# InspectCargoDeliveryStatus.java

    /*
     * Copyright 2011 Marc Grue.
     *
     * 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.sample.dcicargo.sample_b.context.interaction.handling.inspection;

    import org.qi4j.api.injection.scope.This;
    import org.qi4j.api.mixin.Mixins;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.event.InspectArrivedCargo;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.event.InspectCargoInCustoms;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.event.InspectClaimedCargo;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.event.InspectLoadedCargo;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.event.InspectReceivedCargo;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.event.InspectUnhandledCargo;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.event.InspectUnloadedCargo;
    import org.qi4j.sample.dcicargo.sample_b.context.interaction.handling.inspection.exception.InspectionException;
    import org.qi4j.sample.dcicargo.sample_b.data.structure.cargo.Cargo;
    import org.qi4j.sample.dcicargo.sample_b.data.structure.handling.HandlingEvent;
    import org.qi4j.sample.dcicargo.sample_b.data.structure.handling.HandlingEventType;
    import org.qi4j.sample.dcicargo.sample_b.data.structure.location.Location;
    import org.qi4j.sample.dcicargo.sample_b.infrastructure.dci.Context;
    import org.qi4j.sample.dcicargo.sample_b.infrastructure.dci.RoleMixin;

    /**
     * Inspect Cargo Delivery Status (subfunction use case)
     *
     * Third and last step in the ProcessHandlingEvent use case.
     *
     * Updates our knowledge about a cargo delivery. All we know about the delivery is saved in
     * a Delivery value object that is replaced each time it's updated.
     *
     * Cargo is playing the Role of a Delivery Inspector that inspects a specific handling event
     * in order to update the Delivery status for the cargo.
     *
     * If the Delivery Inspector realizes that the cargo is not on track, proper notifications are
     * sent out so that the cargo owner can re-route the cargo or the system take some action.
     *
     * Handling cargo in customs is a completely different process and context than loading it onto
     * a ship, so each handling event has its own use case and thus its own Context. Each of those
     * (sub-)subfunction use cases/Contexts reflects our understanding of a real world process and
     * can be easily reviewed, maintained, specialized, tested etc. It's now easy to understand
     * what our program does and what we can expect from it - basically in one place in the code.
     */
    public class InspectCargoDeliveryStatus extends Context
    {
        DeliveryInspectorRole deliveryInspector;

        Location destination;
        HandlingEvent handlingEvent;
        Location handlingLocation;

        public InspectCargoDeliveryStatus( HandlingEvent handlingEvent )
        {
            this.handlingEvent = handlingEvent;

            Cargo cargo = loadEntity( Cargo.class, handlingEvent.trackingId().get().id().get() );
            deliveryInspector = rolePlayer( DeliveryInspectorRole.class, cargo );

            handlingLocation = handlingEvent.location().get();
            destination = cargo.routeSpecification().get().destination().get();
        }

        public InspectCargoDeliveryStatus( Cargo cargo )
        {
            deliveryInspector = rolePlayer( DeliveryInspectorRole.class, cargo );
            destination = cargo.routeSpecification().get().destination().get();

            handlingEvent = cargo.delivery().get().lastHandlingEvent().get();
            if( handlingEvent != null )
            {
                handlingLocation = handlingEvent.location().get();
            }
        }

        public void update()
            throws InspectionException
        {
            deliveryInspector.delegateInspection();
        }

        @Mixins( DeliveryInspectorRole.Mixin.class )
        public interface DeliveryInspectorRole
        {
            void setContext( InspectCargoDeliveryStatus context );

            void delegateInspection()
                throws InspectionException;

            class Mixin
                extends RoleMixin<InspectCargoDeliveryStatus>
                implements DeliveryInspectorRole
            {
                @This
                Cargo cargo;

                public void delegateInspection()
                    throws InspectionException
                {

                    // Step 1 - Determine handling event type

                    if( c.handlingEvent == null )
                    {
                        new InspectUnhandledCargo( cargo ).inspect();
                        return;
                    }
                    HandlingEventType handlingEventType = c.handlingEvent.handlingEventType().get();

                    // Step 2 - Delegate inspection

                    switch( handlingEventType )
                    {
                    case RECEIVE:
                        new InspectReceivedCargo( cargo, c.handlingEvent ).inspect();
                        break;

                    case LOAD:
                        new InspectLoadedCargo( cargo, c.handlingEvent ).inspect();
                        break;

                    case UNLOAD:
                        if( c.handlingLocation.equals( c.destination ) )
                        {
                            new InspectArrivedCargo( cargo, c.handlingEvent ).inspect();
                        }
                        else
                        {
                            new InspectUnloadedCargo( cargo, c.handlingEvent ).inspect();
                        }
                        break;

                    case CUSTOMS:
                        new InspectCargoInCustoms( cargo, c.handlingEvent ).inspect();
                        break;

                    case CLAIM:
                        new InspectClaimedCargo( cargo, c.handlingEvent ).inspect();
                        break;

                    default:
                        // No other handling event types
                    }
                }
            }
        }
    }