/*
  Copyright (C) 2010 Casey Link <unnamedrambler@gmail.com>
  Copyright (c) 2009-2010 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.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 "visualfreebusywidget.h"
#include "freebusyganttproxymodel.h"
#include "freebusyitemmodel.h"

#include <kdgantt2/kdganttgraphicsview.h>
#include <kdgantt2/kdganttview.h>
#include <kdgantt2/kdganttdatetimegrid.h>
#include <kdgantt2/kdganttabstractrowcontroller.h>

#include <KComboBox>
#include <KDebug>
#include <KLocalizedString>

#include <QHeaderView>
#include <QLabel>
#include <QPointer>
#include <QPushButton>
#include <QScrollBar>
#include <QSplitter>
#include <QTreeView>
#include <QVBoxLayout>

using namespace IncidenceEditorNG;

namespace IncidenceEditorNG {

class RowController : public KDGantt::AbstractRowController
{
  private:
    static const int ROW_HEIGHT ;
    QPointer<QAbstractItemModel> m_model;

  public:
    RowController()
    {
      mRowHeight = 20;
    }

    void setModel( QAbstractItemModel *model )
    {
      m_model = model;
    }

    /*reimp*/
    int headerHeight() const
    {
      return 2 * mRowHeight + 10;
    }

    /*reimp*/
    bool isRowVisible( const QModelIndex & ) const
    {
      return true;
    }

    /*reimp*/
    bool isRowExpanded( const QModelIndex & ) const
    {
      return false;
    }

    /*reimp*/
    KDGantt::Span rowGeometry( const QModelIndex &idx ) const
    {
      return KDGantt::Span( idx.row() * mRowHeight, mRowHeight );
    }

    /*reimp*/
    int maximumItemHeight() const
    {
      return mRowHeight / 2;
    }

    /*reimp*/
    int totalHeight() const
    {
      return m_model->rowCount() * mRowHeight;
    }

    /*reimp*/
    QModelIndex indexAt( int height ) const
    {
      return m_model->index( height / mRowHeight, 0 );
    }

    /*reimp*/
    QModelIndex indexBelow( const QModelIndex &idx ) const
    {
      if ( !idx.isValid() ) {
        return QModelIndex();
      }
      return idx.model()->index( idx.row() + 1, idx.column(), idx.parent() );
    }

    /*reimp*/
    QModelIndex indexAbove( const QModelIndex &idx ) const
    {
      if ( !idx.isValid() ) {
        return QModelIndex();
      }
      return idx.model()->index( idx.row() - 1, idx.column(), idx.parent() );
    }

    void setRowHeight( int height )
    {
      mRowHeight = height;
    }

  private:
    int mRowHeight;

};

class GanttHeaderView : public QHeaderView
{
  public:
    explicit GanttHeaderView( QWidget *parent = 0 ) : QHeaderView( Qt::Horizontal, parent )
    {
    }

    QSize sizeHint() const
    {
      QSize s = QHeaderView::sizeHint();
      s.rheight() *= 2;
      return s;
    }
};

}

VisualFreeBusyWidget::VisualFreeBusyWidget( FreeBusyItemModel *model, int spacing, QWidget *parent )
  : QWidget( parent ), mGanttGrid( 0 ), mScaleCombo( 0 )
{
  QVBoxLayout *topLayout = new QVBoxLayout( this );
  topLayout->setSpacing( spacing );

  // The control panel for the gantt widget
  QBoxLayout *controlLayout = new QHBoxLayout();
  controlLayout->setSpacing( topLayout->spacing() );
  topLayout->addItem( controlLayout );

  QLabel *label = new QLabel( i18nc( "@label", "Scale: " ), this );
  controlLayout->addWidget( label );

  mScaleCombo = new KComboBox( this );
  mScaleCombo->setToolTip(
    i18nc( "@info:tooltip", "Set the Gantt chart zoom level" ) );
  mScaleCombo->setWhatsThis(
    i18nc( "@info:whatsthis",
           "Select the Gantt chart zoom level from one of the following:<nl/>"
           "'Hour' shows a range of several hours,<nl/>"
           "'Day' shows a range of a few days,<nl/>"
           "'Week' shows a range of a few months,<nl/>"
           "and 'Month' shows a range of a few years,<nl/>"
           "while 'Automatic' selects the range most "
           "appropriate for the current event or to-do." ) );
  mScaleCombo->addItem( i18nc( "@item:inlistbox range in hours", "Hour" ),
                        QVariant::fromValue<int>( KDGantt::DateTimeGrid::ScaleHour ) );
  mScaleCombo->addItem( i18nc( "@item:inlistbox range in days", "Day" ),
                        QVariant::fromValue<int>( KDGantt::DateTimeGrid::ScaleDay ) );
  mScaleCombo->addItem( i18nc( "@item:inlistbox range in weeks", "Week" ),
                        QVariant::fromValue<int>( KDGantt::DateTimeGrid::ScaleWeek ) );
  mScaleCombo->addItem( i18nc( "@item:inlistbox range in months", "Month" ),
                        QVariant::fromValue<int>( KDGantt::DateTimeGrid::ScaleMonth ) );
  mScaleCombo->addItem( i18nc( "@item:inlistbox range is computed automatically", "Automatic" ),
                        QVariant::fromValue<int>( KDGantt::DateTimeGrid::ScaleAuto ) );
  mScaleCombo->setCurrentIndex( 0 ); // start with "hour"
  connect( mScaleCombo, SIGNAL(activated(int)), SLOT(slotScaleChanged(int)) );
  controlLayout->addWidget( mScaleCombo );

  QPushButton *button = new QPushButton( i18nc( "@action:button", "Center on Start" ), this );
  button->setToolTip(
    i18nc( "@info:tooltip",
           "Center the Gantt chart on the event start date and time" ) );
  button->setWhatsThis(
    i18nc( "@info:whatsthis",
           "Click this button to center the Gantt chart on the start "
           "time and day of this event." ) );
  connect( button, SIGNAL(clicked()), SLOT(slotCenterOnStart()) );
  controlLayout->addWidget( button );

  controlLayout->addStretch( 1 );

  button = new QPushButton( i18nc( "@action:button", "Pick Date" ), this );
  button->setToolTip(
    i18nc( "@info:tooltip",
           "Move the event to a date and time when all "
           "attendees are available" ) );
  button->setWhatsThis(
    i18nc( "@info:whatsthis",
           "Click this button to move the event to a date "
           "and time when all the attendees have time "
           "available in their Free/Busy lists." ) );
  connect( button, SIGNAL(clicked()), SLOT(slotPickDate()) );
  controlLayout->addWidget( button );

  controlLayout->addStretch( 1 );

  button = new QPushButton( i18nc( "@action:button reload freebusy data", "Reload" ), this );
  button->setToolTip(
    i18nc( "@info:tooltip",
           "Reload Free/Busy data for all attendees" ) );
  button->setWhatsThis(
    i18nc( "@info:whatsthis",
           "Pressing this button will cause the Free/Busy data for all "
           "attendees to be reloaded from their corresponding servers." ) );
  controlLayout->addWidget( button );
  connect( button, SIGNAL(clicked()), SIGNAL(manualReload()) );

  QSplitter *splitter = new QSplitter( Qt::Horizontal, this );
  connect( splitter, SIGNAL(splitterMoved(int,int)), SLOT(splitterMoved()) );
  mLeftView = new QTreeView( this );
  mLeftView->setModel( model );
  mLeftView->setHeader( new GanttHeaderView );
  mLeftView->header()->setStretchLastSection( true );
  mLeftView->setRootIsDecorated( false );
  mLeftView->setHorizontalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
  mLeftView->setContextMenuPolicy( Qt::CustomContextMenu );

  mGanttGraphicsView = new KDGantt::GraphicsView( this );
  mGanttGraphicsView->setObjectName( "mGanttGraphicsView" );
  mGanttGraphicsView->setToolTip(
    i18nc( "@info:tooltip",
           "Shows the Free/Busy status of all attendees" ) );
  mGanttGraphicsView->setWhatsThis(
    i18nc( "@info:whatsthis",
           "Shows the Free/Busy status of all attendees. "
           "Double-clicking on an attendee's entry in the "
           "list will allow you to enter the location of "
           "their Free/Busy Information." ) );
  mModel = new FreeBusyGanttProxyModel( this );
  mModel->setSourceModel( model );

  mRowController = new RowController;
  mRowController->setRowHeight( fontMetrics().height() ); //TODO: detect

  mRowController->setModel( mModel );
  mGanttGraphicsView->setRowController( mRowController );

  mGanttGrid = new KDGantt::DateTimeGrid;
  mGanttGrid->setScale( KDGantt::DateTimeGrid::ScaleHour );
  mGanttGrid->setDayWidth( 800 );
  mGanttGrid->setRowSeparators( true );
  mGanttGraphicsView->setGrid( mGanttGrid );
  mGanttGraphicsView->setModel( mModel );
  mGanttGraphicsView->viewport()->setFixedWidth( 800 * 30 );

  splitter->addWidget( mLeftView );
  splitter->addWidget( mGanttGraphicsView );

  topLayout->addWidget( splitter );
  topLayout->setStretchFactor( splitter, 100 );

  // Initially, show 15 days back and forth
  // set start to even hours, i.e. to 12:AM 0 Min 0 Sec
  QDateTime horizonStart =
    QDateTime( QDateTime::currentDateTime().addDays( -15 ).date() );
  QDateTime horizonEnd = QDateTime::currentDateTime().addDays( 15 );
  mGanttGrid->setStartDateTime( horizonStart );

//connect( mGanttGraphicsView, SIGNAL(timeIntervalSelected(KDateTime,KDateTime)),
//         mGanttGraphicsView, SLOT(zoomToSelection(KDateTime,KDateTime)) );
//connect( mGanttGraphicsView, SIGNAL(doubleClicked(QModelIndex)),
//         SLOT(editFreeBusyUrl(QModelIndex)) );
//connect(mGanttGraphicsView,SIGNAL(intervalColorRectangleMoved(KDateTime,KDateTime)),
//        this, SLOT(slotIntervalColorRectangleMoved(KDateTime,KDateTime)) );

  connect( mLeftView, SIGNAL(customContextMenuRequested(QPoint)),
           this, SLOT(showAttendeeStatusMenu()) );

//   foreach ( FreeBusyItem::Ptr item, mResolver->freeBusyItems() ) {
//     newFreeBusy( item );
//   }
}

VisualFreeBusyWidget::~VisualFreeBusyWidget()
{
}

void VisualFreeBusyWidget::showAttendeeStatusMenu()
{
//   KMenu *menu = new KMenu( 0 );
//
//   QAction *needsaction =
//     menu->addAction( SmallIcon( "help-about" ),
//                      KCalUtils::Stringify::attendeeStatus( KCalCore::Attendee::NeedsAction ) );
//   QAction *accepted =
//     menu->addAction( SmallIcon( "dialog-ok-apply" ),
//                      KCalUtils::Stringify::attendeeStatus( KCalCore::Attendee::Accepted ) );
//   QAction *declined =
//     menu->addAction( SmallIcon( "dialog-cancel" ),
//                      KCalUtils::Stringify::attendeeStatus( KCalCore::Attendee::Declined ) );
//   QAction *tentative =
//     menu->addAction( SmallIcon( "dialog-ok" ),
//                      KCalUtils::Stringify::attendeeStatus( KCalCore::Attendee::Tentative ) );
//   QAction *delegated =
//     menu->addAction( SmallIcon( "mail-forward" ),
//                      KCalUtils::Stringify::attendeeStatus( KCalCore::Attendee::Delegated ) );
//   QAction *completed =
//     menu->addAction( SmallIcon( "mail-mark-read" ),
//                      KCalUtils::Stringify::attendeeStatus( KCalCore::Attendee::Completed ) );
//   QAction *inprocess =
//     menu->addAction( SmallIcon( "help-about" ),
//                      KCalUtils::Stringify::attendeeStatus( KCalCore::Attendee::InProcess ) );
//   QAction *ret = menu->exec( QCursor::pos() );
//   delete menu;
//   if ( ret == needsaction ) {
//     currentAttendee()->setStatus( KCalCore::Attendee::NeedsAction );
//   } else if ( ret == accepted ) {
//     currentAttendee()->setStatus( KCalCore::Attendee::Accepted );
//   } else if ( ret == declined ) {
//     currentAttendee()->setStatus( KCalCore::Attendee::Declined );
//   } else if ( ret == tentative ) {
//     currentAttendee()->setStatus( KCalCore::Attendee::Tentative );
//   } else if ( ret == delegated ) {
//     currentAttendee()->setStatus( KCalCore::Attendee::Delegated );
//   } else if ( ret == completed ) {
//     currentAttendee()->setStatus( KCalCore::Attendee::Completed );
//   } else if ( ret == inprocess ) {
//     currentAttendee()->setStatus( KCalCore::Attendee::InProcess );
//   } else {
//     return;
//   }

//   updateCurrentItem();
}

void VisualFreeBusyWidget::slotCenterOnStart()
{
  KDGantt::DateTimeGrid *grid = static_cast<KDGantt::DateTimeGrid*>( mGanttGraphicsView->grid() );
  int daysTo = grid->startDateTime().daysTo( mDtStart.dateTime() );
  mGanttGraphicsView->horizontalScrollBar()->setValue( daysTo * 800 );
}

void VisualFreeBusyWidget::slotIntervalColorRectangleMoved( const KDateTime &start,
                                                            const KDateTime &end )
{
  mDtStart = start;
  mDtEnd = end;
  emit dateTimesChanged( start, end );
}

/*!
  This slot is called when the user clicks the "Pick a date" button.
*/
void VisualFreeBusyWidget::slotPickDate()
{
  //TODO implement or discard
//  KDateTime::Spec timeSpec = KSystemTimeZones::local();
//  KDateTime start = mDtStart;
//  KDateTime end = mDtEnd;
//  bool success = mResolver->findFreeSlot( KCalCore::Period( start, end ) );
//
//  if ( success ) {
//    if ( start == mDtStart && end == mDtEnd ) {
//      KMessageBox::information(
//        this,
//        i18nc( "@info", "The meeting already has suitable start/end times." ),
//        QString(),
//        "MeetingTimeOKFreeBusy" );
//      } else {
//        if ( KMessageBox::questionYesNo(
//          this,
//          i18nc( "@info",
//                 "The next available time slot for the meeting is:<nl/>"
//                 "Start: %1<nl/>End: %2<nl/>"
//                 "Would you like to move the meeting to this time slot?",
//                 start.dateTime().toString(), end.dateTime().toString() ), QString(),
//                 KStandardGuiItem::yes(), KStandardGuiItem::no(),
//                 "MeetingMovedFreeBusy" ) == KMessageBox::Yes ) {
//          emit dateTimesChanged( start, end );
//          slotUpdateGanttView( start, end );
//          }
//      }
//    } else {
//      KMessageBox::sorry( this, i18nc( "@info", "No suitable date found." ) );
//  }
}

void VisualFreeBusyWidget::slotScaleChanged( int newScale )
{
  const QVariant var = mScaleCombo->itemData( newScale );
  Q_ASSERT( var.isValid() );

  int value = var.value<int>();

  mGanttGrid->setScale( ( KDGantt::DateTimeGrid::Scale )value );
}

void VisualFreeBusyWidget::slotUpdateIncidenceStartEnd( const KDateTime &dtFrom,
                                                        const KDateTime &dtTo )
{
  mDtStart = dtFrom;
  mDtEnd = dtTo;
  QDateTime horizonStart = QDateTime( dtFrom.addDays( -15 ).date() );
  KDGantt::DateTimeGrid *grid = static_cast<KDGantt::DateTimeGrid*>( mGanttGraphicsView->grid() );
  grid->setStartDateTime( horizonStart );
  slotCenterOnStart();
  mGanttGrid->setStartDateTime( horizonStart );
}

void VisualFreeBusyWidget::slotZoomToTime()
{
#if 0
  mGanttGraphicsView->zoomToFit();
#else
  kDebug() << "Disabled code, port to KDGantt2";
#endif
}

void VisualFreeBusyWidget::splitterMoved()
{
//  mLeftView->setColumnWidth( 0, mLeftView->width() );
}