/*
 *  resourcemodelview.cpp  -  model/view classes for alarm resource lists
 *  Program:  kalarm
 *  Copyright © 2007-2011 by David Jarvie <djarvie@kde.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.
 */

#include "kalarm.h"

#include "messagebox.h"
#include "preferences.h"
#include "resourcemodelview.moc"

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

#include <QApplication>
#include <QToolTip>
#include <QMouseEvent>
#include <QKeyEvent>
#include <QHelpEvent>


ResourceModel* ResourceModel::mInstance = 0;


ResourceModel* ResourceModel::instance(QObject* parent)
{
    if (!mInstance)
        mInstance = new ResourceModel(parent);
    return mInstance;
}

ResourceModel::ResourceModel(QObject* parent)
    : QAbstractListModel(parent)
{
    refresh();
    AlarmResources* resources = AlarmResources::instance();
    connect(resources, SIGNAL(signalResourceModified(AlarmResource*)), SLOT(updateResource(AlarmResource*)));
    connect(resources, SIGNAL(standardResourceChange(CalEvent::Type)), SLOT(slotStandardChanged(CalEvent::Type)));
    connect(resources, SIGNAL(resourceStatusChanged(AlarmResource*,AlarmResources::Change)), SLOT(slotStatusChanged(AlarmResource*,AlarmResources::Change)));
    connect(resources, SIGNAL(resourceLoaded(AlarmResource*,bool)), SLOT(slotLoaded(AlarmResource*,bool)));
}

int ResourceModel::rowCount(const QModelIndex& parent) const
{
    if (parent.isValid())
        return 0;
    return mResources.count();
}

QModelIndex ResourceModel::index(int row, int column, const QModelIndex& parent) const
{
    if (parent.isValid()  ||  row >= mResources.count())
        return QModelIndex();
    return createIndex(row, column, mResources[row]);
}

QVariant ResourceModel::data(const QModelIndex& index, int role) const
{
    if (!index.isValid())
        return QVariant();
    AlarmResource* resource = static_cast<AlarmResource*>(index.internalPointer());
    if (!resource)
        return QVariant();
    switch (role)
    {
        case Qt::DisplayRole:
            return resource->resourceName();
        case Qt::CheckStateRole:
            return resource->isEnabled() ? Qt::Checked : Qt::Unchecked;
        case Qt::ForegroundRole:
        {
            QColor colour;
            switch (resource->alarmType())
            {
                case CalEvent::ACTIVE:    colour = KColorScheme(QPalette::Active).foreground(KColorScheme::NormalText).color();  break;
                case CalEvent::ARCHIVED:  colour = Preferences::archivedColour();  break;
                case CalEvent::TEMPLATE:  colour = KColorScheme(QPalette::Active).foreground(KColorScheme::LinkText).color();  break;
                default:  break;
            }
            if (colour.isValid())
                return resource->readOnly() ? KColorUtils::lighten(colour, 0.25) : colour;
            break;
        }
        case Qt::BackgroundRole:
            if (resource->colour().isValid())
                return resource->colour();
            break;
        case Qt::FontRole:
        {
            if (!resource->isEnabled()  ||  !resource->standardResource())
                break;
            QFont font = mFont;
            font.setBold(true);
            return font;
        }
        case Qt::ToolTipRole:
        {
            QString name = '@' + resource->resourceName();   // insert markers for stripping out name
            QString type = '@' + resource->displayType();
            bool inactive = !resource->isActive();
            QString disabled = resource->isWrongAlarmType() ? i18nc("@info/plain", "Disabled (wrong alarm type)") : i18nc("@info/plain", "Disabled");
            QString readonly = i18nc("@info/plain", "Read-only");
            if (inactive  &&  resource->readOnly())
                return i18nc("@info:tooltip",
                             "%1"
                             "<nl/>%2: <filename>%3</filename>"
                             "<nl/>%4, %5",
                             name, type, resource->displayLocation(), disabled, readonly);
            if (inactive  ||  resource->readOnly())
                return i18nc("@info:tooltip",
                             "%1"
                             "<nl/>%2: <filename>%3</filename>"
                             "<nl/>%4",
                             name, type, resource->displayLocation(),
                             (inactive ? disabled : readonly));
            return i18nc("@info:tooltip",
                         "%1"
                         "<nl/>%2: <filename>%3</filename>",
                         name, type, resource->displayLocation());
        }
        default:
            break;
    }
    return QVariant();
}

