package org.apidesign.apifest08.currency;

import static org.apidesign.apifest08.currency.Assert.notNull;

import java.math.BigDecimal;

import java.math.RoundingMode;

import java.util.Currency;

/**

 * An amount representation. Amount is represented as composition of a value and 

 * a currency.

 */

public final class Amount {

	private final BigDecimal value;

	private final Currency currency;

	private final int scale;

	private final RoundingMode roundingMode;

	public static final RoundingMode DEFAULT_ROUNDING = RoundingMode.HALF_EVEN; 

	public Amount(final BigDecimal value, final Currency currency) {

		notNull(value, "value");

		notNull(currency, "currency");

		this.value = value;

		this.currency = currency;

		this.scale = currency.getDefaultFractionDigits();

		this.roundingMode = DEFAULT_ROUNDING;

	}

	public Amount(final BigDecimal value, final Currency currency, final RoundingMode roundingMode) {

		notNull(value, "value");

		notNull(currency, "currency");

		notNull(roundingMode, "roundingMode");

		this.value = value;

		this.currency = currency;

		this.scale = currency.getDefaultFractionDigits();

		this.roundingMode = roundingMode;

	}

	public Amount(final long value, final Currency currency) {

		this(BigDecimal.valueOf(value), currency);

	}

	public Amount(final String value, final Currency currency) {

		this(new BigDecimal(value), currency);

	}

	/**

	 * @return the value with scale of the associated currency and rounded by 

	 * the rounding mode. 

	 */

	public BigDecimal getValue() {

		return value.setScale(scale, roundingMode);

	}

	/**

	 * @return the raw (no explicit scale, no explicit rounding) value 

	 */

	public BigDecimal getRawValue() {

		return value;

	}

	public Currency getCurrency() {

		return currency;

	}

	public int getScale() {

		return scale;

	}

	public RoundingMode getRoundingMode() {

		return roundingMode;

	}

	@Override

	public String toString() {

		return value + ",- " + currency.toString();

	}	

}