/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.opencastproject.distribution.download.remote;
  
  import static java.lang.String.format;
  import static org.opencastproject.util.HttpUtil.param;
  import static org.opencastproject.util.HttpUtil.post;
  
  import org.opencastproject.distribution.api.DistributionException;
  import org.opencastproject.distribution.api.DistributionService;
  import org.opencastproject.distribution.api.DownloadDistributionService;
  import org.opencastproject.job.api.Job;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElement;
  import org.opencastproject.mediapackage.MediaPackageException;
  import org.opencastproject.mediapackage.MediaPackageParser;
  import org.opencastproject.security.api.TrustedHttpClient;
  import org.opencastproject.serviceregistry.api.RemoteBase;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.util.JobUtil;
  import org.opencastproject.util.OsgiUtil;
  
  import com.google.gson.Gson;
  
  import org.apache.http.client.methods.HttpPost;
  import org.osgi.service.component.ComponentContext;
  import org.osgi.service.component.annotations.Activate;
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Reference;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.HashSet;
  import java.util.List;
  import java.util.Optional;
  import java.util.Set;
  
  /** A remote distribution service invoker. */
  @Component(
      immediate = true,
      service = { DistributionService.class,DownloadDistributionService.class },
      property = {
          "service.description=Distribution (Download) Remote Service Proxy",
          "distribution.channel=download"
      }
  )
  public class DownloadDistributionServiceRemoteImpl extends RemoteBase
          implements DistributionService, DownloadDistributionService {
    /** The logger */
    private static final Logger logger = LoggerFactory.getLogger(DownloadDistributionServiceRemoteImpl.class);
  
    /** The property to look up and append to REMOTE_SERVICE_TYPE_PREFIX */
    private static final String PARAM_CHANNEL_ID = "channelId";
    private static final String PARAM_MEDIAPACKAGE = "mediapackage";
    private static final String PARAM_ELEMENT_ID = "elementId";
    private static final String PARAM_CHECK_AVAILABILITY = "checkAvailability";
    private static final String PARAM_PRESERVE_REFERENCE = "preserveReference";
  
    private final Gson gson = new Gson();
  
    /** The distribution channel identifier */
    private String distributionChannel;
  
    public DownloadDistributionServiceRemoteImpl() {
      // the service type is not available at construction time. we need to wait for activation to set this value
      super("waiting for activation");
    }
  
    public String getDistributionType() {
      return this.distributionChannel;
    }
  
    /** activates the component */
    @Activate
    protected void activate(ComponentContext cc) {
      this.distributionChannel = OsgiUtil.getComponentContextProperty(cc, CONFIG_KEY_STORE_TYPE);
      super.serviceType = JOB_TYPE_PREFIX + this.distributionChannel;
    }
  
    @Override
   public Job distribute(String channelId, MediaPackage mediaPackage, String elementId) throws DistributionException {
     return distribute(channelId, mediaPackage, elementId, true);
   }
 
   @Override
   public Job distribute(String channelId, MediaPackage mediaPackage, String elementId, boolean checkAvailability)
           throws DistributionException {
     Set<String> elementIds = new HashSet<String>();
     elementIds.add(elementId);
     return distribute(channelId, mediaPackage, elementIds, checkAvailability);
   }
 
   @Override
   public Job distribute(String channelId, final MediaPackage mediaPackage, Set<String> elementIds,
                         boolean checkAvailability)
           throws DistributionException {
     return distribute(channelId, mediaPackage, elementIds, checkAvailability, false);
   }
   @Override
   public Job distribute(String channelId, final MediaPackage mediaPackage, Set<String> elementIds,
                         boolean checkAvailability, boolean preserveReference)
           throws DistributionException {
     logger.info("Distributing {} elements to {}@{}", elementIds.size(), channelId, distributionChannel);
     final HttpPost req = post(param(PARAM_CHANNEL_ID, channelId),
                               param(PARAM_MEDIAPACKAGE, MediaPackageParser.getAsXml(mediaPackage)),
                               param(PARAM_ELEMENT_ID, gson.toJson(elementIds)),
                               param(PARAM_CHECK_AVAILABILITY, Boolean.toString(checkAvailability)),
                               param(PARAM_PRESERVE_REFERENCE, Boolean.toString(preserveReference)));
     Optional<Job> job = runRequest(req, JobUtil::jobFromHttpResponse);
     if (job.isPresent()) {
       return job.get();
     }
     throw new DistributionException(format("Unable to distribute '%s' elements of "
                                                    + "mediapackage '%s' using a remote destribution service proxy",
                                            elementIds.size(), mediaPackage.getIdentifier().toString()));
   }
 
   @Override
   public Job retract(String channelId, MediaPackage mediaPackage, String elementId) throws DistributionException {
     Set<String> elementIds = new HashSet<String>();
     elementIds.add(elementId);
     return retract(channelId, mediaPackage, elementIds);
   }
 
   @Override
   public Job retract(String channelId, MediaPackage mediaPackage, Set<String> elementIds) throws DistributionException {
     logger.info("Retracting {} elements from {}@{}", elementIds.size(), channelId, distributionChannel);
     final HttpPost req = post("/retract",
                               param(PARAM_MEDIAPACKAGE, MediaPackageParser.getAsXml(mediaPackage)),
                               param(PARAM_ELEMENT_ID, gson.toJson(elementIds)),
                               param(PARAM_CHANNEL_ID, channelId));
     Optional<Job> job = runRequest(req, JobUtil::jobFromHttpResponse);
     if (job.isPresent()) {
       return job.get();
     }
     throw new DistributionException(format("Unable to retract '%s' elements of "
                                                    + "mediapackage '%s' using a remote destribution service proxy",
                                            elementIds.size(), mediaPackage.getIdentifier().toString()));
   }
 
   @Override
   public List<MediaPackageElement> distributeSync(String channelId, MediaPackage mediapackage, String elementId)
           throws DistributionException, MediaPackageException {
     Set<String> elementIds = new HashSet<String>();
     elementIds.add(elementId);
     return distributeSync(channelId, mediapackage, elementIds, true);
   }
 
   @Override
   public List<MediaPackageElement> distributeSync(String channelId, MediaPackage mediapackage, Set<String> elementIds,
          boolean checkAvailability) throws DistributionException {
     logger.info("Distributing {} elements to {}@{}", elementIds.size(), channelId, distributionChannel);
     final HttpPost req = post("/distributesync", param(PARAM_CHANNEL_ID, channelId),
         param(PARAM_MEDIAPACKAGE, MediaPackageParser.getAsXml(mediapackage)),
         param(PARAM_ELEMENT_ID, gson.toJson(elementIds)),
         param(PARAM_CHECK_AVAILABILITY, Boolean.toString(checkAvailability)));
     Optional<List<MediaPackageElement>> elements = runRequest(req, RemoteBase::elementsFromHttpResponse);
     if (elements.isPresent()) {
       return elements.get();
     }
     throw new DistributionException(format("Unable to distribute '%s' elements of "
             + "mediapackage '%s' using a remote destribution service proxy",
         elementIds.size(), mediapackage.getIdentifier().toString()));
   }
 
   @Override
   public List<MediaPackageElement> retractSync(String channelId, MediaPackage mediaPackage, String elementId)
           throws DistributionException {
     Set<String> elementIds = new HashSet<String>();
     elementIds.add(elementId);
     return retractSync(channelId, mediaPackage, elementIds);
   }
 
   @Override
   public List<MediaPackageElement> retractSync(String channelId, MediaPackage mediaPackage, Set<String> elementIds)
           throws DistributionException {
     logger.info("Retracting {} elements from {}@{}", elementIds.size(), channelId, distributionChannel);
     final HttpPost req = post("/retractsync",
         param(PARAM_MEDIAPACKAGE, MediaPackageParser.getAsXml(mediaPackage)),
         param(PARAM_ELEMENT_ID, gson.toJson(elementIds)),
         param(PARAM_CHANNEL_ID, channelId));
     Optional<List<MediaPackageElement>> elements = runRequest(req, RemoteBase::elementsFromHttpResponse);
     if (elements.isPresent()) {
       return elements.get();
     }
     throw new DistributionException(format("Unable to retract '%s' elements of "
             + "mediapackage '%s' using a remote destribution service proxy",
         elementIds.size(), mediaPackage.getIdentifier().toString()));
   }
 
   @Reference
   @Override
   public void setTrustedHttpClient(TrustedHttpClient trustedHttpClient) {
     super.setTrustedHttpClient(trustedHttpClient);
   }
 
   @Reference
   @Override
   public void setRemoteServiceManager(ServiceRegistry serviceRegistry) {
     super.setRemoteServiceManager(serviceRegistry);
   }
 
 }