/*
    * 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.publication.youtube;
  
  import org.opencastproject.mediapackage.Catalog;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElements;
  import org.opencastproject.metadata.dublincore.DublinCore;
  import org.opencastproject.metadata.dublincore.DublinCoreCatalog;
  import org.opencastproject.metadata.dublincore.DublinCores;
  import org.opencastproject.publication.api.PublicationException;
  import org.opencastproject.workspace.api.Workspace;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.InputStream;
  
  /**
   * Strategy to determine destination of publication. Instances of this class are not thread-safe.
   */
  public class YouTubePublicationAdapter {
  
    /** logger instance */
    private static final Logger logger = LoggerFactory.getLogger(YouTubePublicationAdapter.class);
  
    /** Media package containing publication metadata */
    private final MediaPackage mediaPackage;
  
    /** Dublincore metadata catalog for the episode */
    private final DublinCoreCatalog dcEpisode;
  
    /** Dublincore metadata catalog for the series */
    private final DublinCoreCatalog dcSeries;
  
    /**
     * Create a single-use strategy instance for publication to youtube
     *
     * @param mp
     *          the mediapackage identifier
     * @param workspace
     *          the workspace service
     * @throws PublicationException
     */
    public YouTubePublicationAdapter(MediaPackage mp, Workspace workspace) throws PublicationException {
      if (mp == null) {
        throw new PublicationException("Media package is null");
      }
      mediaPackage = mp;
  
      Catalog[] episodeCatalogs = mediaPackage.getCatalogs(MediaPackageElements.EPISODE);
      if (episodeCatalogs.length == 0) {
        dcEpisode = null;
      } else {
        dcEpisode = parseDublinCoreCatalog(episodeCatalogs[0], workspace);
      }
  
      Catalog[] seriesCatalogs = mediaPackage.getCatalogs(MediaPackageElements.SERIES);
      if (seriesCatalogs.length == 0) {
        dcSeries = null;
      } else {
        dcSeries = parseDublinCoreCatalog(seriesCatalogs[0], workspace);
      }
    }
  
    /**
     * Gets the name for a context within a publication channel.
     *
     * @return The playlist ID
     */
    public String getContextName() {
      return mediaPackage.getSeriesTitle();
    }
  
    /**
     * Gets the name for a context within a publication channel.
    *
    * @return Context description
    */
   public String getContextDescription() {
     return dcSeries == null ? null : dcSeries.getFirst(DublinCore.PROPERTY_DESCRIPTION);
   }
 
   /**
    * Gets the name for the episode of the media package
    *
    * @return the title of the episode
    */
   public String getEpisodeName() {
     return dcEpisode == null ? null : dcEpisode.getFirst(DublinCore.PROPERTY_TITLE);
   }
 
   /**
    * Gets the description for the episode of the media package
    *
    * @return the description of the episode
    */
   public String getEpisodeDescription() {
     if (dcEpisode == null) {
       return null;
     }
 
     String description = "";
     if (dcSeries != null) {
       description = StringUtils.trimToEmpty(dcSeries.getFirst(DublinCore.PROPERTY_TITLE));
     }
 
     String episodeDescription = dcEpisode.getFirst(DublinCore.PROPERTY_DESCRIPTION);
     if (episodeDescription != null) {
       description += '\n' + episodeDescription;
     }
 
     String episodeLicense = dcEpisode.getFirst(DublinCore.PROPERTY_LICENSE);
     if (episodeLicense != null) {
       description += '\n' + episodeLicense;
     }
 
     return description;
   }
 
   /**
    * Parse Dublincore metadata from the workspace
    *
    * @param catalog
    *          A mediapackage's catalog file
    * @return Catalog parse from XML
    */
   private DublinCoreCatalog parseDublinCoreCatalog(Catalog catalog, Workspace workspace) {
     InputStream is = null;
     try {
       File dcFile = workspace.get(catalog.getURI());
       is = new FileInputStream(dcFile);
       return DublinCores.read(is);
     } catch (Exception e) {
       logger.error("Error loading Dublin Core metadata: {}", e.getMessage());
     } finally {
       IOUtils.closeQuietly(is);
     }
     return null;
   }
 
 }