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#include "qxcbscreen.h"
#include "qxcbwindow.h"
#include "qxcbcursor.h"
#include "qxcbimage.h"
#include "qnamespace.h"

#include <stdio.h>

#include <QDebug>

#include <qpa/qwindowsysteminterface.h>
#include <private/qmath_p.h>

QT_BEGIN_NAMESPACE

QXcbScreen::QXcbScreen(QXcbConnection *connection, xcb_screen_t *scr,
                       xcb_randr_get_output_info_reply_t *output, QString outputName, int number)
    : QXcbObject(connection)
    , m_screen(scr)
    , m_crtc(output ? output->crtc : 0)
    , m_outputName(outputName)
    , m_sizeMillimeters(output ? QSize(output->mm_width, output->mm_height) : QSize())
    , m_virtualSize(scr->width_in_pixels, scr->height_in_pixels)
    , m_virtualSizeMillimeters(scr->width_in_millimeters, scr->height_in_millimeters)
    , m_orientation(Qt::PrimaryOrientation)
    , m_number(number)
    , m_refreshRate(60)
    , m_forcedDpi(-1)
{
    if (connection->hasXRandr())
        xcb_randr_select_input(xcb_connection(), screen()->root, true);

    updateGeometry(output ? output->timestamp : 0);
    updateRefreshRate();

    // On VNC, it can be that physical size is unknown while
    // virtual size is known (probably back-calculated from DPI and resolution)
    if (m_sizeMillimeters.isEmpty())
        m_sizeMillimeters = m_virtualSizeMillimeters;
    if (m_geometry.isEmpty())
        m_geometry = QRect(QPoint(), m_virtualSize);
    if (m_availableGeometry.isEmpty())
        m_availableGeometry = QRect(QPoint(), m_virtualSize);

    readXResources();


#ifdef Q_XCB_DEBUG
    qDebug();
    qDebug("Screen output %s of xcb screen %d:", m_outputName.toUtf8().constData(), m_number);
    qDebug("  width..........: %lf", m_sizeMillimeters.width());
    qDebug("  height.........: %lf", m_sizeMillimeters.height());
    qDebug("  geometry.......: %d x %d +%d +%d", m_geometry.width(), m_geometry.height(), m_geometry.x(), m_geometry.y());
    qDebug("  virtual width..: %lf", m_virtualSizeMillimeters.width());
    qDebug("  virtual height.: %lf", m_virtualSizeMillimeters.height());
    qDebug("  virtual geom...: %d x %d", m_virtualSize.width(), m_virtualSize.height());
    qDebug("  avail virt geom: %d x %d +%d +%d", m_availableGeometry.width(), m_availableGeometry.height(), m_availableGeometry.x(), m_availableGeometry.y());
    qDebug("  depth..........: %d", screen()->root_depth);
    qDebug("  white pixel....: %x", screen()->white_pixel);
    qDebug("  black pixel....: %x", screen()->black_pixel);
    qDebug("  refresh rate...: %d", m_refreshRate);
    qDebug("  root ID........: %x", screen()->root);
#endif

    const quint32 mask = XCB_CW_EVENT_MASK;
    const quint32 values[] = {
        // XCB_CW_EVENT_MASK
        XCB_EVENT_MASK_ENTER_WINDOW
        | XCB_EVENT_MASK_LEAVE_WINDOW
        | XCB_EVENT_MASK_PROPERTY_CHANGE
    };

    xcb_change_window_attributes(xcb_connection(), screen()->root, mask, values);

    xcb_get_property_reply_t *reply =
        xcb_get_property_reply(xcb_connection(),
            xcb_get_property_unchecked(xcb_connection(), false, screen()->root,
                             atom(QXcbAtom::_NET_SUPPORTING_WM_CHECK),
                             XCB_ATOM_WINDOW, 0, 1024), NULL);

    if (reply && reply->format == 32 && reply->type == XCB_ATOM_WINDOW) {
        xcb_window_t windowManager = *((xcb_window_t *)xcb_get_property_value(reply));

        if (windowManager != XCB_WINDOW_NONE) {
            xcb_get_property_reply_t *windowManagerReply =
                xcb_get_property_reply(xcb_connection(),
                    xcb_get_property_unchecked(xcb_connection(), false, windowManager,
                                     atom(QXcbAtom::_NET_WM_NAME),
                                     atom(QXcbAtom::UTF8_STRING), 0, 1024), NULL);
            if (windowManagerReply && windowManagerReply->format == 8 && windowManagerReply->type == atom(QXcbAtom::UTF8_STRING)) {
                m_windowManagerName = QString::fromUtf8((const char *)xcb_get_property_value(windowManagerReply), xcb_get_property_value_length(windowManagerReply));
#ifdef Q_XCB_DEBUG
                qDebug("  window manager.: %s", qPrintable(m_windowManagerName));
                qDebug();
#endif
            }

            free(windowManagerReply);
        }
    }
    free(reply);

    const xcb_query_extension_reply_t *sync_reply = xcb_get_extension_data(xcb_connection(), &xcb_sync_id);
    if (!sync_reply || !sync_reply->present)
        m_syncRequestSupported = false;
    else
        m_syncRequestSupported = m_windowManagerName != QLatin1String("KWin");

    m_clientLeader = xcb_generate_id(xcb_connection());
    Q_XCB_CALL2(xcb_create_window(xcb_connection(),
                                  XCB_COPY_FROM_PARENT,
                                  m_clientLeader,
                                  screen()->root,
                                  0, 0, 1, 1,
                                  0,
                                  XCB_WINDOW_CLASS_INPUT_OUTPUT,
                                  screen()->root_visual,
                                  0, 0), connection);

    Q_XCB_CALL2(xcb_change_property(xcb_connection(),
                                    XCB_PROP_MODE_REPLACE,
                                    m_clientLeader,
                                    atom(QXcbAtom::WM_CLIENT_LEADER),
                                    XCB_ATOM_WINDOW,
                                    32,
                                    1,
                                    &m_clientLeader), connection);

    xcb_depth_iterator_t depth_iterator =
        xcb_screen_allowed_depths_iterator(screen());

    while (depth_iterator.rem) {
        xcb_depth_t *depth = depth_iterator.data;
        xcb_visualtype_iterator_t visualtype_iterator =
            xcb_depth_visuals_iterator(depth);

        while (visualtype_iterator.rem) {
            xcb_visualtype_t *visualtype = visualtype_iterator.data;
            m_visuals.insert(visualtype->visual_id, *visualtype);
            xcb_visualtype_next(&visualtype_iterator);
        }

        xcb_depth_next(&depth_iterator);
    }

    m_cursor = new QXcbCursor(connection, this);
}

QXcbScreen::~QXcbScreen()
{
    delete m_cursor;
}


QWindow *QXcbScreen::topLevelAt(const QPoint &p) const
{
    xcb_window_t root = m_screen->root;

    int x = p.x();
    int y = p.y();

    xcb_window_t parent = root;
    xcb_window_t child = root;

    do {
        xcb_translate_coordinates_cookie_t translate_cookie =
            xcb_translate_coordinates_unchecked(xcb_connection(), parent, child, x, y);

        xcb_translate_coordinates_reply_t *translate_reply =
            xcb_translate_coordinates_reply(xcb_connection(), translate_cookie, NULL);

        if (!translate_reply) {
            return 0;
        }

        parent = child;
        child = translate_reply->child;
        x = translate_reply->dst_x;
        y = translate_reply->dst_y;

        free(translate_reply);

        if (!child || child == root)
            return 0;

        QPlatformWindow *platformWindow = connection()->platformWindowFromId(child);
        if (platformWindow)
            return platformWindow->window();
    } while (parent != child);

    return 0;
}

const xcb_visualtype_t *QXcbScreen::visualForId(xcb_visualid_t visualid) const
{
    QMap<xcb_visualid_t, xcb_visualtype_t>::const_iterator it = m_visuals.find(visualid);
    if (it == m_visuals.constEnd())
        return 0;
    return &*it;
}

QImage::Format QXcbScreen::format() const
{
    return QImage::Format_RGB32;
}

QDpi QXcbScreen::logicalDpi() const
{
    if (m_forcedDpi > 0)
        return QDpi(m_forcedDpi, m_forcedDpi);

    return QDpi(Q_MM_PER_INCH * m_virtualSize.width() / m_virtualSizeMillimeters.width(),
                Q_MM_PER_INCH * m_virtualSize.height() / m_virtualSizeMillimeters.height());
}

QPlatformCursor *QXcbScreen::cursor() const
{
    return m_cursor;
}

/*!
    \brief handle the XCB screen change event and update properties

    On a mobile device, the ideal use case is that the accelerometer would
    drive the orientation. This could be achieved by using QSensors to read the
    accelerometer and adjusting the rotation in QML, or by reading the
    orientation from the QScreen object and doing the same, or in many other
    ways. However, on X we have the XRandR extension, which makes it possible
    to have the whole screen rotated, so that individual apps DO NOT have to
    rotate themselves. Apps could optionally use the
    QScreen::primaryOrientation property to optimize layout though.
    Furthermore, there is no support in X for accelerometer events anyway. So
    it makes more sense on a Linux system running X to just run a daemon which
    monitors the accelerometer and runs xrandr automatically to do the rotation,
    then apps do not have to be aware of it (but probably the window manager
    would resize them accordingly). updateGeometry() is written with this
    design in mind. Therefore the physical geometry, available geometry,
    virtual geometry, orientation and primaryOrientation should all change at
    the same time.  On a system which cannot rotate the whole screen, it would
    be correct for only the orientation (not the primary orientation) to
    change.
*/
void QXcbScreen::handleScreenChange(xcb_randr_screen_change_notify_event_t *change_event)
{
    updateGeometry(change_event->config_timestamp);

    switch (change_event->rotation) {
    case XCB_RANDR_ROTATION_ROTATE_0: // xrandr --rotate normal
        m_orientation = Qt::LandscapeOrientation;
        m_virtualSize.setWidth(change_event->width);
        m_virtualSize.setHeight(change_event->height);
        m_virtualSizeMillimeters.setWidth(change_event->mwidth);
        m_virtualSizeMillimeters.setHeight(change_event->mheight);
        break;
    case XCB_RANDR_ROTATION_ROTATE_90: // xrandr --rotate left
        m_orientation = Qt::PortraitOrientation;
        m_virtualSize.setWidth(change_event->height);
        m_virtualSize.setHeight(change_event->width);
        m_virtualSizeMillimeters.setWidth(change_event->mheight);
        m_virtualSizeMillimeters.setHeight(change_event->mwidth);
        break;
    case XCB_RANDR_ROTATION_ROTATE_180: // xrandr --rotate inverted
        m_orientation = Qt::InvertedLandscapeOrientation;
        m_virtualSize.setWidth(change_event->width);
        m_virtualSize.setHeight(change_event->height);
        m_virtualSizeMillimeters.setWidth(change_event->mwidth);
        m_virtualSizeMillimeters.setHeight(change_event->mheight);
        break;
    case XCB_RANDR_ROTATION_ROTATE_270: // xrandr --rotate right
        m_orientation = Qt::InvertedPortraitOrientation;
        m_virtualSize.setWidth(change_event->height);
        m_virtualSize.setHeight(change_event->width);
        m_virtualSizeMillimeters.setWidth(change_event->mheight);
        m_virtualSizeMillimeters.setHeight(change_event->mwidth);
        break;
    // We don't need to do anything with these, since QScreen doesn't store reflection state,
    // and Qt-based applications probably don't need to care about it anyway.
    case XCB_RANDR_ROTATION_REFLECT_X: break;
    case XCB_RANDR_ROTATION_REFLECT_Y: break;
    }

