/*
    * 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.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.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.Collection;
  
  /**
   * The <code>prepare media</code> operation will make sure that media where audio and video track come in separate files
   * will be muxed prior to further processing.
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Prepare Media Workflow Operation Handler",
          "workflow.operation=prepare-av"
      }
  )
  public class PrepareAVWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(PrepareAVWorkflowOperationHandler.class);
    private static final String QUESTION_MARK = "?";
  
    /** Name of the 'encode to a/v prepared copy' encoding profile */
    public static final String PREPARE_AV_PROFILE = "av.copy";
  
    /** Name of the muxing encoding profile */
    public static final String MUX_AV_PROFILE = "mux-av.copy";
  
    /** Name of the 'encode to audio only prepared copy' encoding profile */
    public static final String PREPARE_AONLY_PROFILE = "audio-only.copy";
  
    /** Name of the 'encode to video only prepared copy' encoding profile */
    public static final String PREPARE_VONLY_PROFILE = "video-only.copy";
  
    /** Name of the 'rewrite' configuration key */
    public static final String OPT_REWRITE = "rewrite";
  
    /** Name of audio muxing configuration key */
    public static final String OPT_AUDIO_MUXING_SOURCE_FLAVORS = "audio-muxing-source-flavors";
  
    /** 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 {
     try {
       logger.debug("Running a/v muxing workflow operation on workflow {}", workflowInstance.getId());
       return mux(workflowInstance);
     } catch (Exception e) {
       throw new WorkflowOperationException(e);
     }
   }
 
   /**
    * Merges audio and video track of the selected flavor and adds it to the media package. If there is nothing to mux, a
    * new track with the target flavor is created (pointing to the original url).
    *
    * @param wi
    *          the mux workflow instance
    * @return the operation result containing the updated mediapackage
    * @throws EncoderException
    *           if encoding fails
    * @throws IOException
    *           if read/write operations from and to the workspace fail
    * @throws NotFoundException
    *           if the workspace does not contain the requested element
    */
   private WorkflowOperationResult mux(WorkflowInstance wi) throws EncoderException,
           WorkflowOperationException, NotFoundException, MediaPackageException, IOException {
     MediaPackage src = wi.getMediaPackage();
     MediaPackage mediaPackage = (MediaPackage) src.clone();
     WorkflowOperationInstance operation = wi.getCurrentOperation();
 
     // Check which tags have been configured
     ConfiguredTagsAndFlavors tagsAndFlavors = getTagsAndFlavors(wi,
         Configuration.none, Configuration.one, Configuration.many, Configuration.one);
 
     // Read the configuration properties
     MediaPackageElementFlavor sourceFlavor = tagsAndFlavors.getSingleSrcFlavor();
     ConfiguredTagsAndFlavors.TargetTags targetTrackTags = tagsAndFlavors.getTargetTags();
     MediaPackageElementFlavor targetFlavor = tagsAndFlavors.getSingleTargetFlavor();
     String muxEncodingProfileName = StringUtils.trimToNull(operation.getConfiguration("mux-encoding-profile"));
     String audioVideoEncodingProfileName = StringUtils.trimToNull(operation.getConfiguration(
         "audio-video-encoding-profile"));
     String videoOnlyEncodingProfileName = StringUtils.trimToNull(operation.getConfiguration("video-encoding-profile"));
     String audioOnlyEncodingProfileName = StringUtils.trimToNull(operation.getConfiguration("audio-encoding-profile"));
 
     // Reencode when there is no need for muxing?
     boolean rewrite = true;
     if (StringUtils.trimToNull(operation.getConfiguration(OPT_REWRITE)) != null) {
       rewrite = Boolean.parseBoolean(operation.getConfiguration(OPT_REWRITE));
     }
 
     String audioMuxingSourceFlavors = StringUtils.trimToNull(operation.getConfiguration(
         OPT_AUDIO_MUXING_SOURCE_FLAVORS));
 
     // Select those tracks that have matching flavors
     TrackSelector trackSelector = new TrackSelector();
     trackSelector.addFlavor(sourceFlavor);
     Collection<Track> tracks = trackSelector.select(mediaPackage, false);
 
