// SPDX-License-Identifier: GPL-3.0-or-later
// SPDX-FileCopyrightText: 2017-2019 Alejandro Sirgo Rica & Contributors

#include "screengrabber.h"
#include "src/core/qguiappcurrentscreen.h"
#include "src/utils/filenamehandler.h"
#include "src/utils/systemnotification.h"
#include <QApplication>
#include <QDesktopWidget>
#include <QGuiApplication>
#include <QPixmap>
#include <QScreen>

#if defined(Q_OS_LINUX) || defined(Q_OS_UNIX)
#include "request.h"
#include <QDBusInterface>
#include <QDBusReply>
#include <QDir>
#include <QUuid>
#endif

ScreenGrabber::ScreenGrabber(QObject* parent)
  : QObject(parent)
{}

QPixmap ScreenGrabber::grabEntireDesktop(bool& ok)
{
    ok = true;
#if defined(Q_OS_MACOS)
    QScreen* currentScreen = QGuiAppCurrentScreen().currentScreen();
    QPixmap screenPixmap(
      currentScreen->grabWindow(QApplication::desktop()->winId(),
                                currentScreen->geometry().x(),
                                currentScreen->geometry().y(),
                                currentScreen->geometry().width(),
                                currentScreen->geometry().height()));
    screenPixmap.setDevicePixelRatio(currentScreen->devicePixelRatio());
    return screenPixmap;
#elif defined(Q_OS_LINUX) || defined(Q_OS_UNIX)
    if (m_info.waylandDectected()) {
        QPixmap res;
        // handle screenshot based on DE
        switch (m_info.windowManager()) {
            case DesktopInfo::GNOME: {
                // https://github.com/GNOME/gnome-shell/blob/695bfb96160033be55cfb5ac41c121998f98c328/data/org.gnome.Shell.Screenshot.xml
                QString path =
                  FileNameHandler().generateAbsolutePath(QDir::tempPath()) +
                  ".png";
                QDBusInterface gnomeInterface(
                  QStringLiteral("org.gnome.Shell"),
                  QStringLiteral("/org/gnome/Shell/Screenshot"),
                  QStringLiteral("org.gnome.Shell.Screenshot"));
                QDBusReply<bool> reply = gnomeInterface.call(
                  QStringLiteral("Screenshot"), false, false, path);
                if (reply.value()) {
                    res = QPixmap(path);
                    QFile dbusResult(path);
                    dbusResult.remove();
                } else {
                    ok = false;
                }
                break;
            }
            case DesktopInfo::KDE: {
                // https://github.com/KDE/spectacle/blob/517a7baf46a4ca0a45f32fd3f2b1b7210b180134/src/PlatformBackends/KWinWaylandImageGrabber.cpp#L145
                QDBusInterface kwinInterface(
                  QStringLiteral("org.kde.KWin"),
                  QStringLiteral("/Screenshot"),
                  QStringLiteral("org.kde.kwin.Screenshot"));
                QDBusReply<QString> reply =
                  kwinInterface.call(QStringLiteral("screenshotFullscreen"));
                res = QPixmap(reply.value());
                if (!res.isNull()) {
                    QFile dbusResult(reply.value());
                    dbusResult.remove();
                }
                break;
            }
            case DesktopInfo::SWAY: {
                QDBusInterface screenshotInterface(
                  QStringLiteral("org.freedesktop.portal.Desktop"),
                  QStringLiteral("/org/freedesktop/portal/desktop"),
                  QStringLiteral("org.freedesktop.portal.Screenshot"));

                // unique token
                QString token = QUuid::createUuid().toString(QUuid::Id128);

                // premake interface
                auto* request = new OrgFreedesktopPortalRequestInterface(
                  QStringLiteral("org.freedesktop.portal.Desktop"),
                  "/org/freedesktop/portal/desktop/request/" +
                    QDBusConnection::sessionBus()
                      .baseService()
                      .remove(':')
                      .replace('.', '_') +
                    "/" + token,
                  QDBusConnection::sessionBus(),
                  this);

                QEventLoop loop;
                const auto gotSignal = [&res, &loop](uint status,
                                                     const QVariantMap& map) {
                    if (status == 0) {
                        QString uri = map.value("uri").toString().remove(0, 7);
                        res = QPixmap(uri);
                        res.setDevicePixelRatio(qApp->devicePixelRatio());
                        QFile imgFile(uri);
                        imgFile.remove();
                    }
                    loop.quit();
                };

                // prevent racy situations and listen before calling screenshot
                QMetaObject::Connection conn =
                  QObject::connect(request,
                                   &org::freedesktop::portal::Request::Response,
                                   gotSignal);

                screenshotInterface.call(
                  QStringLiteral("Screenshot"),
                  "",
                  QMap<QString, QVariant>(
                    { { "handle_token", QVariant(token) },
                      { "interactive", QVariant(false) } }));

                loop.exec();
                QObject::disconnect(conn);
                request->Close().waitForFinished();
                request->deleteLater();

                if (res.isNull()) {
                    ok = false;
                }
                break;
            }
            default:
                ok = false;
                break;
        }
        if (!ok) {
            SystemNotification().sendMessage(tr("Unable to capture screen"));
        }
        return res;
    }
#endif
#if defined(Q_OS_LINUX) || defined(Q_OS_UNIX) || defined(Q_OS_WIN)
    QRect geometry;
    for (QScreen* const screen : QGuiApplication::screens()) {
        QRect scrRect = screen->geometry();
        scrRect.moveTo(scrRect.x() / screen->devicePixelRatio(),
                       scrRect.y() / screen->devicePixelRatio());
        geometry = geometry.united(scrRect);
    }

    QPixmap p(QApplication::primaryScreen()->grabWindow(
      QApplication::desktop()->winId(),
      geometry.x(),
      geometry.y(),
      geometry.width(),
      geometry.height()));
    auto screenNumber = QApplication::desktop()->screenNumber();
    QScreen* screen = QApplication::screens()[screenNumber];
    p.setDevicePixelRatio(screen->devicePixelRatio());
    return p;
#endif
}

QPixmap ScreenGrabber::grabScreen(int screenNumber, bool& ok)
{
    QPixmap p;
    bool isVirtual = QApplication::desktop()->isVirtualDesktop();
    if (isVirtual || m_info.waylandDectected()) {
        p = grabEntireDesktop(ok);
        if (ok) {
            QPoint topLeft(0, 0);
#ifdef Q_OS_WIN
            for (QScreen* const screen : QGuiApplication::screens()) {
                QPoint topLeftScreen = screen->geometry().topLeft();
                if (topLeft.x() > topLeftScreen.x() ||
                    topLeft.y() > topLeftScreen.y()) {
                    topLeft = topLeftScreen;
                }
            }
#endif
            QRect geometry =
              QApplication::desktop()->screenGeometry(screenNumber);
            geometry.moveTo(geometry.topLeft() - topLeft);
            p = p.copy(geometry);
        }
    } else {
        QScreen* currentScreen = QGuiAppCurrentScreen().currentScreen();
        p = currentScreen->grabWindow(screenNumber,
                                      currentScreen->geometry().x(),
                                      currentScreen->geometry().y(),
                                      currentScreen->geometry().width(),
                                      currentScreen->geometry().height());
        ok = true;
    }
    return p;
}