/*
 * <one line to give the library's name and an idea of what it does.>
 * Copyright 2013  Luca Beltrame <lbeltrame@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) version 3 or any later version
 * accepted by the membership of KDE e.V. (or its successor approved
 * by the membership of KDE e.V.), which shall act as a proxy
 * defined in Section 14 of version 3 of the license.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 */

// Own

#include "danboorupostdelegate.h"
#include "libdanbooru/danboorupost.h"

// Qt

#include <QListView>
#include <QPainter>
#include <QDebug>
#include <QApplication>

// KDE

#include <KPushButton>

namespace Danbooru {

    const int DanbooruPostDelegate::MARGIN = 5;

    DanbooruPostDelegate::DanbooruPostDelegate(QListView* itemView):QStyledItemDelegate(itemView),
                                                                    m_itemView(itemView)
    {


        //FIXME: Copied directly from Gwenview without understanding

        #define pm(x) itemView->style()->pixelMetric(QStyle::x)
        m_margin = pm(PM_ToolBarItemMargin);
        m_spacing = pm(PM_ToolBarItemSpacing);
        #undef pm

        const int iconSize = KIconLoader::global()->currentSize(
            KIconLoader::Toolbar
        );

        const QSize sz = itemView->style()->sizeFromContents(
            QStyle::CT_ToolButton, 0,
            QSize(iconSize, iconSize));

        m_buttonSize = qMax(sz.width(), sz.height());

        m_downloadButton =  new KPushButton(KIcon("download"),
                                            QString(), itemView);
        m_viewButton = new KPushButton(KIcon("view-preview"), QString(),
                                             itemView);

        m_downloadButton->hide();
        m_viewButton->hide();

        m_downloadButton->resize(m_buttonSize, m_buttonSize);
        m_viewButton->resize(m_buttonSize, m_buttonSize);

    }

    void DanbooruPostDelegate::paint(QPainter* painter,
                                     const QStyleOptionViewItem& option,
                                     const QModelIndex& index) const
    {

        if (!index.isValid()) {
            return;
        }

        QStyle *style = QApplication::style();

        style->drawPrimitive(QStyle::PE_PanelItemViewItem, &option, painter, 0);
        painter->setRenderHint(QPainter::Antialiasing);

        QPixmap pixmap = index.data(Qt::DecorationRole).value<QPixmap>();

        if (pixmap.isNull()) {
            return;
        }

        // Scaling is unavoidable to keep things in the right dimension
        //TODO: Replace fixed values by configurable values

        QPixmap scaled = pixmap.scaled(256-MARGIN, 256-MARGIN,
                                       Qt::KeepAspectRatio,
                                       Qt::SmoothTransformation);


        QRect rect = option.rect;

        // Draw in the center

        QPoint centerCoordinate = rect.center() - QPoint(scaled.width() / 2,
                                                         scaled.height() / 2);

        // Get the bottom coordinate for the buttons, made as center - half
        // of the pixmap width (left) then half of the height minus the button
        // size and margin (because the move() call later on uses the
        // coordinates as TOP coordinates, while we want the bottom of the
        // button to align with the bottom of the pixmap)

        QPoint scaleFactor = QPoint(
            -(scaled.width() / 2) + (MARGIN / 2),
            (scaled.height() / 2) - m_buttonSize + (MARGIN * 1.5)
        );

        QPoint bottomCoordinate = rect.center() + scaleFactor;

        painter->drawPixmap(centerCoordinate, scaled);

        if (option.state & QStyle::State_MouseOver) {

            m_downloadButton->move(centerCoordinate + QPoint(MARGIN / 2, 0));
            m_viewButton->move(bottomCoordinate);

            m_downloadButton->show();
            m_viewButton->show();

        } else if (!hoveredIndex().isValid()) {
            m_downloadButton->hide();
            m_viewButton->hide();
        }

    }

    QSize DanbooruPostDelegate::sizeHint(const QStyleOptionViewItem& option,
                                         const QModelIndex& index) const
    {
        Q_UNUSED(option)
        Q_UNUSED(index)
        return m_itemView->gridSize();
    }

    QModelIndex DanbooruPostDelegate::hoveredIndex() const
    {
        const QPoint pos = m_itemView->viewport()->mapFromGlobal(QCursor::pos());
        return m_itemView->indexAt(pos);
    }

} // namespace Danbooru