content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache 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://www.apache.org/licenses/LICENSE-2.0
   *
   * 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.apache.ambari.server.orm.dao;
  
  import java.util.List;
  
  import jakarta.persistence.EntityManager;
  import jakarta.persistence.NoResultException;
  import jakarta.persistence.TypedQuery;
  
  import org.apache.ambari.server.orm.RequiresSession;
  import org.apache.ambari.server.orm.entities.ResourceEntity;
  
  import com.google.inject.Inject;
  import com.google.inject.Provider;
  import com.google.inject.Singleton;
  import com.google.inject.persist.Transactional;
  
  /**
   * Admin resource Data Access Object.
   */
  @Singleton
  public class ResourceDAO {
    /**
     * JPA entity manager
     */
    @Inject
    Provider<EntityManager> entityManagerProvider;
    @Inject
    DaoUtils daoUtils;
  
    /**
     * Find a resource with the given id.
     *
     * @param id  type id
     *
     * @return  a matching resource type  or null
     */
    @RequiresSession
    public ResourceEntity findById(Long id) {
      return entityManagerProvider.get().find(ResourceEntity.class, id);
    }
  
    /**
     * Find a resource with the given resource type id.
     *
     * @param id  type id
     *
     * @return  a matching resource or null
     */
    @RequiresSession
    public ResourceEntity findByResourceTypeId(Integer id) {
      TypedQuery<ResourceEntity> query = entityManagerProvider.get().createQuery(
          "SELECT resource FROM ResourceEntity resource WHERE resource.resourceType.id =:resourceTypeId",
          ResourceEntity.class);
      query.setParameter("resourceTypeId", id);
      try {
        return query.getSingleResult();
      } catch (NoResultException e) {
        return null;
      }
    }
  
    /**
     * Find all resources.
     *
     * @return all resources or an empty List
     */
    @RequiresSession
    public List<ResourceEntity> findAll() {
      TypedQuery<ResourceEntity> query = entityManagerProvider.get().createQuery("SELECT resource FROM ResourceEntity resource", ResourceEntity.class);
      return daoUtils.selectList(query);
    }
  
    /**
     * Make an instance managed and persistent.
     *
     * @param entity  entity to store
     */
    @Transactional
    public void create(ResourceEntity entity) {
      entityManagerProvider.get().persist(entity);
    }
  
  
    @Transactional
    public ResourceEntity merge(ResourceEntity entity) {
      return entityManagerProvider.get().merge(entity);
    }
  
    /**
     * Finds root level resource.
     *
     * @return the matching resource or null
     */
    public ResourceEntity findAmbariResource() {
      return findById(ResourceEntity.AMBARI_RESOURCE_ID);
    }
  }
  