     Track audioTrack = null;
     Track videoTrack = null;
 
     switch (tracks.size()) {
       case 0:
         logger.info("No audio/video tracks with flavor '{}' found to prepare", sourceFlavor);
         return createResult(mediaPackage, Action.CONTINUE);
       case 1:
         videoTrack = tracks.iterator().next();
         if (!videoTrack.hasAudio() && videoTrack.hasVideo() && (audioMuxingSourceFlavors != null)) {
           audioTrack = findAudioTrack(videoTrack, mediaPackage, audioMuxingSourceFlavors);
         } else {
           audioTrack = videoTrack;
         }
         break;
       case 2:
         for (Track track : tracks) {
           if (track.hasAudio() && !track.hasVideo()) {
             audioTrack = track;
           } else if (!track.hasAudio() && track.hasVideo()) {
             videoTrack = track;
           } else {
             throw new WorkflowOperationException("Multiple tracks with competing audio/video streams and flavor '"
                     + sourceFlavor + "' found");
           }
         }
         break;
       default:
         logger.error("More than two tracks with flavor {} found. No idea what we should be doing", sourceFlavor);
         throw new WorkflowOperationException("More than two tracks with flavor '" + sourceFlavor + "' found");
     }
 
     Job job = null;
     Track composedTrack = null;
 
     // Make sure we have a matching combination
     if (audioTrack == null && videoTrack != null) {
       if (rewrite) {
         logger.info("Encoding video only track {} to prepared version", videoTrack);
         if (videoOnlyEncodingProfileName == null) {
           videoOnlyEncodingProfileName = PREPARE_VONLY_PROFILE;
         }
         // Find the encoding profile to make sure the given profile exists
         EncodingProfile profile = composerService.getProfile(videoOnlyEncodingProfileName);
         if (profile == null) {
           throw new IllegalStateException("Encoding profile '" + videoOnlyEncodingProfileName + "' was not found");
         }
         composedTrack = prepare(videoTrack, mediaPackage, videoOnlyEncodingProfileName);
       } else {
         composedTrack = (Track) videoTrack.clone();
         composedTrack.setIdentifier(null);
         mediaPackage.add(composedTrack);
       }
     } else if (videoTrack == null && audioTrack != null) {
       if (rewrite) {
         logger.info("Encoding audio only track {} to prepared version", audioTrack);
         if (audioOnlyEncodingProfileName == null) {
           audioOnlyEncodingProfileName = PREPARE_AONLY_PROFILE;
         }
         // Find the encoding profile to make sure the given profile exists
         EncodingProfile profile = composerService.getProfile(audioOnlyEncodingProfileName);
         if (profile == null) {
           throw new IllegalStateException("Encoding profile '" + audioOnlyEncodingProfileName + "' was not found");
         }
         composedTrack = prepare(audioTrack, mediaPackage, audioOnlyEncodingProfileName);
       } else {
         composedTrack = (Track) audioTrack.clone();
         composedTrack.setIdentifier(null);
         mediaPackage.add(composedTrack);
       }
     } else if (audioTrack == videoTrack) {
       if (rewrite) {
         logger.info("Encoding audiovisual track {} to prepared version", videoTrack);
         if (audioVideoEncodingProfileName == null) {
           audioVideoEncodingProfileName = PREPARE_AV_PROFILE;
         }
         // Find the encoding profile to make sure the given profile exists
         EncodingProfile profile = composerService.getProfile(audioVideoEncodingProfileName);
         if (profile == null) {
           throw new IllegalStateException("Encoding profile '" + audioVideoEncodingProfileName + "' was not found");
         }
         composedTrack = prepare(videoTrack, mediaPackage, audioVideoEncodingProfileName);
       } else {
         composedTrack = (Track) videoTrack.clone();
         composedTrack.setIdentifier(null);
         mediaPackage.add(composedTrack);
       }
     } else {
       logger.info("Muxing audio and video only track {} to prepared version", videoTrack);
 
       if (audioTrack.hasVideo()) {
         logger.info("Stripping video from track {}", audioTrack);
         audioTrack = prepare(audioTrack, null, PREPARE_AONLY_PROFILE);
       }
 
       if (muxEncodingProfileName == null) {
         muxEncodingProfileName = MUX_AV_PROFILE;
       }
 
