/*
    * 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.AdaptivePlaylist;
  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.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.io.FilenameUtils;
  import org.apache.commons.lang3.BooleanUtils;
  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.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.function.Predicate;
  import java.util.stream.Collectors;
  
  /**
   * The workflow definition for handling multiple concurrent outputs in one ffmpeg operation. This allows encoding and
   * tagging to be done in one operation
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=MultiEncode Workflow Operation Handler",
          "workflow.operation=multiencode"
      }
  )
  public class MultiEncodeWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(MultiEncodeWorkflowOperationHandler.class);
  
    /** seperator for independent clauses */
    static final String SEPARATOR = ";";
  
    /** The composer service */
    private ComposerService composerService = null;
  
    /** The local workspace */
    private Workspace workspace = null;
  
    @Activate
    public void activate(ComponentContext cc) {
      super.activate(cc);
    }
  
    /**
     * 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;
   }
 
   private Predicate<EncodingProfile> isManifestEP = p ->  p.getOutputType() == EncodingProfile.MediaType.Manifest;
 
   /**
    * {@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 Multiencode workflow operation on workflow {}", workflowInstance.getId());
 
     try {
       return multiencode(workflowInstance.getMediaPackage(), workflowInstance.getCurrentOperation());
     } catch (Exception e) {
       throw new WorkflowOperationException(e);
     }
   }
 
   protected class ElementProfileTagFlavor {
     private AbstractMediaPackageElementSelector<Track> elementSelector = new TrackSelector();
     private String targetFlavor = null;
     private String targetTags = null;
     private List<String> encodingProfiles = new ArrayList<>(); // redundant storage
     private List<EncodingProfile> encodingProfileList = new ArrayList<>();
 
     ElementProfileTagFlavor(String profiles) {
       List<String> profilelist = asList(profiles);
       for (String profile : profilelist) {
         EncodingProfile encodingprofile = composerService.getProfile(profile);
         if (encodingprofile != null) {
           encodingProfiles.add(encodingprofile.getIdentifier());
           encodingProfileList.add(encodingprofile);
         } else {
           throw new IllegalArgumentException("Encoding profile " + profile + " not found.");
         }
       }
     }
 
     public AbstractMediaPackageElementSelector<Track> getSelector() {
       return this.elementSelector;
     }
 
     public List<String> getProfiles() {
       return this.encodingProfiles;
     }
 
     public List<EncodingProfile> getEncodingProfiles() {
       return this.encodingProfileList;
     }
 
     void addSourceFlavor(String flavor) {
       this.elementSelector.addFlavor(MediaPackageElementFlavor.parseFlavor(flavor));
     }
 
     void addSourceTag(String tag) {
       this.elementSelector.addTag(tag);
     }
 
     void setTargetTags(String tags) {
       this.targetTags = tags;
     }
 
     void setTargetFlavor(String flavor) {
       this.targetFlavor = flavor;
     }
 
     String getTargetFlavor() {
       return this.targetFlavor;
     }
 
     String getTargetTags() {
       return this.targetTags;
     }
   }
 
   /*
    * Figures out the logic of all the source tags, flavors and profiles and sorts out the source tracks and
    * corresponding encoding profiles.
    *
    * Source Tracks are selected by (Flavor AND Tag) if they are both provided
    *
    * There can be multiple sources and flavors to create more than one source tracks. In the workflow, A semi-colon ";"
    * is used to separate the independent operations.
    *
    * The independent operations can be either all share the same set of properties or all have different sets of
    * properties. For example, There are two sets of source flavors: * "presenter/* ; presentation/*", one source tag,
    * eg: "preview", and two sets of encoding profiles, eg: "mp4,flv ; mp4,hdtv" then there are two concurrent
    * operations: the first one is all "presenter" tracks tagged "preview" will be encoded with "mp4" and "flv". The
    * second one is all "presentation" tracks tagged "preview" encoded with "mp4" and "hdtv"
    *
    */
   private List<ElementProfileTagFlavor> getSrcSelector(String[] sourceFlavors, String[] sourceTags,
           String[] targetFlavors, String[] targetTags, String[] profiles) throws WorkflowOperationException {
     int n = 0;
     List<ElementProfileTagFlavor> elementSelectors = new ArrayList<>();
     if (sourceTags == null && sourceFlavors == null)
       throw new WorkflowOperationException("No source tags or Flavor");
     if (profiles == null)
       throw new WorkflowOperationException("Missing profiles");
     if (sourceTags != null) { // If source tags are used to select tracks
       // If use source and target tags, there should be the same number of them or all map into one target
       if (targetTags != null && (targetTags.length != 1 && sourceTags.length != targetTags.length))
         throw new WorkflowOperationException("number of source tags " + sourceTags.length
                 + " does not match number of target tags " + targetTags.length + " (must be the same or one target)");
       // There should be the same number of source tags or profile groups or all use same group of profiles
       if (profiles.length != 1 && sourceTags.length != profiles.length) {
         throw new WorkflowOperationException(
                 "number of source tags segments " + sourceTags.length + " does not match number of profiles segments "
                         + profiles.length + " (must be the same or one profile)");
       }
       // If use source tags and source flavors, there should be the same number of them or one
       if (sourceFlavors != null && (sourceTags.length != 1 && sourceFlavors.length != 1)
               && sourceFlavors.length != sourceTags.length) {
         throw new WorkflowOperationException("number of source tags segments " + sourceTags.length
                 + " does not match number of source Flavor segments " + sourceFlavors.length
                 + " (must be the same or one)");
       }
       n = sourceTags.length; // at least this many tracks
     }
     if (sourceFlavors != null) { // If flavors are used to select tracks
       // If use source and target flavors, there should be the same number of them or all map into one target
       if (targetFlavors != null && (targetFlavors.length != 1 && sourceFlavors.length != targetFlavors.length)) {
         throw new WorkflowOperationException(
                 "number of source flavors " + sourceFlavors.length + " segment does not match number of target flavors"
                         + targetFlavors.length + " (must be the same or one target flavor)");
       }
       // If use target tags, there should be the same number of source flavors and target tags or all map into one
       // target tag
       if (targetTags != null && targetTags.length != 1 && sourceFlavors.length != targetTags.length) {
         throw new WorkflowOperationException(
                 "number of source flavors " + sourceFlavors.length + " segment does not match number of target Tags"
                         + targetTags.length + " (must be the same or one target)");
       }
       // Number of profile groups should match number of source flavors
       if ((profiles.length != 1 && sourceFlavors.length != profiles.length)) {
         throw new WorkflowOperationException("number of source flavors segments " + sourceFlavors.length
                 + " does not match number of profiles segments " + profiles.length
                 + " (must be the same or one profile)");
       }
       if (sourceFlavors.length > n)
         n = sourceFlavors.length; // at least this many tracks
     }
     int numProfiles = 0;
     // One for each source flavor
     for (int i = 0; i < n; i++) {
       elementSelectors.add(new ElementProfileTagFlavor(profiles[numProfiles]));
       if (profiles.length > 1)
         numProfiles++; // All source use the same set of profiles or its own
     }
     // If uses tags to select, but sets target flavor, they must match
     if (sourceTags != null && sourceFlavors != null) {
       if (sourceTags.length != sourceFlavors.length && sourceFlavors.length != 1 && sourceTags.length != 1) {
         throw new WorkflowOperationException(
                 "number of source flavors " + sourceTags.length + " does not match number of source tags "
                         + sourceFlavors.length + " (must be the same or one set of tags or flavors)");
       }
     }
     populateFlavorsAndTags(elementSelectors, sourceFlavors, targetFlavors, sourceTags, targetTags);
     return elementSelectors;
   }
 
   private List<ElementProfileTagFlavor> populateFlavorsAndTags(List<ElementProfileTagFlavor> elementSelectors,
           String[] sourceFlavors, String[] targetFlavors, String[] sourceTags, String[] targetTags)
           throws WorkflowOperationException {
     int sf = 0;
     int tf = 0;
     int st = 0;
     int tt = 0;
     for (ElementProfileTagFlavor ep : elementSelectors) {
       try {
         if (sourceTags != null) {
           for (String tag : asList(sourceTags[st])) {
             ep.addSourceTag(tag);
           }
           if (sourceTags.length != 1)
             st++;
         }
         if (targetTags != null) {
           ep.setTargetTags(targetTags[tt]);
           if (targetTags.length != 1)
             tt++;
         }
         if (sourceFlavors != null) {
           for (String flavor : asList(sourceFlavors[sf])) {
             ep.addSourceFlavor(flavor);
           }
           if (sourceFlavors.length != 1)
             sf++;
         }
         if (targetFlavors != null) {
           for (String flavor : asList(targetFlavors[tf])) {
             ep.setTargetFlavor(flavor);
           }
           if (targetFlavors.length != 1)
             tf++;
         }
       } catch (IllegalArgumentException e) {
         throw new WorkflowOperationException("Set Tags or Flavor " + e.getMessage());
       }
     }
     return elementSelectors;
   }
 
