package com.trendmicro.grid.acl.ds.jpa.entities;
   
   import com.trendmicro.grid.acl.Limits;
   import com.trendmicro.grid.acl.l0.datatypes.FileDetails;
   import com.trendmicro.grid.acl.metadata.Metadata;
   import org.hibernate.annotations.Type;
   
   import javax.persistence.*;
   import java.io.Serializable;
  import java.util.Arrays;
  import java.util.Date;
  
  import static com.trendmicro.grid.acl.ds.jpa.util.JpaUtils.metadataDiffers;
  import static com.trendmicro.grid.acl.ds.jpa.util.JpaUtils.tagsDiffer;
  import static net.sf.tinyjee.util.Assert.assertNotNull;
  
  /**
   * Implements a read and writeable history entry for the FILE_CONTENT_HISTORY table.
   *
   * @author juergen_kellerer, 2010-06-07
   * @version 1.0
   */
  @NamedQueries({
  		@NamedQuery(name = "FileContentHistory.SelectMaxRevisionForPackage",
  				query = "SELECT MAX(h.historyId.revision) " +
  						"FROM FILE_CONTENT_HISTORY h WHERE historyId.parent = :parent"),
  		@NamedQuery(name = "FileContentHistory.SelectFileHistoryDetailsByFileContent",
  						query = "SELECT h " +
  								"FROM FILE_CONTENT_HISTORY h WHERE historyId.parent = :parent")
  })
  @Entity(name = "FILE_CONTENT_HISTORY")
  public class JpaFileHistory implements Serializable {
  
  	private static final long serialVersionUID = -4911356794856270325L;
  
  	/**
  	 * Returns true if history relevant values differ.
  	 *
  	 * @param existingDetails the existing details.
  	 * @param details		 the updated details.
  	 * @param ignoreMetadata  whether metadata is compared or not.
  	 * @return true if history relevant values differ.
  	 */
  	public static boolean wasChanged(JpaFileDetails existingDetails, FileDetails details, boolean ignoreMetadata) {
  		return (!ignoreMetadata && metadataDiffers(existingDetails, details)) ||
  				tagsDiffer(existingDetails.getInformation(), details.getInformation()) ||
  				existingDetails.getInformation().isUnknown();
  	}
  
  	@EmbeddedId
  	private ID historyId;
  
  	@Temporal(TemporalType.TIMESTAMP)
  	@Column(name = "CREATED", nullable = false)
  	private Date created = new Date();
  
  	@Column(name = "UNKNOWN", nullable = false)
  	private boolean unknown;
  
  	@Type(type = "taglist")
  	@Column(name = "TAGS", length = Limits.MAX_TAG_STRING_LENGTH, nullable = true)
  	String[] tags;
  
  	@Type(type = "metadata")
  	@Basic(fetch = FetchType.LAZY)
  	@Column(name = "META_DATA", length = Limits.MAX_SERIALIZED_METADATA_LENGTH)
  	Metadata metadata;
  
  	public JpaFileHistory() {
  	}
  
  	/**
  	 * Creates a new history entry for the given file content entry.
  	 *
  	 * @param fileDetails the instance of fileDetails to create the history from.
  	 */
  	public JpaFileHistory(JpaFileDetails fileDetails) {
  		this.historyId = new ID(fileDetails);
  
  		final JpaFileInformation info = fileDetails.getInformation();
  		unknown = info.isUnknown();
  		tags = info.getTagsAsArray();
  		metadata = fileDetails.getMetadata();
  
  		// Clone all mutable types to avoid side effects.
  		if (tags != null)
  			tags = tags.clone();
  		if (metadata != null)
  			metadata = metadata.clone();
  	}
  
  	public ID getHistoryId() {
  		return historyId;
  	}
  
  	public Date getCreated() {
  		return created;
  	}
  
 	public boolean isUnknown() {
 		return unknown;
 	}
 
 	public String[] getTags() {
 		return tags;
 	}
 
 	public Metadata getMetadata() {
 		return metadata;
 	}
 
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) return true;
 		if (!(o instanceof JpaFileHistory)) return false;
 
 		JpaFileHistory that = (JpaFileHistory) o;
 		return !(historyId != null ? !historyId.equals(that.historyId) : that.historyId != null);
 	}
 
 	@Override
 	public int hashCode() {
 		return historyId != null ? historyId.hashCode() : 0;
 	}
 
 	/**
 	 * Implements the primary key of the table "FILE_CONTENT_HISTORY".
 	 */
 	@Embeddable
 	public static class ID implements Serializable {
 
 		private static final long serialVersionUID = -8535664911794270325L;
 
 		@ManyToOne(optional = false)
 		@JoinColumn(name = "FILE_CONTENT_ID", nullable = false, updatable = false)
 		private JpaFileDetails parent;
 
 		@Column(name = "REVISION", nullable = false, updatable = false)
 		private int revision;
 
 		public ID() {
 		}
 
 		public ID(JpaFileDetails parent) {
 			assertNotNull("JpaFileDetails", parent);
 			this.parent = parent;
 			this.revision = parent.getRevision();
 
 			// increment the revision after creating the history instance.
 			parent.setRevision(revision + 1);
 		}
 
 		public JpaFileDetails getParent() {
 			return parent;
 		}
 
 		public int getRevision() {
 			return revision;
 		}
 
 		@Override
 		public boolean equals(Object o) {
 			if (this == o) return true;
 			if (!(o instanceof ID)) return false;
 			ID id = (ID) o;
 			return revision == id.revision && parent.equals(id.parent);
 		}
 
 		@Override
 		public int hashCode() {
 			int result = parent.hashCode();
 			result = 31 * result + revision;
 			return result;
 		}
 
 		@Override
 		public String toString() {
 			return "ID{" +
 					"fileDetails=" + parent +
 					", revision=" + revision +
 					'}';
 		}
 	}
 
 	@Override
 	public String toString() {
 		return "JpaFileHistory{" +
 				"historyId=" + historyId +
 				", created=" + created +
 				", unknown=" + unknown +
 				", tags=" + (tags == null ? null : Arrays.asList(tags)) +
 				", metadata=" + metadata +
 				'}';
 	}
 }