/*
    * Copyright 2002-2013 the original author or authors.
    *
    * Licensed 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.springframework.batch.core.explore.support;
  
  import javax.sql.DataSource;
  
  import org.springframework.batch.core.repository.ExecutionContextSerializer;
  import org.springframework.batch.core.repository.dao.AbstractJdbcBatchMetadataDao;
  import org.springframework.batch.core.repository.dao.ExecutionContextDao;
  import org.springframework.batch.core.repository.dao.JdbcExecutionContextDao;
  import org.springframework.batch.core.repository.dao.JdbcJobExecutionDao;
  import org.springframework.batch.core.repository.dao.JdbcJobInstanceDao;
  import org.springframework.batch.core.repository.dao.JdbcStepExecutionDao;
  import org.springframework.batch.core.repository.dao.JobExecutionDao;
  import org.springframework.batch.core.repository.dao.JobInstanceDao;
  import org.springframework.batch.core.repository.dao.StepExecutionDao;
  import org.springframework.batch.core.repository.dao.XStreamExecutionContextStringSerializer;
  import org.springframework.batch.item.ExecutionContext;
  import org.springframework.beans.factory.FactoryBean;
  import org.springframework.beans.factory.InitializingBean;
  import org.springframework.jdbc.core.JdbcOperations;
  import org.springframework.jdbc.core.JdbcTemplate;
  import org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer;
  import org.springframework.jdbc.support.incrementer.DataFieldMaxValueIncrementer;
  import org.springframework.jdbc.support.lob.LobHandler;
  import org.springframework.util.Assert;
  
  /**
   * A {@link FactoryBean} that automates the creation of a
   * {@link SimpleJobExplorer} using JDBC DAO implementations. Requires the user
   * to describe what kind of database they are using.
   *
   * @author Dave Syer
   * @since 2.0
   */
  public class JobExplorerFactoryBean extends AbstractJobExplorerFactoryBean
  implements InitializingBean {
  
  	private DataSource dataSource;
  
  	private JdbcOperations jdbcTemplate;
  
  	private String tablePrefix = AbstractJdbcBatchMetadataDao.DEFAULT_TABLE_PREFIX;
  
  	private DataFieldMaxValueIncrementer incrementer = new AbstractDataFieldMaxValueIncrementer() {
  		@Override
  		protected long getNextKey() {
  			throw new IllegalStateException("JobExplorer is read only.");
  		}
  	};
  
  	private LobHandler lobHandler;
  
  	private ExecutionContextSerializer serializer;
  
  	/**
  	 * A custom implementation of the {@link ExecutionContextSerializer}.
  	 * The default, if not injected, is the {@link XStreamExecutionContextStringSerializer}.
  	 *
  	 * @param serializer
  	 * @see ExecutionContextSerializer
  	 */
  	public void setSerializer(ExecutionContextSerializer serializer) {
  		this.serializer = serializer;
  	}
  
  	/**
  	 * Public setter for the {@link DataSource}.
  	 *
  	 * @param dataSource
  	 *            a {@link DataSource}
  	 */
  	public void setDataSource(DataSource dataSource) {
  		this.dataSource = dataSource;
  	}
  
  	/**
  	 * Sets the table prefix for all the batch meta-data tables.
  	 *
  	 * @param tablePrefix
  	 */
  	public void setTablePrefix(String tablePrefix) {
  		this.tablePrefix = tablePrefix;
  	}
  
 	/**
 	 * The lob handler to use when saving {@link ExecutionContext} instances.
 	 * Defaults to null which works for most databases.
 	 *
 	 * @param lobHandler
 	 */
 	public void setLobHandler(LobHandler lobHandler) {
 		this.lobHandler = lobHandler;
 	}
 
 	@Override
 	public void afterPropertiesSet() throws Exception {
 
 		Assert.notNull(dataSource, "DataSource must not be null.");
 
 		jdbcTemplate = new JdbcTemplate(dataSource);
 
 		if(serializer == null) {
 			XStreamExecutionContextStringSerializer defaultSerializer = new XStreamExecutionContextStringSerializer();
 			defaultSerializer.afterPropertiesSet();
 
 			serializer = defaultSerializer;
 		}
 	}
 
 	private Object getTarget() throws Exception {
 		return new SimpleJobExplorer(createJobInstanceDao(),
 				createJobExecutionDao(), createStepExecutionDao(),
 				createExecutionContextDao());
 	}
 
 	@Override
 	protected ExecutionContextDao createExecutionContextDao() throws Exception {
 		JdbcExecutionContextDao dao = new JdbcExecutionContextDao();
 		dao.setJdbcTemplate(jdbcTemplate);
 		dao.setLobHandler(lobHandler);
 		dao.setTablePrefix(tablePrefix);
 		dao.setSerializer(serializer);
 		dao.afterPropertiesSet();
 		return dao;
 	}
 
 	@Override
 	protected JobInstanceDao createJobInstanceDao() throws Exception {
 		JdbcJobInstanceDao dao = new JdbcJobInstanceDao();
 		dao.setJdbcTemplate(jdbcTemplate);
 		dao.setJobIncrementer(incrementer);
 		dao.setTablePrefix(tablePrefix);
 		dao.afterPropertiesSet();
 		return dao;
 	}
 
 	@Override
 	protected JobExecutionDao createJobExecutionDao() throws Exception {
 		JdbcJobExecutionDao dao = new JdbcJobExecutionDao();
 		dao.setJdbcTemplate(jdbcTemplate);
 		dao.setJobExecutionIncrementer(incrementer);
 		dao.setTablePrefix(tablePrefix);
 		dao.afterPropertiesSet();
 		return dao;
 	}
 
 	@Override
 	protected StepExecutionDao createStepExecutionDao() throws Exception {
 		JdbcStepExecutionDao dao = new JdbcStepExecutionDao();
 		dao.setJdbcTemplate(jdbcTemplate);
 		dao.setStepExecutionIncrementer(incrementer);
 		dao.setTablePrefix(tablePrefix);
 		dao.afterPropertiesSet();
 		return dao;
 	}
 
 	@Override
 	public Object getObject() throws Exception {
 		return getTarget();
 	}
 }