/**********************************************************************
** Copyright (C) 2000-2002 Trolltech AS.  All rights reserved.
**
** This file is part of the Qtopia Environment.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/

#include <qdir.h>
#include <qfile.h>
#include <qmessagebox.h>
#include <qtextstream.h>


#include <qpe/qpeapplication.h>
#include "global.h"
#include "resource.h"

#include <qpe/qcopenvelope_qws.h>
#include "alarmserver.h"
#include <qpe/timeconversion.h>

#include <sys/types.h>
#include <sys/stat.h>

#include <stdlib.h>
#include <unistd.h>

struct timerEventItem {
    time_t UTCtime;
    QCString channel, message;
    int data;
    bool operator==( const timerEventItem &right ) const
    {
        return ( UTCtime == right.UTCtime
                 && channel == right.channel
                 && message == right.message
                 && data == right.data );
    }
};

class TimerReceiverObject : public QObject
{
public:
  TimerReceiverObject() { }
  ~TimerReceiverObject() { }
  void resetTimer();
  void setTimerEventItem();
  void deleteTimer();
protected:
  void timerEvent( QTimerEvent *te );
private:
    QString atfilename;
};

TimerReceiverObject *timerEventReceiver = NULL;
QList<timerEventItem> timerEventList;
timerEventItem *nearestTimerEvent = NULL;


// set the timer to go off on the next event in the list
void setNearestTimerEvent()
{
    nearestTimerEvent = NULL;
    QListIterator<timerEventItem> it( timerEventList );
    if ( *it )
	nearestTimerEvent = *it;
    for ( ; *it; ++it )
	if ( (*it)->UTCtime < nearestTimerEvent->UTCtime )
	    nearestTimerEvent = *it;
    if (nearestTimerEvent)
	timerEventReceiver->resetTimer();
    else
	timerEventReceiver->deleteTimer();
}


//store current state to file
//Simple implementation. Should run on a timer.

static void saveState()
{
    QString savefilename = Global::applicationFileName( "AlarmServer", "saveFile" );
    if ( timerEventList.isEmpty() ) {
	unlink( savefilename );
	return;
    }

    QFile savefile(savefilename+".new");
    if ( savefile.open(IO_WriteOnly) ) {
	QDataStream ds( &savefile );

	//save

	QListIterator<timerEventItem> it( timerEventList );
	for ( ; *it; ++it ) {
	    ds << it.current()->UTCtime;
	    ds << it.current()->channel;
	    ds << it.current()->message;
	    ds << it.current()->data;
	}


	savefile.close();
	unlink( savefilename );
	QDir d; d.rename(savefilename+".new",savefilename);

    }
}

/*!
  Sets up the alarm server. Restoring to previous state (session management).
 */
void AlarmServer::initialize()
{
    //read autosave file and put events in timerEventList

    QString savefilename = Global::applicationFileName( "AlarmServer", "saveFile" );

    QFile savefile(savefilename);
    if ( savefile.open(IO_ReadOnly) ) {
	QDataStream ds( &savefile );
	while ( !ds.atEnd() ) {
	    timerEventItem *newTimerEventItem = new timerEventItem;
	    ds >> newTimerEventItem->UTCtime;
	    ds >> newTimerEventItem->channel;
	    ds >> newTimerEventItem->message;
	    ds >> newTimerEventItem->data;
	    timerEventList.append( newTimerEventItem );
	}
	savefile.close();
	if (!timerEventReceiver)
	    timerEventReceiver = new TimerReceiverObject;
	setNearestTimerEvent();
    }
}




static const char* atdir = "/var/spool/at/";

static bool triggerAtd( bool writeHWClock = FALSE )
{
    QFile trigger(QString(atdir) + "trigger");
    if ( trigger.open(IO_WriteOnly|IO_Raw) ) {
	if ( trigger.writeBlock("\n",2) != 2 ) {
	    QMessageBox::critical( 0, QObject::tr( "Out of Space" ),
				   QObject::tr( "Unable to schedule alarm.\nFree some memory and try again." ) );
	    trigger.close();
	    QFile::remove( trigger.name() );
	    return FALSE;
	}
	return TRUE;
    }
    return FALSE;
}

void TimerReceiverObject::deleteTimer()
{
    if ( !atfilename.isEmpty() ) {
	unlink( atfilename );
	atfilename = QString::null;
	triggerAtd( FALSE );
    }
}

void TimerReceiverObject::resetTimer()
{
    const int maxsecs = 2147000;
    int total_written;
    QDateTime nearest = TimeConversion::fromUTC(nearestTimerEvent->UTCtime);
    QDateTime now = QDateTime::currentDateTime();
    if ( nearest < now )
	nearest = now;
    int secs = TimeConversion::secsTo( now, nearest );
    if ( secs > maxsecs ) {
	// too far for millisecond timing
	secs = maxsecs;
    }

    // System timer (needed so that we wake from deep sleep),
    // from the Epoch in seconds.
    //
    int at_secs = TimeConversion::toUTC(nearest);
    // qDebug("reset timer to %d seconds from Epoch",at_secs);
    QString fn = atdir + QString::number(at_secs) + "."
		 + QString::number(getpid());
    if ( fn != atfilename ) {
	QFile atfile(fn+".new");
	if ( atfile.open(IO_WriteOnly|IO_Raw) ) {
	    // just wake up and delete the at file
	    QString cmd = "#!/bin/sh\nrm " + fn;
	    total_written = atfile.writeBlock(cmd.latin1(),cmd.length());
	    if ( total_written != int(cmd.length()) ) {
		QMessageBox::critical( 0, tr("Out of Space"),
				       tr("Unable to schedule alarm.\n"
					  "Please free up space and try again") );
		atfile.close();
		QFile::remove( atfile.name() );
		return;
	    }
	    atfile.close();
	    unlink( atfilename );
	    QDir d; d.rename(fn+".new",fn);
	    chmod(fn.latin1(),0755);
	    atfilename = fn;
	    triggerAtd( FALSE );
	} else {
	    qWarning("Cannot open atd file %s",fn.latin1());
	}
    }
    // Qt timers (does the actual alarm)
    // from now in milliseconds
    //
    qDebug("AlarmServer waiting %d seconds",secs);
    startTimer( 1000 * secs + 500 );
}

void TimerReceiverObject::timerEvent( QTimerEvent * )
{
    bool needSave = FALSE;
    killTimers();
    if (nearestTimerEvent) {
        if ( nearestTimerEvent->UTCtime
	     <= TimeConversion::toUTC(QDateTime::currentDateTime()) ) {
#ifndef QT_NO_COP
	    QCopEnvelope e( nearestTimerEvent->channel,
			    nearestTimerEvent->message );
	    e << TimeConversion::fromUTC( nearestTimerEvent->UTCtime )
	      << nearestTimerEvent->data;
#endif
	    timerEventList.remove( nearestTimerEvent );
	    needSave = TRUE;
	}
        setNearestTimerEvent();
    } else {
        resetTimer();
    }
    if ( needSave )
	saveState();
}

/*!
  \class AlarmServer alarmserver.h
  \brief The AlarmServer class allows alarms to be scheduled and unscheduled.

    Applications can schedule alarms with addAlarm() and can
    unschedule alarms with deleteAlarm(). When the time for an alarm
    to go off is reached the specified \link qcop.html QCop\endlink
    message is sent on the specified channel (optionally with
    additional data).

    Scheduling an alarm using this class is important (rather just using
    a QTimer) since the machine may be asleep and needs to get woken up using
    the Linux kernel which implements this at the kernel level to minimize
    battery usage while asleep.

    \ingroup qtopiaemb
    \sa QCopEnvelope
*/

/*!
  Schedules an alarm to go off at (or soon after) time \a when. When
  the alarm goes off, the \link qcop.html QCop\endlink \a message will
  be sent to \a channel, with \a data as a parameter.

  If this function is called with exactly the same data as a previous
  call the subsequent call is ignored, so there is only ever one alarm
  with a given set of parameters.

  \sa deleteAlarm()
*/
void AlarmServer::addAlarm ( QDateTime when, const QCString& channel,
			     const QCString& message, int data)
{
    if ( qApp->type() == QApplication::GuiServer ) {
	bool needSave = FALSE;
	// Here we are the server so either it has been directly called from
	// within the server or it has been sent to us from a client via QCop
	if (!timerEventReceiver)
	    timerEventReceiver = new TimerReceiverObject;

	timerEventItem *newTimerEventItem = new timerEventItem;
	newTimerEventItem->UTCtime = TimeConversion::toUTC( when );
	newTimerEventItem->channel = channel;
	newTimerEventItem->message = message;
	newTimerEventItem->data = data;
	// explore the case of already having the event in here...
	QListIterator<timerEventItem> it( timerEventList );
	for ( ; *it; ++it )
	    if ( *(*it) == *newTimerEventItem )
		return;
	// if we made it here, it is okay to add the item...
	timerEventList.append( newTimerEventItem );
	needSave = TRUE;
	// quicker than using setNearestTimerEvent()
	if ( nearestTimerEvent ) {
	    if (newTimerEventItem->UTCtime < nearestTimerEvent->UTCtime) {
	        nearestTimerEvent = newTimerEventItem;
	        timerEventReceiver->killTimers();
	        timerEventReceiver->resetTimer();
	    }
	} else {
	    nearestTimerEvent = newTimerEventItem;
	    timerEventReceiver->resetTimer();
	}
	if ( needSave )
	    saveState();
    } else {
#ifndef QT_NO_COP
        QCopEnvelope e( "QPE/System", "addAlarm(QDateTime,QCString,QCString,int)" );
        e << when << channel << message << data;
#endif
    }
}

/*!
  Deletes previously scheduled alarms which match \a when, \a channel,
  \a message, and \a data.

  Passing null values for \a when, \a channel, or for the \link
  qcop.html QCop\endlink \a message, acts as a wildcard meaning "any".
  Similarly, passing -1 for \a data indicates "any".

  If there is no matching alarm, nothing happens.

  \sa addAlarm()

*/
void AlarmServer::deleteAlarm (QDateTime when, const QCString& channel, const QCString& message, int data)
{
    if ( qApp->type() == QApplication::GuiServer) {
	bool needSave = FALSE;
	if ( timerEventReceiver != NULL ) {
	    timerEventReceiver->killTimers();

	    // iterate over the list of events
	    QListIterator<timerEventItem> it( timerEventList );
	    time_t deleteTime = TimeConversion::toUTC( when );
	    for ( ; *it; ++it ) {
		// if its a match, delete it
		if ( ( (*it)->UTCtime == deleteTime || when.isNull() )
		    && ( channel.isNull() || (*it)->channel == channel )
		    && ( message.isNull() || (*it)->message == message )
		    && ( data==-1 || (*it)->data == data ) )
		{
		    // if it's first, then we need to update the timer
		    if ( (*it) == nearestTimerEvent ) {
			timerEventList.remove(*it);
			setNearestTimerEvent();
		    } else {
			timerEventList.remove(*it);
		    }
		    needSave = TRUE;
		}
	    }
	    if ( nearestTimerEvent )
		timerEventReceiver->resetTimer();
	}
	if ( needSave )
	    saveState();
    } else {
#ifndef QT_NO_COP
        QCopEnvelope e( "QPE/System", "deleteAlarm(QDateTime,QCString,QCString,int)" );
        e << when << channel << message << data;
#endif
    }
}

/*!
  Writes the system clock to the hardware clock.
*/
void Global::writeHWClock()
{
    if ( !triggerAtd( TRUE ) ) {
	// atd not running? set it ourselves
	system("/sbin/hwclock --systohc"); // ##### UTC?
    }
}