/*
  Copyright (c) 2007 Bruno Virlet <bruno@virlet.org>

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

  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

  As a special exception, permission is given to link this program
  with any edition of Qt, and distribute the resulting executable,
  without including the source code for Qt in the source distribution.
*/
#include "timelabelszone.h"
#include "agenda.h"
#include "agendaview.h"
#include "prefs.h"
#include "timelabels.h"

#include <KSystemTimeZone>

#include <QHBoxLayout>
#include <QScrollArea>
#include <QScrollBar>

using namespace EventViews;

TimeLabelsZone::TimeLabelsZone( QWidget *parent, const PrefsPtr &preferences, Agenda *agenda )
  : QWidget( parent ), mAgenda( agenda ), mPrefs( preferences ),
    mParent( qobject_cast<AgendaView*>( parent ) )
{
  mTimeLabelsLayout = new QHBoxLayout( this );
  mTimeLabelsLayout->setMargin( 0 );
  mTimeLabelsLayout->setSpacing( 0 );

  init();
}

void TimeLabelsZone::reset()
{
  foreach ( QScrollArea *label, mTimeLabelsList ) {
    label->hide();
    label->deleteLater();
  }
  mTimeLabelsList.clear();

  init();

  // Update some related geometry from the agenda view
  updateAll();
  if ( mParent ) {
    mParent->updateTimeBarWidth();
    mParent->createDayLabels( true );
  }
}

void TimeLabelsZone::init()
{
  QStringList seenTimeZones( mPrefs->timeSpec().timeZone().name() );

  addTimeLabels( mPrefs->timeSpec() );

  foreach ( const QString &zoneStr, mPrefs->timeScaleTimezones() ) {
    if ( !seenTimeZones.contains( zoneStr ) ) {
      KTimeZone zone = KSystemTimeZones::zone( zoneStr );
      if ( zone.isValid() ) {
        addTimeLabels( zone );
        seenTimeZones += zoneStr;
      }
    }
  }
}

void TimeLabelsZone::addTimeLabels( const KDateTime::Spec &spec )
{
  QScrollArea *area = new QScrollArea( this );
  TimeLabels *labels = new TimeLabels( spec, 24, this );
  mTimeLabelsList.prepend( area );
  area->setWidgetResizable( true );
  area->setWidget( labels );
  area->setVerticalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
  area->setHorizontalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
  area->setBackgroundRole( QPalette::Window );
  area->setFrameStyle( QFrame::NoFrame );
  area->show();
  mTimeLabelsLayout->insertWidget( 0, area );

  setupTimeLabel( area );
}

void TimeLabelsZone::setupTimeLabel( QScrollArea *area )
{
  if ( mAgenda && mAgenda->verticalScrollBar() ) {
    // Scrolling the agenda will scroll the timelabel
    connect( mAgenda->verticalScrollBar(), SIGNAL(valueChanged(int)),
             area->verticalScrollBar(), SLOT(setValue(int)) );
    // and vice-versa. ( this won't loop )
    connect( area->verticalScrollBar(), SIGNAL(valueChanged(int)),
             mAgenda->verticalScrollBar(), SLOT(setValue(int)) );

    area->verticalScrollBar()->setValue( mAgenda->verticalScrollBar()->value() );

  }

  TimeLabels *timeLabels = static_cast<TimeLabels*>( area->widget() );
  timeLabels->setAgenda( mAgenda );

  // timelabel's scroll is just a slave, this shouldn't be here
  // if ( mParent ) {
  //  connect( area->verticalScrollBar(), SIGNAL(valueChanged(int)),
  //           mParent, SLOT(setContentsPos(int)) );
  // }
}

int TimeLabelsZone::preferedTimeLabelsWidth() const
{
  if ( mTimeLabelsList.isEmpty() ) {
    return 0;
  } else {
    return mTimeLabelsList.first()->widget()->sizeHint().width();
  }
}

void TimeLabelsZone::updateAll()
{
  foreach ( QScrollArea *area, mTimeLabelsList ) {
    TimeLabels *timeLabel = static_cast<TimeLabels*>( area->widget() );
    timeLabel->updateConfig();
  }
}

QList<QScrollArea*> TimeLabelsZone::timeLabels() const
{
  return mTimeLabelsList;
}

void TimeLabelsZone::setAgendaView( AgendaView *agendaView )
{
  mParent = agendaView;
  mAgenda = agendaView ? agendaView->agenda() : 0;

  foreach ( QScrollArea *timeLabel, mTimeLabelsList ) {
    setupTimeLabel( timeLabel );
  }
}

void TimeLabelsZone::updateTimeLabelsPosition()
{
  if ( mAgenda ) {
    foreach ( QScrollArea *area, timeLabels() ) {
      TimeLabels *label = static_cast<TimeLabels*>( area->widget() );
      const int adjustment = mAgenda->contentsY();
      // y() is the offset to our parent (QScrollArea)
      // and gets negative as we scroll
      if ( adjustment != -label->y() ) {
        area->verticalScrollBar()->setValue( adjustment );
      }
    }
  }
}

PrefsPtr TimeLabelsZone::preferences() const
{
  return mPrefs;
}

void TimeLabelsZone::setPreferences( const PrefsPtr &prefs )
{
  if ( prefs != mPrefs ) {
    mPrefs = prefs;
  }
}