/*
    Copyright (C) 2005, S.R.Haque <srhaque@iee.org>.
    Copyright (C) 2009, David Faure <faure@kde.org>
    This file is part of the KDE project

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License version 2, as published by the Free Software Foundation.

    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 "ktimezonewidget.h"

#include <QtCore/QFile>
#include <QtGui/QPixmap>

#include <kdebug.h>
#include <klocale.h>
#include <kstandarddirs.h>
#include <ksystemtimezone.h>
#include <ktimezone.h>

class KTimeZoneWidget::Private
{
public:
    Private() : itemsCheckable(false), singleSelection(true) {}

    enum Columns
    {
        CityColumn = 0,
        RegionColumn,
        CommentColumn
    };

    enum Roles
    {
        ZoneRole = Qt::UserRole + 0xF3A3CB1
    };

    bool itemsCheckable;
    bool singleSelection;
};

// TODO: duplicate
static bool timeZoneLocaleLessThan (const QString &a, const QString &b)
{
    return QString::localeAwareCompare(a, b) < 0;
}

KTimeZoneWidget::KTimeZoneWidget( QWidget *parent, KTimeZones *db )
  : QTreeWidget( parent ),
    d(new KTimeZoneWidget::Private)
{
  // If the user did not provide a timezone database, we'll use the system default.
  setRootIsDecorated(false);
  setHeaderLabels( QStringList() << i18nc("Define an area in the time zone, like a town area", "Area" ) << i18nc( "Time zone", "Region" ) << i18n( "Comment" ) );

  // Collect zones by localized city names, so that they can be sorted properly.
  QStringList cities;
  QHash<QString, KTimeZone> zonesByCity;

  if (!db) {
      db = KSystemTimeZones::timeZones();

      // add UTC to the defaults default
      KTimeZone utc = KTimeZone::utc();
      cities.append(utc.name());
      zonesByCity.insert(utc.name(), utc);
  }

  const KTimeZones::ZoneMap zones = db->zones();
  for ( KTimeZones::ZoneMap::ConstIterator it = zones.begin(); it != zones.end(); ++it ) {
    const KTimeZone zone = it.value();
    const QString continentCity = displayName( zone );
    const int separator = continentCity.lastIndexOf('/');
    // Make up the localized key that will be used for sorting.
    // Example: i18n(Asia/Tokyo) -> key = "i18n(Tokyo)|i18n(Asia)|Asia/Tokyo"
    // The zone name is appended to ensure unicity even with equal translations (#174918)
    const QString key = continentCity.mid(separator+1) + '|'
                   + continentCity.left(separator) + '|' + zone.name();
    cities.append( key );
    zonesByCity.insert( key, zone );
  }
  qSort( cities.begin(), cities.end(), timeZoneLocaleLessThan );

  foreach ( const QString &key, cities ) {
    const KTimeZone zone = zonesByCity.value(key);
    const QString tzName = zone.name();
    QString comment = zone.comment();

    if ( !comment.isEmpty() )
      comment = i18n( comment.toUtf8() );

    // Convert:
    //
    //  "Europe/London", "GB" -> "London", "Europe/GB".
    //  "UTC",           ""   -> "UTC",    "".
    QStringList continentCity = displayName( zone ).split( '/' );

    QTreeWidgetItem *listItem = new QTreeWidgetItem( this );
    listItem->setText( Private::CityColumn, continentCity[ continentCity.count() - 1 ] );
    QString countryName = KGlobal::locale()->countryCodeToName( zone.countryCode() );
    if ( countryName.isEmpty() ) {
      continentCity[ continentCity.count() - 1 ] = zone.countryCode();
    } else {
      continentCity[ continentCity.count() - 1 ] = countryName;
    }

    listItem->setText( Private::RegionColumn, continentCity.join( QChar('/') ) );
    listItem->setText( Private::CommentColumn, comment );
    listItem->setData( Private::CityColumn, Private::ZoneRole, tzName ); // store complete path in custom role

    // Locate the flag from /l10n/%1/flag.png.
    QString flag = KStandardDirs::locate( "locale", QString( "l10n/%1/flag.png" ).arg( zone.countryCode().toLower() ) );
    if ( QFile::exists( flag ) )
      listItem->setIcon( Private::RegionColumn, QPixmap( flag ) );
  }
}

