/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.resource.adapter.jdbc;

import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Savepoint;
import java.sql.Statement;
import java.sql.CallableStatement;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Properties;
import java.util.Set;

import javax.resource.ResourceException;
import javax.resource.spi.ConnectionEvent;
import javax.resource.spi.ConnectionEventListener;
import javax.resource.spi.ConnectionRequestInfo;
import javax.resource.spi.ManagedConnection;
import javax.resource.spi.ManagedConnectionMetaData;
import javax.resource.spi.ResourceAdapterInternalException;
import javax.security.auth.Subject;

import org.jboss.logging.Logger;
import org.jboss.resource.JBossResourceException;

/**
 * BaseWrapperManagedConnection
 *
 * @author <a href="mailto:d_jencks@users.sourceforge.net">David Jencks</a>
 * @author <a href="mailto:adrian@jboss.com">Adrian Brock</a>
 * @version $Revision: 1.17 $
 */

public abstract class BaseWrapperManagedConnection
   implements  ManagedConnection
{
   protected final BaseWrapperManagedConnectionFactory mcf;
   protected final Connection con;
   protected final Properties props;
   private final int transactionIsolation;
   private final boolean readOnly;

   private final Collection cels = new ArrayList();
   private final Set handles = new HashSet();
   private PreparedStatementCache psCache = null;

   protected final Object stateLock = new Object();
   
   protected boolean inManagedTransaction = false;
   protected boolean jdbcAutoCommit = true;
   protected boolean underlyingAutoCommit = true;
   protected boolean jdbcReadOnly;
   protected boolean underlyingReadOnly;
   protected int jdbcTransactionIsolation;
   protected boolean destroyed = false;

   public BaseWrapperManagedConnection (final BaseWrapperManagedConnectionFactory mcf,
                                  final Connection con,
                                  final Properties props,
                                  final int transactionIsolation,
                                  final int psCacheSize)
      throws SQLException
   {
      this.mcf = mcf;
      this.con = con;
      this.props = props;
      if (psCacheSize > 0)
          psCache = new PreparedStatementCache(psCacheSize);

      if (transactionIsolation == -1)
         this.transactionIsolation = con.getTransactionIsolation();
      else
      {
         this.transactionIsolation = transactionIsolation;
         con.setTransactionIsolation(transactionIsolation);
      }

      readOnly = con.isReadOnly();

      if (mcf.getNewConnectionSQL() != null)
      {
         Statement s = con.createStatement();
         try
         {
            s.execute(mcf.getNewConnectionSQL());
         }
         finally
         {
            s.close();
         }
      }

      underlyingReadOnly = readOnly;
      jdbcReadOnly = readOnly;
      jdbcTransactionIsolation = this.transactionIsolation;
   }

   public void addConnectionEventListener(ConnectionEventListener cel)
   {
      synchronized (cels)
      {
         cels.add(cel);
      }
   }

   public void removeConnectionEventListener(ConnectionEventListener cel)
   {
      synchronized (cels)
      {
         cels.remove(cel);
      }
   }

   public void associateConnection(Object handle) throws ResourceException
   {
      if (!(handle instanceof WrappedConnection))
         throw new JBossResourceException("Wrong kind of connection handle to associate" + handle);
      ((WrappedConnection)handle).setManagedConnection(this);
      synchronized(handles)
      {
         handles.add(handle);
      }
   }

   public PrintWriter getLogWriter() throws ResourceException
   {
      // TODO: implement this javax.resource.spi.ManagedConnection method
      return null;
   }

   public ManagedConnectionMetaData getMetaData() throws ResourceException
   {
      // TODO: implement this javax.resource.spi.ManagedConnection method
      return null;
   }

   public void setLogWriter(PrintWriter param1) throws ResourceException
   {
      // TODO: implement this javax.resource.spi.ManagedConnection method
   }

   public void cleanup() throws ResourceException
   {
      synchronized (handles)
      {
         for (Iterator i = handles.iterator(); i.hasNext(); )
         {
            WrappedConnection lc = (WrappedConnection)i.next();
            lc.setManagedConnection(null);
         }
         handles.clear();
      }
      //reset all the properties we know about to defaults.
      synchronized (stateLock)
      {
         jdbcAutoCommit = true;
         jdbcReadOnly = readOnly;
         if (jdbcTransactionIsolation != transactionIsolation)
         {
            try
            {
               con.setTransactionIsolation(jdbcTransactionIsolation);
               jdbcTransactionIsolation = transactionIsolation;
            }
            catch (SQLException e)
            {
               mcf.log.warn("Error resetting transaction isolation ", e);
            }
         }
      }
   }

   public Object getConnection(Subject subject, ConnectionRequestInfo cri) throws ResourceException
   {
      checkIdentity(subject, cri);
      WrappedConnection lc =  new WrappedConnection(this);
      synchronized (handles)
      {
         handles.add(lc);
      }
      return lc;
   }

   public void destroy() throws ResourceException
   {
      synchronized (stateLock)
      {
         destroyed = true;
      }

      cleanup();
      try
      {
         con.close();
      }
      catch (SQLException ignored)
      {
         getLog().trace("Ignored error during close: ", ignored);
      }
   }

   public boolean checkValid()
   {
      SQLException e = mcf.isValidConnection(con);

      if (e == null)
         // It's ok
         return true;
      else
      {
         getLog().warn("Destroying connection that is not valid, due to the following exception: " + con, e);
         broadcastConnectionError(e);
         return false;
      }
   }

   void closeHandle(WrappedConnection handle)
   {
      synchronized (stateLock)
      {
         if (destroyed)
            return;
      }

      synchronized(handles)
      {
         handles.remove(handle);
      }
      ConnectionEvent ce = new ConnectionEvent(this, ConnectionEvent.CONNECTION_CLOSED);
      ce.setConnectionHandle(handle);
      Collection copy;
      synchronized(cels)
      {
         copy = new ArrayList(cels);
      }
      for (Iterator i = copy.iterator(); i.hasNext(); )
      {
         ConnectionEventListener cel = (ConnectionEventListener)i.next();
         cel.connectionClosed(ce);
      }
   }

   void connectionError(Throwable t)
   {
      if (t instanceof SQLException == false || mcf.isExceptionFatal((SQLException) t))
         broadcastConnectionError(t);
   }

   protected void broadcastConnectionError(Throwable e)
   {
      synchronized (stateLock)
      {
         if (destroyed)
         {
            Logger log = getLog();
            if (log.isTraceEnabled())
               log.trace("Not broadcasting error, already destroyed " + this, e);
            return;
         }
      }
      
      Exception ex;
      if (e instanceof Exception)
         ex = (Exception) e;
      else
         ex = new ResourceAdapterInternalException("Unexpected error", e);
      ConnectionEvent ce = new ConnectionEvent(this, ConnectionEvent.CONNECTION_ERROR_OCCURRED, ex);
      Collection copy;
      synchronized(cels)
      {
         copy = new ArrayList(cels);
      }
      for (Iterator i = copy.iterator(); i.hasNext(); )
      {
         ConnectionEventListener cel = (ConnectionEventListener)i.next();
         try
         {
            cel.connectionErrorOccurred(ce);
         }
         catch (Throwable t)
         {
            getLog().warn("Error notifying of connection error for listener: " + cel, t);
         }
      }
   }

   Connection getConnection()
      throws SQLException
   {
      if (con == null)
         throw new SQLException("Connection has been destroyed!!!");
      return con;
   }

   PreparedStatement prepareStatement(String sql, int resultSetType,
				       int resultSetConcurrency) throws SQLException
   {
      if (psCache != null)
      {
          final PreparedStatementCache.Key key = new PreparedStatementCache.Key(sql, PreparedStatementCache.Key.PREPARED_STATEMENT, resultSetType,  resultSetConcurrency);
          CachedPreparedStatement cachedps = (CachedPreparedStatement)psCache.get(key);
         if (cachedps != null)
         {
            if (canUse(cachedps))
               cachedps.inUse();
            else
               return con.prepareStatement(sql);
         }
         else
         {
            PreparedStatement ps = con.prepareStatement(sql);
            cachedps = new CachedPreparedStatement(ps);
            psCache.insert(key, cachedps);
         }
         return cachedps;
      }
      else
         return con.prepareStatement(sql);
   }
   
   boolean canUse(CachedPreparedStatement cachedps)
   {
      // Nobody is using it so we are ok
      if (!cachedps.isInUse())
         return true;
      
      // Cannot reuse prepared statements in auto commit mode
      // if will close the previous usage of the PS
      if (underlyingAutoCommit)
         return false;
      
      // We have been told not to share
      return mcf.sharePS;
   }
   
   protected Logger getLog()
   {
      return mcf.log;
   }

   private void checkIdentity(Subject subject, ConnectionRequestInfo cri)
      throws ResourceException
   {
      Properties newProps = mcf.getConnectionProperties(subject, cri);
      if (!props.equals(newProps))
      {
         throw new JBossResourceException("Wrong credentials passed to getConnection!");
      } // end of if ()
   }

