/*
    * ModeShape (http://www.modeshape.org)
    * See the COPYRIGHT.txt file distributed with this work for information
    * regarding copyright ownership.  Some portions may be licensed
    * to Red Hat, Inc. under one or more contributor license agreements.
    * See the AUTHORS.txt file in the distribution for a full listing of 
    * individual contributors. 
    *
    * ModeShape is free software. Unless otherwise indicated, all code in ModeShape
   * is licensed to you under the terms of the GNU Lesser General Public License as
   * published by the Free Software Foundation; either version 2.1 of
   * the License, or (at your option) any later version.
   *
   * ModeShape is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this software; if not, write to the Free
   * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
   * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
   */
  package org.modeshape.connector.store.jpa.model.common;
  
  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.NamedQueries;
  import javax.persistence.NamedQuery;
  import javax.persistence.NoResultException;
  import javax.persistence.Query;
  import javax.persistence.Table;
  import org.hibernate.annotations.Index;
  import org.modeshape.common.util.CheckArg;
  
  /**
   * A NamespaceEntity represents a namespace that has been used in the store. NamespaceEntity records are immutable and shared by
   * one or more enities.
   */
  @Entity
  @Table( name = "DNA_NAMESPACES" )
  @org.hibernate.annotations.Table( appliesTo = "DNA_NAMESPACES", indexes = @Index( name = "NS_URI_INX", columnNames = {"URI"} ) )
  @NamedQueries( {@NamedQuery( name = "NamespaceEntity.findAll", query = "select ns from NamespaceEntity as ns" ),
      @NamedQuery( name = "NamespaceEntity.findByUri", query = "select ns from NamespaceEntity as ns where ns.uri = ?1" )} )
  public class NamespaceEntity {
  
      @Id
      @GeneratedValue( strategy = GenerationType.AUTO )
      private Long id;
  
      @Column( name = "URI", nullable = true, unique = false, length = 512, updatable = false )
      private String uri;
  
      /**
       * 
       */
      public NamespaceEntity() {
      }
  
      /**
       * @param uri the namespace URI
       */
      public NamespaceEntity( String uri ) {
          setUri(uri);
      }
  
      /**
       * @return id
       */
      public Long getId() {
          return id;
      }
  
      /**
       * @param id Sets id to the specified value.
       */
      public void setId( Long id ) {
          this.id = id;
      }
  
      /**
       * @return uri
       */
      public String getUri() {
          return uri;
      }
  
      /**
       * @param uri Sets uri to the specified value.
       */
      public void setUri( String uri ) {
          this.uri = uri;
      }
  
      /**
      * {@inheritDoc}
      * 
      * @see java.lang.Object#hashCode()
      */
     @Override
     public int hashCode() {
         return id.hashCode();
     }
 
     /**
      * {@inheritDoc}
      * 
      * @see java.lang.Object#equals(java.lang.Object)
      */
     @Override
     public boolean equals( Object obj ) {
         if (obj == this) return true;
         if (obj instanceof NamespaceEntity) {
             NamespaceEntity that = (NamespaceEntity)obj;
             if (!this.id.equals(that.id)) return false;
             if (!this.uri.equals(that.uri)) return false;
             return true;
         }
         return false;
     }
 
     /**
      * {@inheritDoc}
      * 
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString() {
         return uri;
     }
 
     /**
      * Find an existing namespace by its URI, or create and return one if it does not already exist.
      * 
      * @param manager the entity manager
      * @param uri the URI
      * @return the existing namespace, or null if one does not exist
      * @throws IllegalArgumentException if the manager or URI are null
      */
     public static NamespaceEntity findByUri( EntityManager manager,
                                              String uri ) {
         return findByUri(manager, uri, true);
     }
 
     /**
      * Find an existing namespace by its URI.
      * 
      * @param manager the entity manager
      * @param uri the URI
      * @param createIfRequired if the namespace should be persisted if it does not yet exist
      * @return the existing namespace, or null if one does not exist
      * @throws IllegalArgumentException if the manager or URI are null
      */
     public static NamespaceEntity findByUri( EntityManager manager,
                                              String uri,
                                              boolean createIfRequired ) {
         CheckArg.isNotNull(manager, "manager");
         CheckArg.isNotNull(uri, "uri");
         Query query = manager.createNamedQuery("NamespaceEntity.findByUri");
         query.setParameter(1, uri);
         try {
             return (NamespaceEntity)query.getSingleResult();
         } catch (NoResultException e) {
             if (!createIfRequired) return null;
             NamespaceEntity namespace = new NamespaceEntity(uri);
             manager.persist(namespace);
             return namespace;
         }
     }
 }