/*
    * 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.rename;
  
  import org.opencastproject.job.api.JobContext;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElementFlavor;
  import org.opencastproject.mediapackage.MediaPackageElements;
  import org.opencastproject.mediapackage.Track;
  import org.opencastproject.mediapackage.VideoStream;
  import org.opencastproject.mediapackage.selector.TrackSelector;
  import org.opencastproject.metadata.dublincore.DublinCoreCatalog;
  import org.opencastproject.metadata.dublincore.DublinCoreUtil;
  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.WorkflowOperationResult;
  import org.opencastproject.workflow.api.WorkflowOperationResult.Action;
  import org.opencastproject.workspace.api.Workspace;
  
  import org.apache.commons.io.FilenameUtils;
  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.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.UUID;
  
  /**
   * The <code>RenameFilesWorkflowOperationHandler</code> will rename files referenced in tracks based on metadata
   * contained in the media package.
   */
  @Component(
      property = {
          "service.description=Rename Files Workflow Operation Handler",
          "workflow.operation=rename-files"
      },
      immediate = true,
      service = WorkflowOperationHandler.class
  )
  public class RenameFilesWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    /** The logging facility */
    private static final Logger logger = LoggerFactory.getLogger(RenameFilesWorkflowOperationHandler.class);
  
    /** 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;
    }
  
    /**
     * {@inheritDoc}
     *
     * @see org.opencastproject.workflow.api.WorkflowOperationHandler#start(
     *      org.opencastproject.workflow.api.WorkflowInstance, JobContext)
     */
    @Override
    public WorkflowOperationResult start(WorkflowInstance workflowInstance, JobContext context)
            throws WorkflowOperationException {
  
      final var operation = workflowInstance.getCurrentOperation();
     final var mediaPackage = workflowInstance.getMediaPackage();
     final var mediaPackageId = mediaPackage.getIdentifier().toString();
 
     logger.info("Running rename files workflow operation on workflow {}", workflowInstance.getId());
 
     // Read configuration
     // source-flavors source-tags
     String pattern = operation.getConfiguration("name-pattern");
     if (pattern == null) {
       throw new WorkflowOperationException("name-pattern must be configured");
     }
     logger.debug("name-pattern {}", pattern);
 
 
     var tagsAndFlavors = getTagsAndFlavors(
             workflowInstance,
             Configuration.none,  // source-tags
             Configuration.many,  // source-flavors
             Configuration.none,  // target-tags
             Configuration.none); // target-flavors
 
     // Select tracks by evaluating source tags and flavors
     List<MediaPackageElementFlavor> sourceFlavors = tagsAndFlavors.getSrcFlavors();
 
     TrackSelector trackSelector = new TrackSelector();
     for (MediaPackageElementFlavor sourceFlavor: sourceFlavors) {
       trackSelector.addFlavor(sourceFlavor);
     }
 
     for (var track: trackSelector.select(mediaPackage, false)) {
       var uri = track.getURI();
       var extension = FilenameUtils.getExtension(uri.toString());
       var newElementId = UUID.randomUUID().toString();
 
       // Prepare placeholders and filename
       var filename = pattern;
       for (var entry: placeholders(mediaPackage, track).entrySet()) {
         filename = filename.replace(entry.getKey(), entry.getValue());
       }
       filename = filename.replaceAll("#\\{[a-z.]*}", "_");
 
       // Put updated filename in working file repository and update the track.
       // Make sure it has a new identifier to prevent conflicts with the old files.
       try (var in = workspace.read(uri)) {
         var newUri = workspace.put(mediaPackageId, newElementId, filename, in);
         logger.info("Renaming {} to {}", uri, newUri);
         track.setIdentifier(newElementId);
         track.setURI(newUri);
       } catch (NotFoundException | IOException e) {
         throw new WorkflowOperationException("Failed moving track file", e);
       }
 
       // Delete the old files from the working file repository and workspace if they were in there
       logger.debug("Removing old track file {}", uri);
       try {
         workspace.delete(uri);
       } catch (NotFoundException | IOException e) {
         logger.debug("Could not remove track from workspace. Could be it was never there.");
       }
 
     }
 
     return createResult(mediaPackage, Action.CONTINUE);
   }
 
   /**
    * Generate map or placeholders.
    *
    * @param element
    *          Current media package element
    * @param mediaPackage
    *          Current media package
    * @return Map of placeholders.
    */
   private Map<String, String> placeholders(MediaPackage mediaPackage, Track element) {
 
     var placeholders = new HashMap<String, String>();
 
     var width = Arrays.stream(element.getStreams())
         .filter(s -> s instanceof VideoStream)
         .map(s -> (VideoStream) s)
         .findFirst()
         .map(VideoStream::getFrameWidth)
         .map(Object::toString)
         .orElse("");
     // Placeholder resolution width
     placeholders.put("#{video.width}", width);
 
     var height = Arrays.stream(element.getStreams())
             .filter(h -> h instanceof VideoStream)
             .map(h -> (VideoStream) h)
             .findFirst()
             .map(VideoStream::getFrameHeight)
             .map(Object::toString)
             .orElse("");
     //Placeholder resolution height
     placeholders.put("#{video.height}", height);
 
     // file placeholders
     placeholders.put("#{file.extension}", FilenameUtils.getExtension(element.getURI().toString()));
     placeholders.put("#{file.basename}", FilenameUtils.getBaseName(element.getURI().toString()));
 
     // flavor placeholders
     placeholders.put("#{flavor.type}", element.getFlavor().getType());
     placeholders.put("#{flavor.subtype}", element.getFlavor().getSubtype());
 
     // metadata placeholders
     for (var flavor: Arrays.asList(MediaPackageElements.EPISODE, MediaPackageElements.SERIES)) {
       // Get metadata catalogs
       for (var catalog : mediaPackage.getCatalogs(flavor)) {
         DublinCoreCatalog dc = DublinCoreUtil.loadDublinCore(workspace, catalog);
         for (var entry : dc.getValues().entrySet()) {
           var key = String.format("#{%s.%s}", flavor.getSubtype(), entry.getKey().getLocalName());
           var value = entry.getValue().get(0).getValue();
           placeholders.put(key, value);
         }
       }
     }
 
     logger.debug("Placeholders to use for renaming: {}", placeholders);
     return placeholders;
   }
 
   @Activate
   @Override
   protected void activate(ComponentContext cc) {
     super.activate(cc);
   }
 }