KTimeZoneWidget::~KTimeZoneWidget()
{
    delete d;
}

void KTimeZoneWidget::setItemsCheckable(bool enable)
{
    d->itemsCheckable = enable;
    const int count = topLevelItemCount();
    for (int row = 0; row < count; ++row) {
        QTreeWidgetItem* listItem = topLevelItem(row);
        listItem->setCheckState(Private::CityColumn, Qt::Unchecked);
    }
    QTreeWidget::setSelectionMode(QAbstractItemView::NoSelection);
}

bool KTimeZoneWidget::itemsCheckable() const
{
    return d->itemsCheckable;
}

QString KTimeZoneWidget::displayName( const KTimeZone &zone )
{
    return i18n( zone.name().toUtf8() ).replace( '_', ' ' );
}

QStringList KTimeZoneWidget::selection() const
{
    QStringList selection;

    // Loop through all entries.
    // Do not use selectedItems() because it skips hidden items, making it
    // impossible to use a KTreeWidgetSearchLine.
    // There is no QTreeWidgetItemConstIterator, hence the const_cast :/
    QTreeWidgetItemIterator it(const_cast<KTimeZoneWidget*>(this), d->itemsCheckable ? QTreeWidgetItemIterator::Checked : QTreeWidgetItemIterator::Selected);
    for (; *it; ++it) {
        selection.append( (*it)->data( Private::CityColumn, Private::ZoneRole ).toString() );
    }

    return selection;
}

void KTimeZoneWidget::setSelected( const QString &zone, bool selected )
{
    bool found = false;

    // The code was using findItems( zone, Qt::MatchExactly, Private::ZoneColumn )
    // previously, but the underlying model only has 3 columns, the "hidden" column
    // wasn't available in there.

    if (!d->itemsCheckable) {
        // Runtime compatibility for < 4.3 apps, which don't call the setMultiSelection reimplementation.
        d->singleSelection = (QTreeWidget::selectionMode() == QAbstractItemView::SingleSelection);
    }

    // Loop through all entries.
    const int rowCount = model()->rowCount(QModelIndex());
    for (int row = 0; row < rowCount; ++row) {
        const QModelIndex index = model()->index(row, Private::CityColumn);
        const QString tzName = index.data(Private::ZoneRole).toString();
        if (tzName == zone) {

            if (d->singleSelection && selected) {
                clearSelection();
            }

            if (d->itemsCheckable) {
                QTreeWidgetItem* listItem = itemFromIndex(index);
                listItem->setCheckState(Private::CityColumn, selected ? Qt::Checked : Qt::Unchecked);
            } else {
                selectionModel()->select(index, selected ? (QItemSelectionModel::Select | QItemSelectionModel::Rows) : (QItemSelectionModel::Deselect | QItemSelectionModel::Rows));
            }

            // Ensure the selected item is visible as appropriate.
            scrollTo( index );

            found = true;

            if (d->singleSelection && selected) {
                break;
            }
        }
    }

    if ( !found )
        kDebug() << "No such zone: " << zone;
}

void KTimeZoneWidget::clearSelection()
{
    if (d->itemsCheckable) {
        // Un-select all items
        const int rowCount = model()->rowCount(QModelIndex());
        for (int row = 0; row < rowCount; ++row) {
            const QModelIndex index = model()->index(row, 0);
            QTreeWidgetItem* listItem = itemFromIndex(index);
            listItem->setCheckState(Private::CityColumn, Qt::Unchecked);
        }
    } else {
        QTreeWidget::clearSelection();
    }
}

void KTimeZoneWidget::setSelectionMode(QAbstractItemView::SelectionMode mode)
{
    d->singleSelection = (mode == QAbstractItemView::SingleSelection);
    if (!d->itemsCheckable) {
        QTreeWidget::setSelectionMode(mode);
    }
}

QAbstractItemView::SelectionMode KTimeZoneWidget::selectionMode() const
{
    if (d->itemsCheckable) {
        return d->singleSelection ? QTreeWidget::SingleSelection : QTreeWidget::MultiSelection;
    } else {
        return QTreeWidget::selectionMode();
    }
}

#include "moc_ktimezonewidget.cpp"