/*
    * 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.search.impl.persistence;
  
  import static org.opencastproject.db.Queries.namedQuery;
  import static org.opencastproject.security.api.Permissions.Action.CONTRIBUTE;
  import static org.opencastproject.security.api.Permissions.Action.READ;
  import static org.opencastproject.security.api.Permissions.Action.WRITE;
  import static org.opencastproject.security.api.SecurityConstants.GLOBAL_CAPTURE_AGENT_ROLE;
  
  import org.opencastproject.db.DBSession;
  import org.opencastproject.db.DBSessionFactory;
  import org.opencastproject.mediapackage.MediaPackage;
  import org.opencastproject.mediapackage.MediaPackageException;
  import org.opencastproject.mediapackage.MediaPackageParser;
  import org.opencastproject.security.api.AccessControlList;
  import org.opencastproject.security.api.AccessControlParser;
  import org.opencastproject.security.api.AccessControlParsingException;
  import org.opencastproject.security.api.AccessControlUtil;
  import org.opencastproject.security.api.Organization;
  import org.opencastproject.security.api.SecurityService;
  import org.opencastproject.security.api.UnauthorizedException;
  import org.opencastproject.security.api.User;
  import org.opencastproject.util.NotFoundException;
  import org.opencastproject.util.data.Tuple;
  
  import org.apache.commons.lang3.BooleanUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.lang3.tuple.Pair;
  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.Arrays;
  import java.util.Collection;
  import java.util.Date;
  import java.util.List;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.function.Function;
  import java.util.stream.Stream;
  
  import javax.persistence.EntityManager;
  import javax.persistence.EntityManagerFactory;
  import javax.persistence.TypedQuery;
  
  /**
   * Implements {@link SearchServiceDatabase}. Defines permanent storage for series.
   */
  @Component(
      immediate = true,
      service = SearchServiceDatabase.class,
      property = {
          "service.description=Search Service Persistence"
      }
  )
  public class SearchServiceDatabaseImpl implements SearchServiceDatabase {
  
    /** JPA persistence unit name */
    public static final String PERSISTENCE_UNIT = "org.opencastproject.search.impl.persistence";
  
    private static final String CONFIG_EPISODE_ID_ROLE = "org.opencastproject.episode.id.role.access";
  
    /** Logging utilities */
    private static final Logger logger = LoggerFactory.getLogger(SearchServiceDatabaseImpl.class);
  
    private boolean episodeRoleId = false;
  
    /** Factory used to create {@link EntityManager}s for transactions */
    protected EntityManagerFactory emf;
  
    protected DBSessionFactory dbSessionFactory;
  
    protected DBSession db;
  
   /** The security service */
   protected SecurityService securityService;
 
   /** OSGi DI */
   @Reference(target = "(osgi.unit.name=org.opencastproject.search.impl.persistence)")
   public void setEntityManagerFactory(EntityManagerFactory emf) {
     this.emf = emf;
   }
 
   @Reference
   public void setDBSessionFactory(DBSessionFactory dbSessionFactory) {
     this.dbSessionFactory = dbSessionFactory;
   }
 
   /**
    * Creates {@link EntityManagerFactory} using persistence provider and properties passed via OSGi.
    *
    * @param cc
    * @throws SearchServiceDatabaseException
    */
   @Activate
   public void activate(ComponentContext cc) throws SearchServiceDatabaseException {
     logger.info("Activating persistence manager for search service");
     db = dbSessionFactory.createSession(emf);
     this.populateSeriesData();
 
     episodeRoleId = BooleanUtils.toBoolean(Objects.toString(
         cc.getBundleContext().getProperty(CONFIG_EPISODE_ID_ROLE), "false"));
     logger.debug("Usage of episode ID roles is set to {}", episodeRoleId);
   }
 
   /**
    * OSGi callback to set the security service.
    *
    * @param securityService
    *          the securityService to set
    */
   @Reference
   public void setSecurityService(SecurityService securityService) {
     this.securityService = securityService;
   }
 
   private void populateSeriesData() throws SearchServiceDatabaseException {
     try {
       db.execTxChecked(em -> {
         TypedQuery<SearchEntity> q = em.createNamedQuery("Search.getNoSeries", SearchEntity.class);
         List<SearchEntity> seriesList = q.getResultList();
         for (SearchEntity series : seriesList) {
           String mpSeriesId = MediaPackageParser.getFromXml(series.getMediaPackageXML()).getSeries();
           if (StringUtils.isNotBlank(mpSeriesId) && !mpSeriesId.equals(series.getSeriesId())) {
             logger.info("Fixing missing series ID for episode {}, series is {}", series.getMediaPackageId(),
                 mpSeriesId);
             series.setSeriesId(mpSeriesId);
             em.merge(series);
           }
         }
       });
     } catch (Exception e) {
       logger.error("Could not update media package: {}", e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#deleteMediaPackage(String, Date)
    */
   @Override
   public void deleteMediaPackage(String mediaPackageId, Date deletionDate) throws SearchServiceDatabaseException,
           NotFoundException, UnauthorizedException {
     try {
       db.execTxChecked(em -> {
         Optional<SearchEntity> searchEntity = getSearchEntityQuery(mediaPackageId).apply(em);
         if (searchEntity.isEmpty()) {
           throw new NotFoundException("No media package with id=" + mediaPackageId + " exists");
         }
 
         // Ensure this user is allowed to delete this episode
         User currentUser = securityService.getUser();
         Organization currentOrg = securityService.getOrganization();
         MediaPackage searchMp = MediaPackageParser.getFromXml(searchEntity.get().getMediaPackageXML());
         String accessControlXml = searchEntity.get().getAccessControl();
 
         // allow ca users to retract live publications without putting them into the ACL
         if (!(searchMp.isLive() && currentUser.hasRole(GLOBAL_CAPTURE_AGENT_ROLE)) && accessControlXml != null) {
           AccessControlList acl = AccessControlParser.parseAcl(accessControlXml);
           if (!AccessControlUtil.isAuthorized(acl, currentUser, currentOrg, WRITE.toString(), mediaPackageId)) {
             throw new UnauthorizedException(
                 currentUser + " is not authorized to delete media package " + mediaPackageId);
           }
         }
 
         searchEntity.get().setDeletionDate(deletionDate);
         searchEntity.get().setModificationDate(deletionDate);
         em.merge(searchEntity.get());
       });
     } catch (NotFoundException | UnauthorizedException e) {
       throw e;
     } catch (Exception e) {
       logger.error("Could not delete episode {}: {}", mediaPackageId, e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#countMediaPackages()
    */
   @Override
   public int countMediaPackages() throws SearchServiceDatabaseException {
     try {
       return db.exec(namedQuery.find("Search.getCount", Long.class)).intValue();
     } catch (Exception e) {
       logger.error("Could not find number of mediapackages", e);
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getAllMediaPackages(int, int)
    */
   @Override
   public Stream<Tuple<MediaPackage, String>> getAllMediaPackages(int pagesize, int offset)
           throws SearchServiceDatabaseException {
     List<SearchEntity> searchEntities;
     try {
       int firstResult = pagesize * offset;
       searchEntities = db.exec(namedQuery.findSome("Search.findAll", firstResult, pagesize, SearchEntity.class));
     } catch (Exception e) {
       logger.error("Could not retrieve all episodes: {}", e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
 
     try {
       return searchEntities.stream()
             .map(entity -> {
               try {
                 MediaPackage mediaPackage = MediaPackageParser.getFromXml(entity.getMediaPackageXML());
                 return Tuple.tuple(mediaPackage, entity.getOrganization().getId());
               } catch (Exception e) {
                 logger.error("Could not parse series entity: {}", e.getMessage());
                 throw new RuntimeException(e);
               }
             });
     } catch (Exception e) {
       logger.error("Could not parse series entity: {}", e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getAccessControlList(String)
    */
   @Override
   public AccessControlList getAccessControlList(String mediaPackageId) throws NotFoundException,
           SearchServiceDatabaseException {
     try {
       Optional<SearchEntity> entity = db.exec(getSearchEntityQuery(mediaPackageId));
       if (entity.isEmpty()) {
         throw new NotFoundException("Could not found media package with ID " + mediaPackageId);
       }
       if (entity.get().getAccessControl() == null) {
         return null;
       } else {
         return AccessControlParser.parseAcl(entity.get().getAccessControl());
       }
     } catch (NotFoundException e) {
       throw e;
     } catch (Exception e) {
       logger.error("Could not retrieve ACL {}", mediaPackageId, e);
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getAccessControlLists(String, String...)
    */
   @Override
   public Collection<Pair<String, AccessControlList>> getAccessControlLists(final String seriesId, String ... excludeIds)
           throws SearchServiceDatabaseException {
     List<String> excludes = Arrays.asList(excludeIds);
     List<Pair<String,AccessControlList>> accessControlLists = new ArrayList<>();
     try {
       List<SearchEntity> result = db.exec(namedQuery.findAll(
           "Search.findBySeriesId",
           SearchEntity.class,
           Pair.of("seriesId", seriesId)
       ));
       for (SearchEntity entity: result) {
         if (entity.getAccessControl() != null && !excludes.contains(entity.getMediaPackageId())) {
           accessControlLists.add(Pair.of(
               entity.getMediaPackageId(),
               AccessControlParser.parseAcl(entity.getAccessControl()))
           );
         }
       }
     } catch (IOException | AccessControlParsingException e) {
       throw new SearchServiceDatabaseException(e);
     }
     return accessControlLists;
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getSeries(String)
    */
   public Collection<Pair<Organization, MediaPackage>> getSeries(final String seriesId)
           throws SearchServiceDatabaseException {
     List<Pair<Organization, MediaPackage>> episodes = new ArrayList<>();
     EntityManager em = emf.createEntityManager();
     TypedQuery<SearchEntity> q = em.createNamedQuery("Search.findBySeriesId", SearchEntity.class)
         .setParameter("seriesId", seriesId);
     try {
       for (SearchEntity entity: q.getResultList()) {
         if (entity.getMediaPackageXML() != null) {
           episodes.add(Pair.of(
               entity.getOrganization(),
               MediaPackageParser.getFromXml(entity.getMediaPackageXML())));
         }
       }
     } catch (MediaPackageException e) {
       throw new SearchServiceDatabaseException(e);
     } finally {
       em.close();
     }
     return episodes;
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#storeMediaPackage(MediaPackage,
    *      AccessControlList, Date)
    */
   @Override
   public void storeMediaPackage(MediaPackage mediaPackage, AccessControlList acl, Date now)
           throws SearchServiceDatabaseException, UnauthorizedException {
     String mediaPackageXML = MediaPackageParser.getAsXml(mediaPackage);
     String mediaPackageId = mediaPackage.getIdentifier().toString();
     try {
       db.execTxChecked(em -> {
         Optional<SearchEntity> entity = getSearchEntityQuery(mediaPackageId).apply(em);
         if (entity.isEmpty()) {
           // Create new search entity
           SearchEntity searchEntity = new SearchEntity();
           searchEntity.setOrganization(securityService.getOrganization());
           searchEntity.setMediaPackageId(mediaPackageId);
           searchEntity.setMediaPackageXML(mediaPackageXML);
           searchEntity.setAccessControl(AccessControlParser.toXml(acl));
           searchEntity.setModificationDate(now);
           searchEntity.setSeriesId(mediaPackage.getSeries());
           em.persist(searchEntity);
         } else {
           // Ensure this user is allowed to update this media package
           // If user has ROLE_EPISODE_<ID>_WRITE, no further permission checks are necessary
           String accessControlXml = entity.get().getAccessControl();
           if (accessControlXml != null && entity.get().getDeletionDate() == null) {
             AccessControlList accessList = AccessControlParser.parseAcl(accessControlXml);
             User currentUser = securityService.getUser();
             Organization currentOrg = securityService.getOrganization();
             if (!AccessControlUtil.isAuthorized(accessList, currentUser, currentOrg, WRITE.toString(),
                 mediaPackageId)) {
               throw new UnauthorizedException(currentUser + " is not authorized to update media package "
                   + mediaPackageId);
             }
           }
           entity.get().setOrganization(securityService.getOrganization());
           entity.get().setMediaPackageId(mediaPackageId);
           entity.get().setMediaPackageXML(mediaPackageXML);
           entity.get().setAccessControl(AccessControlParser.toXml(acl));
           entity.get().setModificationDate(now);
           entity.get().setDeletionDate(null);
           entity.get().setSeriesId(mediaPackage.getSeries());
           em.merge(entity.get());
         }
       });
     } catch (UnauthorizedException e) {
       throw e;
     } catch (Exception e) {
       logger.error("Could not update media package: {}", e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getMediaPackage(String)
    */
   @Override
   public MediaPackage getMediaPackage(String mediaPackageId)
           throws NotFoundException, SearchServiceDatabaseException, UnauthorizedException {
     try {
       return db.execTxChecked(em -> {
         Optional<SearchEntity> episodeEntity = getSearchEntityQuery(mediaPackageId).apply(em);
         if (episodeEntity.isEmpty() || episodeEntity.get().getDeletionDate() != null) {
           throw new NotFoundException("No episode with id=" + mediaPackageId + " exists");
         }
 
         String accessControlXml = episodeEntity.get().getAccessControl();
         if (accessControlXml != null) {
           AccessControlList acl = AccessControlParser.parseAcl(accessControlXml);
           User currentUser = securityService.getUser();
           Organization currentOrg = securityService.getOrganization();
           // There are several reasons a user may need to load a episode: to read content, to edit it, or add content
           if (!AccessControlUtil.isAuthorized(acl, currentUser, currentOrg, READ.toString(), mediaPackageId)
                   && !AccessControlUtil.isAuthorized(acl, currentUser, currentOrg, CONTRIBUTE.toString(),
               mediaPackageId)
                   && !AccessControlUtil.isAuthorized(acl, currentUser, currentOrg, WRITE.toString(), mediaPackageId)) {
             throw new UnauthorizedException(currentUser + " is not authorized to see episode " + mediaPackageId);
           }
         }
         return MediaPackageParser.getFromXml(episodeEntity.get().getMediaPackageXML());
       });
     } catch (NotFoundException | UnauthorizedException e) {
       throw e;
     } catch (Exception e) {
       logger.error("Could not get episode {} from database: {} ", mediaPackageId, e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getModificationDate(String)
    */
   @Override
   public Date getModificationDate(String mediaPackageId) throws NotFoundException, SearchServiceDatabaseException {
     try {
       return db.execTxChecked(em -> {
         Optional<SearchEntity> searchEntity = getSearchEntityQuery(mediaPackageId).apply(em);
         if (searchEntity.isEmpty()) {
           throw new NotFoundException("No media package with id=" + mediaPackageId + " exists");
         }
         // Ensure this user is allowed to read this media package
         String accessControlXml = searchEntity.get().getAccessControl();
         if (accessControlXml != null) {
           AccessControlList acl = AccessControlParser.parseAcl(accessControlXml);
           User currentUser = securityService.getUser();
           Organization currentOrg = securityService.getOrganization();
           if (!AccessControlUtil.isAuthorized(acl, currentUser, currentOrg, READ.toString(), mediaPackageId)) {
             throw new UnauthorizedException(
                 currentUser + " is not authorized to read media package " + mediaPackageId);
           }
         }
         return searchEntity.get().getModificationDate();
       });
     } catch (NotFoundException e) {
       throw e;
     } catch (Exception e) {
       logger.error("Could not get modification date {}: {}", mediaPackageId, e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getDeletionDate(String)
    */
   @Override
   public Date getDeletionDate(String mediaPackageId) throws NotFoundException, SearchServiceDatabaseException {
     try {
       return db.execTxChecked(em -> {
         Optional<SearchEntity> searchEntity = getSearchEntityQuery(mediaPackageId).apply(em);
         if (searchEntity.isEmpty()) {
           throw new NotFoundException("No media package with id=" + mediaPackageId + " exists");
         }
         // Ensure this user is allowed to read this media package
         String accessControlXml = searchEntity.get().getAccessControl();
         if (accessControlXml != null) {
           AccessControlList acl = AccessControlParser.parseAcl(accessControlXml);
           User currentUser = securityService.getUser();
           Organization currentOrg = securityService.getOrganization();
           if (!AccessControlUtil.isAuthorized(acl, currentUser, currentOrg, READ.toString(), mediaPackageId)) {
             throw new UnauthorizedException(
                 currentUser + " is not authorized to read media package " + mediaPackageId);
           }
         }
         return searchEntity.get().getDeletionDate();
       });
     } catch (NotFoundException e) {
       throw e;
     } catch (Exception e) {
       logger.error("Could not get deletion date {}: {}", mediaPackageId, e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#isAvailable(String)
    */
   public boolean isAvailable(String mediaPackageId) throws SearchServiceDatabaseException {
     try {
       return db.execTxChecked(em -> {
         Optional<SearchEntity> searchEntity = getSearchEntityQuery(mediaPackageId).apply(em);
         return searchEntity.stream().anyMatch(entity -> entity.getDeletionDate() == null);
       });
     } catch (Exception e) {
       logger.error("Error while checking if mediapackage {} exists in database: {}", mediaPackageId, e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.search.impl.persistence.SearchServiceDatabase#getOrganizationId(String)
    */
   @Override
   public String getOrganizationId(String mediaPackageId) throws NotFoundException, SearchServiceDatabaseException {
     try {
       return db.execTxChecked(em -> {
         Optional<SearchEntity> searchEntity = getSearchEntityQuery(mediaPackageId).apply(em);
         if (searchEntity.isEmpty()) {
           throw new NotFoundException("No media package with id=" + mediaPackageId + " exists");
         }
         // Ensure this user is allowed to read this media package
         String accessControlXml = searchEntity.get().getAccessControl();
         if (accessControlXml != null) {
           AccessControlList acl = AccessControlParser.parseAcl(accessControlXml);
           User currentUser = securityService.getUser();
           Organization currentOrg = securityService.getOrganization();
           if (!AccessControlUtil.isAuthorized(acl, currentUser, currentOrg, READ.toString(), mediaPackageId)) {
             throw new UnauthorizedException(
                 currentUser + " is not authorized to read media package " + mediaPackageId);
           }
         }
         return searchEntity.get().getOrganization().getId();
       });
     } catch (NotFoundException e) {
       throw e;
     } catch (Exception e) {
       logger.error("Could not get deletion date {}: {}", mediaPackageId, e.getMessage());
       throw new SearchServiceDatabaseException(e);
     }
   }
 
   /**
    * Gets a search entity by it's id, using the current organizational context.
    *
    * @param id
    *          the media package identifier
    * @return the search entity, or null if not found
    */
   private Function<EntityManager, Optional<SearchEntity>> getSearchEntityQuery(String id) {
     return namedQuery.findOpt(
         "Search.findById",
         SearchEntity.class,
         Pair.of("mediaPackageId", id)
     );
   }
 }