#include "OutputTracker.hpp"

#include <QCoreApplication>
#include <QGuiApplication>
#include <QJSEngine>
#include <QRect>

OutputTracker::OutputTracker(QObject *parent)
    : QObject(parent)
{
    if (auto *app = qobject_cast<QGuiApplication *>(QCoreApplication::instance())) {
        connect(app, &QGuiApplication::primaryScreenChanged, this, [this](QScreen *screen) {
            bindScreen(screen);
        });
        connect(app, &QGuiApplication::screenAdded, this, [this](QScreen *) {
            if (!m_screen)
                bindScreen(QGuiApplication::primaryScreen());
        });
        connect(app, &QGuiApplication::screenRemoved, this, [this](QScreen *screen) {
            if (m_screen == screen)
                bindScreen(QGuiApplication::primaryScreen());
        });
        bindScreen(app->primaryScreen());
    }
}

OutputTracker *OutputTracker::create(QQmlEngine *engine, QJSEngine *)
{
    auto *tracker = new OutputTracker(engine);
    QQmlEngine::setObjectOwnership(tracker, QQmlEngine::CppOwnership);
    return tracker;
}

void OutputTracker::bindScreen(QScreen *screen)
{
    if (m_screen == screen)
        return;

    if (m_screen) {
        disconnect(m_screen, nullptr, this, nullptr);
    }

    m_screen = screen;
    if (m_screen) {
        connect(m_screen, &QScreen::geometryChanged, this, [this](const QRect &) {
            logGeometry();
            emit geometryChanged();
        });
        connect(m_screen, &QScreen::physicalDotsPerInchChanged, this, &OutputTracker::geometryChanged);
    }

    logGeometry();
    emit geometryChanged();
}

void OutputTracker::logGeometry() const
{
    if (!m_screen) {
        qWarning("nebula-shell: no Wayland output is available yet");
        return;
    }

    const QRect geo = m_screen->geometry();
    qInfo("nebula-shell: output %s %dx%d+%d+%d scale %g",
          qPrintable(m_screen->name()),
          geo.width(),
          geo.height(),
          geo.x(),
          geo.y(),
          m_screen->devicePixelRatio());
}

int OutputTracker::width() const
{
    return m_screen ? m_screen->geometry().width() : 0;
}

int OutputTracker::height() const
{
    return m_screen ? m_screen->geometry().height() : 0;
}

qreal OutputTracker::devicePixelRatio() const
{
    return m_screen ? m_screen->devicePixelRatio() : 1.0;
}

QString OutputTracker::name() const
{
    return m_screen ? m_screen->name() : QString();
}