money representation. The money is allays represented by
 * an amount (the amount of money) and its currency.
 * <br>
 * Moneys are constant; their values cannot be changed after they are
 * created.
 *
 * @see Currency
 *
 * @author Bruno Antunes
 * @version 1.0 7/05/1999
 */
public class Money  implements Comparable, Cloneable, Serializable {
  private double amount;
  private Currency currency;

  /**
   * A zero amount of money in the specified currency
   *
   * @param aCurrency the currency for this amount of money
   */
  public Money(Currency aCurrency) {
    this(0.0,aCurrency);
  }

  /**
   * A specified amount of money in the specified currency
   *
   * @param anAmount the amount of money
   * @param aCurrency the currency for this amount of money
   */
  public Money(double anAmount, Currency aCurrency) {
    amount = anAmount;
    currency = aCurrency;
  }

  /**
   * Converts this money to the <code>Curency</code> specified.
   *
   * @param toCurrency the currency unit to convert the money
   * @return a new Money object in the specified unit. If the unit specified is
   * the same of this <code>Money</code>, the same <code>Money</code> object is
   * returned.
   *
   * @see Currency
   */
  public Money convertTo(Currency toCurrency) {
    Money result = null;
    if (currency.equals(toCurrency)) {
      return this;
    } else {
      // TOSEE: Is it necessary to make rounds?
      // TOSEE: Is it ok for non Euro currencys?
      double newAmount = amount / currency.getExchangeRate();
      newAmount = newAmount * toCurrency.getExchangeRate();
      result = new Money(newAmount, toCurrency);
    }
    return result;
  }

  /**
   * Adds the money specified to this money
   *
   * @param money the money to be added
   * @return (this + money)
   */
  public Money add(Money money) {
    Money toAdd = money.convertTo(currency);
    double newAmount = amount + toAdd.amount;
    return new Money(newAmount,currency);
  }

  /**
   * Subtracts the money specified to this money
   *
   * @param money the money to be subtracted
   * @return (this - money)
   */
  public Money subtract(Money money) {
    Money toSubtract = money.convertTo(currency);
    double newAmount = amount - toSubtract.amount;
    return new Money(newAmount,currency);
  }

  /**
   * Multiplies this money with a specified factor
   *
   * @param factor the value os the multiplier
   * @return this * factor
   */
  public Money multiply(double factor) {
    return new Money(amount * factor, currency);
  }

  /**
   * Compares this money with the specified money.
   *
   * @param money Money to which this Money is to be compared.
   * @return -1, 0 or 1 as this Money is numerically less than, equal
   * to, or greater than money.
   */
  public int compareTo(Money money) {
    money = money.convertTo(currency);
    if (amount < money.amount) {
      return -1;
    } else if (amount == money.amount) {
      return 0;
    } else {
      return 1;
    }
  }

  /**
   * Compares this money with the specified object. If the object is not a
   * <code>Money</code>, then a <code>ClassCastException</code> is thronw.
   *
   * @param obj Money to which this Money is to be compared.
   * @return -1, 0 or 1 as this Money is numerically less than, equal
   * to, or greater than money.
   *
   * @throws ClassCastException if obj is not a BigMoney.
   * @see Comparable
   */
  public int compareTo(Object obj) {
    Money money = (Money) obj;
    money = money.convertTo(currency);
    if (amount < money.amount) {
      return -1;
    } else if (amount == money.amount) {
      return 0;
    } else {
      return 1;
    }
  }

  /**
   * Compares the specified Object with this Money for equality.
   *
   * @param o the Object to be compared for equality with this Money
   * @return true if the specified Object is equal to this Money
   */
  public boolean equals(Object obj) {
    if (obj instanceof Money) {
      Money money = (Money) obj;
      return currency.equals(money.currency) &&
             amount == money.amount;
    } else {
      return false;
    }
  }

  public double getAmount() {
    return amount;
  }

  public Currency getCurrency() {
    return currency;
  }

  /**
   * String representation of the amount of money formatted using the
   * NumberFormatter registered in the <code>CurrenyFormatManager</code>
   *
   * @return the formatted money
   *
   * @see CurrenyFormatManager
   */
  public String format() {
    return CurrenyFormatManager.getCurrencyFormat(currency).format(amount);
  }

  /** @return a String representation of this money */
  public String toString() {
    return amount + ";" + currency.toString();
  }

  public Object clone() {
    return this;
  }
}