/*
      Copyright (C) 2002-2004 MySQL AB

      This program is free software; you can redistribute it and/or modify
      it under the terms of version 2 of the GNU General Public License as 
      published by the Free Software Foundation.

      There are special exceptions to the terms and conditions of the GPL 
      as it is applied to this software. View the full text of the 
      exception in file EXCEPTIONS-CONNECTOR-J in the directory of this 
      software distribution.

      This program 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 General Public License for more details.

      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



 */
package com.mysql.jdbc.jdbc2.optional;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Savepoint;
import java.sql.Statement;


/**
 * This class serves as a wrapper for the org.gjt.mm.mysql.jdbc2.Connection
 * class.   It is returned to the application server which may wrap it again
 * and then return it to the application client in response to
 * dataSource.getConnection().
 *
 * <p>
 * All method invocations are forwarded to org.gjt.mm.mysql.jdbc2.Connection
 * unless the close method was previously called, in which case a sqlException
 * is  thrown.  The close method performs a 'logical close' on the connection.
 * </p>
 *
 * <p>
 * All sqlExceptions thrown by the physical connection are intercepted and sent
 * to  connectionEvent listeners before being thrown to client.
 * </p>
 *
 * @author Todd Wolff todd.wolff_at_prodigy.net
 *
 * @see org.gjt.mm.mysql.jdbc2.Connection
 * @see org.gjt.mm.mysql.jdbc2.optional.MysqlPooledConnection
 */
class ConnectionWrapper extends WrapperBase implements Connection {
    private Connection mc = null;
    private MysqlPooledConnection mpc = null;
    private String invalidHandleStr = "Logical handle no longer valid";
    private boolean closed;

    /**
     * Construct a new LogicalHandle and set instance variables
     *
     * @param mysqlPooledConnection reference to object that instantiated this
     *        object
     * @param mysqlConnection physical connection to db
     *
     * @throws SQLException if an error occurs.
     */
    public ConnectionWrapper(MysqlPooledConnection mysqlPooledConnection,
        Connection mysqlConnection) throws SQLException {
        this.mpc = mysqlPooledConnection;
        this.mc = mysqlConnection;
        this.closed = false;
        this.pooledConnection = this.mpc;
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#setAutoCommit
     */
    public void setAutoCommit(boolean autoCommit) throws SQLException {
        checkClosed();

        try {
            this.mc.setAutoCommit(autoCommit);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#getAutoCommit()
     */
    public boolean getAutoCommit() throws SQLException {
        checkClosed();

        try {
            return this.mc.getAutoCommit();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return false; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#setCatalog()
     */
    public void setCatalog(String catalog) throws SQLException {
        checkClosed();

        try {
            this.mc.setCatalog(catalog);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @return the current catalog
     *
     * @throws SQLException if an error occurs
     */
    public String getCatalog() throws SQLException {
        checkClosed();

        try {
            return this.mc.getCatalog();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#isClosed()
     */
    public boolean isClosed() throws SQLException {
        return (this.closed || this.mc.isClosed());
    }

    /**
     * @see Connection#setHoldability(int)
     */
    public void setHoldability(int arg0) throws SQLException {
        checkClosed();

        try {
            this.mc.setHoldability(arg0);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * @see Connection#getHoldability()
     */
    public int getHoldability() throws SQLException {
        checkClosed();

        try {
            return this.mc.getHoldability();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return Statement.CLOSE_CURRENT_RESULT; // we don't reach this code, compiler can't tell
    }

    /**
     * Allows clients to determine how long this connection has been idle.
     *
     * @return how long the connection has been idle.
     */
    public long getIdleFor() {
        return ((com.mysql.jdbc.Connection) this.mc).getIdleFor();
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @return a metadata instance
     *
     * @throws SQLException if an error occurs
     */
    public java.sql.DatabaseMetaData getMetaData() throws SQLException {
        checkClosed();

        try {
            return this.mc.getMetaData();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#setReadOnly()
     */
    public void setReadOnly(boolean readOnly) throws SQLException {
        checkClosed();

        try {
            this.mc.setReadOnly(readOnly);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#isReadOnly()
     */
    public boolean isReadOnly() throws SQLException {
        checkClosed();

        try {
            return this.mc.isReadOnly();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return false; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#setSavepoint()
     */
    public java.sql.Savepoint setSavepoint() throws SQLException {
        checkClosed();

        try {
            return this.mc.setSavepoint();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#setSavepoint(String)
     */
    public java.sql.Savepoint setSavepoint(String arg0)
        throws SQLException {
        checkClosed();

        try {
            return this.mc.setSavepoint(arg0);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#setTransactionIsolation()
     */
    public void setTransactionIsolation(int level) throws SQLException {
        checkClosed();

        try {
            this.mc.setTransactionIsolation(level);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#getTransactionIsolation()
     */
    public int getTransactionIsolation() throws SQLException {
        checkClosed();

        try {
            return this.mc.getTransactionIsolation();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return TRANSACTION_REPEATABLE_READ; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#setTypeMap()
     */
    public void setTypeMap(java.util.Map map) throws SQLException {
        checkClosed();

        try {
            this.mc.setTypeMap(map);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#getTypeMap()
     */
    public java.util.Map getTypeMap() throws SQLException {
        checkClosed();

        try {
            return this.mc.getTypeMap();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#getWarnings
     */
    public java.sql.SQLWarning getWarnings() throws SQLException {
        checkClosed();

        try {
            return this.mc.getWarnings();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.   Notifies
     * listeners of any caught exceptions before  re-throwing to client.
     *
     * @throws SQLException if an error occurs
     */
    public void clearWarnings() throws SQLException {
        checkClosed();

