# ShippingServiceImpl.java

    /*
     * Copyright 2007, 2008 Niclas Hedhman.
     *
     * Licensed  under the  Apache License,  Version 2.0  (the "License");
     * you may not use  this file  except in  compliance with the License.
     * You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed  under the  License is distributed on an "AS IS" BASIS,
     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
     * implied.
     *
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    package org.qi4j.tutorials.cargo.step1.internal;

    import org.qi4j.tutorials.cargo.step1.BookingPolicy;
    import org.qi4j.tutorials.cargo.step1.Cargo;
    import org.qi4j.tutorials.cargo.step1.ShippingService;
    import org.qi4j.tutorials.cargo.step1.Voyage;

    public class ShippingServiceImpl
        implements ShippingService
    {
        private BookingPolicy bookingPolicy;
        private SimpleSequenceImpl orderConfirmationSequence;

        public ShippingServiceImpl( BookingPolicy bookingPolicy )
        {
            this.bookingPolicy = bookingPolicy;
            orderConfirmationSequence = new SimpleSequenceImpl();
        }

        @Override
        public int makeBooking( Cargo cargo, Voyage voyage )
        {
            if( !bookingPolicy.isAllowed( cargo, voyage ) )
            {
                return -1;
            }
            int confirmation = orderConfirmationSequence.next();
            if( voyage instanceof VoyageImpl )
            {
                ( (VoyageImpl) voyage ).addCargo( cargo, confirmation );
            }
            else
            {
                return -1;
            }
            return confirmation;
        }
    }