/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   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 .

 */

#include <connectivity/conncleanup.hxx>

#include <com/sun/star/beans/XPropertySet.hpp>

#include <com/sun/star/lang/XComponent.hpp>

#include <com/sun/star/sdbc/XRowSet.hpp>

#include <com/sun/star/sdbc/XConnection.hpp>

#include <osl/diagnose.h>

#include <comphelper/diagnose_ex.hxx>

namespace dbtools

{

    using namespace css::uno;

    using namespace css::beans;

    using namespace css::sdbc;

    using namespace css::lang;

    constexpr OUString ACTIVE_CONNECTION_PROPERTY_NAME = u"ActiveConnection"_ustr;

    OAutoConnectionDisposer::OAutoConnectionDisposer(const Reference< XRowSet >& _rxRowSet, const Reference< XConnection >& _rxConnection)

        :m_xRowSet( _rxRowSet )

        ,m_bRSListening( false )

        ,m_bPropertyListening( false )

    {

        Reference< XPropertySet > xProps(_rxRowSet, UNO_QUERY);

        OSL_ENSURE(xProps.is(), "OAutoConnectionDisposer::OAutoConnectionDisposer: invalid rowset (no XPropertySet)!");

        if (!xProps.is())

            return;

        try

        {

            xProps->setPropertyValue( ACTIVE_CONNECTION_PROPERTY_NAME, Any( _rxConnection ) );

            m_xOriginalConnection = _rxConnection;

            startPropertyListening( xProps );

        }

        catch( const Exception& )

        {

            TOOLS_WARN_EXCEPTION( "connectivity.commontools", "OAutoConnectionDisposer::OAutoConnectionDisposer" );

        }

    }

    void OAutoConnectionDisposer::startPropertyListening( const Reference< XPropertySet >& _rxRowSet )

    {

        try

        {

            _rxRowSet->addPropertyChangeListener( ACTIVE_CONNECTION_PROPERTY_NAME, this );

            m_bPropertyListening = true;

        }

        catch( const Exception& )

        {

            TOOLS_WARN_EXCEPTION( "connectivity.commontools", "OAutoConnectionDisposer::startPropertyListening" );

        }

    }

    void OAutoConnectionDisposer::stopPropertyListening( const Reference< XPropertySet >& _rxEventSource )

    {

        // prevent deletion of ourself while we're herein

        Reference< XInterface > xKeepAlive(getXWeak());

        try

        {   // remove ourself as property change listener

            OSL_ENSURE( _rxEventSource.is(), "OAutoConnectionDisposer::stopPropertyListening: invalid event source (no XPropertySet)!" );

            if ( _rxEventSource.is() )

            {

                _rxEventSource->removePropertyChangeListener( ACTIVE_CONNECTION_PROPERTY_NAME, this );

                m_bPropertyListening = false;

            }

        }

        catch( const Exception& )

        {

            TOOLS_WARN_EXCEPTION( "connectivity.commontools", "OAutoConnectionDisposer::stopPropertyListening" );

        }

    }

    void OAutoConnectionDisposer::startRowSetListening()

    {

        OSL_ENSURE( !m_bRSListening, "OAutoConnectionDisposer::startRowSetListening: already listening!" );

        try

        {

            if ( !m_bRSListening )

                m_xRowSet->addRowSetListener( this );

        }

        catch( const Exception& )

        {

            TOOLS_WARN_EXCEPTION( "connectivity.commontools", "OAutoConnectionDisposer::startRowSetListening" );

        }

        m_bRSListening = true;

    }

    void OAutoConnectionDisposer::stopRowSetListening()

    {

        OSL_ENSURE( m_bRSListening, "OAutoConnectionDisposer::stopRowSetListening: not listening!" );

        try

        {

            m_xRowSet->removeRowSetListener( this );

        }

        catch( const Exception& )

        {

            TOOLS_WARN_EXCEPTION( "connectivity.commontools", "OAutoConnectionDisposer::stopRowSetListening" );

        }

        m_bRSListening = false;

    }

    void SAL_CALL OAutoConnectionDisposer::propertyChange( const PropertyChangeEvent& _rEvent )

    {

        if ( _rEvent.PropertyName != ACTIVE_CONNECTION_PROPERTY_NAME )

            return;

// somebody set a new ActiveConnection

        Reference< XConnection > xNewConnection;

        _rEvent.NewValue >>= xNewConnection;

        if ( isRowSetListening() )

        {

            // we're listening at the row set, this means that the row set does not have our

            // m_xOriginalConnection as active connection anymore

            // So there are two possibilities

            // a. somebody sets a new connection which is not our original one

            // b. somebody sets a new connection, which is exactly the original one

            // a. we're not interested in a, but in b: In this case, we simply need to move to the state

            // we had originally: listen for property changes, do not listen for row set changes, and

            // do not dispose the connection until the row set does not need it anymore

            if ( xNewConnection.get() == m_xOriginalConnection.get() )

            {

                stopRowSetListening();

            }

        }

        else

        {

            // start listening at the row set. We're allowed to dispose the old connection as soon

            // as the RowSet changed

            // Unfortunately, the our database form implementations sometimes fire the change of their

            // ActiveConnection twice. This is an error in forms/source/component/DatabaseForm.cxx, but

            // changing this would require incompatible changes we can't do for a while.

            // So for the moment, we have to live with it here.

            //

            // The only scenario where this doubled notification causes problems is when the connection

            // of the form is reset to the one we're responsible for (m_xOriginalConnection), so we

            // check this here.

            //

            // Yes, this is a HACK :(

            if ( xNewConnection.get() != m_xOriginalConnection.get() )

            {

#if OSL_DEBUG_LEVEL > 0

                Reference< XConnection > xOldConnection;

                _rEvent.OldValue >>= xOldConnection;

                OSL_ENSURE( xOldConnection.get() == m_xOriginalConnection.get(), "OAutoConnectionDisposer::propertyChange: unexpected (original) property value!" );

#endif

                startRowSetListening();

            }

        }

    }

    void SAL_CALL OAutoConnectionDisposer::disposing( const EventObject& _rSource )

    {

        // the rowset is being disposed, and nobody has set a new ActiveConnection in the meantime

        if ( isRowSetListening() )

            stopRowSetListening();

        clearConnection();

        if ( m_bPropertyListening )

            stopPropertyListening( Reference< XPropertySet >( _rSource.Source, UNO_QUERY ) );

    }

    void OAutoConnectionDisposer::clearConnection()

    {

        try

        {

            // dispose the old connection

            Reference< XComponent > xComp(m_xOriginalConnection, UNO_QUERY);

            if (xComp.is())

                xComp->dispose();

            m_xOriginalConnection.clear();

        }

        catch(Exception&)

        {

            TOOLS_WARN_EXCEPTION("connectivity.commontools", "OAutoConnectionDisposer::clearConnection");

        }

    }

    void SAL_CALL OAutoConnectionDisposer::cursorMoved( const css::lang::EventObject& /*event*/ )

    {

    }

    void SAL_CALL OAutoConnectionDisposer::rowChanged( const css::lang::EventObject& /*event*/ )

    {

    }

    void SAL_CALL OAutoConnectionDisposer::rowSetChanged( const css::lang::EventObject& /*event*/ )

    {

        stopRowSetListening();

        clearConnection();

    }

}   // namespace dbtools

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