/*
    * 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.themes;
  
  import static java.lang.String.format;
  import static org.opencastproject.composer.layout.Offset.offset;
  
  import org.opencastproject.composer.layout.AbsolutePositionLayoutSpec;
  import org.opencastproject.composer.layout.AnchorOffset;
  import org.opencastproject.composer.layout.Anchors;
  import org.opencastproject.composer.layout.Serializer;
  import org.opencastproject.job.api.JobContext;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageElement;
  import org.opencastproject.mediapackage.MediaPackageElement.Type;
  import org.opencastproject.mediapackage.MediaPackageElementBuilderFactory;
  import org.opencastproject.mediapackage.MediaPackageElementFlavor;
  import org.opencastproject.security.api.UnauthorizedException;
  import org.opencastproject.series.api.SeriesException;
  import org.opencastproject.series.api.SeriesService;
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.staticfiles.api.StaticFileService;
  import org.opencastproject.themes.Theme;
  import org.opencastproject.themes.ThemesServiceDatabase;
  import org.opencastproject.themes.persistence.ThemesServiceDatabaseException;
  import org.opencastproject.util.MimeType;
  import org.opencastproject.util.MimeTypes;
  import org.opencastproject.util.NotFoundException;
  import org.opencastproject.util.UnknownFileTypeException;
  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 com.entwinemedia.fn.Fn;
  import com.entwinemedia.fn.Stream;
  import com.entwinemedia.fn.data.Opt;
  import com.entwinemedia.fn.fns.Strings;
  
  import org.apache.commons.lang3.StringUtils;
  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.io.InputStream;
  import java.net.URI;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.UUID;
  
  /**
   * The workflow definition for handling "theme" operations
   */
  @Component(
      immediate = true,
      service = WorkflowOperationHandler.class,
      property = {
          "service.description=Theme Workflow Operation Handler",
          "workflow.operation=theme"
      }
  )
  public class ThemeWorkflowOperationHandler extends AbstractWorkflowOperationHandler {
  
    private static final String BUMPER_FLAVOR = "bumper-flavor";
    private static final String BUMPER_TAGS = "bumper-tags";
  
    private static final String TRAILER_FLAVOR = "trailer-flavor";
    private static final String TRAILER_TAGS = "trailer-tags";
  
    private static final String TITLE_SLIDE_FLAVOR = "title-slide-flavor";
    private static final String TITLE_SLIDE_TAGS = "title-slide-tags";
  
    private static final String LICENSE_SLIDE_FLAVOR = "license-slide-flavor";
    private static final String LICENSE_SLIDE_TAGS = "license-slide-tags";
  
   private static final String WATERMARK_FLAVOR = "watermark-flavor";
   private static final String WATERMARK_TAGS = "watermark-tags";
   private static final String WATERMARK_LAYOUT = "watermark-layout";
   private static final String WATERMARK_LAYOUT_VARIABLE = "watermark-layout-variable";
 
   /** Workflow property names */
   private static final String THEME_ACTIVE = "theme_active";
   private static final String THEME_BUMPER_ACTIVE = "theme_bumper_active";
   private static final String THEME_TRAILER_ACTIVE = "theme_trailer_active";
   private static final String THEME_TITLE_SLIDE_ACTIVE = "theme_title_slide_active";
   private static final String THEME_TITLE_SLIDE_UPLOADED = "theme_title_slide_uploaded";
   private static final String THEME_WATERMARK_ACTIVE = "theme_watermark_active";
 
   /** The series theme property name */
   private static final String THEME_PROPERTY_NAME = "theme";
 
   /** The logging facility */
   private static final Logger logger = LoggerFactory.getLogger(ThemeWorkflowOperationHandler.class);
 
   private static final MediaPackageElementBuilderFactory elementBuilderFactory = MediaPackageElementBuilderFactory
           .newInstance();
 
   /** The series service */
   private SeriesService seriesService;
 
   /** The themes database service */
   private ThemesServiceDatabase themesServiceDatabase;
 
   /** The static file service */
   private StaticFileService staticFileService;
 
   /** The workspace */
   private Workspace workspace;
 
   /** OSGi callback for the series service. */
   @Reference
   public void setSeriesService(SeriesService seriesService) {
     this.seriesService = seriesService;
   }
 
   /** OSGi callback for the themes database service. */
   @Reference
   public void setThemesServiceDatabase(ThemesServiceDatabase themesServiceDatabase) {
     this.themesServiceDatabase = themesServiceDatabase;
   }
 
   /** OSGi callback for the static file service. */
   @Reference
   public void setStaticFileService(StaticFileService staticFileService) {
     this.staticFileService = staticFileService;
   }
 
   /** OSGi callback for the workspace. */
   @Reference
   public void setWorkspace(Workspace workspace) {
     this.workspace = workspace;
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
   @Override
   public WorkflowOperationResult start(final WorkflowInstance workflowInstance, JobContext context)
           throws WorkflowOperationException {
     logger.debug("Running theme workflow operation on workflow {}", workflowInstance.getId());
 
     final MediaPackageElementFlavor bumperFlavor = getOptConfig(workflowInstance, BUMPER_FLAVOR).map(
             toMediaPackageElementFlavor).getOr(new MediaPackageElementFlavor("branding", "bumper"));
     final MediaPackageElementFlavor trailerFlavor = getOptConfig(workflowInstance, TRAILER_FLAVOR).map(
             toMediaPackageElementFlavor).getOr(new MediaPackageElementFlavor("branding", "trailer"));
     final MediaPackageElementFlavor titleSlideFlavor = getOptConfig(workflowInstance, TITLE_SLIDE_FLAVOR).map(
             toMediaPackageElementFlavor).getOr(new MediaPackageElementFlavor("branding", "title-slide"));
     final MediaPackageElementFlavor licenseSlideFlavor = getOptConfig(workflowInstance, LICENSE_SLIDE_FLAVOR).map(
             toMediaPackageElementFlavor).getOr(new MediaPackageElementFlavor("branding", "license-slide"));
     final MediaPackageElementFlavor watermarkFlavor = getOptConfig(workflowInstance, WATERMARK_FLAVOR).map(
             toMediaPackageElementFlavor).getOr(new MediaPackageElementFlavor("branding", "watermark"));
     final List<String> bumperTags = asList(workflowInstance.getConfiguration(BUMPER_TAGS));
     final List<String> trailerTags = asList(workflowInstance.getConfiguration(TRAILER_TAGS));
     final List<String> titleSlideTags = asList(workflowInstance.getConfiguration(TITLE_SLIDE_TAGS));
     final List<String> licenseSlideTags = asList(workflowInstance.getConfiguration(LICENSE_SLIDE_TAGS));
     final List<String> watermarkTags = asList(workflowInstance.getConfiguration(WATERMARK_TAGS));
 
     Opt<String> layoutStringOpt = getOptConfig(workflowInstance, WATERMARK_LAYOUT);
     Opt<String> watermarkLayoutVariable = getOptConfig(workflowInstance, WATERMARK_LAYOUT_VARIABLE);
 
     List<String> layoutList = new ArrayList<>(Stream.$(layoutStringOpt).bind(Strings.split(";")).toList());
 
     try {
       MediaPackage mediaPackage = workflowInstance.getMediaPackage();
       String series = mediaPackage.getSeries();
       if (series == null) {
         logger.info("Skipping theme workflow operation, no series assigned to mediapackage {}",
                 mediaPackage.getIdentifier());
         return createResult(Action.SKIP);
       }
 
       Long themeId;
       try {
         themeId = Long.parseLong(seriesService.getSeriesProperty(series, THEME_PROPERTY_NAME));
       } catch (NotFoundException e) {
         logger.info("Skipping theme workflow operation, no theme assigned to series {} on mediapackage {}.", series,
                 mediaPackage.getIdentifier());
         return createResult(Action.SKIP);
       } catch (UnauthorizedException e) {
         logger.warn("Skipping theme workflow operation, user not authorized to perform operation:", e);
         return createResult(Action.SKIP);
       }
 
       Theme theme;
       try {
         theme = themesServiceDatabase.getTheme(themeId);
       } catch (NotFoundException e) {
         logger.warn("Skipping theme workflow operation, no theme with id {} found.", themeId);
         return createResult(Action.SKIP);
       }
 
       logger.info("Applying theme {} to mediapackage {}", themeId, mediaPackage.getIdentifier());
 
       /* Make theme settings available to workflow instance */
       workflowInstance.setConfiguration(THEME_ACTIVE, Boolean.toString(
                  theme.isBumperActive()
               || theme.isTrailerActive()
               || theme.isTitleSlideActive()
               || theme.isWatermarkActive()
           )
       );
       workflowInstance.setConfiguration(THEME_BUMPER_ACTIVE, Boolean.toString(theme.isBumperActive()));
       workflowInstance.setConfiguration(THEME_TRAILER_ACTIVE, Boolean.toString(theme.isTrailerActive()));
       workflowInstance.setConfiguration(THEME_TITLE_SLIDE_ACTIVE, Boolean.toString(theme.isTitleSlideActive()));
       workflowInstance.setConfiguration(
           THEME_TITLE_SLIDE_UPLOADED,
           Boolean.toString(StringUtils.isNotBlank(theme.getTitleSlideBackground())));
       workflowInstance.setConfiguration(THEME_WATERMARK_ACTIVE, Boolean.toString(theme.isWatermarkActive()));
 
       if (theme.isBumperActive() && StringUtils.isNotBlank(theme.getBumperFile())) {
         try (InputStream bumper = staticFileService.getFile(theme.getBumperFile())) {
           addElement(mediaPackage, bumperFlavor, bumperTags, bumper,
                   staticFileService.getFileName(theme.getBumperFile()), Type.Track);
         } catch (NotFoundException e) {
           logger.warn("Bumper file {} not found in static file service, skip applying it", theme.getBumperFile());
         }
       }
 
       if (theme.isTrailerActive() && StringUtils.isNotBlank(theme.getTrailerFile())) {
         try (InputStream trailer = staticFileService.getFile(theme.getTrailerFile())) {
           addElement(mediaPackage, trailerFlavor, trailerTags, trailer,
                   staticFileService.getFileName(theme.getTrailerFile()), Type.Track);
         } catch (NotFoundException e) {
           logger.warn("Trailer file {} not found in static file service, skip applying it", theme.getTrailerFile());
         }
       }
 
       if (theme.isTitleSlideActive()) {
         if (StringUtils.isNotBlank(theme.getTitleSlideBackground())) {
           try (InputStream titleSlideBackground = staticFileService.getFile(theme.getTitleSlideBackground())) {
             addElement(mediaPackage, titleSlideFlavor, titleSlideTags, titleSlideBackground,
                     staticFileService.getFileName(theme.getTitleSlideBackground()), Type.Attachment);
           } catch (NotFoundException e) {
             logger.warn("Title slide file {} not found in static file service, skip applying it",
                     theme.getTitleSlideBackground());
           }
         }
 
         // TODO add the title slide metadata to the workflow properties to be used by the cover-image WOH
         // String titleSlideMetadata = theme.getTitleSlideMetadata();
       }
 
       if (theme.isLicenseSlideActive()) {
         if (StringUtils.isNotBlank(theme.getLicenseSlideBackground())) {
           try (InputStream licenseSlideBackground = staticFileService.getFile(theme.getLicenseSlideBackground())) {
             addElement(mediaPackage, licenseSlideFlavor, licenseSlideTags, licenseSlideBackground,
                     staticFileService.getFileName(theme.getLicenseSlideBackground()), Type.Attachment);
           } catch (NotFoundException e) {
             logger.warn("License slide file {} not found in static file service, skip applying it",
                     theme.getLicenseSlideBackground());
           }
         } else {
           // TODO define what to do here (maybe extract image as background)
         }
 
         // TODO add the license slide description to the workflow properties to be used by the cover-image WOH
         // String licenseSlideDescription = theme.getLicenseSlideDescription();
       }
 
       if (theme.isWatermarkActive() && StringUtils.isNotBlank(theme.getWatermarkFile())) {
         try (InputStream watermark = staticFileService.getFile(theme.getWatermarkFile())) {
           addElement(mediaPackage, watermarkFlavor, watermarkTags, watermark,
                   staticFileService.getFileName(theme.getWatermarkFile()), Type.Attachment);
         } catch (NotFoundException e) {
           logger.warn("Watermark file {} not found in static file service, skip applying it", theme.getWatermarkFile());
         }
 
         if (layoutStringOpt.isNone() || watermarkLayoutVariable.isNone()) {
           throw new WorkflowOperationException(format("Configuration key '%s' or '%s' is either missing or empty",
                   WATERMARK_LAYOUT, WATERMARK_LAYOUT_VARIABLE));
         }
 
         AbsolutePositionLayoutSpec watermarkLayout = parseLayout(theme.getWatermarkPosition());
         layoutList.set(layoutList.size() - 1, Serializer.json(watermarkLayout).toJson());
         layoutStringOpt = Opt.some(Stream.$(layoutList).mkString(";"));
       }
 
       if (watermarkLayoutVariable.isSome() && layoutStringOpt.isSome()) {
         workflowInstance.setConfiguration(watermarkLayoutVariable.get(), layoutStringOpt.get());
       }
 
       return createResult(mediaPackage, Action.CONTINUE);
     } catch (SeriesException | ThemesServiceDatabaseException | IllegalStateException | IllegalArgumentException
             | IOException e) {
       throw new WorkflowOperationException(e);
     }
   }
 
   private AbsolutePositionLayoutSpec parseLayout(String watermarkPosition) {
     switch (watermarkPosition) {
       case "topLeft":
         return new AbsolutePositionLayoutSpec(new AnchorOffset(Anchors.TOP_LEFT, Anchors.TOP_LEFT, offset(20, 20)));
       case "topRight":
         return new AbsolutePositionLayoutSpec(new AnchorOffset(Anchors.TOP_RIGHT, Anchors.TOP_RIGHT, offset(-20, 20)));
       case "bottomLeft":
         return new AbsolutePositionLayoutSpec(new AnchorOffset(Anchors.BOTTOM_LEFT, Anchors.BOTTOM_LEFT,
                 offset(20, -20)));
       case "bottomRight":
         return new AbsolutePositionLayoutSpec(new AnchorOffset(Anchors.BOTTOM_RIGHT, Anchors.BOTTOM_RIGHT, offset(-20,
                 -20)));
       default:
         throw new IllegalStateException("Unknown watermark position: " + watermarkPosition);
     }
   }
 
   private void addElement(MediaPackage mediaPackage, final MediaPackageElementFlavor flavor, final List<String> tags,
           InputStream file, String filename, Type type) throws IOException {
     MediaPackageElement element = elementBuilderFactory.newElementBuilder().newElement(type, flavor);
     element.setIdentifier(UUID.randomUUID().toString());
     for (String tag : tags) {
       element.addTag(tag);
     }
     URI uri = workspace.put(mediaPackage.getIdentifier().toString(), element.getIdentifier(), filename, file);
     element.setURI(uri);
     try {
       MimeType mimeType = MimeTypes.fromString(filename);
       element.setMimeType(mimeType);
     } catch (UnknownFileTypeException e) {
       logger.warn("Unable to detect the mime type of file {}", filename);
     }
     mediaPackage.add(element);
   }
 
   private static Fn<String, MediaPackageElementFlavor> toMediaPackageElementFlavor
       = new Fn<String, MediaPackageElementFlavor>() {
         @Override
         public MediaPackageElementFlavor apply(String flavorString) {
           return MediaPackageElementFlavor.parseFlavor(flavorString);
         }
       };
 
 }