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/**
 * Copyright (C) 2014 uniknow. All rights reserved.
 * 
 * This Java class is subject of the following restrictions:
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The end-user documentation included with the redistribution, if any, must
 * include the following acknowledgment: "This product includes software
 * developed by uniknow." Alternately, this acknowledgment may appear in the
 * software itself, if and wherever such third-party acknowledgments normally
 * appear.
 * 
 * 4. The name ''uniknow'' must not be used to endorse or promote products
 * derived from this software without prior written permission.
 * 
 * 5. Products derived from this software may not be called ''UniKnow'', nor may
 * ''uniknow'' appear in their name, without prior written permission of
 * uniknow.
 * 
 * THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WWS OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package org.uniknow.spring.cqrs.example;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.uniknow.spring.cqrs.*;
import org.uniknow.spring.cqrs.example.event.BaseEvent;
import org.uniknow.spring.eventStore.EventState;
import org.uniknow.spring.eventStore.EventStore;
import org.uniknow.spring.eventStore.EventStream;

import java.util.List;

@Component
public class ApplicationService {

    /**
     * Store in which (domain) events are persisted
     */
    @Autowired
    private EventStore eventStore;

    /**
     * Provider by which Command Handlers for specific commands can be found
     */
    @Autowired
    private CommandHandlerProvider commandHandlerProvider;

    /**
     * Provider by which Event Handlers for specific event can be found
     */
    @Autowired
    private EventHandlerProvider eventHandlerProvider;

    public void handle(Command command) throws Exception {
        EventStream eventStream = eventStore
            .loadEventStream(command.aggregateId());

        // Process command
        List events = (List) commandHandlerProvider
            .getHandler(command).handle(command);

        // Persist events generated by command within event store
        if (events != null && events.size() > 0) {
            eventStore.store(command.aggregateId(), eventStream.version(),
                events);
            // Notify event handlers
            notifyAll(events);
        } else {
            // Command generated no events
        }
    }

    private void notifyAll(List events) {
        for (BaseEvent event : events) {
            if (event.getState() == EventState.OK) {
                // Get handlers for event
                List> eventHandlers = eventHandlerProvider
                    .getHandler(event);
                for (EventHandler eventHandler : eventHandlers) {
                    eventHandler.handle(event);
                }
            } else {
                throw new RuntimeException("Event should have state OK");
            }
        }
    }

    // private Object newAggregateInstance(Command command)
    // throws InstantiationException, IllegalAccessException {
    // return commandHandlerLookup.targetType(command).newInstance();
    // }
}