/*
    * 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.transcription.workflowoperation;
  
  import org.opencastproject.job.api.Job;
  import org.opencastproject.job.api.JobContext;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElement;
  import org.opencastproject.mediapackage.MediaPackageElementFlavor;
  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.transcription.api.TranscriptionService;
  import org.opencastproject.transcription.api.TranscriptionServiceException;
  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.apache.commons.lang3.StringUtils;
  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.Collection;
  import java.util.List;
  
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Start Google Speech Transcription Workflow Operation Handler",
          "workflow.operation=google-speech-start-transcription"
      }
  )
  public class GoogleSpeechStartTranscriptionOperationHandler extends AbstractWorkflowOperationHandler {
  
    /**
     * The logging facility
     */
    private static final Logger logger = LoggerFactory.getLogger(GoogleSpeechStartTranscriptionOperationHandler.class);
  
    /**
     * Workflow configuration option keys
     */
    static final String LANGUAGE_CODE = "language-code";
    static final String SKIP_IF_FLAVOR_EXISTS = "skip-if-flavor-exists";
  
    /**
     * The transcription service
     */
    private TranscriptionService service = null;
  
    /**
     * The language code
     */
    private String language = null;
  
    @Override
    @Activate
    protected void activate(ComponentContext cc) {
      super.activate(cc);
    }
  
    /**
     * {@inheritDoc}
     *
     * @see
     * org.opencastproject.workflow.api.WorkflowOperationHandler#start(org.opencastproject.workflow.api.WorkflowInstance,
     * JobContext)
     */
    @Override
    public WorkflowOperationResult start(final WorkflowInstance workflowInstance, JobContext context)
           throws WorkflowOperationException {
     MediaPackage mediaPackage = workflowInstance.getMediaPackage();
     WorkflowOperationInstance operation = workflowInstance.getCurrentOperation();
 
     String skipOption = StringUtils.trimToNull(operation.getConfiguration(SKIP_IF_FLAVOR_EXISTS));
     if (skipOption != null) {
       MediaPackageElement[] mpes = mediaPackage.getElementsByFlavor(MediaPackageElementFlavor.parseFlavor(skipOption));
       if (mpes != null && mpes.length > 0) {
         logger.info(
                 "Start transcription operation will be skipped because flavor {} already exists in the media package",
                 skipOption);
         return createResult(Action.SKIP);
       }
     }
 
     logger.debug("Start transcription for mediapackage {} started", mediaPackage);
 
     // Get language code if configured
     String langCode = operation.getConfiguration(LANGUAGE_CODE);
 
     // Check which tags have been configured
     ConfiguredTagsAndFlavors tagsAndFlavors = getTagsAndFlavors(
         workflowInstance, Configuration.many, Configuration.many, Configuration.none, Configuration.none);
     List<String> sourceTagOption = tagsAndFlavors.getSrcTags();
     List<MediaPackageElementFlavor> sourceFlavorOption = tagsAndFlavors.getSrcFlavors();
 
     AbstractMediaPackageElementSelector<Track> elementSelector = new TrackSelector();
 
     // Make sure either one of tags or flavors are provided
     if (sourceTagOption.isEmpty() && sourceFlavorOption.isEmpty()) {
       throw new WorkflowOperationException("No source tag or flavor have been specified!");
     }
 
     if (!sourceFlavorOption.isEmpty()) {
       MediaPackageElementFlavor flavor = sourceFlavorOption.get(0);
       elementSelector.addFlavor(flavor);
     }
     if (StringUtils.isNotBlank(langCode)) {
       language = StringUtils.trim(langCode);
     }
     if (!sourceTagOption.isEmpty()) {
       elementSelector.addTag(sourceTagOption.get(0));
     }
 
     Collection<Track> elements = elementSelector.select(mediaPackage, false);
     Job job = null;
     for (Track track : elements) {
       if (track.hasVideo()) {
         logger.info("Skipping track {} since it contains a video stream", track);
         continue;
       }
       if (!track.hasAudio()) {
         logger.info("Track {} from media package {} doesn't contain audio stream. Skip subtitle generation.",
             track.getFlavor(), mediaPackage.getIdentifier());
         continue;
       }
       try {
         job = service.startTranscription(mediaPackage.getIdentifier().toString(), track, language);
         // Only one job per media package
         break;
       } catch (TranscriptionServiceException e) {
         throw new WorkflowOperationException(e);
       }
     }
 
     if (job == null) {
       logger.info("No matching tracks found");
       return createResult(mediaPackage, Action.CONTINUE);
     }
 
     // Wait for the jobs to return
     if (!waitForStatus(job).isSuccess()) {
       throw new WorkflowOperationException("Transcription job did not complete successfully");
     }
     // Return OK means that the Google speech job was created, but not finished yet
 
     logger.debug("External transcription job for mediapackage {} was created", mediaPackage);
 
     // Results are empty, we should get a callback when transcription is done
     return createResult(Action.CONTINUE);
   }
 
   @Reference(target = "(provider=google.speech)")
   public void setTranscriptionService(TranscriptionService service) {
     this.service = service;
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }