package org.TEST

import java.beans.PropertyEditor;
import java.beans.PropertyEditorManager;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.Properties;

import javax.management.InstanceNotFoundException;
import javax.management.MBeanException;
import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.naming.InitialContext;
import javax.sql.ConnectionEvent;
import javax.sql.ConnectionEventListener;
import javax.sql.XAConnection;
import javax.sql.XADataSource;
import javax.transaction.xa.XAResource;

import com.arjuna.ats.jta.recovery.XAResourceRecovery;

import org.jboss.logging.Logger;

/**
 * This is an enhanced version of JBossTM's AppServerJDBCXARecovery implementation.
 * The only thing this implementation does differently is it becomes tolerant of
 * the times when the data source is not yet deployed.
 * 
 * This provides recovery for compliant JDBC drivers accessed via datasources deployed in JBossAS 4.2
 * It is not meant to be db driver specific.
 *
 * This code is based on JDBCXARecovery, which expects JNDI to contain an XADataSource implementation.
 * In JBossAS, the object created in JNDI when a -ds.xml file containing <xa-datasource> element is used,
 * does not implement the XADataSource interface. We therefore use this modified code to pull the
 * datasource configuration information from the app server's JMX and instantiate an XADataSource from
 * which it can then create an XAConnection.
 *
 * To use this class, add an XAResourceRecovery entry in the jta section of jbossjta-properties.xml
 * for each datasource for which you need recovery, ensuring the value ends with ;<datasource-name>
 * i.e. the same value as is in the -ds.xml jndi-name element.
 * You also need the XARecoveryModule enabled and appropriate values for nodeIdentifier and xaRecoveryNode set.
 * See the JBossTS recovery guide if you are unclear on how the recovery system works.
 *
 * Note: This implementation expects to run inside the app server JVM. It probably won't work
 * if you configure the recovery manager to run as a separate process. (JMX can be accessed remotely,
 * but it would need code changes to the lookup function and some classpath additions).
 *
 *  <properties depends="arjuna" name="jta">
 *  ...
 *    <property name="com.arjuna.ats.jta.recovery.XAResourceRecovery1" value= "com.arjuna.ats.internal.jbossatx.jta.AppServerJDBCXARecovery;MyExampleDbName"/>
 *    <!-- xaRecoveryNode should match value in nodeIdentifier or be * -->
 *    <property name="com.arjuna.ats.jta.xaRecoveryNode" value="1"/>
 *
 */
public class AppServerJDBCXARecovery implements XAResourceRecovery {

    // implementation based on com.arjuna.ats.internal.jdbc.recovery.JDBCXARecovery

    public AppServerJDBCXARecovery() throws SQLException {
        if (log.isDebugEnabled()) {
            log.debug("AppServerJDBCXARecovery<init>");
        }

        _hasMoreResources = false;
        _connectionEventListener = new LocalConnectionEventListener();
    }

    /**
     * The recovery module will have chopped off this class name already. The
     * parameter should specify a jndi name for the datasource.
     */

    public boolean initialise(String parameter) throws SQLException {
        if (log.isDebugEnabled()) {
            log.debug("AppServerJDBCXARecovery.initialise(" + parameter + ")");
        }

        if (parameter == null)
            return false;

        // don't create the datasource yet, we'll do it lazily. Just keep its id.
        _dataSourceId = parameter;

        return true;
    }

    public synchronized XAResource getXAResource() throws SQLException {
        createConnection();

        if (_connection == null) {
            throw new SQLException("The data source named [" + _dataSourceId + "] is not deployed.");
        }

        return _connection.getXAResource();
    }

    public boolean hasMoreResources() {
        if (_dataSource == null)
            try {
                createDataSource();
            } catch (SQLException sqlException) {
                return false;
            }

        if (_dataSource != null) {
            _hasMoreResources = !_hasMoreResources;

            return _hasMoreResources;
        } else
            return false;
    }

    /**
     * Lookup the XADataSource in JNDI.
     */
    private final void createDataSource() throws SQLException {
        try {
            if (_dataSource == null) {
                // This is where we do JBossAS specific magic. Use the JMX to fetch the name of the XADataSource class
                // and its config params so that we don't have to duplicate the information in the -ds.xml file.

                // TODO: can we make this flexible enough to handle remote app server processes, so that
                // we can run the recovery manager out of process? The server addr would need to be on a per
                // jndiname basis, as we may be doing recovery for a whole cluster. We would need AS
                // jmx classes (and the db drivers naturally) on the recovery manager classpath.

                InitialContext context = new InitialContext();
                MBeanServerConnection server = (MBeanServerConnection) context.lookup("jmx/invoker/RMIAdaptor");
                ObjectName objectName = new ObjectName("jboss.jca:name=" + _dataSourceId
                    + ",service=ManagedConnectionFactory");
                String className = (String) server.invoke(objectName, "getManagedConnectionFactoryAttribute",
                    new Object[] { "XADataSourceClass" }, new String[] { "java.lang.String" });
                log.debug("AppServerJDBCXARecovery datasource classname = " + className);
                String properties = (String) server.invoke(objectName, "getManagedConnectionFactoryAttribute",
                    new Object[] { "XADataSourceProperties" }, new String[] { "java.lang.String" });
                // debug disabled due to security paranoia - it may log datasource password in cleartext.
                // log.debug("AppServerJDBCXARecovery.result="+properties);

                try {
                    _dataSource = getXADataSource(className, properties);
                    _supportsIsValidMethod = true; // assume it does; we'll lazily check the first time we try to connect
                } catch (Exception e) {
                    _dataSource = null;
                    log.error("AppServerJDBCXARecovery.createDataSource got exception during getXADataSource call: "
                        + e.toString(), e);
                    throw new SQLException(e.toString());
                }
            }
        } catch (MBeanException mbe) {
            if (mbe.getTargetException() instanceof InstanceNotFoundException) {
                // this is an expected condition when the data source is not yet deployed
                // just ignore this for now, the next time around, we try again to see if its deployed yet
                return;
            }
            log.error("AppServerJDBCXARecovery.createDataSource got exception " + mbe.toString(), mbe);

            throw new SQLException(mbe.toString());
        } catch (SQLException ex) {
            log.error("AppServerJDBCXARecovery.createDataSource got exception " + ex.toString(), ex);

            throw ex;
        } catch (Exception e) {
            log.error("AppServerJDBCXARecovery.createDataSource got exception " + e.toString(), e);

            throw new SQLException(e.toString());
        }
    }

    /**
     * Create the XAConnection from the XADataSource.
     */

    private final void createConnection() throws SQLException {
        try {
            if (_dataSource == null) {
                createDataSource();
                // if we still don't have it, its because the data source isn't deployed yet
                if (_dataSource == null) {
                    return;
                }
            }

            Boolean isConnectionValid;
            try {
                if (_connection != null && _supportsIsValidMethod) {
                    Connection connection = _connection.getConnection();
                    Method method = connection.getClass().getMethod("isValid", Integer.class);
                    isConnectionValid = (Boolean) method.invoke(connection, Integer.valueOf(5));
                } else {
                    isConnectionValid = Boolean.FALSE;
                }
            } catch (NoSuchMethodException nsme) {
                isConnectionValid = Boolean.FALSE;
                _supportsIsValidMethod = false;
                log.info("XA datasource does not support isValid method - connection will always be recreated");
            } catch (Throwable t) {
                isConnectionValid = Boolean.FALSE;
                log.debug("XA connection is invalid - will recreate a new one. Cause: " + t);
            }

            if (!isConnectionValid.booleanValue()) {
                if (_connection != null) {
                    try {
                        _connection.close(); // just attempt to clean up anything that we can
                    } catch (Throwable t) {
                    }
                }

                _connection = _dataSource.getXAConnection();
                _connection.addConnectionEventListener(_connectionEventListener);
                log.debug("Created new XAConnection");
            }
        } catch (SQLException ex) {
            log.error("AppServerJDBCXARecovery.createConnection got exception " + ex.toString(), ex);

            throw ex;
        } catch (Exception e) {
            log.error("AppServerJDBCXARecovery.createConnection got exception " + e.toString(), e);

            throw new SQLException(e.toString());
        }
    }

    private class LocalConnectionEventListener implements ConnectionEventListener {
        public void connectionErrorOccurred(ConnectionEvent connectionEvent) {
            _connection.removeConnectionEventListener(_connectionEventListener);
            _connection = null;
        }

        public void connectionClosed(ConnectionEvent connectionEvent) {
            _connection.removeConnectionEventListener(_connectionEventListener);
            _connection = null;
        }
    }

    // borrowed from org.jboss.resource.adapter.jdbc.xa.XAManagedConnectionFactory
    // in which the equivalent functionality is protected not public :-(
    private XADataSource getXADataSource(String xaDataSourceClassname, String propertiesString) throws Exception {
        // Map any \ to \\
        propertiesString = propertiesString.replaceAll("\\\\", "\\\\\\\\");

        Properties properties = new Properties();
        InputStream is = new ByteArrayInputStream(propertiesString.getBytes());
        properties.load(is);

        Class clazz = Thread.currentThread().getContextClassLoader().loadClass(xaDataSourceClassname);
        XADataSource xads = (XADataSource) clazz.newInstance();
        Class[] NOCLASSES = new Class[] {};
        for (Iterator i = properties.keySet().iterator(); i.hasNext();) {
            String name = (String) i.next();
            String value = properties.getProperty(name);
            //This is a bad solution.  On the other hand the only known example
            // of a setter with no getter is for Oracle with password.
            //Anyway, each xadatasource implementation should get its
            //own subclass of this that explicitly sets the
            //properties individually.
            Class type = null;
            try {
                Method getter = clazz.getMethod("get" + name, NOCLASSES);
                type = getter.getReturnType();
            } catch (NoSuchMethodException e) {
                type = String.class;

                try {
                    //HACK for now until we can rethink the XADataSourceProperties variable and pass type information
                    Method getter = clazz.getMethod("is" + name, NOCLASSES);
                    type = getter.getReturnType();

                } catch (NoSuchMethodException nsme) {
                    type = String.class;

                }

            }

            Method setter = clazz.getMethod("set" + name, new Class[] { type });
            PropertyEditor editor = PropertyEditorManager.findEditor(type);
            editor.setAsText(value);
            setter.invoke(xads, new Object[] { editor.getValue() });
        }
        return xads;
    }

    private boolean _supportsIsValidMethod;

    private XAConnection _connection;
    private XADataSource _dataSource;
    private LocalConnectionEventListener _connectionEventListener;
    private boolean _hasMoreResources;

    private String _dataSourceId;
    private Logger log = org.jboss.logging.Logger.getLogger(AppServerJDBCXARecovery.class);
}