/*
    * 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.workflow.handler.composer;
  
  import org.opencastproject.composer.api.ComposerService;
  import org.opencastproject.composer.api.EncoderException;
  import org.opencastproject.composer.api.EncodingProfile;
  import org.opencastproject.composer.api.EncodingProfile.MediaType;
  import org.opencastproject.job.api.Job;
  import org.opencastproject.job.api.JobContext;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElementFlavor;
  import org.opencastproject.mediapackage.MediaPackageElementParser;
  import org.opencastproject.mediapackage.MediaPackageException;
  import org.opencastproject.mediapackage.Track;
  import org.opencastproject.mediapackage.selector.AbstractMediaPackageElementSelector;
  import org.opencastproject.mediapackage.selector.TrackSelector;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.util.NotFoundException;
  import org.opencastproject.workflow.api.AbstractWorkflowOperationHandler;
  import org.opencastproject.workflow.api.ConfiguredTagsAndFlavors;
  import org.opencastproject.workflow.api.WorkflowInstance;
  import org.opencastproject.workflow.api.WorkflowOperationException;
  import org.opencastproject.workflow.api.WorkflowOperationHandler;
  import org.opencastproject.workflow.api.WorkflowOperationInstance;
  import org.opencastproject.workflow.api.WorkflowOperationResult;
  import org.opencastproject.workflow.api.WorkflowOperationResult.Action;
  import org.opencastproject.workspace.api.Workspace;
  
  import org.apache.commons.lang3.StringUtils;
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Reference;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * The workflow definition for handling "compose" operations
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Encode Workflow Operation Handler",
          "workflow.operation=encode"
      }
  )
  public class EncodeWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(EncodeWorkflowOperationHandler.class);
  
    /** The composer service */
    private ComposerService composerService = null;
  
    /** The local workspace */
    private Workspace workspace = null;
  
    /**
     * Callback for the OSGi declarative services configuration.
     *
     * @param composerService
     *          the local composer service
     */
    @Reference
    protected void setComposerService(ComposerService composerService) {
      this.composerService = composerService;
    }
  
    /**
     * Callback for declarative services configuration that will introduce us to the local workspace service.
     * Implementation assumes that the reference is configured as being static.
     *
     * @param workspace
    *          an instance of the workspace
    */
   @Reference
   public void setWorkspace(Workspace workspace) {
     this.workspace = workspace;
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.workflow.api.WorkflowOperationHandler#start(org.opencastproject.workflow.api.WorkflowInstance,
    *      JobContext)
    */
   public WorkflowOperationResult start(final WorkflowInstance workflowInstance, JobContext context)
           throws WorkflowOperationException {
     logger.debug("Running parallel encoding workflow operation on workflow {}", workflowInstance.getId());
 
     try {
       return encode(workflowInstance);
     } catch (Exception e) {
       throw new WorkflowOperationException(e);
     }
   }
 
   /**
    * Encode tracks from MediaPackage using profiles stored in properties and updates current MediaPackage.
    *
    * @param workflowInstance
    *          the current workflow instance
    * @return the operation result containing the updated media package
    * @throws EncoderException
    *           if encoding fails
    * @throws WorkflowOperationException
    *           if errors occur during processing
    * @throws IOException
    *           if the workspace operations fail
    * @throws NotFoundException
    *           if the workspace doesn't contain the requested file
    */
   private WorkflowOperationResult encode(WorkflowInstance workflowInstance)
           throws EncoderException, IOException, NotFoundException, MediaPackageException, WorkflowOperationException {
     MediaPackage src = workflowInstance.getMediaPackage();
     MediaPackage mediaPackage = (MediaPackage) src.clone();
     WorkflowOperationInstance operation = workflowInstance.getCurrentOperation();
     // Check which tags have been configured
     ConfiguredTagsAndFlavors tagsAndFlavors = getTagsAndFlavors(workflowInstance,
         Configuration.many, Configuration.many, Configuration.many, Configuration.one);
     List<String> sourceTagsOption = tagsAndFlavors.getSrcTags();
     List<String> targetTagsOption = tagsAndFlavors.getTargetTags();
     List<MediaPackageElementFlavor> sourceFlavorsOption = tagsAndFlavors.getSrcFlavors();
     MediaPackageElementFlavor targetFlavor = tagsAndFlavors.getSingleTargetFlavor();
 
     AbstractMediaPackageElementSelector<Track> elementSelector = new TrackSelector();
 
     // Make sure either one of tags or flavors are provided
     if (sourceTagsOption.isEmpty() && sourceFlavorsOption.isEmpty()) {
       logger.warn("No source tags or flavors have been specified, not matching anything");
       return createResult(mediaPackage, Action.SKIP);
     }
 
     // Select the source flavors
     for (MediaPackageElementFlavor flavor : sourceFlavorsOption) {
         elementSelector.addFlavor(flavor);
     }
 
     // Select the source tags
     for (String tag : sourceTagsOption) {
       elementSelector.addTag(tag);
     }
 
     // Find the encoding profile
     String profilesOption = StringUtils.trimToNull(operation.getConfiguration("encoding-profiles"));
     List<EncodingProfile> profiles = new ArrayList<EncodingProfile>();
     for (String profileName : asList(profilesOption)) {
       EncodingProfile profile = composerService.getProfile(profileName);
       if (profile == null)
         throw new WorkflowOperationException("Encoding profile '" + profileName + "' was not found");
       profiles.add(profile);
     }
 
     // Support legacy "encoding-profile" option
     String profileOption = StringUtils.trimToNull(operation.getConfiguration("encoding-profile"));
     if (StringUtils.isNotBlank(profileOption)) {
       String profileId = StringUtils.trim(profileOption);
       EncodingProfile profile = composerService.getProfile(profileId);
       if (profile == null)
         throw new WorkflowOperationException("Encoding profile '" + profileId + "' was not found");
       profiles.add(profile);
     }
 
     // Make sure there is at least one profile
     if (profiles.isEmpty())
       throw new WorkflowOperationException("No encoding profile was specified");
 
     // Look for elements matching the tag
     Collection<Track> elements = elementSelector.select(mediaPackage, false);
 
     // Encode all tracks found
     long totalTimeInQueue = 0;
     Map<Job, JobInformation> encodingJobs = new HashMap<Job, JobInformation>();
     for (Track track : elements) {
 
       // Encode the track with all profiles
       for (EncodingProfile profile : profiles) {
 
         // Check if the track supports the input type of the profile
         MediaType inputType = profile.getApplicableMediaType();
         if (inputType.equals(MediaType.Audio) && !track.hasAudio()) {
           logger.info("Skipping encoding of '{}', since it lacks an audio stream", track);
           continue;
         } else if (inputType.equals(MediaType.Visual) && !track.hasVideo()) {
           logger.info("Skipping encoding of '{}', since it lacks a video stream", track);
           continue;
         }
 
         logger.info("Encoding track {} using encoding profile '{}'", track, profile);
 
         // Start encoding and wait for the result
         encodingJobs.put(composerService.parallelEncode(track, profile.getIdentifier()), new JobInformation(track, profile));
       }
     }
 
     if (encodingJobs.isEmpty()) {
       logger.info("No matching tracks found");
       return createResult(mediaPackage, Action.SKIP);
     }
 
     // Wait for the jobs to return
     if (!waitForStatus(encodingJobs.keySet().toArray(new Job[encodingJobs.size()])).isSuccess()) {
       throw new WorkflowOperationException("One of the encoding jobs did not complete successfully");
     }
 
     // Process the result
     for (Map.Entry<Job, JobInformation> entry : encodingJobs.entrySet()) {
       Job job = entry.getKey();
       Track track = entry.getValue().getTrack();
 
       // add this receipt's queue time to the total
       totalTimeInQueue += job.getQueueTime();
       // it is allowed for compose jobs to return an empty payload. See the EncodeEngine interface
       if (job.getPayload().length() > 0) {
         List <Track> composedTracks = (List <Track>) MediaPackageElementParser.getArrayFromXml(job.getPayload());
 
         // Adjust the target tags
         for (Track encodedTrack : composedTracks) {
           for (String tag : targetTagsOption) {
             logger.trace("Tagging composed track {} with '{}'", encodedTrack.toString(), tag);
             encodedTrack.addTag(tag);
           }
         }
 
         // Adjust the target flavor. Make sure to account for partial updates
         if (targetFlavor != null) {
           String flavorType = targetFlavor.getType();
           String flavorSubtype = targetFlavor.getSubtype();
           if ("*".equals(flavorType))
             flavorType = track.getFlavor().getType();
           if ("*".equals(flavorSubtype))
             flavorSubtype = track.getFlavor().getSubtype();
           for (Track encodedTrack : composedTracks) {
             encodedTrack.setFlavor(new MediaPackageElementFlavor(flavorType, flavorSubtype));
             logger.debug("Composed track {} has flavor '{}'", encodedTrack.toString(), encodedTrack.getFlavor());
           }
         }
 
         // store new tracks to mediaPackage
         for (Track encodedTrack : composedTracks) {
           mediaPackage.addDerived(encodedTrack, track);
           String fileName = getFileNameFromElements(track, encodedTrack);
           encodedTrack.setURI(workspace.moveTo(encodedTrack.getURI(), mediaPackage.getIdentifier().toString(),
                                                 encodedTrack.getIdentifier(), fileName));
         }
       }
     }
 
     WorkflowOperationResult result = createResult(mediaPackage, Action.CONTINUE, totalTimeInQueue);
     logger.debug("Parallel encode operation completed");
     return result;
   }
 
   /**
    * This class is used to store context information for the jobs.
    */
   private static final class JobInformation {
 
     private Track track = null;
     private EncodingProfile profile = null;
 
     JobInformation(Track track, EncodingProfile profile) {
       this.track = track;
       this.profile = profile;
     }
 
     /**
      * Returns the track.
      *
      * @return the track
      */
     public Track getTrack() {
       return track;
     }
 
     /**
      * Returns the profile.
      *
      * @return the profile
      */
     public EncodingProfile getProfile() {
       return profile;
     }
 
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }