/*
    * Copyright 2004-2026 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
    *
    *    https://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 com.ibatis.sqlmap.engine.transaction.external;
  
  import com.ibatis.common.jdbc.logging.ConnectionLogProxy;
  import com.ibatis.common.logging.Log;
  import com.ibatis.common.logging.LogFactory;
  import com.ibatis.sqlmap.engine.transaction.IsolationLevel;
  import com.ibatis.sqlmap.engine.transaction.Transaction;
  import com.ibatis.sqlmap.engine.transaction.TransactionException;
  
  import java.sql.Connection;
  import java.sql.SQLException;
  
  import javax.sql.DataSource;
  
  /**
   * The Class ExternalTransaction.
   */
  public class ExternalTransaction implements Transaction {
  
    /** The Constant connectionLog. */
    private static final Log connectionLog = LogFactory.getLog(Connection.class);
  
    /** The data source. */
    private DataSource dataSource;
  
    /** The default auto commit. */
    private boolean defaultAutoCommit;
  
    /** The set auto commit allowed. */
    private boolean setAutoCommitAllowed;
  
    /** The connection. */
    private Connection connection;
  
    /** The isolation level. */
    private IsolationLevel isolationLevel = new IsolationLevel();
  
    /**
     * Instantiates a new external transaction.
     *
     * @param ds
     *          the ds
     * @param defaultAutoCommit
     *          the default auto commit
     * @param setAutoCommitAllowed
     *          the set auto commit allowed
     * @param isolationLevel
     *          the isolation level
     *
     * @throws TransactionException
     *           the transaction exception
     */
    public ExternalTransaction(DataSource ds, boolean defaultAutoCommit, boolean setAutoCommitAllowed, int isolationLevel)
        throws TransactionException {
      // Check Parameters
      dataSource = ds;
      if (dataSource == null) {
        throw new TransactionException("ExternalTransaction initialization failed.  DataSource was null.");
      }
  
      this.defaultAutoCommit = defaultAutoCommit;
      this.setAutoCommitAllowed = setAutoCommitAllowed;
      this.isolationLevel.setIsolationLevel(isolationLevel);
    }
  
    /**
     * Inits the.
     *
     * @throws SQLException
     *           the SQL exception
     * @throws TransactionException
     *           the transaction exception
     */
    private void init() throws SQLException, TransactionException {
      // Open JDBC Transaction
      connection = dataSource.getConnection();
      if (connection == null) {
        throw new TransactionException(
            "ExternalTransaction could not start transaction.  Cause: The DataSource returned a null connection.");
      }
      // Isolation Level
      isolationLevel.applyIsolationLevel(connection);
      // AutoCommit
      if (setAutoCommitAllowed && connection.getAutoCommit() != defaultAutoCommit) {
       connection.setAutoCommit(defaultAutoCommit);
     }
     // Debug
     if (connectionLog.isDebugEnabled()) {
       connection = ConnectionLogProxy.newInstance(connection);
     }
   }
 
   @Override
   public void commit() throws SQLException, TransactionException {
   }
 
   @Override
   public void rollback() throws SQLException, TransactionException {
   }
 
   @Override
   public void close() throws SQLException, TransactionException {
     if (connection != null) {
       try {
         isolationLevel.restoreIsolationLevel(connection);
       } finally {
         connection.close();
         connection = null;
       }
     }
   }
 
   @Override
   public Connection getConnection() throws SQLException, TransactionException {
     if (connection == null) {
       init();
     }
     return connection;
   }
 
 }