/*
 * Copyright 2002-2004 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.orm.ibatis;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;

import javax.sql.DataSource;

import com.ibatis.common.util.PaginatedList;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapExecutor;
import com.ibatis.sqlmap.client.SqlMapSession;
import com.ibatis.sqlmap.client.event.RowHandler;
import com.ibatis.sqlmap.engine.impl.ExtendedSqlMapClient;

import org.springframework.dao.DataAccessException;
import org.springframework.dao.InvalidDataAccessApiUsageException;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.jdbc.support.JdbcAccessor;

/**
 * Helper class that simplifies data access via the SqlMapClient API of the
 * iBATIS Database Layer, and converts checked SQLExceptions into unchecked
 * DataAccessExceptions, compatible to the org.springframework.dao exception
 * hierarchy. Uses the same SQLExceptionTranslator mechanism as JdbcTemplate.
 *
 * <p>The main method of this class executes a callback that implements a
 * data access action. Furthermore, this class provides numerous convenience
 * methods that mirror SqlMapSession's execution methods. See the SqlMapClient
 * javadocs for details on those methods.
 *
 * <p>Needs a SqlMapClient to work on, passed in via the "sqlMapClient" property.
 * Can additionally be configured with a DataSource for fetching Connections,
 * although this is not necessary if a DataSource is specified for the SqlMapClient.
 *
 * <p>NOTE: The SqlMapClient/SqlMapSession API is the API of iBATIS SQL Maps 2.
 * With SQL Maps 1.x, the SqlMap/MappedStatement API has to be used.
 *
 * @author Juergen Hoeller
 * @since 24.02.2004
 * @see #execute
 * @see #setSqlMapClient
 * @see #setDataSource
 * @see #setExceptionTranslator
 * @see SqlMapClientFactoryBean#setDataSource
 * @see com.ibatis.sqlmap.client.SqlMapClient#getDataSource
 * @see com.ibatis.sqlmap.client.SqlMapExecutor
 */
public class SqlMapClientTemplate extends JdbcAccessor implements SqlMapClientOperations {

	private SqlMapClient sqlMapClient;

	/**
	 * Create a new SqlMapClientTemplate.
	 */
	public SqlMapClientTemplate() {
	}

	/**
	 * Create a new SqlMapTemplate.
	 * @param dataSource JDBC DataSource to obtain connections from
	 * @param sqlMapClient iBATIS SqlMapClient that defines the mapped statements
	 */
	public SqlMapClientTemplate(DataSource dataSource, SqlMapClient sqlMapClient) {
		setDataSource(dataSource);
		this.sqlMapClient = sqlMapClient;
	}

	/**
	 * Set the iBATIS Database Layer SqlMapClient that defines the mapped statements.
	 */
	public void setSqlMapClient(SqlMapClient sqlMapClient) {
		this.sqlMapClient = sqlMapClient;
	}

	/**
	 * Return the iBATIS Database Layer SqlMapClient that this template works with.
	 */
	public SqlMapClient getSqlMapClient() {
		return sqlMapClient;
	}

	public void afterPropertiesSet() {
		if (this.sqlMapClient == null) {
			throw new IllegalArgumentException("sqlMapClient is required");
		}

		// if no DataSource specified, use SqlMapClient's DataSource
		if (getDataSource() == null) {
			setDataSource(this.sqlMapClient.getDataSource());
		}

		// call this last, to guarantee available DataSource
		super.afterPropertiesSet();
	}


	/**
	 * Execute the given data access action on a SqlMapSession.
	 * @param action callback object that specifies the data access action
	 * @return a result object returned by the action, or null
	 * @throws DataAccessException in case of SQL Maps errors
	 */
	public Object execute(SqlMapClientCallback action) throws DataAccessException {
		SqlMapSession session = this.sqlMapClient.openSession();
		try {
			Connection con = DataSourceUtils.getConnection(getDataSource());
			try {
				session.setUserConnection(con);
				return action.doInSqlMapClient(session);
			}
			catch (SQLException ex) {
				throw getExceptionTranslator().translate("SqlMapClientTemplate", "(mapped statement)", ex);
			}
			finally {
				DataSourceUtils.closeConnectionIfNecessary(con, getDataSource());
			}
		}
		finally {
			session.close();
		}
	}

	/**
	 * Execute the given data access action on a SqlMapSession,
	 * expecting a List result.
	 * @param action callback object that specifies the data access action
	 * @return the List result
	 * @throws DataAccessException in case of SQL Maps errors
	 */
	public List executeWithListResult(SqlMapClientCallback action) throws DataAccessException {
		return (List) execute(action);
	}

	/**
	 * Execute the given data access action on a SqlMapSession,
	 * expecting a Map result.
	 * @param action callback object that specifies the data access action
	 * @return the Map result
	 * @throws DataAccessException in case of SQL Maps errors
	 */
	public Map executeWithMapResult(SqlMapClientCallback action) throws DataAccessException {
		return (Map) execute(action);
	}
	

	public Object queryForObject(final String statementName, final Object parameterObject)
			throws DataAccessException {
		return execute(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForObject(statementName, parameterObject);
			}
		});
	}

	public Object queryForObject(final String statementName, final Object parameterObject,
															 final Object resultObject) throws DataAccessException {
		return execute(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForObject(statementName, parameterObject, resultObject);
			}
		});
	}

	public List queryForList(final String statementName, final Object parameterObject)
			throws DataAccessException {
		return executeWithListResult(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForList(statementName, parameterObject);
			}
		});
	}

	public List queryForList(final String statementName, final Object parameterObject,
													 final int skipResults, final int maxResults)
			throws DataAccessException {
		return executeWithListResult(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForList(statementName, parameterObject, skipResults, maxResults);
			}
		});
	}

	public void queryWithRowHandler(final String statementName, final Object parameterObject,
																	final RowHandler rowHandler) {
		execute(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				executor.queryWithRowHandler(statementName, parameterObject, rowHandler);
				return null;
			}
		});
	}

	public List queryForList(final String statementName, final Object parameterObject,
													 final RowHandler rowHandler) throws DataAccessException {
		return executeWithListResult(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForList(statementName, parameterObject, rowHandler);
			}
		});
	}

	public PaginatedList queryForPaginatedList(final String statementName, final Object parameterObject,
																		final int pageSize) throws DataAccessException {

		// throw exception if lazy loading will not work
		if (this.sqlMapClient instanceof ExtendedSqlMapClient &&
				((ExtendedSqlMapClient) this.sqlMapClient).getDelegate().getTxManager() == null) {
			throw new InvalidDataAccessApiUsageException("SqlMapClient needs to have DataSource to allow for lazy loading" +
																									 " - specify SqlMapClientFactoryBean's 'dataSource' property");
		}

		return (PaginatedList) execute(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForPaginatedList(statementName, parameterObject, pageSize);
			}
		});
	}

	public Map queryForMap(final String statementName, final Object parameterObject,
												 final String keyProperty) throws DataAccessException {
		return executeWithMapResult(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForMap(statementName, parameterObject, keyProperty);
			}
		});
	}

	public Map queryForMap(final String statementName, final Object parameterObject,
												 final String keyProperty, final String valueProperty)
			throws DataAccessException {
		return executeWithMapResult(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.queryForMap(statementName, parameterObject, keyProperty, valueProperty);
			}
		});
	}

	public Object insert(final String statementName, final Object parameterObject)
			throws DataAccessException {
		return execute(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return executor.insert(statementName, parameterObject);
			}
		});
	}

	public int update(final String statementName, final Object parameterObject)
			throws DataAccessException {
		Integer result = (Integer) execute(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return new Integer(executor.update(statementName, parameterObject));
			}
		});
		return result.intValue();
	}

	public int delete(final String statementName, final Object parameterObject)
			throws DataAccessException {
		Integer result = (Integer) execute(new SqlMapClientCallback() {
			public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
				return new Integer(executor.delete(statementName, parameterObject));
			}
		});
		return result.intValue();
	}

}