/*
    * 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.videoeditor;
  
  import org.opencastproject.job.api.Job;
  import org.opencastproject.job.api.JobContext;
  import org.opencastproject.mediapackage.Catalog;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElement;
  import org.opencastproject.mediapackage.MediaPackageElementBuilder;
  import org.opencastproject.mediapackage.MediaPackageElementBuilderFactory;
  import org.opencastproject.mediapackage.MediaPackageElementFlavor;
  import org.opencastproject.mediapackage.Track;
  import org.opencastproject.mediapackage.selector.TrackSelector;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.silencedetection.api.SilenceDetectionFailedException;
  import org.opencastproject.silencedetection.api.SilenceDetectionService;
  import org.opencastproject.smil.api.SmilException;
  import org.opencastproject.smil.api.SmilService;
  import org.opencastproject.smil.entity.api.Smil;
  import org.opencastproject.smil.entity.media.api.SmilMediaObject;
  import org.opencastproject.smil.entity.media.container.api.SmilMediaContainer;
  import org.opencastproject.smil.entity.media.element.api.SmilMediaElement;
  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.WorkflowOperationResult;
  import org.opencastproject.workflow.api.WorkflowOperationResult.Action;
  import org.opencastproject.workspace.api.Workspace;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang3.BooleanUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.osgi.service.component.ComponentContext;
  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.InputStream;
  import java.net.URI;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.TimeUnit;
  import java.util.stream.Collectors;
  
  /**
   * workflowoperationhandler for silencedetection executes the silencedetection and adds a SMIL document to the
   * mediapackage containing the cutting points
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Silence Detection Workflow Operation Handler",
          "workflow.operation=silence"
      }
  )
  public class SilenceDetectionWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** Logger */
    private static final Logger logger = LoggerFactory.getLogger(SilenceDetectionWorkflowOperationHandler.class);
  
    /** Name of the configuration option that provides the source flavors we are looking for. */
    private static final String SOURCE_FLAVORS_PROPERTY = "source-flavors";
  
    /** Name of the configuration option that provides the source flavor we are looking for. */
    private static final String SOURCE_FLAVOR_PROPERTY = "source-flavor";
  
    /** Name of the configuration option that provides the smil flavor subtype we will produce. */
    private static final String SMIL_FLAVOR_SUBTYPE_PROPERTY = "smil-flavor-subtype";
  
    /** Name of the configuration option that provides the smil target flavor we will produce. */
    private static final String SMIL_TARGET_FLAVOR_PROPERTY = "target-flavor";
  
    /** Name of the configuration option for track flavors to reference in generated smil. */
   private static final String REFERENCE_TRACKS_FLAVOR_PROPERTY = "reference-tracks-flavor";
 
   /** Name of the configuration option whether to set workflow properties with sum of
    * segments duration in seconds and relation to the whole track length for each track.*/
   private static final String EXPORT_SEGMENTS_DURATION = "export-segments-duration";
 
   /** Name of the configuration option that provides the smil file name */
   private static final String TARGET_FILE_NAME = "smil.smil";
 
   /** The silence detection service. */
   private SilenceDetectionService detetionService;
 
   /** The smil service for smil parsing. */
   private SmilService smilService;
 
   /** The workspace. */
   private Workspace workspace;
 
   @Override
   public WorkflowOperationResult start(WorkflowInstance workflowInstance, JobContext context)
           throws WorkflowOperationException {
 
     MediaPackage mp = workflowInstance.getMediaPackage();
     logger.debug("Start silence detection workflow operation for mediapackage {}", mp.getIdentifier().toString());
 
     ConfiguredTagsAndFlavors tagsAndFlavors = getTagsAndFlavors(workflowInstance,
         Configuration.none, Configuration.many, Configuration.none, Configuration.none);
     List<MediaPackageElementFlavor> sourceFlavors = tagsAndFlavors.getSrcFlavors();
     String smilFlavorSubType = StringUtils.trimToNull(workflowInstance.getCurrentOperation().getConfiguration(
             SMIL_FLAVOR_SUBTYPE_PROPERTY));
     String smilTargetFlavorString = StringUtils.trimToNull(workflowInstance.getCurrentOperation().getConfiguration(
             SMIL_TARGET_FLAVOR_PROPERTY));
     String exportSegmentsDurationString = StringUtils.trimToNull(
         workflowInstance.getCurrentOperation().getConfiguration(EXPORT_SEGMENTS_DURATION));
     boolean exportSegmentsDuration = false;
 
     if (StringUtils.isNotBlank(exportSegmentsDurationString)) {
       try {
         exportSegmentsDuration = BooleanUtils.toBoolean(exportSegmentsDurationString);
       } catch (IllegalArgumentException e) {
         exportSegmentsDuration = false;
         logger.warn("Unable to parse {} option value {}. Deactivating export of workflow properties.",
                 EXPORT_SEGMENTS_DURATION, exportSegmentsDurationString);
       }
     }
 
     MediaPackageElementFlavor smilTargetFlavor = null;
     if (smilTargetFlavorString != null) {
       smilTargetFlavor = MediaPackageElementFlavor.parseFlavor(smilTargetFlavorString);
     }
 
     if (sourceFlavors.isEmpty()) {
       throw new WorkflowOperationException(String.format("No %s or %s have been specified", SOURCE_FLAVOR_PROPERTY,
               SOURCE_FLAVORS_PROPERTY));
     }
     if (smilFlavorSubType == null && smilTargetFlavor == null) {
       throw new WorkflowOperationException(String.format("No %s or %s have been specified",
               SMIL_FLAVOR_SUBTYPE_PROPERTY, SMIL_TARGET_FLAVOR_PROPERTY));
     }
     if (sourceFlavors != null && smilTargetFlavor != null) {
       throw new WorkflowOperationException(String.format("Can't use %s and %s together", SOURCE_FLAVORS_PROPERTY,
               SMIL_TARGET_FLAVOR_PROPERTY));
     }
 
     final String finalSourceFlavors;
     if (smilTargetFlavor != null) {
       finalSourceFlavors = sourceFlavors.get(sourceFlavors.size()).toString();
     } else {
       finalSourceFlavors = sourceFlavors.stream().map(MediaPackageElementFlavor::toString)
           .collect(Collectors.joining(","));
     }
 
     String referenceTracksFlavor = StringUtils.trimToNull(workflowInstance.getCurrentOperation().getConfiguration(
             REFERENCE_TRACKS_FLAVOR_PROPERTY));
     if (referenceTracksFlavor == null) {
       referenceTracksFlavor = finalSourceFlavors;
     }
 
     TrackSelector trackSelector = new TrackSelector();
     for (String flavor : asList(finalSourceFlavors)) {
       trackSelector.addFlavor(flavor);
     }
     Collection<Track> sourceTracks = trackSelector.select(mp, false);
     if (sourceTracks.isEmpty()) {
       logger.info("No source tracks found, skip silence detection");
       return createResult(mp, Action.SKIP);
     }
 
     trackSelector = new TrackSelector();
     for (String flavor : asList(referenceTracksFlavor)) {
       trackSelector.addFlavor(flavor);
     }
     Collection<Track> referenceTracks = trackSelector.select(mp, false);
     if (referenceTracks.isEmpty()) {
       // REFERENCE_TRACKS_FLAVOR_PROPERTY was set to wrong value
       throw new WorkflowOperationException(String.format("No tracks found filtered by flavor(s) '%s'",
               referenceTracksFlavor));
     }
     MediaPackageElementBuilder mpeBuilder = MediaPackageElementBuilderFactory.newInstance().newElementBuilder();
     Map<String, String> exportWorkflowProperties = new HashMap<>();
     for (Track sourceTrack : sourceTracks) {
       // Skip over track with no audio stream
       if (!sourceTrack.hasAudio()) {
         logger.info("Skipping silence detection of track {} since it has no audio", sourceTrack);
         if (exportSegmentsDuration) {
           exportWorkflowProperties = exportEmptySegmentDuration(exportWorkflowProperties, sourceTrack);
         }
         continue;
       }
       logger.info("Executing silence detection on track {}", sourceTrack.getIdentifier());
       try {
         Job detectionJob = detetionService.detect(sourceTrack,
                 referenceTracks.toArray(new Track[referenceTracks.size()]));
         if (!waitForStatus(detectionJob).isSuccess()) {
           throw new WorkflowOperationException("Silence Detection failed");
         }
         Smil smil = smilService.fromXml(detectionJob.getPayload()).getSmil();
 
         if (smil.getBody().getMediaElements().isEmpty()) {
           logger.debug("No segments detected in track {}, skip attaching smil file.", sourceTrack.getIdentifier());
           if (exportSegmentsDuration) {
             exportWorkflowProperties = exportEmptySegmentDuration(exportWorkflowProperties, sourceTrack);
           }
           continue;
         }
 
