/* This file is part of the KDE project
   Copyright (C) 2002 Lubos Lunak <l.lunak@kde.org>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#include "preloader.h"
#include "konq_settingsxt.h"

#include <tdeconfig.h>
#include <dcopref.h>
#include <tdeapplication.h>
#include <dcopclient.h>
#include <kdebug.h>

KonqyPreloader::KonqyPreloader( const TQCString& obj )
    : KDEDModule( obj )
    {
    reconfigure();
    connect( kapp->dcopClient(), TQ_SIGNAL( applicationRemoved( const TQCString& )),
        TQ_SLOT( appRemoved( const TQCString& )));
    connect( &check_always_preloaded_timer, TQ_SIGNAL( timeout()),
	TQ_SLOT( checkAlwaysPreloaded()));
    }

KonqyPreloader::~KonqyPreloader()
    {
    updateCount();
    }

bool KonqyPreloader::registerPreloadedKonqy( TQCString id, int screen )
    {
    if( instances.count() >= (uint)KonqSettings::maxPreloadCount() )
        return false;
    instances.append( KonqyData( id, screen ));
    return true;
    }

TQCString KonqyPreloader::getPreloadedKonqy( int screen )
    {
    if( instances.count() == 0 )
        return "";
    for( InstancesList::Iterator it = instances.begin();
         it != instances.end();
         ++it )
        {
        if( (*it).screen == screen )
            {
            TQCString ret = (*it).id;
            instances.remove( it );
            check_always_preloaded_timer.start( 5000, true );
            return ret;
            }
        }
    return "";
    }

void KonqyPreloader::unregisterPreloadedKonqy( TQCString id_P )
    {
    for( InstancesList::Iterator it = instances.begin();
         it != instances.end();
         ++it )
        if( (*it).id == id_P )
            {
            instances.remove( it );
            return;
            }
    }

void KonqyPreloader::appRemoved( const TQCString& id )
    {
    unregisterPreloadedKonqy( id );
    }
    
void KonqyPreloader::reconfigure()
    {
    KonqSettings::self()->readConfig();
    updateCount();
    // Ignore "PreloadOnStartup" here, it's used by the .desktop file
    // in the autostart folder, which will do 'konqueror --preload' in autostart
    // phase 2. This will also cause activation of this kded module.
    }

void KonqyPreloader::updateCount()
    {
    while( instances.count() > (uint)KonqSettings::maxPreloadCount() )
        {
        KonqyData konqy = instances.first();
        instances.pop_front();
        DCOPRef ref( konqy.id, "KonquerorIface" );
        ref.send( "terminatePreloaded" );
        }
    if( KonqSettings::alwaysHavePreloaded() &&
        KonqSettings::maxPreloadCount() > 0 &&
        instances.count() == 0 )
	{
	if( !check_always_preloaded_timer.isActive())
	    {
	    if( kapp->tdeinitExec( TQString::fromLatin1( "konqueror" ),
		TQStringList() << TQString::fromLatin1( "--preload" ), NULL, NULL, "0" ) == 0 )
		{
		kdDebug( 1202 ) << "Preloading Konqueror instance" << endl;
	        check_always_preloaded_timer.start( 5000, true );
		}
	    // else do nothing, the launching failed
	    }
	}
    }

// have 5s interval between attempts to preload a new konqy
// in order not to start many of them at the same time
void KonqyPreloader::checkAlwaysPreloaded()
    {
    // TODO here should be detection whether the system is too busy,
    // and delaying preloading another konqy in such case
    // but I have no idea how to do it
    updateCount();
    }
    
void KonqyPreloader::unloadAllPreloaded()
    {
    while( instances.count() > 0 )
        {
        KonqyData konqy = instances.first();
        instances.pop_front();
        DCOPRef ref( konqy.id, "KonquerorIface" );
        ref.send( "terminatePreloaded" );
        }
    // ignore 'always_have_preloaded' here
    }
    
extern "C"
TDE_EXPORT KDEDModule *create_konqy_preloader( const TQCString& obj )
    {
    return new KonqyPreloader( obj );
    }

#include "preloader.moc"
