/*
    * Copyright 2004-2022 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;
  
  import com.ibatis.sqlmap.engine.scope.SessionScope;
  
  import java.sql.SQLException;
  
  /**
   * The Class TransactionManager.
   */
  public class TransactionManager {
  
    /** The config. */
    private TransactionConfig config;
  
    /**
     * Instantiates a new transaction manager.
     *
     * @param transactionConfig
     *          the transaction config
     */
    public TransactionManager(TransactionConfig transactionConfig) {
      this.config = transactionConfig;
    }
  
    /**
     * Begin.
     *
     * @param sessionScope
     *          the session scope
     *
     * @throws SQLException
     *           the SQL exception
     * @throws TransactionException
     *           the transaction exception
     */
    public void begin(SessionScope sessionScope) throws SQLException, TransactionException {
      begin(sessionScope, IsolationLevel.UNSET_ISOLATION_LEVEL);
    }
  
    /**
     * Begin.
     *
     * @param sessionScope
     *          the session scope
     * @param transactionIsolation
     *          the transaction isolation
     *
     * @throws SQLException
     *           the SQL exception
     * @throws TransactionException
     *           the transaction exception
     */
    public void begin(SessionScope sessionScope, int transactionIsolation) throws SQLException, TransactionException {
      Transaction trans = sessionScope.getTransaction();
      TransactionState state = sessionScope.getTransactionState();
      if (state == TransactionState.STATE_STARTED) {
        throw new TransactionException(
            "TransactionManager could not start a new transaction.  " + "A transaction is already started.");
      } else if (state == TransactionState.STATE_USER_PROVIDED) {
        throw new TransactionException("TransactionManager could not start a new transaction.  "
            + "A user provided connection is currently being used by this session.  "
            + "The calling .setUserConnection (null) will clear the user provided transaction.");
      }
  
      trans = config.newTransaction(transactionIsolation);
      sessionScope.setCommitRequired(false);
  
      sessionScope.setTransaction(trans);
      sessionScope.setTransactionState(TransactionState.STATE_STARTED);
    }
  
    /**
     * Commit.
     *
     * @param sessionScope
     *          the session scope
     *
     * @throws SQLException
     *           the SQL exception
     * @throws TransactionException
     *           the transaction exception
     */
    public void commit(SessionScope sessionScope) throws SQLException, TransactionException {
      Transaction trans = sessionScope.getTransaction();
     TransactionState state = sessionScope.getTransactionState();
     if (state == TransactionState.STATE_USER_PROVIDED) {
       throw new TransactionException("TransactionManager could not commit.  "
           + "A user provided connection is currently being used by this session.  "
           + "You must call the commit() method of the Connection directly.  "
           + "The calling .setUserConnection (null) will clear the user provided transaction.");
     } else if (state != TransactionState.STATE_STARTED && state != TransactionState.STATE_COMMITTED) {
       throw new TransactionException("TransactionManager could not commit.  No transaction is started.");
     }
     if (sessionScope.isCommitRequired() || config.isForceCommit()) {
       trans.commit();
       sessionScope.setCommitRequired(false);
     }
     sessionScope.setTransactionState(TransactionState.STATE_COMMITTED);
   }
 
   /**
    * End.
    *
    * @param sessionScope
    *          the session scope
    *
    * @throws SQLException
    *           the SQL exception
    * @throws TransactionException
    *           the transaction exception
    */
   public void end(SessionScope sessionScope) throws SQLException, TransactionException {
     Transaction trans = sessionScope.getTransaction();
     TransactionState state = sessionScope.getTransactionState();
 
     if (state == TransactionState.STATE_USER_PROVIDED) {
       throw new TransactionException("TransactionManager could not end this transaction.  "
           + "A user provided connection is currently being used by this session.  "
           + "You must call the rollback() method of the Connection directly.  "
           + "The calling .setUserConnection (null) will clear the user provided transaction.");
     }
 
     try {
       if (trans != null) {
         try {
           if (state != TransactionState.STATE_COMMITTED) {
             if (sessionScope.isCommitRequired() || config.isForceCommit()) {
               trans.rollback();
               sessionScope.setCommitRequired(false);
             }
           }
         } finally {
           sessionScope.closePreparedStatements();
           trans.close();
         }
       }
     } finally {
       sessionScope.setTransaction(null);
       sessionScope.setTransactionState(TransactionState.STATE_ENDED);
     }
   }
 
   /**
    * Gets the config.
    *
    * @return the config
    */
   public TransactionConfig getConfig() {
     return config;
   }
 
 }