/*
  Copyright (c) 2010 Bertjan Broeksema <broeksema@kde.org>
  Copyright (C) 2010 Klaralvdalens Datakonsult AB, a KDAB Group company <info@kdab.net>

  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 "incidencerecurrence.h"
#include "incidencedatetime.h"
#ifdef KDEPIM_MOBILE_UI
#include "ui_eventortodomoremobile.h"
#else
#include "ui_eventortododesktop.h"
#endif

#include <KCalendarSystem>

#include <KDebug>

using namespace IncidenceEditorNG;

enum {
  // Keep in sync with mRecurrenceEndCombo
  RecurrenceEndNever = 0,
  RecurrenceEndOn,
  RecurrenceEndAfter
};

/**

Description of available recurrence types:

0 - None
1 -
2 -
3 - rDaily
4 - rWeekly
5 - rMonthlyPos  - 3rd Saturday of month, last Wednesday of month...
6 - rMonthlyDay  - 17th day of month
7 - rYearlyMonth - 10th of July
8 - rYearlyDay   - on the 117th day of the year
9 - rYearlyPos   - 1st Wednesday of July
*/

enum {
  // Indexes of the month combo, keep in sync with descriptions.
  ComboIndexMonthlyDay = 0,     // 11th of June
  ComboIndexMonthlyDayInverted, // 20th of June ( 11 to end )
  ComboIndexMonthlyPos,         // 1st Monday of the Month
  ComboIndexMonthlyPosInverted  // Last Monday of the Month
};

enum {
  // Indexes of the year combo, keep in sync with descriptions.
  ComboIndexYearlyMonth = 0,
  ComboIndexYearlyMonthInverted,
  ComboIndexYearlyPos,
  ComboIndexYearlyPosInverted,
  ComboIndexYearlyDay
};

#ifdef KDEPIM_MOBILE_UI
IncidenceRecurrence::IncidenceRecurrence( IncidenceDateTime *dateTime, Ui::EventOrTodoMore *ui )
#else
IncidenceRecurrence::IncidenceRecurrence( IncidenceDateTime *dateTime, Ui::EventOrTodoDesktop *ui )
#endif
  : mUi( ui ), mDateTime( dateTime ), mMonthlyInitialType( 0 ), mYearlyInitialType( 0 )
{
  setObjectName( "IncidenceRecurrence" );
  // Set some sane defaults
  mUi->mRecurrenceTypeCombo->setCurrentIndex( RecurrenceTypeNone );
  mUi->mRecurrenceEndCombo->setCurrentIndex( RecurrenceEndNever );
  mUi->mRecurrenceEndStack->setCurrentIndex( 0 );
  mUi->mRepeatStack->setCurrentIndex( 0 );
  mUi->mEndDurationEdit->setValue( 1 );
  handleEndAfterOccurrencesChange( 1 );
  toggleRecurrenceWidgets( false );
  fillCombos();

  connect( mDateTime, SIGNAL(endDateTimeToggled(bool)),
           SLOT(handleDateTimeToggle()) );

  connect( mDateTime, SIGNAL(startDateChanged(QDate)),
           SLOT(handleStartDateChange(QDate)) );
  connect( mDateTime, SIGNAL(endDateChanged(QDate)),
           SLOT(handleEndDateChange(QDate)) );

  connect( mUi->mExceptionAddButton, SIGNAL(clicked()),
           SLOT(addException()));
  connect( mUi->mExceptionRemoveButton, SIGNAL(clicked()),
           SLOT(removeExceptions()) );
  connect( mUi->mExceptionDateEdit, SIGNAL(dateChanged(QDate)),
           SLOT(handleExceptionDateChange(QDate)) );
  connect( mUi->mExceptionList, SIGNAL(itemSelectionChanged()),
           SLOT(updateRemoveExceptionButton()) );
  connect( mUi->mRecurrenceTypeCombo, SIGNAL(currentIndexChanged(int)),
           SLOT(handleRecurrenceTypeChange(int)));
  connect( mUi->mEndDurationEdit, SIGNAL(valueChanged(int)),
           SLOT(handleEndAfterOccurrencesChange(int)) );
  connect( mUi->mFrequencyEdit, SIGNAL(valueChanged(int)),
           SLOT(handleFrequencyChange()) );

  // Check the dirty status when the user changes values.
  connect( mUi->mRecurrenceTypeCombo, SIGNAL(currentIndexChanged(int)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mFrequencyEdit, SIGNAL(valueChanged(int)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mFrequencyEdit, SIGNAL(valueChanged(int)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mWeekDayCombo, SIGNAL(checkedItemsChanged(QStringList)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mMonthlyCombo, SIGNAL(currentIndexChanged(int)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mYearlyCombo, SIGNAL(currentIndexChanged(int)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mRecurrenceEndCombo, SIGNAL(currentIndexChanged(int)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mEndDurationEdit, SIGNAL(valueChanged(int)),
           SLOT(checkDirtyStatus()) );
  connect( mUi->mRecurrenceEndDate, SIGNAL(dateChanged(QDate)),
           SLOT(checkDirtyStatus()) );
}

// this method must be at the top of this file in order to ensure
// that its message to translators appears before any usages of this method.
KLocalizedString IncidenceRecurrence::subsOrdinal ( const KLocalizedString &text, int number ) const
{
  QString q = i18nc( "In several of the messages below, "
                     "an ordinal number is substituted into the message. "
                     "Translate this as \"0\" if English ordinal suffixes "
                     "should be added (1st, 22nd, 123rd); "
                     "translate this as \"1\" if just the number itself "
                     "should be substituted (1, 22, 123).",
                     "0" );
  if ( q == "0" ) {
    QString ordinal;
    ordinal = numberToString( number );
    return text.subs( ordinal );
  } else {
    return text.subs( number );
  }
}

void IncidenceRecurrence::load( const KCalCore::Incidence::Ptr &incidence )
{
  Q_ASSERT( incidence );

  mLoadedIncidence = incidence;
  // We must be sure that the date/time in mDateTime is the correct date time.
  // So don't depend on CombinedIncidenceEditor or whatever external factor to
  // load the date/time before loading the recurrence

  mCurrentDate = mLoadedIncidence->dateTime( KCalCore::IncidenceBase::RoleRecurrenceStart ).date();

  mDateTime->load( incidence );
  mDateTime->endDate();
  fillCombos();
  setDefaults();

  int f = 0;
  KCalCore::Recurrence *r = 0;
  if ( mLoadedIncidence->recurrenceType() != KCalCore::Recurrence::rNone ) {
    r = mLoadedIncidence->recurrence();
    f = r->frequency();
  }

  switch ( mLoadedIncidence->recurrenceType() ) {
  case KCalCore::Recurrence::rNone:
    mUi->mRecurrenceTypeCombo->setCurrentIndex( RecurrenceTypeNone );
    handleRecurrenceTypeChange( RecurrenceTypeNone );
    break;
  case KCalCore::Recurrence::rDaily:
    mUi->mRecurrenceTypeCombo->setCurrentIndex( RecurrenceTypeDaily );
    handleRecurrenceTypeChange( RecurrenceTypeDaily );
    setFrequency( f );
    break;
  case KCalCore::Recurrence::rWeekly:
  {
    mUi->mRecurrenceTypeCombo->setCurrentIndex( RecurrenceTypeWeekly );
    handleRecurrenceTypeChange( RecurrenceTypeWeekly );
    QBitArray disableDays( 7/*size*/, 0/*default value*/ );
    // dayOfWeek returns between 1 and 7
    disableDays.setBit( currentDate().dayOfWeek()-1, 1 );
    mUi->mWeekDayCombo->setDays( r->days(), disableDays );
    setFrequency( f );
    break;
  }
  case KCalCore::Recurrence::rMonthlyPos: // Fall through
  case KCalCore::Recurrence::rMonthlyDay:
  {
    mUi->mRecurrenceTypeCombo->setCurrentIndex( RecurrenceTypeMonthly );
    handleRecurrenceTypeChange( RecurrenceTypeMonthly );
    selectMonthlyItem( r, mLoadedIncidence->recurrenceType() );
    setFrequency( f );
    break;
  }
  case KCalCore::Recurrence::rYearlyMonth: // Fall through
  case KCalCore::Recurrence::rYearlyPos:   // Fall through
  case KCalCore::Recurrence::rYearlyDay:
  {
    mUi->mRecurrenceTypeCombo->setCurrentIndex( RecurrenceTypeYearly );
    handleRecurrenceTypeChange( RecurrenceTypeYearly );
    selectYearlyItem( r, mLoadedIncidence->recurrenceType() );
    setFrequency( f );
    break;
  }
  default:
    break;
  }

  if ( mLoadedIncidence->recurs() && r ) {
    setDuration( r->duration() );
    if ( r->duration() == 0 ) {
      mUi->mRecurrenceEndDate->setDate( r->endDate() );
    }
  }

  setExceptionDates( mLoadedIncidence->recurrence()->exDates() );
  handleDateTimeToggle();
  mWasDirty = false;
}

void IncidenceRecurrence::writeToIncidence( const KCalCore::Incidence::Ptr &incidence ) const
{
  // clear out any old settings;
  KCalCore::Recurrence *r = incidence->recurrence();
  r->unsetRecurs(); // Why not clear() ?

  if ( mUi->mRecurrenceTypeCombo->currentIndex() == RecurrenceTypeNone ||
       !mUi->mRecurrenceTypeCombo->isEnabled() ) {
    return;
  }

  const int lDuration = duration();
  QDate endDate;
  if ( lDuration == 0 ) {
    endDate = mUi->mRecurrenceEndDate->date();
  }

  const int recurrenceType = mUi->mRecurrenceTypeCombo->currentIndex();
  if ( recurrenceType == RecurrenceTypeDaily ) {
    r->setDaily( mUi->mFrequencyEdit->value() );
  } else if ( recurrenceType == RecurrenceTypeWeekly ) {
    r->setWeekly( mUi->mFrequencyEdit->value(), mUi->mWeekDayCombo->days() );
  } else if ( recurrenceType == RecurrenceTypeMonthly ) {
    r->setMonthly( mUi->mFrequencyEdit->value() );

    if ( mUi->mMonthlyCombo->currentIndex() == ComboIndexMonthlyDay ) {
      // Every nth
      r->addMonthlyDate( dayOfMonthFromStart() );
    } else if ( mUi->mMonthlyCombo->currentIndex() == ComboIndexMonthlyDayInverted ) {
      // Every (last - n)th last day
      r->addMonthlyDate( -dayOfMonthFromEnd() );
    } else if ( mUi->mMonthlyCombo->currentIndex() == ComboIndexMonthlyPos ) {
      // Every ith weekday
      r->addMonthlyPos( monthWeekFromStart(), weekday() );
    } else {
      // Every (last - i)th last weekday
      r->addMonthlyPos( -monthWeekFromEnd(), weekday() );
    }
  } else if ( recurrenceType == RecurrenceTypeYearly ) {
    r->setYearly( mUi->mFrequencyEdit->value() );

    if ( mUi->mYearlyCombo->currentIndex() == ComboIndexYearlyMonth ) {
      //Every nth of month
      r->addYearlyDate( dayOfMonthFromStart() );
      r->addYearlyMonth( currentDate().month() );
    } else if ( mUi->mYearlyCombo->currentIndex() == ComboIndexYearlyMonthInverted ) {
      //Every (last - n)th last day of month
      r->addYearlyDate( -dayOfMonthFromEnd() );
      r->addYearlyMonth( currentDate().month() );
    } else if ( mUi->mYearlyCombo->currentIndex() == ComboIndexYearlyPos ) {
      //Every ith weekday of month
      r->addYearlyMonth( currentDate().month() );
      r->addYearlyPos( monthWeekFromStart(), weekday() );
    } else if ( mUi->mYearlyCombo->currentIndex() == ComboIndexYearlyPosInverted ) {
      //Every (last - i)th last weekday of month
      r->addYearlyMonth( currentDate().month() );
      r->addYearlyPos( -monthWeekFromEnd(), weekday() );
    } else {
      // The lth day of the year (l : 1 - 356)
      r->addYearlyDay( dayOfYearFromStart() );
    }
  }

  r->setDuration( lDuration );
  if ( lDuration == 0 ) {
    r->setEndDate( endDate );
  }

  r->setExDates( mExceptionDates );
}

void IncidenceRecurrence::save( const KCalCore::Incidence::Ptr &incidence )
{
  writeToIncidence( incidence );
  mMonthlyInitialType = mUi->mMonthlyCombo->currentIndex();
  mYearlyInitialType = mUi->mYearlyCombo->currentIndex();
}

bool IncidenceRecurrence::isDirty() const
{
  if ( mLoadedIncidence->recurs() &&
       mUi->mRecurrenceTypeCombo->currentIndex() == RecurrenceTypeNone ) {
    return true;
  }

  if ( !mLoadedIncidence->recurs() && mUi->mRecurrenceTypeCombo->currentIndex() > 0 ) {
    return true;
  }

  // The incidence is not recurring and that hasn't changed, so don't check the
  // other values.
  if ( mUi->mRecurrenceTypeCombo->currentIndex() == RecurrenceTypeNone ) {
    return false;
  }

  const KCalCore::Recurrence *recurrence = mLoadedIncidence->recurrence();
  switch ( recurrence->recurrenceType() ) {
  case KCalCore::Recurrence::rDaily:
    if ( mUi->mRecurrenceTypeCombo->currentIndex() != RecurrenceTypeDaily ||
         mUi->mFrequencyEdit->value() != recurrence->frequency() ) {
      return true;
    }

    break;
  case KCalCore::Recurrence::rWeekly:
    if ( mUi->mRecurrenceTypeCombo->currentIndex() != RecurrenceTypeWeekly ||
         mUi->mFrequencyEdit->value() != recurrence->frequency() ||
         mUi->mWeekDayCombo->days() != recurrence->days() ) {
      return true;
    }
    break;
  case KCalCore::Recurrence::rMonthlyDay:
    if ( mUi->mRecurrenceTypeCombo->currentIndex() != RecurrenceTypeMonthly ||
         mUi->mFrequencyEdit->value() != recurrence->frequency() ||
         mUi->mMonthlyCombo->currentIndex() != mMonthlyInitialType ) {
      return true;
    }
    break;
  case KCalCore::Recurrence::rMonthlyPos:
    if ( mUi->mRecurrenceTypeCombo->currentIndex() != RecurrenceTypeMonthly ||
         mUi->mFrequencyEdit->value() != recurrence->frequency() ||
         mUi->mMonthlyCombo->currentIndex() != mMonthlyInitialType ) {
      return true;
    }
    break;
  case KCalCore::Recurrence::rYearlyDay:
    if ( mUi->mRecurrenceTypeCombo->currentIndex() != RecurrenceTypeYearly ||
         mUi->mFrequencyEdit->value() != recurrence->frequency() ||
         mUi->mYearlyCombo->currentIndex() != mYearlyInitialType ) {
      return true;
    }
    break;
  case KCalCore::Recurrence::rYearlyMonth:
    if ( mUi->mRecurrenceTypeCombo->currentIndex() != RecurrenceTypeYearly ||
         mUi->mFrequencyEdit->value() != recurrence->frequency() ||
         mUi->mYearlyCombo->currentIndex() != mYearlyInitialType ) {
      return true;
    }
    break;
  case KCalCore::Recurrence::rYearlyPos:
    if ( mUi->mRecurrenceTypeCombo->currentIndex() != RecurrenceTypeYearly ||
         mUi->mFrequencyEdit->value() != recurrence->frequency() ||
         mUi->mYearlyCombo->currentIndex() != mYearlyInitialType ) {
      return true;
    }
    break;
  }

  // Recurrence end
  // -1 means "recurs forever"
  if ( recurrence->duration() == -1 &&
       mUi->mRecurrenceEndCombo->currentIndex() != RecurrenceEndNever ) {
    return true;
  } else if ( recurrence->duration() == 0 ) {
    // 0 means "end date is set"
    if ( mUi->mRecurrenceEndCombo->currentIndex() != RecurrenceEndOn ||
         recurrence->endDate() != mUi->mRecurrenceEndDate->date() ) {
      return true;
    }
  } else if ( recurrence->duration() > 0 ) {
    if ( mUi->mEndDurationEdit->value() != recurrence->duration() ||
         mUi->mRecurrenceEndCombo->currentIndex() != RecurrenceEndAfter ) {
      return true;
    }
  }

  // Exceptions
  if ( mExceptionDates != recurrence->exDates() ) {
    return true;
  }

  return false;
}

bool IncidenceRecurrence::isValid() const
{
  mLastErrorString.clear();
  KCalCore::Incidence::Ptr incidence( mLoadedIncidence->clone() );

  // Write start and end dates to the incidence
  mDateTime->save( incidence );

  // Write new recurring parameters to incidence
  writeToIncidence( incidence );

  // Check if the incidence will occur at least once
  if ( incidence->recurs() ) {
    // dtStart for events, dtDue for to-dos
    const KDateTime referenceDate = incidence->dateTime( KCalCore::Incidence::RoleRecurrenceStart );

    if ( referenceDate.isValid() ) {
      if ( incidence->recurrence()->recursOn( referenceDate.date(), referenceDate.timeSpec() ) ||
           incidence->recurrence()->getNextDateTime( referenceDate ).isValid() ) {
        return true;
      } else {
        mLastErrorString = i18n( "A recurring event or to-do must occur at least once. "
                                 "Adjust the recurring parameters." );
        return false;
      }
    } else {
      mLastErrorString = i18n( "The event's start date or the to-do's due date is invalid." );
      return false;
    }
  }

  return true;
}

void IncidenceRecurrence::addException()
{
  const QDate date = mUi->mExceptionDateEdit->date();
  const QString dateStr = KGlobal::locale()->formatDate( date );
  if( mUi->mExceptionList->findItems( dateStr, Qt::MatchExactly ).isEmpty() ) {
    mExceptionDates.append( date );
    mUi->mExceptionList->addItem( dateStr );
  }

  mUi->mExceptionAddButton->setEnabled( false );
  checkDirtyStatus();
}

void IncidenceRecurrence::fillCombos()
{
  if ( !currentDate().isValid() ) {
    // Can happen if you're editing with keyboard
    return;
  }

  const KCalendarSystem *calSys = KGlobal::locale()->calendar();
  // Next the monthly combo. This contains the following elements:
  // - nth day of the month
  // - (month.lastDay() - n)th day of the month
  // - the ith ${weekday} of the month
  // - the (month.weekCount() - i)th day of the month
  const int currentMonthlyIndex = mUi->mMonthlyCombo->currentIndex();
  mUi->mMonthlyCombo->clear();
  const QDate date = ( mLoadedIncidence &&
                       mLoadedIncidence->type() == KCalCore::Incidence::TypeTodo ) ?
                         mDateTime->endDate() :
                         mDateTime->startDate();

  QString item = subsOrdinal(
    ki18nc( "example: the 30th", "the %1" ), dayOfMonthFromStart() ).toString();
  mUi->mMonthlyCombo->addItem( item );

  item = subsOrdinal( ki18nc( "example: the 4th to last day",
                              "the %1 to last day" ), dayOfMonthFromEnd() ).toString();
  mUi->mMonthlyCombo->addItem( item );

  item = subsOrdinal(
    ki18nc( "example: the 5th Wednesday", "the %1 %2" ), monthWeekFromStart() ).
         subs(
           calSys->weekDayName( date.dayOfWeek(), KCalendarSystem::LongDayName ) ).toString();
  mUi->mMonthlyCombo->addItem( item );

  if ( monthWeekFromEnd() == 1 ) {
    item = ki18nc( "example: the last Wednesday", "the last %1" ).
           subs( calSys->weekDayName(
                   date.dayOfWeek(), KCalendarSystem::LongDayName ) ).toString();
  } else {
    item = subsOrdinal(
      ki18nc( "example: the 5th to last Wednesday", "the %1 to last %2" ), monthWeekFromEnd() ).
           subs( calSys->weekDayName(
                   date.dayOfWeek(), KCalendarSystem::LongDayName ) ).toString();
  }
  mUi->mMonthlyCombo->addItem( item );
  mUi->mMonthlyCombo->setCurrentIndex( currentMonthlyIndex == -1 ? 0 : currentMonthlyIndex );

  // Finally the yearly combo. This contains the following options:
  // - ${n}th of ${long-month-name}
  // - ${month.lastDay() - n}th last day of ${long-month-name}
  // - the ${i}th ${weekday} of ${long-month-name}
  // - the ${month.weekCount() - i}th day of ${long-month-name}
  // - the ${m}th day of the year
  const int currentYearlyIndex = mUi->mYearlyCombo->currentIndex();
  mUi->mYearlyCombo->clear();
  const QString longMonthName = calSys->monthName( date );
  item = subsOrdinal( ki18nc( "example: the 5th of June", "the %1 of %2" ), date.day() ).
         subs( longMonthName ).toString();
  mUi->mYearlyCombo->addItem( item );

  item = subsOrdinal(
    ki18nc( "example: the 3rd to last day of June", "the %1 to last day of %2" ),
    date.daysInMonth() - date.day() ).subs( longMonthName ).toString();
  mUi->mYearlyCombo->addItem( item );

  item = subsOrdinal(
    ki18nc( "example: the 4th Wednesday of June", "the %1 %2 of %3" ), monthWeekFromStart() ).
         subs( calSys->weekDayName( date.dayOfWeek(), KCalendarSystem::LongDayName ) ).
         subs( longMonthName ).toString();
  mUi->mYearlyCombo->addItem( item );

  if ( monthWeekFromEnd() == 1 ) {
    item = ki18nc( "example: the last Wednesday of June", "the last %1 of %2" ).
           subs( calSys->weekDayName( date.dayOfWeek(), KCalendarSystem::LongDayName ) ).
           subs( longMonthName ).toString();
  } else {
    item = subsOrdinal(
      ki18nc( "example: the 4th to last Wednesday of June", "the %1 to last %2 of %3 " ),
      monthWeekFromEnd() ).
           subs( calSys->weekDayName( date.dayOfWeek(), KCalendarSystem::LongDayName ) ).
           subs( longMonthName ).toString();
  }
  mUi->mYearlyCombo->addItem( item );

  item = subsOrdinal(
    ki18nc( "example: the 15th day of the year", "the %1 day of the year" ),
    date.dayOfYear() ).toString();
  mUi->mYearlyCombo->addItem( item );
  mUi->mYearlyCombo->setCurrentIndex( currentYearlyIndex == -1 ? 0 : currentYearlyIndex );
}

void IncidenceRecurrence::handleDateTimeToggle()
{
  QWidget *parent = mUi->mRepeatStack->parentWidget(); // Take the parent of a toplevel widget;
  if ( parent ) {
    parent->setEnabled( mDateTime->endDateTimeEnabled() );
  }
}

void IncidenceRecurrence::handleEndAfterOccurrencesChange( int currentValue )
{
  mUi->mRecurrenceOccurrencesLabel->setText(
    i18ncp( "Recurrence ends after n occurrences", "occurrence", "occurrences", currentValue ) );
}

void IncidenceRecurrence::handleExceptionDateChange( const QDate &currentDate )
{
  const QDate date = mUi->mExceptionDateEdit->date();
  const QString dateStr = KGlobal::locale()->formatDate( date );

  mUi->mExceptionAddButton->setEnabled(
    currentDate >= mDateTime->startDate() &&
    mUi->mExceptionList->findItems( dateStr, Qt::MatchExactly ).isEmpty() );
}

void IncidenceRecurrence::handleFrequencyChange()
{
  handleRecurrenceTypeChange( mUi->mRecurrenceTypeCombo->currentIndex() );
}

void IncidenceRecurrence::handleRecurrenceTypeChange( int currentIndex )
{
  toggleRecurrenceWidgets( currentIndex > 0 );
  QString labelFreq;
  QString freqKey;
  int frequency = mUi->mFrequencyEdit->value();
  switch ( currentIndex ) {
  case 2:
    labelFreq = i18ncp( "repeat every N >weeks<", "week", "weeks", frequency );
    freqKey = 'w';
    break;
  case 3:
    labelFreq = i18ncp( "repeat every N >months<", "month", "months", frequency );
    freqKey = 'm';
    break;
  case 4:
    labelFreq = i18ncp( "repeat every N >years<", "year", "years", frequency );
    freqKey = 'y';
    break;
  default:
    labelFreq = i18ncp( "repeat every N >days<", "day", "days", frequency );
    freqKey = 'd';
  }

  QString labelEvery;
  labelEvery = ki18ncp( "repeat >every< N years/months/...; "
                        "dynamic context 'type': 'd' days, 'w' weeks, "
                        "'m' months, 'y' years",
                        "every", "every" ).
               subs( frequency ).inContext( "type", freqKey ).toString();
  mUi->mFrequencyLabel->setText( labelEvery );
  mUi->mRecurrenceRuleLabel->setText( labelFreq );

#ifndef KDEPIM_MOBILE_UI
  mUi->mOnLabel->setVisible( currentIndex > 1 );
#endif

  emit recurrenceChanged( static_cast<RecurrenceType>( currentIndex ) );
}

void IncidenceRecurrence::removeExceptions()
{
  QList<QListWidgetItem *> selectedExceptions = mUi->mExceptionList->selectedItems();
  foreach ( QListWidgetItem *selectedException, selectedExceptions ) {
    const int row = mUi->mExceptionList->row( selectedException );
    mExceptionDates.removeAt( row );
    delete mUi->mExceptionList->takeItem( row );
  }

  handleExceptionDateChange( mUi->mExceptionDateEdit->date() );
  checkDirtyStatus();
}

void IncidenceRecurrence::updateRemoveExceptionButton()
{
  mUi->mExceptionRemoveButton->setEnabled( mUi->mExceptionList->selectedItems().count() > 0 );
}

void IncidenceRecurrence::updateWeekDays( const QDate &newStartDate )
{
  const int oldStartDayIndex = mUi->mWeekDayCombo->weekdayIndex( mCurrentDate );
  const int newStartDayIndex = mUi->mWeekDayCombo->weekdayIndex( newStartDate );

  if ( oldStartDayIndex >= 0 ) {
    mUi->mWeekDayCombo->setItemCheckState( oldStartDayIndex, Qt::Unchecked );
    mUi->mWeekDayCombo->setItemEnabled( oldStartDayIndex, true );
  }

  if ( newStartDayIndex >= 0 ) {
    mUi->mWeekDayCombo->setItemCheckState( newStartDayIndex, Qt::Checked );
    mUi->mWeekDayCombo->setItemEnabled( newStartDayIndex, false );
  }

  if ( newStartDate.isValid() ) {
    mCurrentDate = newStartDate;
  }
}

short IncidenceRecurrence::dayOfMonthFromStart() const
{
  return currentDate().day();
}

short IncidenceRecurrence::dayOfMonthFromEnd() const
{
  const QDate start = currentDate();
  return start.daysInMonth() - start.day() + 1;
}

short IncidenceRecurrence::dayOfYearFromStart() const
{
  return currentDate().dayOfYear();
}

int IncidenceRecurrence::duration() const
{
  if ( mUi->mRecurrenceEndCombo->currentIndex() == RecurrenceEndNever ) {
    return -1;
  } else if ( mUi->mRecurrenceEndCombo->currentIndex() == RecurrenceEndAfter ) {
    return mUi->mEndDurationEdit->value();
  } else {
    // 0 means "end date set"
    return 0;
  }
}

short IncidenceRecurrence::monthWeekFromStart() const
{
  const QDate date = currentDate();
  int count;
  if ( date.isValid() ) {
    count = 1;
    QDate tmp = date.addDays( -7 );
    while ( tmp.month() == date.month() ) {
      tmp = tmp.addDays( -7 ); // Count backward
      ++count;
    }
  } else {
    // date can be invalid if you're editing the date with your keyboard
    count = -1;
  }

  // 1 is the first week, 4/5 is the last week of the month
  return count;
}

short IncidenceRecurrence::monthWeekFromEnd() const
{
  const QDate date = currentDate();
  int count;
  if ( date.isValid() ) {
    count = 1;
    QDate tmp = date.addDays( 7 );
    while ( tmp.month() == date.month() ) {
      tmp = tmp.addDays( 7 );  // Count forward
      ++count;
    }
  } else {
    // date can be invalid if you're editing the date with your keyboard
    count = -1;
  }

  // 1 is the last week, 4/5 is the first week of the month
  return count;
}

QString IncidenceRecurrence::numberToString( int number ) const
{
  // The code in here was adapted from an article by Johnathan Wood, see:
  // http://www.blackbeltcoder.com/Articles/strings/converting-numbers-to-ordinal-strings

  static QString _numSuffixes[] = { "th", "st", "nd", "rd", "th", "th", "th", "th", "th", "th" };

  int i = ( number % 100 );
  int j = ( i > 10 && i < 20 ) ? 0 : ( number % 10 );
  return  QString::number( number ) + _numSuffixes[j];
}

void IncidenceRecurrence::selectMonthlyItem( KCalCore::Recurrence *recurrence,
                                             ushort recurenceType )
{
  Q_ASSERT( recurenceType == KCalCore::Recurrence::rMonthlyPos ||
            recurenceType == KCalCore::Recurrence::rMonthlyDay );

  if ( recurenceType == KCalCore::Recurrence::rMonthlyPos ) {
    QList<KCalCore::RecurrenceRule::WDayPos> rmp = recurrence->monthPositions();
    if ( rmp.isEmpty() ) {
      return; // Use the default values. Probably marks the editor as dirty
    }

    if ( rmp.first().pos() > 0 ) { // nth day
      // TODO if ( rmp.first().pos() != mDateTime->startDate().day() ) { warn user }
      // NOTE: This silencly changes the recurrence when:
      //       rmp.first().pos() != mDateTime->startDate().day()
      mUi->mMonthlyCombo->setCurrentIndex( ComboIndexMonthlyPos );
    } else { // (month.last() - n)th day
      // TODO: Handle recurrences we cannot represent
      // QDate startDate = mDateTime->startDate();
      // const int dayFromEnd = startDate.daysInMonth() - startDate.day();
      // if ( qAbs( rmp.first().pos() ) != dayFromEnd ) { /* warn user */ }
      mUi->mMonthlyCombo->setCurrentIndex( ComboIndexMonthlyPosInverted );
    }
  } else { // Monthly by day