        try {
            this.mc.clearWarnings();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * The physical connection is not actually closed.  the physical connection
     * is closed when the application server calls
     * mysqlPooledConnection.close().  this object is  de-referenced by the
     * pooled connection each time mysqlPooledConnection.getConnection()  is
     * called by app server.
     *
     * @throws SQLException if an error occurs
     */
    public void close() throws SQLException {
        close(true);
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @throws SQLException if an error occurs
     */
    public void commit() throws SQLException {
        checkClosed();

        try {
            this.mc.commit();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#createStatement()
     */
    public java.sql.Statement createStatement() throws SQLException {
        checkClosed();

        try {
            return new StatementWrapper(this, this.mpc, this.mc.createStatement());
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#createStatement()
     */
    public java.sql.Statement createStatement(int resultSetType,
        int resultSetConcurrency) throws SQLException {
        checkClosed();

        try {
            return new StatementWrapper(this, this.mpc,
                this.mc.createStatement(resultSetType, resultSetConcurrency));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#createStatement(int, int, int)
     */
    public java.sql.Statement createStatement(int arg0, int arg1, int arg2)
        throws SQLException {
        checkClosed();

        try {
            return new StatementWrapper(this, this.mpc,
                this.mc.createStatement(arg0, arg1, arg2));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#nativeSQL()
     */
    public String nativeSQL(String sql) throws SQLException {
        checkClosed();

        try {
            return this.mc.nativeSQL(sql);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#prepareCall()
     */
    public java.sql.CallableStatement prepareCall(String sql)
        throws SQLException {
        checkClosed();

        try {
            return new CallableStatementWrapper(this, this.mpc, this.mc.prepareCall(sql));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#prepareCall()
     */
    public java.sql.CallableStatement prepareCall(String sql,
        int resultSetType, int resultSetConcurrency) throws SQLException {
        checkClosed();

        try {
            return new CallableStatementWrapper(this, this.mpc, this.mc.prepareCall(sql, resultSetType, resultSetConcurrency));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#prepareCall(String, int, int, int)
     */
    public java.sql.CallableStatement prepareCall(String arg0, int arg1,
        int arg2, int arg3) throws SQLException {
        checkClosed();

        try {
        	return new CallableStatementWrapper(this, this.mpc, this.mc.prepareCall(arg0, arg1, arg2, arg3));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#prepareStatement()
     */
    public java.sql.PreparedStatement prepareStatement(String sql)
        throws SQLException {
        checkClosed();

        try {
            return new PreparedStatementWrapper(this, this.mpc,
                this.mc.prepareStatement(sql));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#prepareStatement()
     */
    public java.sql.PreparedStatement prepareStatement(String sql,
        int resultSetType, int resultSetConcurrency) throws SQLException {
        checkClosed();

        try {
            return new PreparedStatementWrapper(this, this.mpc,
                this.mc.prepareStatement(sql, resultSetType,
                    resultSetConcurrency));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#prepareStatement(String, int, int, int)
     */
    public java.sql.PreparedStatement prepareStatement(String arg0, int arg1,
        int arg2, int arg3) throws SQLException {
        checkClosed();

        try {
            return new PreparedStatementWrapper(this, this.mpc,
                this.mc.prepareStatement(arg0, arg1, arg2, arg3));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#prepareStatement(String, int)
     */
    public java.sql.PreparedStatement prepareStatement(String arg0, int arg1)
        throws SQLException {
        checkClosed();

        try {
            return new PreparedStatementWrapper(this, this.mpc,
                this.mc.prepareStatement(arg0, arg1));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#prepareStatement(String, int[])
     */
    public java.sql.PreparedStatement prepareStatement(String arg0, int[] arg1)
        throws SQLException {
        checkClosed();

        try {
            return new PreparedStatementWrapper(this, this.mpc,
                this.mc.prepareStatement(arg0, arg1));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#prepareStatement(String, String[])
     */
    public java.sql.PreparedStatement prepareStatement(String arg0,
        String[] arg1) throws SQLException {
        checkClosed();

        try {
            return new PreparedStatementWrapper(this, this.mpc,
                this.mc.prepareStatement(arg0, arg1));
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }

        return null; // we don't reach this code, compiler can't tell
    }

    /**
     * @see Connection#releaseSavepoint(Savepoint)
     */
    public void releaseSavepoint(Savepoint arg0) throws SQLException {
        checkClosed();

        try {
            this.mc.releaseSavepoint(arg0);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * Passes call to method on physical connection instance.  Notifies
     * listeners of any caught exceptions before re-throwing to client.
     *
     * @see java.sql.Connection#rollback()
     */
    public void rollback() throws SQLException {
        checkClosed();

        try {
            this.mc.rollback();
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    /**
     * @see Connection#rollback(Savepoint)
     */
    public void rollback(Savepoint arg0) throws SQLException {
        checkClosed();

        try {
            this.mc.rollback(arg0);
        } catch (SQLException sqlException) {
            checkAndFireConnectionError(sqlException);
        }
    }

    protected void close(boolean fireClosedEvent) throws SQLException {
        synchronized (this.mpc) {
            if (this.closed) {
                return;
            }

            if (((com.mysql.jdbc.Connection) this.mc).getRollbackOnPooledClose() &&
                    !this.getAutoCommit()) {
                rollback();
            }

            if (fireClosedEvent) {
                this.mpc.callListener(MysqlPooledConnection.CONNECTION_CLOSED_EVENT,
                    null);
            }

            // set closed status to true so that if application client tries to make additional
            // calls a sqlException will be thrown.  The physical connection is
            // re-used by the pooled connection each time getConnection is called.
            this.closed = true;
        }
    }

    private void checkClosed() throws SQLException {
        if (this.closed) {
            throw new SQLException(this.invalidHandleStr);
        }
    }
}