/*
 * Copyright (C) 2012 Igalia S.L.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "RedirectedXCompositeWindow.h"

#if PLATFORM(X11)
#include <X11/extensions/Xcomposite.h>
#include <X11/extensions/Xdamage.h>
#include <cairo-xlib.h>
#include <gdk/gdkx.h>
#include <glib.h>
#include <gtk/gtk.h>
#include <wtf/HashMap.h>

namespace WebCore {

typedef HashMap<Window, RedirectedXCompositeWindow*> WindowHashMap;
static WindowHashMap& getWindowHashMap()
{
    DEFINE_STATIC_LOCAL(WindowHashMap, windowHashMap, ());
    return windowHashMap;
}

static int gDamageEventBase;
static GdkFilterReturn filterXDamageEvent(GdkXEvent* gdkXEvent, GdkEvent* event, void*)
{
    XEvent* xEvent = static_cast<XEvent*>(gdkXEvent);
    if (xEvent->type != gDamageEventBase + XDamageNotify)
        return GDK_FILTER_CONTINUE;

    XDamageNotifyEvent* damageEvent = reinterpret_cast<XDamageNotifyEvent*>(xEvent);
    WindowHashMap& windowHashMap = getWindowHashMap();
    WindowHashMap::iterator i = windowHashMap.find(damageEvent->drawable);
    if (i == windowHashMap.end())
        return GDK_FILTER_CONTINUE;

    i->value->callDamageNotifyCallback();
    XDamageSubtract(GDK_DISPLAY_XDISPLAY(gdk_display_get_default()), damageEvent->damage, None, None);
    return GDK_FILTER_REMOVE;
}

static bool supportsXDamageAndXComposite()
{
    static bool initialized = false;
    static bool hasExtensions = false;

    if (initialized)
        return hasExtensions;

    initialized = true;

    int errorBase;
    Display* display = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
    if (!XDamageQueryExtension(display, &gDamageEventBase, &errorBase))
        return false;

    int eventBase;
    if (!XCompositeQueryExtension(display, &eventBase, &errorBase))
        return false;

    // We need to support XComposite version 0.2.
    int major, minor;
    XCompositeQueryVersion(display, &major, &minor);
    if (major < 0 || (!major && minor < 2))
        return false;

    hasExtensions = true;
    return true;
}

PassOwnPtr<RedirectedXCompositeWindow> RedirectedXCompositeWindow::create(const IntSize& size)
{
    return supportsXDamageAndXComposite() ? adoptPtr(new RedirectedXCompositeWindow(size)) : nullptr;
}

RedirectedXCompositeWindow::RedirectedXCompositeWindow(const IntSize& size)
    : m_size(size)
    , m_window(0)
    , m_parentWindow(0)
    , m_pixmap(0)
    , m_surface(0)
    , m_needsNewPixmapAfterResize(false)
    , m_damage(0)
    , m_damageNotifyCallback(0)
    , m_damageNotifyData(0)
{
    Display* display = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
    Screen* screen = DefaultScreenOfDisplay(display);

    // This is based on code from Chromium: src/content/common/gpu/image_transport_surface_linux.cc
    XSetWindowAttributes windowAttributes;
    windowAttributes.override_redirect = True;
    m_parentWindow = XCreateWindow(display,
        RootWindowOfScreen(screen),
        WidthOfScreen(screen) + 1, 0, 1, 1,
        0,
        CopyFromParent,
        InputOutput,
        CopyFromParent,
        CWOverrideRedirect,
        &windowAttributes);
    XMapWindow(display, m_parentWindow);

    windowAttributes.event_mask = StructureNotifyMask;
    windowAttributes.override_redirect = False;
    m_window = XCreateWindow(display,
                             m_parentWindow,
                             0, 0, size.width(), size.height(),
                             0,
                             CopyFromParent,
                             InputOutput,
                             CopyFromParent,
                             CWEventMask,
                             &windowAttributes);
    XMapWindow(display, m_window);

    if (getWindowHashMap().isEmpty())
        gdk_window_add_filter(0, reinterpret_cast<GdkFilterFunc>(filterXDamageEvent), 0);
    getWindowHashMap().add(m_window, this);

    while (1) {
        XEvent event;
        XWindowEvent(display, m_window, StructureNotifyMask, &event);
        if (event.type == MapNotify && event.xmap.window == m_window)
            break;
    }
    XSelectInput(display, m_window, NoEventMask);
    XCompositeRedirectWindow(display, m_window, CompositeRedirectManual);
    m_damage = XDamageCreate(display, m_window, XDamageReportNonEmpty);
}

RedirectedXCompositeWindow::~RedirectedXCompositeWindow()
{
    ASSERT(m_damage);
    ASSERT(m_window);
    ASSERT(m_parentWindow);

    getWindowHashMap().remove(m_window);
    if (getWindowHashMap().isEmpty())
        gdk_window_remove_filter(0, reinterpret_cast<GdkFilterFunc>(filterXDamageEvent), 0);

    Display* display = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
    XDamageDestroy(display, m_damage);
    XDestroyWindow(display, m_window);
    XDestroyWindow(display, m_parentWindow);
    cleanupPixmapAndPixmapSurface();
}

void RedirectedXCompositeWindow::resize(const IntSize& size)
{
    Display* display = GDK_DISPLAY_XDISPLAY(gdk_display_get_default());
    XResizeWindow(display, m_window, size.width(), size.height());

    XFlush(display);
    context()->waitNative();

    // This swap is based on code in Chromium. It tries to work-around a bug in the Intel drivers
    // where a swap is necessary to ensure the front and back buffers are properly resized.
    if (context() == GLContext::getCurrent())
        context()->swapBuffers();

    m_size = size;
    m_needsNewPixmapAfterResize = true;
}

GLContext* RedirectedXCompositeWindow::context()
{
    if (m_context)
        return m_context.get();

    ASSERT(m_window);
    m_context = GLContext::createContextForWindow(m_window, GLContext::sharingContext());
    return m_context.get();
}

void RedirectedXCompositeWindow::cleanupPixmapAndPixmapSurface()
{
    if (!m_pixmap)
        return;

    XFreePixmap(cairo_xlib_surface_get_display(m_surface.get()), m_pixmap);
    m_pixmap = 0;
    m_surface = nullptr;
}

cairo_surface_t* RedirectedXCompositeWindow::cairoSurfaceForWidget(GtkWidget* widget)
{
    if (!m_needsNewPixmapAfterResize && m_surface)
        return m_surface.get();

    m_needsNewPixmapAfterResize = false;

    // It's important that the new pixmap be created with the same Display pointer as the target
    // widget or else drawing speed can be 100x slower.
    Display* newPixmapDisplay = GDK_DISPLAY_XDISPLAY(gtk_widget_get_display(widget));
    Pixmap newPixmap = XCompositeNameWindowPixmap(newPixmapDisplay, m_window);
    if (!newPixmap) {
        cleanupPixmapAndPixmapSurface();
        return 0;
    }

    XWindowAttributes windowAttributes;
    if (!XGetWindowAttributes(newPixmapDisplay, m_window, &windowAttributes)) {
        cleanupPixmapAndPixmapSurface();
        XFreePixmap(newPixmapDisplay, newPixmap);
        return 0;
    }

    RefPtr<cairo_surface_t> newSurface = adoptRef(cairo_xlib_surface_create(newPixmapDisplay, newPixmap,
                                                                            windowAttributes.visual,
                                                                            m_size.width(), m_size.height()));

    // Nvidia drivers seem to prepare their redirected window pixmap asynchronously, so for a few fractions
    // of a second after each resize, while doing continuous resizing (which constantly destroys and creates
    // pixmap window-backings), the pixmap memory is uninitialized. To work around this issue, paint the old
    // pixmap to the new one to properly initialize it.
    if (m_surface) {
        RefPtr<cairo_t> cr = adoptRef(cairo_create(newSurface.get()));
        cairo_set_source_rgb(cr.get(), 1, 1, 1);
        cairo_paint(cr.get());
        cairo_set_source_surface(cr.get(), m_surface.get(), 0, 0);
        cairo_paint(cr.get());
    }

    cleanupPixmapAndPixmapSurface();
    m_pixmap = newPixmap;
    m_surface = newSurface;

    return m_surface.get();
}

void RedirectedXCompositeWindow::callDamageNotifyCallback()
{
    if (m_damageNotifyCallback)
        m_damageNotifyCallback(m_damageNotifyData);
}

} // namespace WebCore

#endif // PLATFORM(X11)