/*
    * 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.EncoderException;
  import org.opencastproject.job.api.JobContext;
  import org.opencastproject.mediapackage.AdaptivePlaylist;
  import org.opencastproject.mediapackage.AdaptivePlaylist.HLSMediaPackageCheck;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElementFlavor;
  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.util.data.Function2;
  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.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Reference;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.function.Function;
  
  /**
   * The <code></code> operation will make sure that media where hls playlists and video track come in separate files
   * will have appropriately references prior to further processing such as inspection.
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Sanitize Adaptive Workflow Operation Handler",
          "workflow.operation=sanitize-adaptive"
      }
  )
  public class SanitizeAdaptiveWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(SanitizeAdaptiveWorkflowOperationHandler.class);
    private static final String PLUS = "+";
    private static final String MINUS = "-";
  
    /** The local workspace */
    private Workspace workspace = null;
  
    /**
     * 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;
    }
  
    @Reference
    @Override
    public void setServiceRegistry(ServiceRegistry serviceRegistry) {
      super.setServiceRegistry(serviceRegistry);
   }
 
   /**
    * {@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 HLS Check workflow operation on workflow {}", workflowInstance.getId());
     try {
       return sanitizeHLS(workflowInstance);
     } catch (Exception e) {
       throw new WorkflowOperationException(e);
     }
   }
 
   /**
    * Checks the references in the playists and make sure that the playlists can pass though an ffmpeg inspection. If the
    * file references are off, they will be rewritten. The problem is mainly the media package elementID.
    *
    * @param wi
    *          the sanitizeHLS 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
    * @throws URISyntaxException
    */
   private WorkflowOperationResult sanitizeHLS(WorkflowInstance wi)
           throws EncoderException,
           WorkflowOperationException, NotFoundException, MediaPackageException, IOException, URISyntaxException {
     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();
     List<String> targetTrackTags = tagsAndFlavors.getTargetTags();
     MediaPackageElementFlavor targetFlavor = tagsAndFlavors.getSingleTargetFlavor();
 
     List<String> removeTags = new ArrayList<String>();
     List<String> addTags = new ArrayList<String>();
     List<String> overrideTags = new ArrayList<String>();
 
     if (!targetTrackTags.isEmpty()) {
       for (String tag : targetTrackTags) {
         if (tag.startsWith(MINUS)) {
           removeTags.add(tag);
         } else if (tag.startsWith(PLUS)) {
           addTags.add(tag);
         } else {
           overrideTags.add(tag);
         }
       }
     }
 
     // Select those tracks that have matching flavors
     TrackSelector trackSelector = new TrackSelector();
     trackSelector.addFlavor(sourceFlavor);
     Collection<Track> tracks = trackSelector.select(mediaPackage, false);
     List<Track> tracklist = new ArrayList<>(tracks);
 
     // Nothing to sanitize, do not set target tags or flavor on tracks, just return
     if (!tracklist.stream().filter(AdaptivePlaylist.isHLSTrackPred).findAny().isPresent()) {
       return createResult(mediaPackage, Action.CONTINUE, 0);
     }
     HLSMediaPackageCheck hlstree;
     try {
       hlstree = new HLSMediaPackageCheck(tracklist, new Function<URI, File>() {
         @Override
         public File apply(URI uri) {
           try {
             return workspace.get(uri);
           } catch (NotFoundException | IOException e1) { // from workspace.get
             logger.error("Cannot get {} from workspace", uri, e1);
           }
           return null;
         }
       });
     } catch (URISyntaxException e1) {
       throw new MediaPackageException("Cannot process tracks from workspace");
     }
     /**
      * Adds new file to Mediapackage to replace old Track, while retaining all properties. Also sets the target flavor
      * and target tags
      */
     Function2<File, Track, Track> replaceHLSPlaylistInWS = new Function2<File, Track, Track>() {
       @Override
       public Track apply(File file, Track track) {
         try {
           InputStream inputStream = new FileInputStream(file);
           // put file into workspace for mp
           URI uri = workspace.put(mediaPackage.getIdentifier().toString(), track.getIdentifier(), file.getName(),
                   inputStream);
           track.setURI(uri); // point track to new URI
           handleTags(track, targetFlavor, overrideTags, removeTags, addTags); // add tags and flavor
           return track;
         } catch (Exception e) {
           logger.error("Cannot add track file to mediapackage in workspace: {} {} ",
                   mediaPackage.getIdentifier().toString(),
                   file);
           return null;
         }
       }
     };
     // remove old tracks if the entire operation succeeds, or remove new tracks if any of them fails
     Function<Track, Void> removeFromWS = new Function<Track, Void>() {
       @Override
       public Void apply(Track track) {
         try {
           workspace.delete(track.getURI());
         } catch (NotFoundException e) {
           logger.error("Cannot delete from workspace: File not found {} ", track);
         } catch (IOException e) {
           logger.error("Cannot delete from workspace: IO Error {} ", track);
         }
         return null;
       }
     };
     if (hlstree.needsRewriting()) {
       // rewrites the playlists and replaced the old ones in the mp
       try {
         hlstree.rewriteHLS(mediaPackage, replaceHLSPlaylistInWS, removeFromWS);
       } catch (Exception e) {
         logger.error("Error: cannot rewrite HLS renditions", e);
         throw new WorkflowOperationException(e);
       }
       for (Track track : tracks) { // Update the flavor and tags for all non HLS segments
         if (!AdaptivePlaylist.isPlaylist(track.getURI().getPath())) {
           handleTags(track, targetFlavor, overrideTags, removeTags, addTags);
           logger.info("Set flavor {} and tags to {} ", track, targetFlavor);
         }
       }
     } else { // change flavor to mark as sanitized
       for (Track track : tracks) {
         handleTags(track, targetFlavor, overrideTags, removeTags, addTags);
         logger.info("Set flavor {} and tags to {} ", track, targetFlavor);
       }
     }
     return createResult(mediaPackage, Action.CONTINUE, 0);
   }
 
   // Add the target tags and flavor
   private void handleTags(Track track, MediaPackageElementFlavor targetFlavor, List<String> overrideTags,
           List<String> removeTags, List<String> addTags) {
     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();
       track.setFlavor(new MediaPackageElementFlavor(flavorType, flavorSubtype));
       logger.debug("Composed track has flavor '{}'", track.getFlavor());
     }
     if (overrideTags.size() > 0) {
       track.clearTags();
       for (String tag : overrideTags) {
         logger.trace("Tagging composed track with '{}'", tag);
         track.addTag(tag);
       }
     } else {
       for (String tag : removeTags) {
         logger.trace("Remove tagging '{}' from composed track", tag);
         track.removeTag(tag.substring(MINUS.length()));
       }
       for (String tag : addTags) {
         logger.trace("Add tagging '{}' to composed track", tag);
         track.addTag(tag.substring(PLUS.length()));
       }
     }
   }
 }