         InputStream is = null;
         try {
           is = IOUtils.toInputStream(smil.toXML(), "UTF-8");
           URI smilURI = workspace.put(mp.getIdentifier().toString(), smil.getId(), TARGET_FILE_NAME, is);
           MediaPackageElementFlavor smilFlavor = smilTargetFlavor;
           if (smilFlavor == null) {
             smilFlavor = new MediaPackageElementFlavor(sourceTrack.getFlavor().getType(), smilFlavorSubType);
           }
           Catalog catalog = (Catalog) mpeBuilder.elementFromURI(smilURI, MediaPackageElement.Type.Catalog, smilFlavor);
           catalog.setIdentifier(smil.getId());
           mp.add(catalog);
         } catch (Exception ex) {
           throw new WorkflowOperationException(String.format(
                   "Failed to put smil into workspace. Silence detection for track %s failed",
                   sourceTrack.getIdentifier()), ex);
         } finally {
           IOUtils.closeQuietly(is);
         }
         if (exportSegmentsDuration) {
           long durationMS = 0;
           for (SmilMediaObject smilElement : smil.getBody().getMediaElements()) {
             durationMS += getSegmentDurationMS(smilElement);
           }
           String durationWfPropertyName = getDurationWfPropertyName(sourceTrack);
           exportWorkflowProperties.put(durationWfPropertyName,
                   Long.toString(TimeUnit.MILLISECONDS.toSeconds(durationMS)));
           String relationWfPropertyName = getRelationWfPropertyName(sourceTrack);
           double durationTrackLengthRelation = 0;
           if (sourceTrack.getDuration() > 0) {
             durationTrackLengthRelation = (double)durationMS / (double)sourceTrack.getDuration();
             durationTrackLengthRelation *= 100;
           }
           durationTrackLengthRelation = Math.floor(durationTrackLengthRelation);
           durationTrackLengthRelation = Math.min(100, durationTrackLengthRelation);
           durationTrackLengthRelation = Math.max(0, durationTrackLengthRelation);
           exportWorkflowProperties.put(relationWfPropertyName, String.format("%.0f", durationTrackLengthRelation));
         }
         logger.info("Finished silence detection on track {}", sourceTrack.getIdentifier());
       } catch (SilenceDetectionFailedException ex) {
         throw new WorkflowOperationException(String.format("Failed to create silence detection job for track %s",
                 sourceTrack.getIdentifier()));
       } catch (SmilException ex) {
         throw new WorkflowOperationException(String.format(
                 "Failed to get smil from silence detection job for track %s", sourceTrack.getIdentifier()));
       }
     }
     logger.debug("Finished silence detection workflow operation for media package {}", mp.getIdentifier());
     return createResult(mp, exportWorkflowProperties, Action.CONTINUE, 0);
   }
 
   /**
    * Return first media segment length in milliseconds. If smilElement is a container, look for sub elements and
    * return duration from the first matching element.
    * @param smilElement smil media or container element to query duration
    * @return media duration in milliseconds
    * @throws SmilException on smil parsing error
    */
   protected long getSegmentDurationMS(SmilMediaObject smilElement) throws SmilException {
     if (smilElement.isContainer()) {
       for (SmilMediaObject element : ((SmilMediaContainer) smilElement).getElements()) {
         return getSegmentDurationMS(element);
       }
     }
     SmilMediaElement smilMediaElement = (SmilMediaElement) smilElement;
     return smilMediaElement.getClipEndMS() - smilMediaElement.getClipBeginMS();
   }
 
   /**
    * If the track has no audio, still add workflow variables that reflect this
    * @param properties workflow variable map
    * @param sourceTrack track without audio
    * @return The updated workflow variable map
    */
   private Map<String, String> exportEmptySegmentDuration(Map<String, String> properties, Track sourceTrack) {
     String durationWfPropertyName = getDurationWfPropertyName(sourceTrack);
     properties.put(durationWfPropertyName, Long.toString(0L));
     String relationWfPropertyName = getRelationWfPropertyName(sourceTrack);
     properties.put(relationWfPropertyName, String.format("%.0f", 0D));
     return properties;
   }
 
   private String getDurationWfPropertyName(Track sourceTrack) {
     return String.format("%s_%s_active_audio_duration",
         sourceTrack.getFlavor().getType(),
         sourceTrack.getFlavor().getSubtype());
   }
 
   private String getRelationWfPropertyName(Track sourceTrack) {
     return String.format("%s_%s_active_audio_duration_percent",
         sourceTrack.getFlavor().getType(),
         sourceTrack.getFlavor().getSubtype());
   }
 
   @Override
   public void activate(ComponentContext cc) {
     super.activate(cc);
     logger.info("Registering silence detection workflow operation handler");
   }
 
   @Reference
   public void setDetectionService(SilenceDetectionService detectionService) {
     this.detetionService = detectionService;
   }
 
   @Reference
   public void setSmilService(SmilService smilService) {
     this.smilService = smilService;
   }
 
   @Reference
   public void setWorkspace(Workspace workspace) {
     this.workspace = workspace;
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }