/*
    Copyright (c) 2010 Casey Link <unnamedrambler@gmail.com>
    Copyright (c) 2009-2010 Klaralvdalens Datakonsult AB, a KDAB Group company <info@kdab.net>
    Copyright (c) 2006-2008 Tobias Koenig <tokoe@kde.org>

    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 "configagentdelegate.h"

#include <AkonadiCore/AgentInstanceModel>
#include <AkonadiCore/AgentInstance>

#include <QIcon>
#include <KLocalizedString>
#include <KIconLoader>

#include <QUrl>
#include <QApplication>
#include <QPainter>
#include <QTextDocument>
#include <QMouseEvent>

using Akonadi::AgentInstanceModel;
using Akonadi::AgentInstance;

static const int s_delegatePaddingSize = 7;

struct Icons {
    Icons()
        : readyPixmap(QIcon::fromTheme(QStringLiteral("user-online")).pixmap(QSize(16, 16)))
        , syncPixmap(QIcon::fromTheme(QStringLiteral("network-connect")).pixmap(QSize(16, 16)))
        , errorPixmap(QIcon::fromTheme(QStringLiteral("dialog-error")).pixmap(QSize(16, 16)))
        , offlinePixmap(QIcon::fromTheme(QStringLiteral("network-disconnect")).pixmap(QSize(16, 16)))
        , checkMailIcon(QIcon::fromTheme(QStringLiteral("mail-receive")))
    {
    }
    QPixmap readyPixmap, syncPixmap, errorPixmap, offlinePixmap;
    QIcon checkMailIcon;
};

Q_GLOBAL_STATIC(Icons, s_icons)

ConfigAgentDelegate::ConfigAgentDelegate(QObject *parent)
    : QStyledItemDelegate(parent)
{
}

QTextDocument *ConfigAgentDelegate::document(const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    if (!index.isValid()) {
        return Q_NULLPTR;
    }

    const QString name = index.model()->data(index, Qt::DisplayRole).toString();
    int status = index.model()->data(index, AgentInstanceModel::StatusRole).toInt();
    uint progress = index.model()->data(index, AgentInstanceModel::ProgressRole).toUInt();
    const QString statusMessage = index.model()->data(index, AgentInstanceModel::StatusMessageRole).toString();

    QTextDocument *document = new QTextDocument(Q_NULLPTR);

    const QSize decorationSize(KIconLoader::global()->currentSize(KIconLoader::Desktop), KIconLoader::global()->currentSize(KIconLoader::Desktop));
    const QVariant data = index.model()->data(index, Qt::DecorationRole);
    if (data.isValid() && data.type() == QVariant::Icon) {
        document->addResource(QTextDocument::ImageResource, QUrl(QStringLiteral("agent_icon")),
                              qvariant_cast<QIcon> (data).pixmap(decorationSize));
    }

    if (!index.data(AgentInstanceModel::OnlineRole).toBool()) {
        document->addResource(QTextDocument::ImageResource, QUrl(QStringLiteral("status_icon")), s_icons->offlinePixmap);
    } else if (status == AgentInstance::Idle) {
        document->addResource(QTextDocument::ImageResource, QUrl(QStringLiteral("status_icon")), s_icons->readyPixmap);
    } else if (status == AgentInstance::Running) {
        document->addResource(QTextDocument::ImageResource, QUrl(QStringLiteral("status_icon")), s_icons->syncPixmap);
    } else {
        document->addResource(QTextDocument::ImageResource, QUrl(QStringLiteral("status_icon")), s_icons->errorPixmap);
    }

    QPalette::ColorGroup cg = option.state & QStyle::State_Enabled ? QPalette::Normal : QPalette::Disabled;
    if (cg == QPalette::Normal && !(option.state & QStyle::State_Active)) {
        cg = QPalette::Inactive;
    }

    QColor textColor;
    if (option.state & QStyle::State_Selected) {
        textColor = option.palette.color(cg, QPalette::HighlightedText);
    } else {
        textColor = option.palette.color(cg, QPalette::Text);
    }

    const QString content = QStringLiteral(
                                "<html style=\"color:%1\">"
                                "<body>"
                                "<table>"
                                "<tr>"
                                "<td rowspan=\"2\"><img src=\"agent_icon\">&nbsp;&nbsp;</td>"
                                "<td><b>%2</b></td>"
                                "</tr>").arg(textColor.name().toUpper()).arg(name)
                            + QStringLiteral(
                                "<tr>"
                                "<td><img src=\"status_icon\"/> %1 %2</td>"
                                "</tr>").arg(statusMessage).arg(status == 1 ? QStringLiteral("(%1%)").arg(progress) : QLatin1String(""))
                            + QLatin1String("</table></body></html>");

    document->setHtml(content);

    return document;
}

void ConfigAgentDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    if (!index.isValid()) {
        return;
    }

    QTextDocument *doc = document(option, index);
    if (!doc) {
        return;
    }

    QStyleOptionButton buttonOpt = buttonOption(option);

    doc->setTextWidth(option.rect.width() - buttonOpt.rect.width());
    painter->setRenderHint(QPainter::Antialiasing);

    QPen pen = painter->pen();

    QPalette::ColorGroup cg = option.state & QStyle::State_Enabled ? QPalette::Normal : QPalette::Disabled;
    if (cg == QPalette::Normal && !(option.state & QStyle::State_Active)) {
        cg = QPalette::Inactive;
    }

    QStyleOptionViewItemV4 opt(option);
    opt.showDecorationSelected = true;
    QApplication::style()->drawPrimitive(QStyle::PE_PanelItemViewItem, &opt, painter);
    painter->save();
    painter->translate(option.rect.topLeft());

    doc->drawContents(painter);

    QApplication::style()->drawControl(QStyle::CE_PushButton, &buttonOpt, painter);

    painter->restore();
    painter->setPen(pen);

    drawFocus(painter, option, option.rect);
    delete doc;
}

QSize ConfigAgentDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &) const
{
    const int iconHeight = KIconLoader::global()->currentSize(KIconLoader::Desktop) + (s_delegatePaddingSize * 2);  //icon height + padding either side
    const int textHeight = option.fontMetrics.height() + qMax(option.fontMetrics.height(), 16) + (s_delegatePaddingSize * 2);   //height of text + icon/text + padding either side

    return QSize(1, qMax(iconHeight, textHeight));    //any width,the view will give us the whole thing in list mode
}

QWidget   *ConfigAgentDelegate::createEditor(QWidget *, const QStyleOptionViewItem &, const QModelIndex &) const
{
    return Q_NULLPTR;
}

bool ConfigAgentDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index)
{
    Q_UNUSED(model);
    if (!index.isValid()) {
        return false;
    }
    if (!((event->type() == QEvent::MouseButtonRelease)
            || (event->type() == QEvent::MouseButtonPress)
            || (event->type() == QEvent::MouseMove))) {
        return false;
    }

    QMouseEvent *me = static_cast<QMouseEvent *>(event);
    const QPoint mousePos = me->pos() - option.rect.topLeft();

    QStyleOptionButton buttonOpt = buttonOption(option);

    if (buttonOpt.rect.contains(mousePos)) {

        switch (event->type()) {
        case QEvent::MouseButtonPress:
            return false;
        case QEvent::MouseButtonRelease: {
            QPoint pos = buttonOpt.rect.bottomLeft() + option.rect.topLeft();
            const QString ident = index.data(Akonadi::AgentInstanceModel::InstanceIdentifierRole).toString();
            Q_EMIT optionsClicked(ident, pos);
            return true;
        }
        default:
            return false;
        }
    }
    return false;
}

void ConfigAgentDelegate::drawFocus(QPainter *painter, const QStyleOptionViewItem &option, const QRect &rect) const
{
    if (option.state & QStyle::State_HasFocus) {
        QStyleOptionFocusRect o;
        o.QStyleOption::operator= (option);
        o.rect = rect;
        o.state |= QStyle::State_KeyboardFocusChange;
        QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled) ? QPalette::Normal : QPalette::Disabled;
        o.backgroundColor = option.palette.color(cg, (option.state & QStyle::State_Selected)
                            ? QPalette::Highlight : QPalette::Background);
        QApplication::style()->drawPrimitive(QStyle::PE_FrameFocusRect, &o, painter);
    }
}

QStyleOptionButton ConfigAgentDelegate::buttonOption(const QStyleOptionViewItem &option) const
{
    const QString label = i18n("Retrieval Options");
    QStyleOptionButton buttonOpt;
    QRect buttonRect = option.rect;
    int height = option.rect.height() / 2;
    int width = 22 + option.fontMetrics.width(label) + 40;   // icon size + label size + arrow and padding
    buttonRect.setTop(0/*( option.rect.height() /2  ) - height / 2)*/);    // center the button vertically
    buttonRect.setHeight(height);
    buttonRect.setLeft(option.rect.right() - width);
    buttonRect.setWidth(width);

    buttonOpt.rect = buttonRect;
    buttonOpt.state = option.state;
    buttonOpt.text = label;
    buttonOpt.palette = option.palette;
    buttonOpt.features = QStyleOptionButton::HasMenu;
    buttonOpt.icon = s_icons->checkMailIcon;
    buttonOpt.iconSize = QSize(22, 22);    // FIXME don't hardcode this icon size

    return buttonOpt;
}