/**
 * Unit-API - Units of Quantity API for Java
 * Copyright (c) 2014 Jean-Marie Dautelle, Werner Keil, V2COM
 * All rights reserved.
 *
 * See LICENSE.txt for details.
 */
package javax.measure;

/**
 * <p>
 * Represents a quantitative property of a phenomenon, body, or substance, that can be quantified by measurement. {@link javax.measure.quantity.Mass Mass}, time,
 * distance, heat, and angular separation are among the familiar examples of
 * quantitative properties.
 * </p>
 *
 * <code> Unit<Mass> pound = ... Quantity<Length> size = ... Sensor<Temperature><br>
 * thermometer = ... Vector3D<Speed> aircraftSpeed = ... </code>
 * </p>
 * 
 * @implSpec
 * This interface places no restrictions on the mutability of implementations,
 * however immutability is strongly recommended.
 * All implementations must be {@link Comparable}.
 *
 * @param <Q>
 *            The type of the quantity.
 *
 * @author <a href="mailto:[email protected]">Jean-Marie Dautelle</a>
 * @author <a href="mailto:[email protected]">Martin
 *         Desruisseaux</a>
 * @author <a href="mailto:[email protected]">Werner Keil</a>
 * @author <a href="mailto:[email protected]">Otavio Santana</a>
 * @see <a href="http://en.wikipedia.org/wiki/Quantity">Wikipedia: Quantity</a>
 * @see <a href="http://martinfowler.com/eaaDev/quantity.html"> Martin Fowler -
 *      Quantity</a>
 * @see <a href="http://en.wikipedia.org/wiki/Conversion_of_units">Wikipedia:
 *      Conversion of units</a>
 * @version 0.25, Date: 2014-12-07
 */
public interface Quantity<Q extends Quantity<Q>> {

        /**
         * Returns the sum of this {@code Quantity} with the one specified.
         *
         * @param augend
         *            the {@code Quantity} to be added.
         * @return {@code this + augend}.
         */
        Quantity<Q> add(Quantity<Q> augend);

        /**
         * Returns the difference between this {@code Quantity} and the one
         * specified.
         *
         * @param subtrahend
         *            the {@code Quantity} to be subtracted.
         * @return <code>this - that</code>.
         */
        Quantity<Q> subtract(Quantity<Q> subtrahend);

        /**
         * Returns the product of this {@code Quantity} divided by the {@code Quantity}
         * specified.
         *
         * @throws ClassCastException if the type of an element
         *         in the specified operation is incompatible with this
         *         quantity
         *         (<a href="#optional-restrictions">optional</a>)
         *
         * @param divisor
         *            the {@code Quantity} divisor.
         * @return <code>this / that</code>.
         */
        Quantity<?> divide(Quantity<?> divisor);

        /**
         * Returns the product of this {@code Quantity} divided by the {@code Number}
         * specified.
         *
         * @param divisor
         *            the {@code Number} divisor.
         * @return <code>this / that</code>.
         */
        Quantity<Q> divide(Number divisor);

        /**
         * Returns the product of this {@code Quantity} with the one specified.
         *
         * @throws ClassCastException if the type of an element
     *         in the specified operation is incompatible with this
     *         quantity
     *         (<a href="#optional-restrictions">optional</a>)
         *
         * @param that
         *            the {@code Quantity} multiplier.
         * @return <code>this * multiplier</code>.
         */
        Quantity<?> multiply(Quantity<?> multiplier);
        
        /**
         * Returns the product of this {@code Quantity} with the {@code Number} value
         * specified.
         *
         * @param that
         *            the {@code Number} multiplier.
         * @return <code>this * multiplier</code>.
         */
        Quantity<Q> multiply(Number multiplier);

        /**
         * Returns a {@code Quantity} whose unit is {@code unit.inverse()}.
         *
         * @return {@code Quantity with this.getUnit().inverse()}.
         */
        Quantity<?> inverse();

       /**
        * Returns this {@code Quantity} converted into another (compatible) {@code Unit}.
        *
        * @param unit the {@code Unit} to convert to.
        * @return the converted result.
        */
        Quantity<Q> to(Unit<Q> unit);
    
       /**
        * Casts this quantity to a parameterized unit of specified nature or throw a
        * <code>ClassCastException</code> if the dimension of the specified
        * quantity and this measure unit's dimension do not match. For example:<br/>
        * <code>
        *     Quantity<Length> length = BaseQuantity.of("2 km").asType(Length.class);
        * </code>
        * or
        * <code>
        *      Quantity<Speed> C = length.multiply(299792458).divide(second).asType(Speed.class);
        * </code>
        *
        * @param  <T> The type of the quantity.
        * @param  type the quantity class identifying the nature of the quantity.
        * @return this quantity parameterized with the specified type.
        * @throws ClassCastException
        *             if the dimension of this unit is different from the specified
        *             quantity dimension.
        * @throws UnsupportedOperationException
        *             if the specified quantity class does not have a public static
        *             field named "UNIT" holding the SI unit for the quantity.
        * @see Unit#asType(Class)
        */
        <T extends Quantity<T>> Quantity<T> asType(Class<T> type) throws ClassCastException;

        /**
         * Returns the value of this {@code Quantity}.
         *
         * @return a value.
         */
        Number getValue();

        /**
         * Returns the unit of this {@code Quantity}.
         *
         * @return the unit (shall not be {@code null}).
         */
        Unit<Q> getUnit();
}