/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.camel.component.docker.consumer;

import com.github.dockerjava.api.command.EventsCmd;
import com.github.dockerjava.api.model.Event;
import com.github.dockerjava.core.command.EventsResultCallback;
import org.apache.camel.AsyncCallback;
import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.Processor;
import org.apache.camel.component.docker.DockerClientFactory;
import org.apache.camel.component.docker.DockerComponent;
import org.apache.camel.component.docker.DockerConstants;
import org.apache.camel.component.docker.DockerEndpoint;
import org.apache.camel.component.docker.DockerHelper;
import org.apache.camel.support.DefaultConsumer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DockerEventsConsumer extends DefaultConsumer {

    private static final Logger LOG = LoggerFactory.getLogger(DockerEventsConsumer.class);

    private DockerEndpoint endpoint;
    private DockerComponent component;
    private EventsCmd eventsCmd;
    
    public DockerEventsConsumer(DockerEndpoint endpoint, Processor processor) throws Exception {
        super(endpoint, processor);
        this.endpoint = endpoint;
        this.component = (DockerComponent)endpoint.getComponent();

    }

    @Override
    public DockerEndpoint getEndpoint() {
        return (DockerEndpoint)super.getEndpoint();
    }

    /**
     * Determine the point in time to begin streaming events
     */
    private long processInitialEvent() {
        long currentTime = System.currentTimeMillis();
        Long initialRange = DockerHelper.getProperty(DockerConstants.DOCKER_INITIAL_RANGE, endpoint.getConfiguration(), null, Long.class);
        if (initialRange != null) {
            currentTime = currentTime - initialRange;
        }
        
        return currentTime;
    }

    @Override
    protected void doStart() throws Exception {
        this.eventsCmd = DockerClientFactory.getDockerClient(component, endpoint.getConfiguration(), null).eventsCmd().withSince(String.valueOf(processInitialEvent()));
        this.eventsCmd.exec(new EventsCallback());

        super.doStart();
    }

    @Override
    protected void doStop() throws Exception {
        this.eventsCmd.close();
        
        super.doStop();
    }

    protected class EventsCallback extends EventsResultCallback {

        @Override
        public void onNext(Event event) {
            LOG.debug("Received Docker Event: {}", event);

            final Exchange exchange = getEndpoint().createExchange();
            Message message = exchange.getIn();
            message.setBody(event);

            try {
                LOG.trace("Processing exchange [{}]...", exchange);
                getAsyncProcessor().process(exchange, new AsyncCallback() {
                    @Override
                    public void done(boolean doneSync) {
                        LOG.trace("Done processing exchange [{}]...", exchange);
                    }
                });
            } catch (Exception e) {
                exchange.setException(e);
            }
            if (exchange.getException() != null) {
                getExceptionHandler().handleException("Error processing exchange", exchange, exchange.getException());
            }
        }
    }
}
