/*
 * SPDX-FileCopyrightText: 2020 Mathias Wein <lynx.mw+kde@gmail.com>
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

#include "WGSelectorConfigGrid.h"

#include "KisVisualColorSelector.h"

#include "kis_debug.h"

#include <QAction>
#include <QActionGroup>
#include <QEvent>
#include <QGridLayout>
#include <QIcon>
#include <QPainter>
#include <QString>
#include <QTimer>
#include <QToolButton>


class SelectorConfigAction: public QAction
{
public:
    explicit SelectorConfigAction(const KisColorSelectorConfiguration &cfg, QObject *parent)
        : QAction(parent)
        , m_config(cfg)
    {
        setCheckable(true);
    }
    const KisColorSelectorConfiguration& configuration() { return m_config; }
private:
    KisColorSelectorConfiguration m_config;
};

WGSelectorConfigGrid::WGSelectorConfigGrid(QWidget *parent, bool multiSelect)
    : QWidget(parent)
    , m_layout(new QGridLayout(this))
    , m_actionGroup(new QActionGroup(this))
    , m_selector(new KisVisualColorSelector(this))
{
    m_actionGroup->setExclusive(!multiSelect);
    connect(m_actionGroup, SIGNAL(triggered(QAction*)), SLOT(slotActionTriggered(QAction*)));

    m_selector->setMinimumSliderWidth(10);
    m_selector->setGeometry(0, 0, m_iconSize, m_iconSize - 2);
    m_selector->setVisible(false);
    m_selector->setEnabled(false);
    m_selector->slotSetColorSpace(KoColorSpaceRegistry::instance()->rgb8());
    m_selector->slotSetColor(KoColor(QColor(255, 0, 0), KoColorSpaceRegistry::instance()->rgb8()));
}

void WGSelectorConfigGrid::clear()
{
    while (QLayoutItem *child = m_layout->takeAt(0)) {
        delete child->widget();
        delete child;
    }
    qDeleteAll(m_actionGroup->actions());
}

QIcon WGSelectorConfigGrid::currentIcon() const
{
    return (m_currentAction && m_currentAction != m_dummyAction) ? m_currentAction->icon() : QIcon();
}

KisColorSelectorConfiguration WGSelectorConfigGrid::currentConfiguration() const
{
    if (m_currentAction != m_dummyAction) {
        SelectorConfigAction *sa = dynamic_cast<SelectorConfigAction *>(m_currentAction);
        if (sa) {
            return sa->configuration();
        }
    }
    return KisColorSelectorConfiguration();
}

QVector<KisColorSelectorConfiguration> WGSelectorConfigGrid::selectedConfigurations() const
{
    QVector<KisColorSelectorConfiguration> configurations;
    const QList<QAction*> actions = m_actionGroup->actions();
    for (QAction *action : actions) {
        SelectorConfigAction *sa = dynamic_cast<SelectorConfigAction *>(action);
        if (sa && sa->isChecked()) {
            configurations.append(sa->configuration());
        }
    }
    return configurations;
}

void WGSelectorConfigGrid::setColorModel(KisVisualColorModel::ColorModel model)
{
    if (model != m_selector->selectorModel()->colorModel()) {
        m_selector->selectorModel()->setRGBColorModel(model);
        updateIcons();
    }
}

void WGSelectorConfigGrid::setConfigurations(const QVector<KisColorSelectorConfiguration> &configurations)
{
    clear();
    // exclusive action groups have no nice way to set none as checked, and
    // ExclusiveOptional is not what we want either, so use a dummy action
    m_dummyAction = new QAction("dummy", m_actionGroup);
    m_dummyAction->setCheckable(true);
    m_dummyAction->setChecked(true);
    m_currentAction = m_dummyAction;

    for (int i = 0; i < configurations.size(); i++) {
        const KisColorSelectorConfiguration &config = configurations.at(i);
        SelectorConfigAction *action = new SelectorConfigAction(config, m_actionGroup);
        //action->setText(QString("TBD %1").arg(i));
        action->setIcon(generateIcon(config, devicePixelRatioF(), true));

        QToolButton *button = new QToolButton(this);
        button->setAutoRaise(true);
        button->setDefaultAction(action);
        button->setIconSize(QSize(m_iconSize, m_iconSize));
        m_layout->addWidget(button, i/m_columns, i%m_columns);
    }
}

void WGSelectorConfigGrid::setChecked(const KisColorSelectorConfiguration &configuration)
{
    const QList<QAction*> actions = m_actionGroup->actions();
    for (QAction *action : actions) {
        SelectorConfigAction *sa = dynamic_cast<SelectorConfigAction *>(action);
        if (sa && sa->configuration() == configuration) {
            sa->setChecked(true);
            m_currentAction = action;
            return;
        }
    }
    m_dummyAction->setChecked(true);
    m_currentAction = m_dummyAction;
}

QIcon WGSelectorConfigGrid::generateIcon(const KisColorSelectorConfiguration &configuration, qreal pixelRatio, bool dualState) const
{
    QSize sz(m_selector->width() * pixelRatio, m_selector->height() * pixelRatio);
    QPixmap pixmap(sz);
    pixmap.setDevicePixelRatio(pixelRatio);
    pixmap.fill(Qt::transparent);
    m_selector->setConfiguration(&configuration);
    QPoint offset(0, dualState ? 2 : 1);
    m_selector->render(&pixmap, offset, QRegion(), RenderFlag::DrawChildren);
    QIcon icon(pixmap);

    if (!dualState) {
        return icon;
    }

    // highlight bar for on-icon
    QPainter painter(&pixmap);
    painter.setRenderHint(QPainter::Antialiasing);
    QBrush highlight(palette().brush(QPalette::Active, QPalette::Highlight));
    painter.setPen(QPen(highlight, 2.0,  Qt::SolidLine, Qt::RoundCap));
    painter.drawLine(1, 1, m_iconSize-1, 1);
    painter.end();
    icon.addPixmap(pixmap, QIcon::Normal, QIcon::On);
    return icon;
}

QVector<KisColorSelectorConfiguration> WGSelectorConfigGrid::hueBasedConfigurations()
{
    using KCSC = KisColorSelectorConfiguration;
    QVector<KCSC> configs;
    configs.push_back(KCSC(KCSC::Triangle, KCSC::Ring, KCSC::SV, KCSC::H));
    configs.push_back(KCSC(KCSC::Square, KCSC::Ring, KCSC::SV, KCSC::H));
    configs.push_back(KCSC(KCSC::Wheel, KCSC::Slider, KCSC::VH, KCSC::hsvS));
    configs.push_back(KCSC(KCSC::Wheel, KCSC::Slider, KCSC::hsvSH, KCSC::V));
    configs.push_back(KCSC(KCSC::Square, KCSC::Slider, KCSC::SV, KCSC::H));
    configs.push_back(KCSC(KCSC::Square, KCSC::Slider, KCSC::VH, KCSC::hsvS));
    configs.push_back(KCSC(KCSC::Square, KCSC::Slider, KCSC::hsvSH, KCSC::V));
    return configs;
}

bool WGSelectorConfigGrid::event(QEvent *event)
{
    bool handled = QWidget::event(event);
    if (event->type() == QEvent::PaletteChange) {
        // For some reason, Qt doesn't like if we recreate the icons from this
        // even handler and randomly crashes somewhere after this function returns
        QTimer::singleShot(0, this, &WGSelectorConfigGrid::updateIcons);
        event->accept();
        handled = true;
    }
    return handled;
}

void WGSelectorConfigGrid::slotActionTriggered(QAction *action)
{
    // Unfortunately, exclusive QActionGroups don't filter out attempts to toggle
    // an action that is already checked, so need to check ourselves if checked
    // action really changed. Checking the hidden dummy also is a silent operation.
    if (action == m_currentAction) {
        return;
    }
    m_currentAction = action;
    if (action != m_dummyAction) {
        SelectorConfigAction *sa = dynamic_cast<SelectorConfigAction *>(action);
        KIS_SAFE_ASSERT_RECOVER_RETURN(sa);

        Q_EMIT sigConfigSelected(sa->configuration());
    }
}

void WGSelectorConfigGrid::updateIcons() {
    const QList<QAction*> actions = m_actionGroup->actions();
    for (QAction *action : actions) {
        SelectorConfigAction *sa = dynamic_cast<SelectorConfigAction *>(action);
        if (sa) {
            sa->setIcon(generateIcon(sa->configuration(), devicePixelRatioF(), true));
        }
    }
}
