/*
    * 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.assetmanager.impl.persistence;
  
  import org.opencastproject.util.MimeType;
  
  import java.util.Optional;
  import java.util.function.Function;
  
  import javax.persistence.Column;
  import javax.persistence.Entity;
  import javax.persistence.EntityManager;
  import javax.persistence.GeneratedValue;
  import javax.persistence.GenerationType;
  import javax.persistence.Id;
  import javax.persistence.Index;
  import javax.persistence.JoinColumn;
  import javax.persistence.ManyToOne;
  import javax.persistence.NamedQueries;
  import javax.persistence.NamedQuery;
  import javax.persistence.Table;
  import javax.persistence.TableGenerator;
  import javax.persistence.TypedQuery;
  
  /** JPA DTO modeling the asset database table. */
  @Entity(name = "Asset")
  @Table(name = "oc_assets_asset", indexes = {
      @Index(name = "IX_oc_assets_asset_checksum", columnList = ("checksum")),
      @Index(name = "IX_oc_assets_asset_mediapackage_element_id", columnList = ("mediapackage_element_id")) })
  @NamedQueries({
      @NamedQuery(
          name = "Asset.findMediumByMpIdMpeIdAndVersion",
          query = "SELECT a, s.availability, s.organizationId FROM Asset a "
              + "JOIN a.snapshot s "
              + "WHERE s.mediaPackageId = :mpId "
              + "AND a.mediaPackageElementId = :mpeId "
              + "AND s.version = :version "
              + "ORDER BY s.version DESC"
      ),
      @NamedQuery(
          name = "Asset.findByChecksumStorageIdAndOrganizationId",
          query = "SELECT a FROM Asset a "
              + "INNER JOIN a.snapshot s "
              + "WHERE a.checksum = :checksum "
              + "AND a.storageId = :storageId "
              + "AND s.organizationId = :orgId "
      ),
      @NamedQuery(
          name = "Asset.updateStorageIdBySnapshot",
          query = "UPDATE Asset a SET a.storageId = :storageId "
              + "WHERE a.snapshot = :snapshot "
      ),
      @NamedQuery(
          name = "Asset.updateStorageIdBySnapshotAndMpElementId",
          query = "UPDATE Asset a SET a.storageId = :storageId "
              + "WHERE a.snapshot = :snapshot "
              + "AND a.mediaPackageElementId = :mediaPackageElementId "
      ),
      @NamedQuery(
          name = "Asset.countAssets",
          query = "SELECT COUNT(a) FROM Asset a "
      ),
  })
  // Maintain own generator to support database migrations from Archive to AssetManager
  // The generator's initial value has to be set after the data migration.
  // Otherwise duplicate key errors will most likely happen.
  @TableGenerator(name = "seq_oc_assets_asset", initialValue = 0, allocationSize = 50)
  public class AssetDto {
  
    @Id
    @GeneratedValue(strategy = GenerationType.TABLE, generator = "seq_oc_assets_asset")
    @Column(name = "id")
    private Long id;
  
    // foreign key referencing SnapshotDto.id
    @ManyToOne(targetEntity = SnapshotDto.class)
    @JoinColumn(name = "snapshot_id", referencedColumnName = "id", nullable = false)
    private SnapshotDto snapshot;
  
    @Column(name = "mediapackage_element_id", nullable = false, length = 128)
    private String mediaPackageElementId;
 
   @Column(name = "checksum", nullable = false, length = 64)
   private String checksum;
 
   @Column(name = "mime_type", nullable = true, length = 255)
   private String mimeType;
 
   @Column(name = "size", nullable = false)
   private Long size;
 
   @Column(name = "storage_id", nullable = false, length = 256)
   private String storageId;
 
   /**
    * Create a new DTO.
    */
   public static AssetDto mk(
       String mediaPackageElementId,
       SnapshotDto snapshot,
       String checksum,
       Optional<MimeType> mimeType,
       String storeageId,
       long size
   ) {
     final AssetDto dto = new AssetDto();
     dto.snapshot = snapshot;
     dto.mediaPackageElementId = mediaPackageElementId;
     dto.checksum = checksum;
     dto.mimeType = mimeType.isPresent() ? mimeType.get().toString() : null;
     dto.storageId = storeageId;
     dto.size = size;
     return dto;
   }
 
   public Long getId() {
     return id;
   }
 
   public String getMediaPackageElementId() {
     return mediaPackageElementId;
   }
 
   public String getChecksum() {
     return checksum;
   }
 
   public Optional<MimeType> getMimeType() {
     return Conversions.toMimeType(mimeType);
   }
 
   public Long getSize() {
     return size;
   }
 
   public String getStorageId() {
     return storageId;
   }
 
   void setStorageId(String storage) {
     this.storageId = storage;
   }
 
   public SnapshotDto getSnapshot() {
     return snapshot;
   }
 
   public void setSnapshot(SnapshotDto snapshot) {
     this.snapshot = snapshot;
   }
 
   /**
    * Count assets in the asset manager
    *
    * @return Number of assts
    */
   public static Function<EntityManager, Long> countAssetsQuery() {
     return em -> {
       TypedQuery<Long> query;
       query = em.createNamedQuery("Asset.countAssets", Long.class);
       return query.getSingleResult();
     };
   }
 
 }