   /**
    * The <code>checkTransaction</code> method makes sure the adapter follows the JCA
    * autocommit contract, namely all statements executed outside a container managed transaction
    * or a component managed transaction should be autocommitted. To avoid continually calling
    * setAutocommit(enable) before and after container managed transactions, we keep track of the state
    * and check it before each transactional method call.
    */
   void checkTransaction() throws SQLException
   {
      synchronized (stateLock)
      {
         if (inManagedTransaction)
            return;

         // Check autocommit
         if (jdbcAutoCommit != underlyingAutoCommit)
         {
            con.setAutoCommit(jdbcAutoCommit);
            underlyingAutoCommit = jdbcAutoCommit;
         }
      }

      checkState();
   }

   protected void checkState() throws SQLException
   {
      synchronized (stateLock)
      {
         // Check readonly
         if (jdbcReadOnly != underlyingReadOnly)
         {
            con.setReadOnly(jdbcReadOnly);
            underlyingReadOnly = jdbcReadOnly;
         }
      }
   }

   boolean isJdbcAutoCommit()
   {
      return !inManagedTransaction && jdbcAutoCommit;
   }

   void setJdbcAutoCommit(final boolean jdbcAutoCommit) throws SQLException
   {
      synchronized (stateLock)
      {
         if (inManagedTransaction)
            throw new SQLException("You cannot set autocommit during a managed transaction!");
         this.jdbcAutoCommit = jdbcAutoCommit;
      }
   }

   boolean isJdbcReadOnly()
   {
      return jdbcReadOnly;
   }

   void setJdbcReadOnly(final boolean readOnly) throws SQLException
   {
      synchronized (stateLock)
      {
         if (inManagedTransaction)
            throw new SQLException("You cannot set read only during a managed transaction!");
         this.jdbcReadOnly = readOnly;
      }
   }

   int getJdbcTransactionIsolation()
   {
      return jdbcTransactionIsolation;
   }

   void setJdbcTransactionIsolation(final int isolationLevel) throws SQLException
   {
      synchronized (stateLock)
      {
         this.jdbcTransactionIsolation = isolationLevel;
         con.setTransactionIsolation(jdbcTransactionIsolation);
      }
   }

   void jdbcCommit() throws SQLException
   {
      synchronized (stateLock)
      {
         if (inManagedTransaction)
            throw new SQLException("You cannot commit during a managed transaction!");
         if (jdbcAutoCommit)
            throw new SQLException("You cannot commit with autocommit set!");
      }
      con.commit();
   }

   void jdbcRollback() throws SQLException
   {
      synchronized (stateLock)
      {
         if (inManagedTransaction)
            throw new SQLException("You cannot rollback during a managed transaction!");
         if (jdbcAutoCommit)
            throw new SQLException("You cannot rollback with autocommit set!");
      }
      con.rollback();
   }

   void jdbcRollback(Savepoint savepoint) throws SQLException
   {
      synchronized (stateLock)
      {
         if (inManagedTransaction)
            throw new SQLException("You cannot rollback during a managed transaction!");
         if (jdbcAutoCommit)
            throw new SQLException("You cannot rollback with autocommit set!");
      }
      con.rollback(savepoint);
   }

   int getTrackStatements()
   {
      return mcf.trackStatements;
   }

   boolean isTransactionQueryTimeout()
   {
      return mcf.isTransactionQueryTimeout;
   }
   
   int getQueryTimeout()
   {
      return mcf.getQueryTimeout();
   }
   
   protected void checkException(SQLException e) throws ResourceException
   {
      connectionError(e);
      throw new JBossResourceException("SQLException", e);
   }

    public CallableStatement prepareCall(String sql, int resultSetType,
				       int resultSetConcurrency) throws SQLException {
        if (psCache != null)
        {
            final PreparedStatementCache.Key key = new PreparedStatementCache.Key(sql, PreparedStatementCache.Key.CALLABLE_STATEMENT, resultSetType, resultSetConcurrency);
            CachedCallableStatement cachedps = (CachedCallableStatement)psCache.get(key);
           if (cachedps != null)
           {
              if (canUse(cachedps))
                 cachedps.inUse();
              else
                 return con.prepareCall(sql);
           }
           else
           {
              CallableStatement cs = con.prepareCall(sql);
              cachedps = new CachedCallableStatement(cs);
              psCache.insert(key, cachedps);
           }
           return cachedps;
        }
        else
           return con.prepareCall(sql);
    }
}