/*
    KWin - the KDE window manager
    This file is part of the KDE project.

    SPDX-FileCopyrightText: 2009 Lucas Murray <lmurray@undefinedfire.com>
    SPDX-FileCopyrightText: 2021 David Redondo <kde@david-redondo.de>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#include "highlightwindow.h"

#include <QDBusConnection>
#include <QUuid>

Q_LOGGING_CATEGORY(KWIN_HIGHLIGHTWINDOW, "kwin_effect_highlightwindow", QtWarningMsg)

namespace KWin
{

HighlightWindowEffect::HighlightWindowEffect()
    : m_easingCurve(QEasingCurve::Linear)
    , m_fadeDuration(animationTime(150))
    , m_monitorWindow(nullptr)
{
    // TODO KF6 remove atom support
    m_atom = effects->announceSupportProperty("_KDE_WINDOW_HIGHLIGHT", this);
    connect(effects, &EffectsHandler::windowAdded, this, &HighlightWindowEffect::slotWindowAdded);
    connect(effects, &EffectsHandler::windowClosed, this, &HighlightWindowEffect::slotWindowClosed);
    connect(effects, &EffectsHandler::windowDeleted, this, &HighlightWindowEffect::slotWindowDeleted);
    connect(effects, &EffectsHandler::propertyNotify, this, [this](EffectWindow *w, long atom) {
        slotPropertyNotify(w, atom, nullptr);
    });
    connect(effects, &EffectsHandler::xcbConnectionChanged, this, [this]() {
        m_atom = effects->announceSupportProperty("_KDE_WINDOW_HIGHLIGHT", this);
    });

    QDBusConnection::sessionBus().registerObject(QStringLiteral("/org/kde/KWin/HighlightWindow"),
                                                 QStringLiteral("org.kde.KWin.HighlightWindow"),
                                                 this,
                                                 QDBusConnection::ExportScriptableContents);
    QDBusConnection::sessionBus().registerService(QStringLiteral("org.kde.KWin.HighlightWindow"));
}

HighlightWindowEffect::~HighlightWindowEffect()
{
    QDBusConnection::sessionBus().unregisterService(QStringLiteral("org.kde.KWin.HighlightWindow"));
}

static bool isInitiallyHidden(EffectWindow *w)
{
    // Is the window initially hidden until it is highlighted?
    return w->isMinimized() || !w->isOnCurrentDesktop();
}

static bool isHighlightWindow(EffectWindow *window)
{
    return window->isNormalWindow() || window->isDialog();
}

void HighlightWindowEffect::highlightWindows(const QStringList &windows)
{
    QVector<EffectWindow *> effectWindows;
    effectWindows.reserve(windows.count());
    for (const auto &window : windows) {
        if (auto effectWindow = effects->findWindow(QUuid(window)); effectWindow) {
            effectWindows.append(effectWindow);
        } else if (auto effectWindow = effects->findWindow(window.toLong()); effectWindow) {
            effectWindows.append(effectWindow);
        }
    }
    highlightWindows(effectWindows);
}

void HighlightWindowEffect::slotWindowAdded(EffectWindow *w)
{
    if (!m_highlightedWindows.isEmpty()) {
        // On X11, the tabbox may ask us to highlight itself before the windowAdded signal
        // is emitted because override-redirect windows are shown after synthetic 50ms delay.
        if (m_highlightedWindows.contains(w)) {
            return;
        }
        // This window was demanded to be highlighted before it appeared on the screen.
        for (const WId &id : std::as_const(m_highlightedIds)) {
            if (w == effects->findWindow(id)) {
                const quint64 animationId = startHighlightAnimation(w);
                complete(animationId);
                return;
            }
        }
        if (isHighlightWindow(w)) {
            const quint64 animationId = startGhostAnimation(w); // this window is not currently highlighted
            complete(animationId);
        }
    }
    slotPropertyNotify(w, m_atom, w); // Check initial value
}

void HighlightWindowEffect::slotWindowClosed(EffectWindow *w)
{
    if (m_monitorWindow == w) { // The monitoring window was destroyed
        finishHighlighting();
    }
}

void HighlightWindowEffect::slotWindowDeleted(EffectWindow *w)
{
    m_animations.remove(w);
}

void HighlightWindowEffect::slotPropertyNotify(EffectWindow *w, long a, EffectWindow *addedWindow)
{
    if (a != m_atom || m_atom == XCB_ATOM_NONE) {
        return; // Not our atom
    }

    // if the window is null, the property was set on the root window - see events.cpp
    QByteArray byteData = w ? w->readProperty(m_atom, m_atom, 32) : effects->readRootProperty(m_atom, m_atom, 32);
    if (byteData.length() < 1) {
        // Property was removed, clearing highlight
        if (!addedWindow || w != addedWindow) {
            finishHighlighting();
        }
        return;
    }
    auto *data = reinterpret_cast<uint32_t *>(byteData.data());

    if (!data[0]) {
        // Purposely clearing highlight by issuing a NULL target
        finishHighlighting();
        return;
    }
    m_monitorWindow = w;
    bool found = false;
    int length = byteData.length() / sizeof(data[0]);
    // foreach ( EffectWindow* e, m_highlightedWindows )
    //     effects->setElevatedWindow( e, false );
    m_highlightedWindows.clear();
    m_highlightedIds.clear();
    for (int i = 0; i < length; i++) {
        m_highlightedIds << data[i];
        EffectWindow *foundWin = effects->findWindow(data[i]);
        if (!foundWin) {
            qCDebug(KWIN_HIGHLIGHTWINDOW) << "Invalid window targetted for highlight. Requested:" << data[i];
            continue; // might come in later.
        }
        m_highlightedWindows.append(foundWin);
        // TODO: We cannot just simply elevate the window as this will elevate it over
        // Plasma tooltips and other such windows as well
        // effects->setElevatedWindow( foundWin, true );
        found = true;
    }
    if (!found) {
        finishHighlighting();
        return;
    }
    prepareHighlighting();
}

void HighlightWindowEffect::prepareHighlighting()
{
    const EffectWindowList windows = effects->stackingOrder();
    for (EffectWindow *window : windows) {
        if (window->isWaterMark()) {
            effects->setElevatedWindow(window, true);
        }
        if (!isHighlightWindow(window)) {
            continue;
        }
        if (isHighlighted(window)) {
            startHighlightAnimation(window);
        } else {
            startGhostAnimation(window);
        }
    }
}

void HighlightWindowEffect::finishHighlighting()
{
    const EffectWindowList windows = effects->stackingOrder();
    for (EffectWindow *window : windows) {
        if (isHighlightWindow(window)) {
            startRevertAnimation(window);
        }
    }

    // Sanity check, ideally, this should never happen.
    if (!m_animations.isEmpty()) {
        for (quint64 &animationId : m_animations) {
            cancel(animationId);
        }
        m_animations.clear();
    }

    m_monitorWindow = nullptr;
    m_highlightedWindows.clear();
}

void HighlightWindowEffect::highlightWindows(const QVector<KWin::EffectWindow *> &windows)
{
    if (windows.isEmpty()) {
        finishHighlighting();
        return;
    }

    m_monitorWindow = nullptr;
    m_highlightedWindows.clear();
    m_highlightedIds.clear();
    for (auto w : windows) {
        m_highlightedWindows << w;
    }
    prepareHighlighting();
}

quint64 HighlightWindowEffect::startGhostAnimation(EffectWindow *window)
{
    quint64 &animationId = m_animations[window];
    const float ghostOpacity = isInitiallyHidden(window) ? 0 : m_ghostOpacity;
    if (animationId) {
        retarget(animationId, FPx2(ghostOpacity, ghostOpacity), m_fadeDuration);
    } else {
        const qreal startOpacity = isInitiallyHidden(window) ? 0 : 1;
        if (m_highlightedWindows.contains(window) || startOpacity == 1)
            animationId = set(window, Opacity, 0, m_fadeDuration, FPx2(ghostOpacity, ghostOpacity),
                          m_easingCurve, 0, FPx2(startOpacity, startOpacity), false, false);
    }
    return animationId;
}

quint64 HighlightWindowEffect::startHighlightAnimation(EffectWindow *window)
{
    quint64 &animationId = m_animations[window];
    if (animationId) {
        retarget(animationId, FPx2(1.0, 1.0), m_fadeDuration);
    } else {
        const qreal startOpacity = isInitiallyHidden(window) ? 0 : 1;
        animationId = set(window, Opacity, 0, m_fadeDuration, FPx2(1.0, 1.0),
                          m_easingCurve, 0, FPx2(startOpacity, startOpacity), false, false);
    }
    return animationId;
}

void HighlightWindowEffect::startRevertAnimation(EffectWindow *window)
{
    const quint64 animationId = m_animations.take(window);
    if (animationId) {
        const qreal startOpacity = isHighlighted(window) ? 1 : (isInitiallyHidden(window) ? 0 : m_ghostOpacity);
        const qreal endOpacity = isInitiallyHidden(window) ? 0 : 1;
        animate(window, Opacity, 0, m_fadeDuration, FPx2(endOpacity, endOpacity),
                m_easingCurve, 0, FPx2(startOpacity, startOpacity), false, false);
        cancel(animationId);
    }
}

bool HighlightWindowEffect::isHighlighted(EffectWindow *window) const
{
    return m_highlightedWindows.contains(window);
}

bool HighlightWindowEffect::provides(Feature feature)
{
    switch (feature) {
    case HighlightWindows:
        return true;
    default:
        return false;
    }
}

bool HighlightWindowEffect::perform(Feature feature, const QVariantList &arguments)
{
    if (feature != HighlightWindows) {
        return false;
    }
    if (arguments.size() != 1) {
        return false;
    }
    highlightWindows(arguments.first().value<QVector<EffectWindow *>>());
    return true;
}

} // namespace