    // check if we have any setting for which day (vcs import is broken and
    // does not set any day, thus we need to check)
    const int day = recurrence->monthDays().isEmpty() ? currentDate().day() :
                                                        recurrence->monthDays().first();

    // Days from the end are after the ones from the begin, so correct for the
    // negative sign and add 30 (index starting at 0)
    // TODO: Do similar checks as in the monthlyPos case
    if ( day > 0 && day <= 31 ) {
      mUi->mMonthlyCombo->setCurrentIndex( ComboIndexMonthlyDay );
    } else if ( day < 0 ) {
      mUi->mMonthlyCombo->setCurrentIndex( ComboIndexMonthlyDayInverted );
    }
  }

  // So we can easily detect if the user changed the type, without going through this logic ^
  mMonthlyInitialType = mUi->mMonthlyCombo->currentIndex();
}

void IncidenceRecurrence::selectYearlyItem( KCalCore::Recurrence *recurrence, ushort recurenceType )
{
  Q_ASSERT( recurenceType == KCalCore::Recurrence::rYearlyDay ||
            recurenceType == KCalCore::Recurrence::rYearlyMonth ||
            recurenceType == KCalCore::Recurrence::rYearlyPos );

  if ( recurenceType == KCalCore::Recurrence::rYearlyDay ) {

    /*
    const int day = recurrence->yearDays().isEmpty() ? currentDate().dayOfYear() :
                                                       recurrence->yearDays().first();
    */
    // TODO Check if day has actually the same value as in the combo.
    mUi->mYearlyCombo->setCurrentIndex( ComboIndexYearlyDay );
  } else if ( recurenceType == KCalCore::Recurrence::rYearlyMonth ) {

    const int day = recurrence->yearDates().isEmpty() ? currentDate().day() :
                                                        recurrence->yearDates().first();

    /*
    int month = currentDate().month();
    if ( !recurrence->yearMonths().isEmpty() ) {
      month = recurrence->yearMonths().first();
    }
    */

    // TODO check month and day to be correct values with respect to what is
    //      presented in the combo box.
    if ( day > 0 ) {
      mUi->mYearlyCombo->setCurrentIndex( ComboIndexYearlyMonth );
    } else {
      mUi->mYearlyCombo->setCurrentIndex( ComboIndexYearlyMonthInverted );
    }

  } else { //KCalCore::Recurrence::rYearlyPos

    /*
    int month = currentDate().month();
    if ( !recurrence->yearMonths().isEmpty() ) {
      month = recurrence->yearMonths().first();
    }
    */

    // count is the nth weekday of the month or the ith last weekday of the month.
    int count = ( currentDate().day() - 1 ) / 7;
    if ( !recurrence->yearPositions().isEmpty() ) {
      count = recurrence->yearPositions().first().pos();
    }

    // TODO check month,count and day to be correct values with respect to what is
    //      presented in the combo box.
    if ( count > 0 ) {
      mUi->mYearlyCombo->setCurrentIndex( ComboIndexYearlyPos );
    } else {
      mUi->mYearlyCombo->setCurrentIndex( ComboIndexYearlyPosInverted );
    }
  }

  // So we can easily detect if the user changed the type, without going through this logic ^
  mYearlyInitialType = mUi->mYearlyCombo->currentIndex();
}

void IncidenceRecurrence::setDefaults()
{
  mUi->mRecurrenceEndCombo->setCurrentIndex( RecurrenceEndNever );
  mUi->mRecurrenceEndDate->setDate( currentDate() );
  mUi->mRecurrenceTypeCombo->setCurrentIndex( RecurrenceTypeNone );

  setFrequency( 1 );

  // -1 because we want between 0 and 6
  const int day = KGlobal::locale()->calendar()->dayOfWeek( currentDate() ) - 1;

  QBitArray checkDays( 7, 0 );
  checkDays.setBit( day );

  QBitArray disableDays( 7, 0 );
  disableDays.setBit( day );

  mUi->mWeekDayCombo->setDays( checkDays, disableDays );

  mUi->mMonthlyCombo->setCurrentIndex( 0 ); // Recur on the nth of the month
  mUi->mYearlyCombo->setCurrentIndex( 0 );  // Recur on the nth of the month
}

void IncidenceRecurrence::setDuration( int duration )
{
  if ( duration == -1 ) { // No end date
    mUi->mRecurrenceEndCombo->setCurrentIndex( RecurrenceEndNever );
    mUi->mRecurrenceEndStack->setCurrentIndex( 0 );
  } else if ( duration == 0 ) {
    mUi->mRecurrenceEndCombo->setCurrentIndex( RecurrenceEndOn );
    mUi->mRecurrenceEndStack->setCurrentIndex( 1 );
  } else {
    mUi->mRecurrenceEndCombo->setCurrentIndex( RecurrenceEndAfter );
    mUi->mRecurrenceEndStack->setCurrentIndex( 2 );
    mUi->mEndDurationEdit->setValue( duration );
  }
}

void IncidenceRecurrence::setExceptionDates( const KCalCore::DateList &dates )
{
  mUi->mExceptionList->clear();
  mExceptionDates.clear();
  KCalCore::DateList::ConstIterator dit;
  for ( dit = dates.begin(); dit != dates.end(); ++dit ) {
    mUi->mExceptionList->addItem( KGlobal::locale()->formatDate(* dit ) );
    mExceptionDates.append( *dit );
  }
}

void IncidenceRecurrence::setFrequency( int frequency )
{
  if ( frequency < 1 ) {
    frequency = 1;
  }

  mUi->mFrequencyEdit->setValue( frequency );
}

void IncidenceRecurrence::toggleRecurrenceWidgets( bool enable )
{
#ifndef KDEPIM_MOBILE_UI
  mUi->mRecurrenceEndLabel->setVisible( enable );
  mUi->mOnLabel->setVisible( enable && mUi->mRepeatStack->currentIndex() > 0 );
  if ( !enable ) {
    // So we can hide the exceptions labels and not trigger column resizing.
    mUi->mRepeatLabel->setMinimumSize( mUi->mExceptionsLabel->sizeHint() );
  }
#endif

  mUi->mFrequencyLabel->setVisible( enable );
  mUi->mFrequencyEdit->setVisible( enable );
  mUi->mRecurrenceRuleLabel->setVisible( enable );
  mUi->mRepeatStack->setVisible( enable && mUi->mRecurrenceTypeCombo->currentIndex() > 1 );
  mUi->mRepeatStack->setCurrentIndex( mUi->mRecurrenceTypeCombo->currentIndex() );
  mUi->mRecurrenceEndCombo->setVisible( enable );
  mUi->mEndDurationEdit->setVisible( enable );
  mUi->mRecurrenceEndStack->setVisible( enable );

  // Exceptions widgets
  mUi->mExceptionsLabel->setVisible( enable );
  mUi->mExceptionDateEdit->setVisible( enable );
  mUi->mExceptionAddButton->setVisible( enable );
  mUi->mExceptionAddButton->setEnabled( mUi->mExceptionDateEdit->date() >= currentDate() );
  mUi->mExceptionRemoveButton->setVisible( enable );
  mUi->mExceptionRemoveButton->setEnabled( mUi->mExceptionList->selectedItems().count() > 0 );
  mUi->mExceptionList->setVisible( enable );
}

QBitArray IncidenceRecurrence::weekday() const
{
  QBitArray days( 7 );
  // QDate::dayOfWeek() -> returns [1 - 7], 1 == monday
  days.setBit( currentDate().dayOfWeek() - 1, true );
  return days;
}

int IncidenceRecurrence::weekdayCountForMonth( const QDate &date ) const
{
  Q_ASSERT( date.isValid() );
  // This methods returns how often the weekday specified by @param date occurs
  // in the month represented by @param date.

  int count = 1;
  QDate tmp = date.addDays( -7 );
  while ( tmp.month() == date.month() ) {
    tmp = tmp.addDays( -7 );
    ++count;
  }

  tmp = date.addDays( 7 );
  while ( tmp.month() == date.month() ) {
    tmp = tmp.addDays( 7 );
    ++count;
  }

  return count;
}

RecurrenceType IncidenceRecurrence::currentRecurrenceType() const
{
  const int currentIndex = mUi->mRecurrenceTypeCombo->currentIndex();
  Q_ASSERT_X( currentIndex >= 0 && currentIndex < RecurrenceTypeUnknown, "currentRecurrenceType",
              "Keep the combo-box values in sync with the enum" );
  return static_cast<RecurrenceType>( currentIndex );
}

void IncidenceRecurrence::handleStartDateChange( const QDate &date )
{
  // If it's a to-do, recurrence is calculated from dtDue.
  // ( not rfc compliant, but it's what we have now )
  if ( currentDate().isValid() && !( mLoadedIncidence &&
                                     mLoadedIncidence->type() == KCalCore::Incidence::TypeTodo ) ) {
    fillCombos();
    updateWeekDays( date );
    mUi->mExceptionDateEdit->setDate( date );
  }
}

void IncidenceRecurrence::handleEndDateChange( const QDate &date )
{
  // If it's a to-do, recurrence is calculated from dtDue, not dtStart.
  // ( not rfc compliant, but it's what we have now )
  if ( currentDate().isValid() && mLoadedIncidence &&
       mLoadedIncidence->type() == KCalCore::Incidence::TypeTodo ) {
    fillCombos();
    updateWeekDays( date );
    mUi->mExceptionDateEdit->setDate( date );
  }
}

QDate IncidenceRecurrence::currentDate() const
{
  // If it's a to-do, recurrence is calculated from dtDue, not dtStart.
  // ( not rfc compliant, but it's what we have now )
  return
    ( mLoadedIncidence && mLoadedIncidence->type() == KCalCore::Incidence::TypeTodo ) ?
      mDateTime->endDate():
      mDateTime->startDate();
}
