/**
 * Copyright 2015 Tampere University of Technology, Pori Department
 * 
 * Licensed under the Apache 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://www.apache.org/licenses/LICENSE-2.0
 * 
 * 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 service.tut.pori.subtitles;

import java.util.Arrays;

import org.apache.log4j.Logger;

import service.tut.pori.contentanalysis.video.VideoDAO;
import service.tut.pori.contentanalysis.video.VideoList;
import core.tut.pori.context.ServiceInitializer;
import core.tut.pori.http.StringResponse.StringData;
import core.tut.pori.http.parameters.DataGroups;
import core.tut.pori.users.UserIdentity;


/**
 * Subtitle service core methods.
 * 
 */
public final class SubtitlesCore {
  private static final DataGroups DATA_GROUP_TIMECODES = new DataGroups(service.tut.pori.contentanalysis.Definitions.DATA_GROUP_TIMECODES);
  private static final Logger LOGGER = Logger.getLogger(SubtitlesCore.class);
  
  /**
   * Subtitle file format
   * 
   */
  public enum FileFormat {
    /**  
     * File format for WebVTT
     * 
     * <a href="http://dev.w3.org/html5/webvtt">WebVTT: The Web Video Text Tracks Format</a> 
     */
    WEBVTT;
    
    /**
     * 
     * @param value
     * @return the value converted to file format
     * @throws IllegalArgumentException on bad value
     */
    public static FileFormat fromFormatString(String value) throws IllegalArgumentException {
      if(value != null){
        switch(value.toUpperCase()){
          case Definitions.FILE_FORMAT_WEBVTT:
            return WEBVTT;
          default:
            break;
        }
      }
      throw new IllegalArgumentException("Bad value : "+value);
    }
    
    /**
     * 
     * @return this format as a string
     */
    public String toFormatString(){
      switch(this){
        case WEBVTT:
          return Definitions.FILE_FORMAT_WEBVTT;
        default:
          throw new UnsupportedOperationException("Unhandeled "+FileFormat.class.toString()+" : "+name());
      }
    }
  } // enum FileFormat
  
  /**
   * Formatting option for media objects in a subtitle
   * 
   */
  public enum SubtitleFormat {
    /** 
     * media objects will appear grouped by timecodes, combined in a single line 
     * 
     * An example in <a href="http://dev.w3.org/html5/webvtt">WEBVTT</a> format:
     * <pre>
     * 00:44.000 --&gt; 01:19.000
     * Keyword1, Keyword2
     *
     * 01:24.000 --&gt; 05:00.000
     * Keyword1, Keyword3
     * </pre>
     */
    GROUPED,
    /** 
     * media objects will appear in individual lines, with one timecode sequence per media object 
     * 
     * An example in <a href="http://dev.w3.org/html5/webvtt">WEBVTT</a> format:
     * <pre>
     * 00:44.000 --&gt; 01:19.000
     * Keyword1
     *
     * 00:44.000 --&gt; 01:19.000
     * Keyword2
     *
     * 01:24.000 --&gt; 05:00.000
     * Keyword1
     * 
     * 01:24.000 --&gt; 05:00.000
     * Keyword3
     * </pre>
     */
    INDIVIDUAL;
    
    /**
     * 
     * @param value
     * @return value converted to SubtitleFormat
     * @throws IllegalArgumentException on bad value
     */
    public static SubtitleFormat fromFormatString(String value) throws IllegalArgumentException {
      if(value != null){
        switch(value.toUpperCase()){
          case Definitions.SUBTITLE_FORMAT_GROUPED:
            return GROUPED;
          case Definitions.SUBTITLE_FORMAT_INDIVIDUAL:
            return INDIVIDUAL;
          default:
            break;
        }
      }
      throw new IllegalArgumentException("Bad value: "+value);
    }
    
    /**
     * 
     * @return the formatting option as a string
     */
    public String toFormatString() {
      switch(this){
        case GROUPED:
          return Definitions.SUBTITLE_FORMAT_GROUPED;
        case INDIVIDUAL:
          return Definitions.SUBTITLE_FORMAT_INDIVIDUAL;
        default:
          throw new UnsupportedOperationException("Unhandeled "+SubtitleFormat.class.toString()+" : "+name());
      }
    }
  } // enum SubtitleFormat
  
  /**
   * 
   */
  private SubtitlesCore(){
    // nothing needed
  }

  /**
   * 
   * @param authenticatedUser
   * @param guid video GUID
   * @param fileFormat
   * @param subtitleFormat
   * @param userIdFilter optional user id filter
   * @return the formatted subtitle track or null on failure
   * @throws IllegalArgumentException on bad values
   */
  public static StringData generateSubtitles(UserIdentity authenticatedUser, String guid, FileFormat fileFormat, SubtitleFormat subtitleFormat, long[] userIdFilter) throws IllegalArgumentException {
    StringData data = null;
    switch(fileFormat){
      case WEBVTT:
        if(subtitleFormat != SubtitleFormat.INDIVIDUAL){
          throw new IllegalArgumentException("Unsupported subtitle format : "+subtitleFormat.toFormatString()+" for file format : "+fileFormat.toFormatString());
        }
        VideoList videos = ServiceInitializer.getDAOHandler().getSolrDAO(VideoDAO.class).search(authenticatedUser, DATA_GROUP_TIMECODES, Arrays.asList(guid), null, null, null, userIdFilter);
        if(VideoList.isEmpty(videos)){
          LOGGER.warn("Video not found or permission denied, GUID: "+guid);
        }else{
          WebVTTSubtitle vsub = new WebVTTSubtitle();
          vsub.setSubtitleFormat(subtitleFormat);
          vsub.setMediaObjects(videos.getVideos().get(0).getMediaObjects());
          data = vsub;
        }
        break;
      default:
        throw new UnsupportedOperationException("Unhandeled "+FileFormat.class.toString()+" : "+fileFormat.name());
    }
    
    return data;
  }
}