       // Find the encoding profile
       EncodingProfile profile = composerService.getProfile(muxEncodingProfileName);
       if (profile == null) {
         throw new IllegalStateException("Encoding profile '" + muxEncodingProfileName + "' was not found");
       }
 
       job = composerService.mux(videoTrack, audioTrack, profile.getIdentifier());
       if (!waitForStatus(job).isSuccess()) {
         throw new WorkflowOperationException("Muxing video track " + videoTrack + " and audio track " + audioTrack
                 + " failed");
       }
       composedTrack = (Track) MediaPackageElementParser.getFromXml(job.getPayload());
       mediaPackage.add(composedTrack);
       String fileName = getFileNameFromElements(videoTrack, composedTrack);
       composedTrack.setURI(workspace.moveTo(composedTrack.getURI(), mediaPackage.getIdentifier().toString(),
               composedTrack.getIdentifier(), fileName));
     }
 
     long timeInQueue = 0;
     if (job != null) {
       // add this receipt's queue time to the total
       timeInQueue = job.getQueueTime();
     }
 
     // Update the track's flavor
     composedTrack.setFlavor(targetFlavor);
     logger.debug("Composed track has flavor '{}'", composedTrack.getFlavor());
 
     // Update the track's tags
     applyTargetTagsToElement(targetTrackTags, composedTrack);
 
     return createResult(mediaPackage, Action.CONTINUE, timeInQueue);
   }
 
   /**
    * Prepares a video track. If the mediapackage is specified, the prepared track will be added to it.
    *
    * @param videoTrack
    *          the track containing the video
    * @param mediaPackage
    *          the mediapackage
    * @return the rewritten track
    * @throws WorkflowOperationException
    * @throws NotFoundException
    * @throws IOException
    * @throws EncoderException
    * @throws MediaPackageException
    */
   private Track prepare(Track videoTrack, MediaPackage mediaPackage, String encodingProfile)
           throws WorkflowOperationException, NotFoundException, IOException, EncoderException, MediaPackageException {
     Track composedTrack = null;
     logger.info("Encoding video only track {} to prepared version", videoTrack);
     Job job = composerService.encode(videoTrack, encodingProfile);
     if (!waitForStatus(job).isSuccess()) {
       throw new WorkflowOperationException("Rewriting container for video track " + videoTrack + " failed");
     }
     composedTrack = (Track) MediaPackageElementParser.getFromXml(job.getPayload());
     if (mediaPackage != null) {
       mediaPackage.add(composedTrack);
       String fileName = getFileNameFromElements(videoTrack, composedTrack);
 
       // Note that the composed track must have an ID before being moved to the mediapackage in the working file
       // repository. This ID is generated when the track is added to the mediapackage. So the track must be added
       // to the mediapackage before attempting to move the file.
       composedTrack.setURI(workspace.moveTo(composedTrack.getURI(), mediaPackage.getIdentifier().toString(),
               composedTrack.getIdentifier(), fileName));
     }
     return composedTrack;
   }
 
   /**
    * Finds a suitable audio track from the mediapackage by scanning a source flavor sequence
    *
    * @param videoTrack
    *          the video track
    * @param mediaPackage
    *          the mediapackage
    * @param audioMuxingSourceFlavors
    *          sequence of source flavors where an audio track should be searched for
    * @return the found audio track
    */
   private Track findAudioTrack(Track videoTrack, MediaPackage mediaPackage, String audioMuxingSourceFlavors) {
 
     if (audioMuxingSourceFlavors != null) {
       String type;
       String subtype;
       for (String flavorStr : audioMuxingSourceFlavors.split("[\\s,]")) {
         if (!flavorStr.isEmpty()) {
           MediaPackageElementFlavor flavor = null;
           try {
             flavor = MediaPackageElementFlavor.parseFlavor(flavorStr);
           } catch (IllegalArgumentException e) {
             logger.error("The parameter {} contains an invalid flavor: {}", OPT_AUDIO_MUXING_SOURCE_FLAVORS, flavorStr);
             throw e;
           }
           type = (QUESTION_MARK.equals(flavor.getType())) ? videoTrack.getFlavor().getType() : flavor.getType();
           subtype = (QUESTION_MARK.equals(flavor.getSubtype()))
               ? videoTrack.getFlavor().getSubtype() : flavor.getSubtype();
           // Recreate the (possibly) modified flavor
           flavor = new MediaPackageElementFlavor(type, subtype);
           for (Track track : mediaPackage.getTracks(flavor)) {
             if (track.hasAudio()) {
               logger.info("Audio muxing found audio source {} with flavor {}", track, track.getFlavor());
               return track;
             }
           }
         }
       }
     }
     return null;
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }