/*
    * 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.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.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * The workflow definition for handling demux operations.
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Demux Workflow Operation Handler",
          "workflow.operation=demux"
      }
  )
  public class DemuxWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(DemuxWorkflowOperationHandler.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)
    */
   @Override
   public WorkflowOperationResult start(final WorkflowInstance workflowInstance, JobContext context)
           throws WorkflowOperationException {
     logger.debug("Running demux workflow operation on workflow {}", workflowInstance.getId());
 
     try {
       return demux(workflowInstance.getMediaPackage(), workflowInstance);
     } catch (Exception e) {
       throw new WorkflowOperationException(e);
     }
   }
 
   /**
    * Encode tracks from MediaPackage using profiles stored in properties and updates current MediaPackage.
    *
    * @param src
    *          The source media package
    * @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 demux(MediaPackage src, WorkflowInstance workflowInstance)
           throws EncoderException, IOException, NotFoundException, MediaPackageException, WorkflowOperationException {
     MediaPackage mediaPackage = (MediaPackage) src.clone();
     WorkflowOperationInstance operation = workflowInstance.getCurrentOperation();
     final String sectionSeparator = ";";
     // Check which tags have been configured
     ConfiguredTagsAndFlavors tagsAndFlavors = getTagsAndFlavors(workflowInstance, Configuration.many,
         Configuration.many, Configuration.many, Configuration.many);
 
     List<String> sourceTagsOption = tagsAndFlavors.getSrcTags();
     List<MediaPackageElementFlavor> sourceFlavorsOption = tagsAndFlavors.getSrcFlavors();
     //get target tags directly from operation since we need a list separated by a semicolon
     String targetTagsOption = StringUtils.trimToNull(operation.getConfiguration("target-tags"));
     List<MediaPackageElementFlavor> targetFlavorsOption = tagsAndFlavors.getTargetFlavors();
     String encodingProfile = StringUtils.trimToEmpty(operation.getConfiguration("encoding-profile"));
 
     // Make sure either one of tags or flavors are provided
     if (sourceTagsOption.isEmpty() && sourceFlavorsOption.isEmpty()) {
       logger.info("No source tags or flavors have been specified, not matching anything");
       return createResult(mediaPackage, Action.CONTINUE);
     }
 
     List<MediaPackageElementFlavor> targetFlavors = targetFlavorsOption;
     String[] targetTags = StringUtils.split(targetTagsOption, sectionSeparator);
     AbstractMediaPackageElementSelector<Track> elementSelector = new TrackSelector();
 
     // 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 - should only be one
     EncodingProfile profile = composerService.getProfile(encodingProfile);
     if (profile == null) {
       throw new WorkflowOperationException(String.format("Encoding profile '%s' was not found", encodingProfile));
     }
     // Look for elements matching the tag
     Collection<Track> sourceTracks = elementSelector.select(mediaPackage, false);
     if (sourceTracks.isEmpty()) {
       logger.info("No matching tracks found");
       return createResult(mediaPackage, Action.CONTINUE);
     }
 
     long totalTimeInQueue = 0;
     Map<Job, Track> encodingJobs = new HashMap<>();
     for (Track track : sourceTracks) {
       logger.info("Demuxing track {} using encoding profile '{}'", track, profile);
       // Start encoding and wait for the result
       encodingJobs.put(composerService.demux(track, profile.getIdentifier()), track);
     }
 
     // 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, Track> entry : encodingJobs.entrySet()) {
       Job job = entry.getKey();
       Track sourceTrack = entry.getValue();
 
       // 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) {
         logger.warn("No output from Demux operation");
         continue;
       }
 
       List<Track> composedTracks = (List<Track>) MediaPackageElementParser.getArrayFromXml(job.getPayload());
       if (composedTracks.size() != targetFlavors.size() && targetFlavors.size() != 1) {
         throw new WorkflowOperationException(String.format("Number of target flavors (%d) and output tracks (%d) do "
                 + "not match", targetFlavors.size(), composedTracks.size()));
       }
       if (composedTracks.size() != targetTags.length && targetTags.length != 1 && targetTags.length != 0) {
         throw new WorkflowOperationException(String.format("Number of target tag groups (%d) and output tracks (%d) "
                 + "do not match", targetTags.length, composedTracks.size()));
       }
 
       // Flavor each track in the order read
       int flavorIndex = 0;
       int tagsIndex = 0;
       for (Track composedTrack : composedTracks) {
         // set flavor to the matching flavor in the order listed
         composedTrack.setFlavor(newFlavor(sourceTrack, targetFlavors.get(flavorIndex).toString()));
         if (targetFlavors.size() > 1) {
           flavorIndex++;
         }
         if (targetTags.length > 0) {
           asList(targetTags[tagsIndex]).forEach(composedTrack::addTag);
           logger.trace("Tagging composed track with '{}'", targetTags[tagsIndex]);
           if (targetTags.length > 1) {
             tagsIndex++;
           }
         }
         // store new tracks to mediaPackage
         String fileName = getFileNameFromElements(sourceTrack, composedTrack);
         composedTrack.setURI(workspace.moveTo(composedTrack.getURI(), mediaPackage.getIdentifier().toString(),
                 composedTrack.getIdentifier(), fileName));
         mediaPackage.addDerived(composedTrack, sourceTrack);
       }
     }
 
     logger.debug("Demux operation completed");
     return createResult(mediaPackage, Action.CONTINUE, totalTimeInQueue);
   }
 
   private MediaPackageElementFlavor newFlavor(Track track, String flavor) throws WorkflowOperationException {
     MediaPackageElementFlavor targetFlavor;
 
     try {
       targetFlavor = MediaPackageElementFlavor.parseFlavor(flavor);
       String flavorType = targetFlavor.getType();
       String flavorSubtype = targetFlavor.getSubtype();
       // Adjust the target flavor. Make sure to account for partial updates
       if ("*".equals(flavorType)) {
         flavorType = track.getFlavor().getType();
       }
       if ("*".equals(flavorSubtype)) {
         flavorSubtype = track.getFlavor().getSubtype();
       }
       return (new MediaPackageElementFlavor(flavorType, flavorSubtype));
     } catch (IllegalArgumentException e) {
       throw new WorkflowOperationException(String.format("Target flavor '%s' is malformed", flavor));
     }
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }