/*
    This file is part of libkcal.

    Copyright (c) 1998 Preston Brown <pbrown@kde.org>
    Copyright (c) 2001,2003,2004 Cornelius Schumacher <schumacher@kde.org>
    Copyright (C) 2003-2004 Reinhold Kainhofer <reinhold@kainhofer.com>

    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 <tqdatetime.h>
#include <tqstring.h>
#include <tqptrlist.h>

#include <kdebug.h>
#include <klocale.h>
#include <kmessagebox.h>

#include "vcaldrag.h"
#include "vcalformat.h"
#include "icalformat.h"
#include "exceptions.h"
#include "incidence.h"
#include "journal.h"
#include "filestorage.h"

#include "calendarlocal.h"

using namespace KCal;

CalendarLocal::CalendarLocal( const TQString &timeZoneId )
  : Calendar( timeZoneId ), mEvents( 47 )
{
  init();
}

void CalendarLocal::init()
{
  mDeletedIncidences.setAutoDelete( true );
  mFileName = TQString::null;
}


CalendarLocal::~CalendarLocal()
{
  close();
}

bool CalendarLocal::load( const TQString &fileName, CalFormat *format )
{
  mFileName = fileName;
  FileStorage storage( this, fileName, format );
  return storage.load();
}

bool CalendarLocal::reload( const TQString &tz )
{
  const TQString filename = mFileName;
  save();
  close();
  mFileName = filename;
  setTimeZoneId( tz );
  FileStorage storage( this, mFileName );
  return storage.load();
}

bool CalendarLocal::save( const TQString &fileName, CalFormat *format )
{
  // Save only if the calendar is either modified, or saved to a
  // different file than it was loaded from
  if ( mFileName != fileName || isModified() ) {
    FileStorage storage( this, fileName, format );
    return storage.save();
  } else {
    return true;
  }
}

void CalendarLocal::close()
{
  setObserversEnabled( false );
  mFileName = TQString::null;

  deleteAllEvents();
  deleteAllTodos();
  deleteAllJournals();

  mDeletedIncidences.clear();
  setModified( false );

  setObserversEnabled( true );
}


bool CalendarLocal::addEvent( Event *event )
{
  insertEvent( event );

  event->registerObserver( this );

  setModified( true );

  notifyIncidenceAdded( event );

  return true;
}

bool CalendarLocal::deleteEvent( Event *event )
{
//  kdDebug(5800) << "CalendarLocal::deleteEvent" << endl;

  if ( mEvents.remove( event->uid() ) ) {
    setModified( true );
    notifyIncidenceDeleted( event );
    mDeletedIncidences.append( event );
    return true;
  } else {
    kdWarning() << "CalendarLocal::deleteEvent(): Event not found." << endl;
    return false;
  }
}

void CalendarLocal::deleteAllEvents()
{
  // kdDebug(5800) << "CalendarLocal::deleteAllEvents" << endl;
  TQDictIterator<Event> it( mEvents );
  while( it.current() ) {
    notifyIncidenceDeleted( it.current() );
    ++it;
  }

  mEvents.setAutoDelete( true );
  mEvents.clear();
  mEvents.setAutoDelete( false );
}

Event *CalendarLocal::event( const TQString &uid )
{
//  kdDebug(5800) << "CalendarLocal::event(): " << uid << endl;
  return mEvents[ uid ];
}

bool CalendarLocal::addTodo( Todo *todo )
{
  mTodoList.append( todo );

  todo->registerObserver( this );

  // Set up subtask relations
  setupRelations( todo );

  setModified( true );

  notifyIncidenceAdded( todo );

  return true;
}

bool CalendarLocal::deleteTodo( Todo *todo )
{
  // Handle orphaned children
  removeRelations( todo );

  if ( mTodoList.removeRef( todo ) ) {
    setModified( true );
    notifyIncidenceDeleted( todo );
    mDeletedIncidences.append( todo );
    return true;
  } else {
    kdWarning() << "CalendarLocal::deleteTodo(): Todo not found." << endl;
    return false;
  }
}

void CalendarLocal::deleteAllTodos()
{
  // kdDebug(5800) << "CalendarLocal::deleteAllTodos()\n";
  Todo::List::ConstIterator it;
  for( it = mTodoList.begin(); it != mTodoList.end(); ++it ) {
    notifyIncidenceDeleted( *it );
  }

  mTodoList.setAutoDelete( true );
  mTodoList.clearAll();
  mTodoList.setAutoDelete( false );
}

Todo::List CalendarLocal::rawTodos( TodoSortField sortField,
                                    SortDirection sortDirection )
{
  return sortTodos( &mTodoList, sortField, sortDirection );
}

Todo *CalendarLocal::todo( const TQString &uid )
{
  Todo::List::ConstIterator it;
  for ( it = mTodoList.begin(); it != mTodoList.end(); ++it ) {
    if ( (*it)->uid() == uid ) return *it;
  }

  return 0;
}

Todo::List CalendarLocal::rawTodosForDate( const TQDate &date )
{
  Todo::List todos;

  Todo::List::ConstIterator it;
  for ( it = mTodoList.begin(); it != mTodoList.end(); ++it ) {
    Todo *todo = *it;
    if ( todo->hasDueDate() && todo->dtDue().date() == date ) {
      todos.append( todo );
    }
  }

  return todos;
}

Alarm::List CalendarLocal::alarmsTo( const TQDateTime &to )
{
  return alarms( TQDateTime( TQDate( 1900, 1, 1 ) ), to );
}

Alarm::List CalendarLocal::alarms( const TQDateTime &from, const TQDateTime &to )
{
//  kdDebug(5800) << "CalendarLocal::alarms(" << from.toString() << " - "
//                << to.toString() << ")" << endl;

  Alarm::List alarms;

  EventDictIterator it( mEvents );
  for( ; it.current(); ++it ) {
    Event *e = *it;
    if ( e->doesRecur() ) appendRecurringAlarms( alarms, e, from, to );
    else appendAlarms( alarms, e, from, to );
  }

  Todo::List::ConstIterator it2;
  for( it2 = mTodoList.begin(); it2 != mTodoList.end(); ++it2 ) {
    if (! (*it2)->isCompleted() ) appendAlarms( alarms, *it2, from, to );
  }

  return alarms;
}

void CalendarLocal::appendAlarms( Alarm::List &alarms, Incidence *incidence,
                                  const TQDateTime &from, const TQDateTime &to )
{
  TQDateTime preTime = from.addSecs(-1);
  Alarm::List::ConstIterator it;
  for( it = incidence->alarms().begin(); it != incidence->alarms().end();
       ++it ) {
    if ( (*it)->enabled() ) {
      TQDateTime dt = (*it)->nextRepetition(preTime);
      if ( dt.isValid() && dt <= to ) {
        kdDebug(5800) << "CalendarLocal::appendAlarms() '"
                      << incidence->summary() << "': "
                      << dt.toString() << endl;
        alarms.append( *it );
      }
    }
  }
}

void CalendarLocal::appendRecurringAlarms( Alarm::List &alarms,
                                           Incidence *incidence,
                                           const TQDateTime &from,
                                           const TQDateTime &to )
{
  TQDateTime qdt;
  int  endOffset = 0;
  bool endOffsetValid = false;
  int  period = from.secsTo(to);
  Alarm::List::ConstIterator it;
  for( it = incidence->alarms().begin(); it != incidence->alarms().end();
       ++it ) {
    Alarm *alarm = *it;
    if ( alarm->enabled() ) {
      if ( alarm->hasTime() ) {
        // The alarm time is defined as an absolute date/time
        qdt = alarm->nextRepetition( from.addSecs(-1) );
        if ( !qdt.isValid() || qdt > to )
          continue;
      } else {
        // The alarm time is defined by an offset from the event start or end time.
        // Find the offset from the event start time, which is also used as the
        // offset from the recurrence time.
        int offset = 0;
        if ( alarm->hasStartOffset() ) {
          offset = alarm->startOffset().asSeconds();
        } else if ( alarm->hasEndOffset() ) {
          if ( !endOffsetValid ) {
            endOffset = incidence->dtStart().secsTo( incidence->dtEnd() );
            endOffsetValid = true;
          }
          offset = alarm->endOffset().asSeconds() + endOffset;
        }

        // Adjust the 'from' date/time and find the next recurrence at or after it
        qdt = incidence->recurrence()->getNextDateTime( from.addSecs(-offset - 1) );
        if ( !qdt.isValid()
        ||   (qdt = qdt.addSecs( offset )) > to )    // remove the adjustment to get the alarm time
        {
          // The next recurrence is too late.
          if ( !alarm->repeatCount() )
            continue;
          // The alarm has repetitions, so check whether repetitions of previous
          // recurrences fall within the time period.
          bool found = false;
          qdt = from.addSecs( -offset );
          while ( (qdt = incidence->recurrence()->getPreviousDateTime( qdt )).isValid() ) {
            int toFrom = qdt.secsTo( from ) - offset;
            if ( toFrom > alarm->duration() )
              break;     // this recurrence's last repetition is too early, so give up
            // The last repetition of this recurrence is at or after 'from' time.
            // Check if a repetition occurs between 'from' and 'to'.
            int snooze = alarm->snoozeTime() * 60;   // in seconds
            if ( period >= snooze
            ||   toFrom % snooze == 0
            ||   (toFrom / snooze + 1) * snooze <= toFrom + period ) {
              found = true;
#ifndef NDEBUG
              qdt = qdt.addSecs( offset + ((toFrom-1) / snooze + 1) * snooze );   // for debug output
#endif
              break;
            }
          }
          if ( !found )
            continue;
        }
      }
      kdDebug(5800) << "CalendarLocal::appendAlarms() '" << incidence->summary()
                    << "': " << qdt.toString() << endl;
      alarms.append( alarm );
    }
  }
}


void CalendarLocal::incidenceUpdated( IncidenceBase *incidence )
{
  incidence->setSyncStatusSilent( Event::SYNCMOD );
  incidence->setLastModified( TQDateTime::currentDateTime() );
  // we should probably update the revision number here,
  // or internally in the Event itself when certain things change.
  // need to verify with ical documentation.

  // The static_cast is ok as the CalendarLocal only observes Incidence objects
  notifyIncidenceChanged( static_cast<Incidence *>( incidence ) );

  setModified( true );
}

void CalendarLocal::insertEvent( Event *event )
{
  TQString uid = event->uid();
  if ( mEvents[ uid ] == 0 ) {
    mEvents.insert( uid, event );
  }
#ifndef NDEBUG
  else // if we already have an event with this UID, it has to be the same event,
      // otherwise something's really broken
      Q_ASSERT( mEvents[uid] == event );
#endif
}

Event::List CalendarLocal::rawEventsForDate( const TQDate &qd,
                                             EventSortField sortField,
                                             SortDirection sortDirection )
{
  Event::List eventList;

  EventDictIterator it( mEvents );
  for( ; it.current(); ++it ) {
    Event *event = *it;

    if ( event->doesRecur() ) {
      if ( event->isMultiDay() ) {
        int extraDays = event->dtStart().date().daysTo( event->dtEnd().date() );
        int i;
        for ( i = 0; i <= extraDays; i++ ) {
          if ( event->recursOn( qd.addDays( -i ) ) ) {
            eventList.append( event );
            break;
          }
        }
      } else {
        if ( event->recursOn( qd ) )
          eventList.append( event );
      }
    } else {
      if ( event->dtStart().date() <= qd && event->dateEnd() >= qd ) {
        eventList.append( event );
      }
    }
  }

  return sortEvents( &eventList, sortField, sortDirection );
}

Event::List CalendarLocal::rawEvents( const TQDate &start, const TQDate &end,
                                          bool inclusive )
{
  Event::List eventList;
  TQDate yesterStart = start.addDays(-1);

  // Get non-recurring events
  EventDictIterator it( mEvents );
  for( ; it.current(); ++it ) {
    Event *event = *it;

    TQDate rStart = event->dtStart().date();
    if (end < rStart) {
//      kdDebug(5800) << "Skipping event starting after TOI" << endl;
      continue;
    }
    if ( inclusive && rStart < start) {
//      kdDebug(5800) << "Skipping event starting before TOI while inclusive" << endl;
      continue;
    }

    if ( ! event->doesRecur() ) { // non-recurring events
      TQDate rEnd = event->dtEnd().date();
      if (rEnd < start) {
//        kdDebug(5800) << "Skipping event ending before TOI" << endl;
        continue;
      }
      if ( inclusive && end < rEnd ) {
//        kdDebug(5800) << "Skipping event ending after TOI while inclusive" << endl;
        continue;
      }
    } else { // recurring events
      switch ( event->recurrence()->duration() ) {
        case -1: // infinite
          if ( inclusive ) {
//            kdDebug(5800) << "Skipping infinite event because inclusive" << endl;
            continue;
          }
          break;
        case 0: // end date given
        default: // count given
          TQDate rEnd = event->recurrence()->endDate();
          if ( ! rEnd.isValid() ) {
//            kdDebug(5800) << "Skipping recurring event without occurences" << endl;
            continue;
          }
          if ( rEnd < start ) {
//            kdDebug(5800) << "Skipping recurring event ending before TOI" << endl;
            continue;
          }
          if ( inclusive && end < rEnd ) {
//            kdDebug(5800) << "Skipping recurring event ending after TOI while inclusive" << endl;
            continue;
          }
          /* FIXME: too much conversion between TQDate and TQDateTime makes this useless:
           *   freebusy(end=TQDateTime(day, "00:00:00")) ->
           *   rawEvents(end=TQDate(day)) ->
           *   durationTo(TQDateTime(day, "23:59:59"))
           * so events repeating at the end day match and are included.
           */
#if 0
          int durationBeforeStart = event->recurrence()->durationTo(yesterStart);
          int durationUntilEnd = event->recurrence()->durationTo(end);
          if (durationBeforeStart == durationUntilEnd) {
            kdDebug(5800) << "Skipping recurring event without occurences in TOI" << endl;
            continue;
          }
#endif
          break;
      } // switch(duration)
    } // if(doesRecur)

    eventList.append( event );
  }

  return eventList;
}

Event::List CalendarLocal::rawEventsForDate( const TQDateTime &qdt )
{
  return rawEventsForDate( qdt.date() );
}

Event::List CalendarLocal::rawEvents( EventSortField sortField, SortDirection sortDirection )
{
  Event::List eventList;
  EventDictIterator it( mEvents );
  for( ; it.current(); ++it )
    eventList.append( *it );
  return sortEvents( &eventList, sortField, sortDirection );
}

bool CalendarLocal::addJournal(Journal *journal)
{
//   if (journal->dtStart().isValid())
//     kdDebug(5800) << "Adding Journal on " << journal->dtStart().toString() << endl;
//   else
//     kdDebug(5800) << "Adding Journal without a DTSTART" << endl;

  mJournalList.append(journal);

  journal->registerObserver( this );

  setModified( true );

  notifyIncidenceAdded( journal );

  return true;
}

bool CalendarLocal::deleteJournal( Journal *journal )
{
  if ( mJournalList.removeRef( journal ) ) {
    setModified( true );
    notifyIncidenceDeleted( journal );
    mDeletedIncidences.append( journal );
    return true;
  } else {
    kdWarning() << "CalendarLocal::deleteJournal(): Journal not found." << endl;
    return false;
  }
}

void CalendarLocal::deleteAllJournals()
{
  Journal::List::ConstIterator it;
  for( it = mJournalList.begin(); it != mJournalList.end(); ++it ) {
    notifyIncidenceDeleted( *it );
  }

  mJournalList.setAutoDelete( true );
  mJournalList.clearAll();
  mJournalList.setAutoDelete( false );
}

Journal *CalendarLocal::journal( const TQString &uid )
{
  Journal::List::ConstIterator it;
  for ( it = mJournalList.begin(); it != mJournalList.end(); ++it )
    if ( (*it)->uid() == uid )
      return *it;

  return 0;
}

Journal::List CalendarLocal::rawJournals( JournalSortField sortField, SortDirection sortDirection )
{
  return sortJournals( &mJournalList, sortField, sortDirection );
}

Journal::List CalendarLocal::rawJournalsForDate( const TQDate &date )
{
  Journal::List journals;

  Journal::List::ConstIterator it;
  for ( it = mJournalList.begin(); it != mJournalList.end(); ++it ) {
    Journal *journal = *it;
    if ( journal->dtStart().date() == date ) {
      journals.append( journal );
    }
  }

  return journals;
}

void CalendarLocal::setTimeZoneIdViewOnly( const TQString& tz )
{
  const TQString question( i18n("The timezone setting was changed. In order to display the calendar "
      "you are looking at in the new timezone, it needs to be saved. Do you want to save the pending "
      "changes or rather wait and apply the new timezone on the next reload?" ) );
  int rc = KMessageBox::Yes;
  if ( isModified() ) {
    rc = KMessageBox::questionYesNo( 0, question,
                                       i18n("Save before applying timezones?"),
                                       KStdGuiItem::save(),
                                       KGuiItem(i18n("Apply Timezone Change on Next Reload")),
                                       "calendarLocalSaveBeforeTimezoneShift");
  }
  if ( rc == KMessageBox::Yes ) {
    reload( tz );
  }
}