/******************************************************************************
* Set the font to use for all items, or the checked state of one item.
* The font must always be set at initialisation.
*/
bool ResourceModel::setData(const QModelIndex& index, const QVariant& value, int role)
{
    mErrorPrompt.clear();
    if (role == Qt::FontRole)
    {
        // Set the font used in all views.
        // This enables data(index, Qt::FontRole) to return bold when appropriate.
        mFont = value.value<QFont>();
        return true;
    }
    if (role != Qt::CheckStateRole  ||  !index.isValid())
        return false;
    AlarmResource* resource = static_cast<AlarmResource*>(index.internalPointer());
    if (!resource)
        return false;
    Qt::CheckState state = static_cast<Qt::CheckState>(value.toInt());
    bool active = (state == Qt::Checked);
    bool saveChange = false;
    AlarmResources* resources = AlarmResources::instance();
    if (active)
    {
        // Enable the resource
        resource->setActive(true);     // enable it now so that load() will work
        saveChange = resources->load(resource);
        resource->setActive(false);    // reset so that setEnabled() will work
    }
    else
    {
        // Disable the resource
        saveChange = resource->saveAndClose();   // close resource after it is saved
    }
    if (saveChange)
        resource->setEnabled(active);
    emit dataChanged(index, index);
    return true;
}

Qt::ItemFlags ResourceModel::flags(const QModelIndex&) const
{
    return Qt::ItemIsSelectable | Qt::ItemIsEnabled | Qt::ItemIsUserCheckable;
}

/******************************************************************************
* Return the resource referred to by an index.
*/
AlarmResource* ResourceModel::resource(const QModelIndex& index) const
{
    if (!index.isValid())
        return 0;
    return static_cast<AlarmResource*>(index.internalPointer());
}

/******************************************************************************
* Emit a signal that a resource has changed.
*/
void ResourceModel::notifyChange(const QModelIndex& index)
{
    if (index.isValid())
        emit dataChanged(index, index);
}

/******************************************************************************
* Reload the resources list.
*/
void ResourceModel::refresh()
{
    // This would be better done by a reset(), but the signals are private to QAbstractItemModel
    if (!mResources.isEmpty())
    {
        beginRemoveRows(QModelIndex(), 0, mResources.count() - 1);
        mResources.clear();
        endRemoveRows();
    }
    QList<AlarmResource*> newResources;
    AlarmResourceManager* manager = AlarmResources::instance()->resourceManager();
    for (AlarmResourceManager::Iterator it = manager->begin();  it != manager->end();  ++it)
        newResources += *it;
    if (!newResources.isEmpty())
    {
        beginInsertRows(QModelIndex(), 0, newResources.count() - 1);
        mResources = newResources;
        endInsertRows();
    }
}

/******************************************************************************
* Add the specified resource to the list.
*/
void ResourceModel::addResource(AlarmResource* resource)
{
    int row = mResources.count();
    beginInsertRows(QModelIndex(), row, row);
    mResources += resource;
    endInsertRows();
}

/******************************************************************************
* Delete the specified resource from the list.
*/
void ResourceModel::removeResource(AlarmResource* resource)
{
    int row = mResources.indexOf(resource);
    if (row >= 0)
    {
        beginRemoveRows(QModelIndex(), row, row);
        mResources.removeAt(row);
        endRemoveRows();
    }
}

/******************************************************************************
* Called when the resource has been updated , to update the
* active status displayed for the resource item.
*/
void ResourceModel::updateResource(AlarmResource* resource)
{
    int row = mResources.indexOf(resource);
    if (row >= 0)
    {
        QModelIndex ix = index(row, 0, QModelIndex());
        emit dataChanged(ix, ix);
    }
}

/******************************************************************************
* Called when a different resource has been set as the standard resource.
*/
void ResourceModel::slotStandardChanged(CalEvent::Type type)
{
    for (int row = 0, end = mResources.count();  row < end;  ++row)
    {
        if (mResources[row]->alarmType() == type)
        {
            QModelIndex ix = index(row, 0, QModelIndex());
            emit dataChanged(ix, ix);
        }
    }
}

/******************************************************************************
* Called when a resource has completed loading.
* Check in case its status has changed.
*/
void ResourceModel::slotLoaded(AlarmResource* resource, bool active)
{
    if (active)
        updateResource(resource);
}

/******************************************************************************
* Called when a resource status has changed, to update the list.
*/
void ResourceModel::slotStatusChanged(AlarmResource* resource, AlarmResources::Change change)
{
    switch (change)
    {
        case AlarmResources::Added:
            addResource(resource);
            break;
        case AlarmResources::Enabled:
        case AlarmResources::ReadOnly:
        case AlarmResources::Colour:
            updateResource(resource);
            break;
        default:
            break;
    }
}


/*=============================================================================
= Class: ResourceFilterModel
= Proxy model for filtering resource lists.
=============================================================================*/

ResourceFilterModel::ResourceFilterModel(QAbstractItemModel* baseModel, QObject* parent)
    : QSortFilterProxyModel(parent),
      mResourceType(CalEvent::EMPTY)
{
    setSourceModel(baseModel);
}

void ResourceFilterModel::setFilter(CalEvent::Type type)
{
    if (type != mResourceType)
    {
        mResourceType = type;
        invalidateFilter();
    }
}

bool ResourceFilterModel::filterAcceptsRow(int sourceRow, const QModelIndex&) const
{
    return static_cast<ResourceModel*>(sourceModel())->resource(sourceModel()->index(sourceRow, 0))->alarmType() == mResourceType;
}

/******************************************************************************
* Return the resource referred to by an index.
*/
AlarmResource* ResourceFilterModel::resource(int row) const
{
    return static_cast<ResourceModel*>(sourceModel())->resource(mapToSource(index(row, 0)));
}

AlarmResource* ResourceFilterModel::resource(const QModelIndex& index) const
{
    return static_cast<ResourceModel*>(sourceModel())->resource(mapToSource(index));
}

/******************************************************************************
* Emit a signal that a resource has changed.
*/
void ResourceFilterModel::notifyChange(int row)
{
    static_cast<ResourceModel*>(sourceModel())->notifyChange(mapToSource(index(row, 0)));
}

void ResourceFilterModel::notifyChange(const QModelIndex& index)
{
    static_cast<ResourceModel*>(sourceModel())->notifyChange(mapToSource(index));
}


/*=============================================================================
= Class: ResourceDelegate
= Model/view delegate for resource list.
=============================================================================*/

/******************************************************************************
* Process a change of state of the checkbox for a resource.
*/
bool ResourceDelegate::editorEvent(QEvent* event, QAbstractItemModel* model, const QStyleOptionViewItem& option, const QModelIndex& index)
{
    if (!(model->flags(index) & Qt::ItemIsEnabled))
        return false;
    if (event->type() == QEvent::MouseButtonRelease
    ||  event->type() == QEvent::MouseButtonDblClick)
    {
        const int textMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
        QRect checkRect = QStyle::alignedRect(option.direction, Qt::AlignLeft | Qt::AlignVCenter,
                                              check(option, option.rect, Qt::Checked).size(),
                                              QRect(option.rect.x() + textMargin, option.rect.y(), option.rect.width(), option.rect.height()));
        if (!checkRect.contains(static_cast<QMouseEvent*>(event)->pos()))
            return false;
        if (event->type() == QEvent::MouseButtonDblClick)
            return true;    // ignore double clicks
    }
    else if (event->type() == QEvent::KeyPress)
    {
        if (static_cast<QKeyEvent*>(event)->key() != Qt::Key_Space
        &&  static_cast<QKeyEvent*>(event)->key() != Qt::Key_Select)
            return false;
    }
    else
        return false;

    QVariant value = index.data(Qt::CheckStateRole);
    if (!value.isValid())
        return false;
    Qt::CheckState state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked ? Qt::Unchecked : Qt::Checked);
    if (state == Qt::Unchecked)
    {
        // The resource is to be disabled.
        // Check for eligibility.
        AlarmResource* resource = static_cast<ResourceFilterModel*>(model)->resource(index);
        if (!resource)
            return false;
        if (resource->standardResource())
        {
            // It's the standard resource for its type.
            if (resource->alarmType() == CalEvent::ACTIVE)
            {
                KAMessageBox::sorry(static_cast<QWidget*>(parent()),
                                    i18nc("@info", "You cannot disable your default active alarm calendar."));
                return false;

            }
            if (resource->alarmType() == CalEvent::ARCHIVED  &&  Preferences::archivedKeepDays())
            {
                // Only allow the archived alarms standard resource to be disabled if
                // we're not saving archived alarms.
                KAMessageBox::sorry(static_cast<QWidget*>(parent()),
                                    i18nc("@info", "You cannot disable your default archived alarm calendar "
                                          "while expired alarms are configured to be kept."));
                return false;
            }
            if (KAMessageBox::warningContinueCancel(static_cast<QWidget*>(parent()),
                                                    i18nc("@info", "Do you really want to disable your default calendar?"))
                       == KMessageBox::Cancel)
                return false;
        }
    }
    return model->setData(index, state, Qt::CheckStateRole);
}


/*=============================================================================
= Class: ResourceView
= View displaying a list of resources.
=============================================================================*/

void ResourceView::setModel(QAbstractItemModel* model)
{
    model->setData(QModelIndex(), viewOptions().font, Qt::FontRole);
    QListView::setModel(model);
    setItemDelegate(new ResourceDelegate(this));
}

/******************************************************************************
* Return the resource for a given row.
*/
AlarmResource* ResourceView::resource(int row) const
{
    return static_cast<ResourceFilterModel*>(model())->resource(row);
}

AlarmResource* ResourceView::resource(const QModelIndex& index) const
{
    return static_cast<ResourceFilterModel*>(model())->resource(index);
}

/******************************************************************************
* Emit a signal that a resource has changed.
*/
void ResourceView::notifyChange(int row) const
{
    static_cast<ResourceFilterModel*>(model())->notifyChange(row);
}

void ResourceView::notifyChange(const QModelIndex& index) const
{
    static_cast<ResourceFilterModel*>(model())->notifyChange(index);
}

/******************************************************************************
* Called when a mouse button is released.
* Any currently selected resource is deselected.
*/
void ResourceView::mouseReleaseEvent(QMouseEvent* e)
{
    if (!indexAt(e->pos()).isValid())
        clearSelection();
    QListView::mouseReleaseEvent(e);
}

/******************************************************************************
* Called when a ToolTip or WhatsThis event occurs.
*/
bool ResourceView::viewportEvent(QEvent* e)
{
    if (e->type() == QEvent::ToolTip  &&  isActiveWindow())
    {
        QHelpEvent* he = static_cast<QHelpEvent*>(e);
        QModelIndex index = indexAt(he->pos());
        QVariant value = model()->data(index, Qt::ToolTipRole);
        if (qVariantCanConvert<QString>(value))
        {
            QString toolTip = value.toString();
            int i = toolTip.indexOf('@');
            if (i > 0)
            {
                int j = toolTip.indexOf(QRegExp("<(nl|br)", Qt::CaseInsensitive), i + 1);
                int k = toolTip.indexOf('@', j);
                QString name = toolTip.mid(i + 1, j - i - 1);
                value = model()->data(index, Qt::FontRole);
                QFontMetrics fm(qvariant_cast<QFont>(value).resolve(viewOptions().font));
                int textWidth = fm.boundingRect(name).width() + 1;
                const int margin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
                QStyleOptionButton opt;
                opt.QStyleOption::operator=(viewOptions());
                opt.rect = rectForIndex(index);
                int checkWidth = QApplication::style()->subElementRect(QStyle::SE_ViewItemCheckIndicator, &opt).width();
                int left = spacing() + 3*margin + checkWidth + viewOptions().decorationSize.width();   // left offset of text
                int right = left + textWidth;
                if (left >= horizontalOffset() + spacing()
                &&  right <= horizontalOffset() + width() - spacing() - 2*frameWidth())
                {
                    // The whole of the resource name is already displayed,
                    // so omit it from the tooltip.
                    if (k > 0)
                        toolTip.remove(i, k + 1 - i);
                }
                else
                {
                    toolTip.remove(k, 1);
                    toolTip.remove(i, 1);
                }
            }
            QToolTip::showText(he->globalPos(), toolTip, this);
            return true;
        }
    }
    return QListView::viewportEvent(e);
}

// vim: et sw=4: