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.TypedQuery;
  
  import org.apache.ambari.server.AmbariException;
  import org.apache.ambari.server.orm.RequiresSession;
  import org.apache.ambari.server.orm.entities.ExtensionEntity;
  
  import com.google.inject.Inject;
  import com.google.inject.Provider;
  import com.google.inject.Singleton;
  import com.google.inject.persist.Transactional;
  
  /**
   * The {@link ExtensionDAO} class is used to manage the persistence and retrieval of
   * {@link ExtensionEntity} instances.
   *
   * An extension version is like a stack version but it contains custom services.  Linking an extension
   * version to the current stack version allows the cluster to install the custom services contained in
   * the extension version.
   */
  @Singleton
  public class ExtensionDAO {
  
    /**
     * JPA entity manager
     */
    @Inject
    private Provider<EntityManager> entityManagerProvider;
  
    /**
     * DAO utilities for dealing mostly with {@link TypedQuery} results.
     */
    @Inject
    private DaoUtils daoUtils;
  
    /**
     * Gets a extension with the specified ID.
     *
     * @param extensionId
     *          the ID of the extension to retrieve.
     * @return the extension or {@code null} if none exists.
     */
    @RequiresSession
    public ExtensionEntity findById(long extensionId) {
      return entityManagerProvider.get().find(ExtensionEntity.class, extensionId);
    }
  
    /**
     * Gets all of the defined extensions.
     *
     * @return all of the extensions loaded from resources or an empty list (never
     *         {@code null}).
     */
    @RequiresSession
    public List<ExtensionEntity> findAll() {
      TypedQuery<ExtensionEntity> query = entityManagerProvider.get().createNamedQuery(
          "ExtensionEntity.findAll", ExtensionEntity.class);
  
      return daoUtils.selectList(query);
    }
  
    /**
     * Gets the extension that matches the specified name and version.
     *
     * @return the extension matching the specified name and version or {@code null}
     *         if none.
     */
    @RequiresSession
    public ExtensionEntity find(String extensionName, String extensionVersion) {
      TypedQuery<ExtensionEntity> query = entityManagerProvider.get().createNamedQuery(
          "ExtensionEntity.findByNameAndVersion", ExtensionEntity.class);
  
      query.setParameter("extensionName", extensionName);
      query.setParameter("extensionVersion", extensionVersion);
  
      return daoUtils.selectOne(query);
    }
  
    /**
     * Persists a new extension instance.
     *
     * @param extension
     *          the extension to persist (not {@code null}).
     */
    @Transactional
    public void create(ExtensionEntity extension)
        throws AmbariException {
      EntityManager entityManager = entityManagerProvider.get();
      entityManager.persist(extension);
    }
  
    /**
     * Refresh the state of the extension instance from the database.
     *
     * @param extension
     *          the extension to refresh (not {@code null}).
     */
    @Transactional
    public void refresh(ExtensionEntity extension) {
      entityManagerProvider.get().refresh(extension);
    }
  
    /**
     * Merge the specified extension with the existing extension in the database.
     *
     * @param extension
     *          the extension to merge (not {@code null}).
     * @return the updated extension with merged content (never {@code null}).
     */
    @Transactional
    public ExtensionEntity merge(ExtensionEntity extension) {
      return entityManagerProvider.get().merge(extension);
    }
  
    /**
     * Creates or updates the specified entity. This method will check
     * {@link ExtensionEntity#getExtensionId()} in order to determine whether the entity
     * should be created or merged.
     *
     * @param extension
     *          the extension to create or update (not {@code null}).
     */
    public void createOrUpdate(ExtensionEntity extension)
        throws AmbariException {
      if (null == extension.getExtensionId()) {
        create(extension);
      } else {
        merge(extension);
      }
    }
  
    /**
     * Removes the specified extension and all related clusters, services and
     * components.
     *
     * @param extension
     *          the extension to remove.
     */
    @Transactional
    public void remove(ExtensionEntity extension) {
      EntityManager entityManager = entityManagerProvider.get();
      extension = findById(extension.getExtensionId());
      if (null != extension) {
        entityManager.remove(extension);
      }
    }
  }
  