    QWindowSystemInterface::handleScreenGeometryChange(QPlatformScreen::screen(), geometry());
    QWindowSystemInterface::handleScreenAvailableGeometryChange(QPlatformScreen::screen(), availableGeometry());
    QWindowSystemInterface::handleScreenOrientationChange(QPlatformScreen::screen(), m_orientation);
    QWindowSystemInterface::handleScreenLogicalDotsPerInchChange(QPlatformScreen::screen(),
        Q_MM_PER_INCH * m_virtualSize.width() / m_virtualSizeMillimeters.width(),
        Q_MM_PER_INCH * m_virtualSize.height() / m_virtualSizeMillimeters.height());
}

void QXcbScreen::updateGeometry(xcb_timestamp_t timestamp)
{
    if (connection()->hasXRandr()) {
        xcb_randr_get_crtc_info_reply_t *crtc = xcb_randr_get_crtc_info_reply(xcb_connection(),
            xcb_randr_get_crtc_info_unchecked(xcb_connection(), m_crtc, timestamp), NULL);
        if (crtc) {
            m_geometry = QRect(crtc->x, crtc->y, crtc->width, crtc->height);
            m_availableGeometry = m_geometry;
            free(crtc);
        }
    }

    xcb_get_property_reply_t * workArea =
        xcb_get_property_reply(xcb_connection(),
            xcb_get_property_unchecked(xcb_connection(), false, screen()->root,
                             atom(QXcbAtom::_NET_WORKAREA),
                             XCB_ATOM_CARDINAL, 0, 1024), NULL);

    if (workArea && workArea->type == XCB_ATOM_CARDINAL && workArea->format == 32 && workArea->value_len >= 4) {
        // If workArea->value_len > 4, the remaining ones seem to be for virtual desktops.
        // But QScreen doesn't know about that concept.  In reality there could be a
        // "docked" panel (with _NET_WM_STRUT_PARTIAL atom set) on just one desktop.
        // But for now just assume the first 4 values give us the geometry of the
        // "work area", AKA "available geometry"
        uint32_t *geom = (uint32_t*)xcb_get_property_value(workArea);
        QRect virtualAvailableGeometry(geom[0], geom[1], geom[2], geom[3]);
        // Take the intersection of the desktop's available geometry with this screen's geometry
        // to get the part of the available geometry which belongs to this screen.
        m_availableGeometry = m_geometry & virtualAvailableGeometry;
    }
    free(workArea);
}

void QXcbScreen::updateRefreshRate()
{
    if (!connection()->hasXRandr())
        return;

    int rate = m_refreshRate;

    xcb_randr_get_screen_info_reply_t *screenInfoReply =
        xcb_randr_get_screen_info_reply(xcb_connection(), xcb_randr_get_screen_info_unchecked(xcb_connection(), m_screen->root), 0);

    if (screenInfoReply) {
        rate = screenInfoReply->rate;
        free(screenInfoReply);
    }

    if (rate == m_refreshRate)
        return;

    m_refreshRate = rate;

    QWindowSystemInterface::handleScreenRefreshRateChange(QPlatformScreen::screen(), rate);
}

QPixmap QXcbScreen::grabWindow(WId window, int x, int y, int width, int height) const
{
    if (width == 0 || height == 0)
        return QPixmap();

    // TODO: handle multiple screens
    QXcbScreen *screen = const_cast<QXcbScreen *>(this);
    xcb_window_t root = screen->root();

    if (window == 0)
        window = root;

    xcb_get_geometry_cookie_t geometry_cookie = xcb_get_geometry_unchecked(xcb_connection(), window);

    xcb_get_geometry_reply_t *reply =
        xcb_get_geometry_reply(xcb_connection(), geometry_cookie, NULL);

    if (!reply) {
        return QPixmap();
    }

    if (width < 0)
        width = reply->width - x;
    if (height < 0)
        height = reply->height - y;

    geometry_cookie = xcb_get_geometry_unchecked(xcb_connection(), root);
    xcb_get_geometry_reply_t *root_reply =
        xcb_get_geometry_reply(xcb_connection(), geometry_cookie, NULL);

    if (!root_reply) {
        free(reply);
        return QPixmap();
    }

    if (reply->depth == root_reply->depth) {
        // if the depth of the specified window and the root window are the
        // same, grab pixels from the root window (so that we get the any
        // overlapping windows and window manager frames)

        // map x and y to the root window
        xcb_translate_coordinates_cookie_t translate_cookie =
            xcb_translate_coordinates_unchecked(xcb_connection(), window, root, x, y);

        xcb_translate_coordinates_reply_t *translate_reply =
            xcb_translate_coordinates_reply(xcb_connection(), translate_cookie, NULL);

        if (!translate_reply) {
            free(reply);
            free(root_reply);
            return QPixmap();
        }

        x = translate_reply->dst_x;
        y = translate_reply->dst_y;

        window = root;

        free(translate_reply);
        free(reply);
        reply = root_reply;
    } else {
        free(root_reply);
        root_reply = 0;
    }

    xcb_get_window_attributes_reply_t *attributes_reply =
        xcb_get_window_attributes_reply(xcb_connection(), xcb_get_window_attributes_unchecked(xcb_connection(), window), NULL);

    if (!attributes_reply) {
        free(reply);
        return QPixmap();
    }

    const xcb_visualtype_t *visual = screen->visualForId(attributes_reply->visual);
    free(attributes_reply);

    xcb_pixmap_t pixmap = xcb_generate_id(xcb_connection());
    xcb_create_pixmap(xcb_connection(), reply->depth, pixmap, window, width, height);

    uint32_t gc_value_mask = XCB_GC_SUBWINDOW_MODE;
    uint32_t gc_value_list[] = { XCB_SUBWINDOW_MODE_INCLUDE_INFERIORS };

    xcb_gcontext_t gc = xcb_generate_id(xcb_connection());
    xcb_create_gc(xcb_connection(), gc, pixmap, gc_value_mask, gc_value_list);

    xcb_copy_area(xcb_connection(), window, pixmap, gc, x, y, 0, 0, width, height);

    QPixmap result = qt_xcb_pixmapFromXPixmap(connection(), pixmap, width, height, reply->depth, visual);

    free(reply);
    xcb_free_gc(xcb_connection(), gc);
    xcb_free_pixmap(xcb_connection(), pixmap);

    return result;
}

void QXcbScreen::readXResources()
{
    int offset = 0;
    QByteArray resources;
    while(1) {
        xcb_get_property_reply_t *reply =
            xcb_get_property_reply(xcb_connection(),
                xcb_get_property_unchecked(xcb_connection(), false, screen()->root,
                                 XCB_ATOM_RESOURCE_MANAGER,
                                 XCB_ATOM_STRING, offset/4, 8192), NULL);
        bool more = false;
        if (reply && reply->format == 8 && reply->type == XCB_ATOM_STRING) {
            resources += QByteArray((const char *)xcb_get_property_value(reply), xcb_get_property_value_length(reply));
            offset += xcb_get_property_value_length(reply);
            more = reply->bytes_after != 0;
        }

        if (reply)
            free(reply);

        if (!more)
            break;
    }

    QList<QByteArray> split = resources.split('\n');
    for (int i = 0; i < split.size(); ++i) {
        const QByteArray &r = split.at(i);
        if (r.startsWith("Xft.dpi:\t")) {
            bool ok;
            int dpi = r.mid(sizeof("Xft.dpi:")).toInt(&ok);
            if (ok)
                m_forcedDpi = dpi;
            break;
        }
    }
}

QT_END_NAMESPACE