/*
 * 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.geode.internal.datasource;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.sql.ConnectionEvent;
import javax.sql.ConnectionEventListener;
import javax.sql.PooledConnection;
import javax.sql.XAConnection;
import javax.sql.XADataSource;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import javax.transaction.xa.XAResource;

import org.apache.logging.log4j.Logger;

import org.apache.geode.annotations.VisibleForTesting;
import org.apache.geode.internal.jndi.JNDIInvoker;
import org.apache.geode.logging.internal.log4j.api.LogService;

/**
 * GemFireTransactionDataSource extends AbstractDataSource. This is a datasource class which
 * provides connections from the pool. These connection can participate in the transaction. The
 * objects of these class are ConnectionEventListener for connection close and error events.
 *
 * Modified the exception handling & changed the name of some functions.
 */
public class GemFireTransactionDataSource extends AbstractDataSource
    implements ConnectionEventListener {

  private static final Logger logger = LogService.getLogger();

  private static final long serialVersionUID = -3095123666092414103L;
  private transient TransactionManager transManager;
  ConnectionProvider provider;
  private Map xaResourcesMap = Collections.synchronizedMap(new HashMap());

  /**
   * Place holder for abstract method isWrapperFor(java.lang.Class) in java.sql.Wrapper required by
   * jdk 1.6
   *
   * @param iface - a Class defining an interface.
   */
  @Override
  public boolean isWrapperFor(Class iface) throws SQLException {
    return true;
  }

  /**
   * Place holder for abstract method java.lang Object unwrap(java.lang.Class) in java.sql.Wrapper
   * required by jdk 1.6
   *
   * @param iface - a Class defining an interface.
   * @return java.lang.Object
   */

  @Override
  public Object unwrap(Class iface) throws SQLException {
    return iface;
  }

  /**
   * Creates a new instance of GemFireTransactionDataSource
   *
   * @param xaDS The XADataSource object for the database driver.
   * @param configs - The ConfiguredDataSourceProperties containing the datasource properties.
   */
  public GemFireTransactionDataSource(XADataSource xaDS, ConfiguredDataSourceProperties configs)
      throws SQLException {
    super(configs);
    if ((xaDS == null) || (configs == null)) {
      throw new SQLException(
          "GemFireTransactionDataSource::XADataSource class object is null or ConfiguredDataSourceProperties object is null");
    }
    try {
      provider = new GemFireConnectionPoolManager(xaDS, configs, this);
      transManager = JNDIInvoker.getTransactionManager();
    } catch (Exception ex) {
      String exception = "GemFireTransactionDataSource::Exception = " + ex;
      if (logger.isDebugEnabled()) {
        logger.debug(exception, ex);
      }
      throw new SQLException(exception);
    }
  }

  /**
   * Implementation of datasource function. This method is used to get the connection from the pool.
   * Default user name and password will be used.
   *
   * @return ???
   */
  @Override
  public Connection getConnection() throws SQLException {
    if (!isActive) {
      throw new SQLException(
          "GemFireTransactionDataSource::getConnection::No valid Connection available");
    }
    XAConnection xaConn = null;
    try {
      xaConn = (XAConnection) provider.borrowConnection();
      Connection conn = getSQLConnection(xaConn);
      registerTranxConnection(xaConn);
      return conn;
    } catch (Exception ex) {
      SQLException se = new SQLException(ex.getMessage());
      se.initCause(ex);
      throw se;
    }
  }

  /**
   * Implementation of datasource function. This method is used to get the connection. The specified
   * user name and passowrd will be used.
   *
   * @param clUsername The username for the database connection.
   * @param clPassword The password for the database connection.
   * @return ???
   */
  @Override
  public Connection getConnection(String clUsername, String clPassword) throws SQLException {
    checkCredentials(clUsername, clPassword);
    return getConnection();
  }

  /**
   * Implementation of call back function from ConnectionEventListener interface. This callback will
   * be invoked on connection close event.
   *
   * @param event Connection event object
   */
  @Override
  public void connectionClosed(ConnectionEvent event) {
    if (isActive) {
      try {
        XAConnection conn = (XAConnection) event.getSource();
        XAResource xar = (XAResource) xaResourcesMap.get(conn);
        xaResourcesMap.remove(conn);
        Transaction txn = transManager.getTransaction();
        if (txn != null && xar != null)
          txn.delistResource(xar, XAResource.TMSUCCESS);
        provider.returnConnection(conn);
      } catch (Exception e) {
        String exception =
            "GemFireTransactionDataSource::connectionClosed: Exception occurred due to " + e;
        if (logger.isDebugEnabled()) {
          logger.debug(exception, e);
        }
      }
    }
  }

  /**
   * Implementation of call back function from ConnectionEventListener interface. This callback will
   * be invoked on connection error event.
   *
   * @param event Connection event object
   */
  @Override
  public void connectionErrorOccurred(ConnectionEvent event) {
    if (isActive) {
      try {
        PooledConnection conn = (PooledConnection) event.getSource();
        provider.returnAndExpireConnection(conn);
      } catch (Exception ex) {
        String exception =
            "GemFireTransactionDataSource::connectionErrorOccurred: Exception occurred due to "
                + ex;
        if (logger.isDebugEnabled()) {
          logger.debug(exception, ex);
        }
      }
    }
  }

  void registerTranxConnection(XAConnection xaConn) throws Exception {
    try {
      synchronized (this) {
        if (transManager == null) {
          transManager = JNDIInvoker.getTransactionManager();
        }
      }
      Transaction txn = transManager.getTransaction();
      if (txn != null) {
        XAResource xar = xaConn.getXAResource();
        txn.enlistResource(xar);
        // Add in the Map after successful registration of XAResource
        this.xaResourcesMap.put(xaConn, xar);
      }
    } catch (Exception ex) {
      provider.returnAndExpireConnection(xaConn);
      Exception e = new Exception(
          String.format(
              "GemFireTransactionDataSource-registerTranxConnection(). Exception in registering the XAResource with the Transaction.Exception occurred= %s",
              ex));
      e.initCause(ex);
      throw e;
    }
  }

  /**
   * gets the connection from the pool
   *
   * @return ???
   */
  protected Connection getSQLConnection(PooledConnection poolC) throws SQLException {
    Connection connection;
    try {
      connection = poolC.getConnection();
    } catch (SQLException e) {
      provider.returnAndExpireConnection(poolC);
      throw e;
    }
    boolean val = validateConnection(connection);
    if (val) {
      return connection;
    } else {
      provider.returnAndExpireConnection(poolC);
      throw new SQLException(
          "GemFireConnPooledDataSource::getConnFromConnPool:java.sql.Connection obtained is invalid");
    }
  }

  /**
   * Returns the connection provider for the datasource.
   *
   * @return ConnectionProvider object for the datasource
   */
  public ConnectionProvider getConnectionProvider() {
    return provider;
  }

  /*
   * Clean up the resources before restart of Cache
   */
  @Override
  public void close() {
    super.close();
    provider.clearUp();
  }

  /**
   * Used by unit tests
   */
  @VisibleForTesting
  void setTransactionManager(TransactionManager transManager) {
    this.transManager = transManager;
  }
}