   private String[] getConfigAsArray(WorkflowOperationInstance operation, String name) {
     String sourceOption = StringUtils.trimToNull(operation.getConfiguration(name));
     return StringUtils.split(sourceOption, SEPARATOR);
   }
 
   private List<Track> getManifest(Collection<Track> tracks) {
     return tracks.stream().filter(AdaptivePlaylist.isHLSTrackPred).collect(Collectors.toList());
   }
 
   /*
    * Encode multiple tracks in a mediaPackage concurrently with different encoding profiles for each track. The encoding
    * profiles are specified by names in a list and are the names used to tag each corresponding output. Each source
    * track will start one operation on one worker. concurrency is achieved by running on different workers
    *
    * @param src The source media package
    *
    * @param operation the current workflow operation
    *
    * @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 multiencode(MediaPackage src, WorkflowOperationInstance operation)
           throws EncoderException, IOException, NotFoundException, MediaPackageException, WorkflowOperationException {
     MediaPackage mediaPackage = (MediaPackage) src.clone();
     // Check which tags have been configured
     String[] sourceTags = getConfigAsArray(operation, "source-tags");
     String[] sourceFlavors = getConfigAsArray(operation, "source-flavors");
     String[] targetTags = getConfigAsArray(operation, "target-tags");
     String[] targetFlavors = getConfigAsArray(operation, "target-flavors");
     String tagWithProfileConfig = StringUtils.trimToNull(operation.getConfiguration("tag-with-profile"));
     boolean tagWithProfile = BooleanUtils.toBoolean(tagWithProfileConfig);
 
     // Make sure either one of tags or flavors are provided
     if (sourceFlavors == null && sourceTags == null) {
       logger.info("No source tags or flavors have been specified, not matching anything");
       return createResult(mediaPackage, Action.CONTINUE);
     }
     String[] profiles = getConfigAsArray(operation, "encoding-profiles");
     if (profiles == null)
       throw new WorkflowOperationException("Missing encoding profiles");
 
     // Sort out the combinatorics of all the tags and flavors
     List<ElementProfileTagFlavor> selectors = getSrcSelector(sourceFlavors, sourceTags, targetFlavors, targetTags,
             profiles);
 
     long totalTimeInQueue = 0;
     Map<Job, JobInformation> encodingJobs = new HashMap<>();
     // Find the encoding profiles - should only be one per flavor or tag
     for (ElementProfileTagFlavor eptf : selectors) {
       // Look for elements matching the tag and flavor
       Collection<Track> elements = eptf.elementSelector.select(mediaPackage, true);
       for (Track sourceTrack : elements) {
         logger.info("Encoding track {} using encoding profile '{}'", sourceTrack, eptf.getProfiles().get(0).toString());
         // Start encoding and wait for the result
         encodingJobs.put(composerService.multiEncode(sourceTrack, eptf.getProfiles()),
                 new JobInformation(sourceTrack, eptf, tagWithProfile));
       }
     }
 
     if (encodingJobs.isEmpty()) {
       logger.info("No matching tracks found");
       return createResult(mediaPackage, Action.CONTINUE);
     }
 
     // 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, JobInformation> entry : encodingJobs.entrySet()) {
       Job job = entry.getKey();
       Track sourceTrack = entry.getValue().getTrack(); // source
       ElementProfileTagFlavor info = entry.getValue().getInfo(); // tags and flavors
       List<EncodingProfile> eplist = entry.getValue().getProfileList();
       // 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) {
         @SuppressWarnings("unchecked")
         List<Track> composedTracks = (List<Track>) MediaPackageElementParser.getArrayFromXml(job.getPayload());
         // HLS Manifest profile has precedence and overrides individual encoding profiles
         boolean isHLS = eplist.stream().anyMatch(isManifestEP);
         if (isHLS) { // check that manifests and segments counts are correct
           decipherHLSPlaylistResults(sourceTrack, entry.getValue(), mediaPackage, composedTracks);
         } else if (composedTracks.size() != info.getProfiles().size()) {
           logger.info("Encoded {} tracks, with {} profiles", composedTracks.size(), info.getProfiles().size());
           throw new WorkflowOperationException("Number of output tracks does not match number of encoding profiles");
         }
         for (Track composedTrack : composedTracks) {
           if (info.getTargetFlavor() != null) { // Has Flavors
             // set it to the matching flavor in the order listed
             composedTrack.setFlavor(newFlavor(sourceTrack, info.getTargetFlavor()));
             logger.debug("Composed track has flavor '{}'", composedTrack.getFlavor());
           }
           if (info.getTargetTags() != null) { // Has Tags
             for (String tag : asList(info.getTargetTags())) {
               logger.trace("Tagging composed track with '{}'", tag);
               composedTrack.addTag(tag);
             }
           }
           // Tag each output with encoding profile name if configured
           if (entry.getValue().getTagWithProfile()) {
             tagByProfile(composedTrack, eplist);
           }
           String fileName;
           if (!isHLS || composedTrack.isMaster()) {
             // name after source track if user facing
             fileName = getFileNameFromElements(sourceTrack, composedTrack);
           } else { // HLS-VOD
             // Should all the files be renamed to the same as source
             // which defeats the purpose of the suffix in encoding profiles
             fileName = FilenameUtils.getName(composedTrack.getURI().getPath());
           }
           // store new tracks to mediaPackage
           composedTrack.setURI(workspace.moveTo(composedTrack.getURI(), mediaPackage.getIdentifier().toString(),
                   composedTrack.getIdentifier(), fileName));
           mediaPackage.addDerived(composedTrack, sourceTrack);
         }
       } else {
         logger.warn("No output from MultiEncode operation");
       }
     }
     WorkflowOperationResult result = createResult(mediaPackage, Action.CONTINUE, totalTimeInQueue);
     logger.debug("MultiEncode operation completed");
     return result;
   }
 
   /**
    * Find the matching encoding profile for this track and tag by name
    *
    * @param track
    * @param profiles
    *          - profiles used to encode a track to multiple formats
    * @return
    */
   private void tagByProfile(Track track, List<EncodingProfile> profiles) {
     String rawfileName = track.getURI().getRawPath();
     for (EncodingProfile ep : profiles) {
       // #DCE
       // Add any character at the beginning of the suffix so that it is properly
       // converted in toSafeName (because the regex used there may treat the first
       // character differently; the default one does now).
       String suffixToSanitize = "X" + ep.getSuffix();
       // !! workspace.putInCollection renames the file - need to do the same with suffix
       String suffix = workspace.toSafeName(suffixToSanitize).substring(1);
       if (suffix.length() > 0 && rawfileName.endsWith(suffix)) {
         track.addTag(ep.getIdentifier());
         return;
       }
     }
   }
 
   private void decipherHLSPlaylistResults(Track track, JobInformation jobInfo, MediaPackage mediaPackage,
           List<Track> composedTracks)
           throws WorkflowOperationException, IllegalArgumentException, NotFoundException, IOException {
     int nprofiles = jobInfo.getInfo().getProfiles().size();
     List<Track> manifests = getManifest(composedTracks);
 
     if (manifests.size() != nprofiles) {
       throw new WorkflowOperationException("Number of output playlists does not match number of encoding profiles");
     }
     if (composedTracks.size() != manifests.size() * 2 - 1) {
       throw new WorkflowOperationException("Number of output media does not match number of encoding profiles");
     }
   }
 
   private MediaPackageElementFlavor newFlavor(Track track, String flavor) throws WorkflowOperationException {
     if (StringUtils.isNotBlank(flavor)) {
       try {
         MediaPackageElementFlavor 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("Target flavor '" + flavor + "' is malformed");
       }
     }
     return null;
   }
 
   /**
    * This class is used to store context information for the jobs.
    */
   private static final class JobInformation {
 
     private Track track = null;
     private ElementProfileTagFlavor info = null;
     private boolean tagWithProfile;
 
     JobInformation(Track track, ElementProfileTagFlavor info, boolean tagWithProfile) {
       this.track = track;
       this.info = info;
       this.tagWithProfile = tagWithProfile;
     }
 
     public List<EncodingProfile> getProfileList() {
       return info.encodingProfileList;
     }
 
     /**
      * Returns the track.
      *
      * @return the track
      */
     public Track getTrack() {
       return track;
     }
 
     public boolean getTagWithProfile() {
       return this.tagWithProfile;
     }
 
     public ElementProfileTagFlavor getInfo() {
       return info;
     }
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }