/*
 *  gstvaapidisplay_x11.c - VA/X11 display abstraction
 *
 *  Copyright (C) 2010-2011 Splitted-Desktop Systems
 *  Copyright (C) 2011-2012 Intel Corporation
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2.1
 *  of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301 USA
 */

/**
 * SECTION:gstvaapidisplay_x11
 * @short_description: VA/X11 display abstraction
 */

#include "sysdeps.h"
#include <string.h>
#include "gstvaapiutils.h"
#include "gstvaapidisplay_priv.h"
#include "gstvaapidisplay_x11.h"
#include "gstvaapidisplay_x11_priv.h"

#ifdef HAVE_XRANDR
# include <X11/extensions/Xrandr.h>
#endif

#define DEBUG 1
#include "gstvaapidebug.h"

static const guint g_display_types =
    (1U << GST_VAAPI_DISPLAY_TYPE_X11) |
    (1U << GST_VAAPI_DISPLAY_TYPE_GLX);

static inline const gchar *
get_default_display_name(void)
{
    static const gchar *g_display_name;

    if (!g_display_name)
        g_display_name = getenv("DISPLAY");
    return g_display_name;
}

static gint
compare_display_name(gconstpointer a, gconstpointer b)
{
    const GstVaapiDisplayInfo * const info = a;
    const gchar *cached_name = info->display_name, *cached_name_end;
    const gchar *tested_name = b, *tested_name_end;
    guint cached_name_length, tested_name_length;

    g_return_val_if_fail(cached_name, FALSE);
    g_return_val_if_fail(tested_name, FALSE);

    cached_name_end = strchr(cached_name, ':');
    if (cached_name_end)
        cached_name_length = cached_name_end - cached_name;
    else
        cached_name_length = strlen(cached_name);

    tested_name_end = strchr(tested_name, ':');
    if (tested_name_end)
        tested_name_length = tested_name_end - tested_name;
    else
        tested_name_length = strlen(tested_name);

    if (cached_name_length != tested_name_length)
        return FALSE;
    if (strncmp(cached_name, tested_name, cached_name_length) != 0)
        return FALSE;

    /* XXX: handle screen number? */
    return TRUE;
}

/* Reconstruct a display name without our prefix */
static const gchar *
get_display_name(GstVaapiDisplayX11 *display)
{
    GstVaapiDisplayX11Private * const priv = &display->priv;
    const gchar *display_name = priv->display_name;

    if (!display_name || *display_name == '\0')
        return NULL;
    return display_name;
}

/* Mangle display name with our prefix */
static gboolean
set_display_name(GstVaapiDisplayX11 *display, const gchar *display_name)
{
    GstVaapiDisplayX11Private * const priv = &display->priv;

    g_free(priv->display_name);

    if (!display_name) {
        display_name = get_default_display_name();
        if (!display_name)
            display_name = "";
    }
    priv->display_name = g_strdup(display_name);
    return priv->display_name != NULL;
}

/* Set synchronous behavious on the underlying X11 display */
static void
set_synchronous(GstVaapiDisplayX11 *display, gboolean synchronous)
{
    GstVaapiDisplayX11Private * const priv = &display->priv;

    if (priv->synchronous != synchronous) {
        priv->synchronous = synchronous;
        if (priv->x11_display) {
            GST_VAAPI_DISPLAY_LOCK(display);
            XSynchronize(priv->x11_display, synchronous);
            GST_VAAPI_DISPLAY_UNLOCK(display);
        }
    }
}

/* Check whether XRANDR extension is available */
static void
check_xrandr(GstVaapiDisplayX11 *display)
{
#ifdef HAVE_XRANDR
    GstVaapiDisplayX11Private * const priv =
        GST_VAAPI_DISPLAY_X11_PRIVATE(display);
    int evt_base, err_base;

    priv->use_xrandr = XRRQueryExtension(priv->x11_display,
        &evt_base, &err_base);
#endif
}

static gboolean
gst_vaapi_display_x11_bind_display(GstVaapiDisplay *base_display,
    gpointer native_display)
{
    GstVaapiDisplayX11 * const display =
        GST_VAAPI_DISPLAY_X11_CAST(base_display);
    GstVaapiDisplayX11Private * const priv = &display->priv;

    priv->x11_display = native_display;
    priv->x11_screen = DefaultScreen(native_display);
    priv->use_foreign_display = TRUE;

    check_xrandr(display);

    if (!set_display_name(display, XDisplayString(priv->x11_display)))
        return FALSE;
    return TRUE;
}

static gboolean
gst_vaapi_display_x11_open_display(GstVaapiDisplay *base_display,
    const gchar *name)
{
    GstVaapiDisplayX11 * const display =
        GST_VAAPI_DISPLAY_X11_CAST(base_display);
    GstVaapiDisplayX11Private * const priv = &display->priv;
    GstVaapiDisplayCache *cache;
    const GstVaapiDisplayInfo *info;

    cache = gst_vaapi_display_get_cache();
    g_return_val_if_fail(cache != NULL, FALSE);

    if (!set_display_name(display, name))
        return FALSE;

    info = gst_vaapi_display_cache_lookup_custom(cache, compare_display_name,
        priv->display_name, GST_VAAPI_DISPLAY_TYPES(display));
    if (info) {
        priv->x11_display = info->native_display;
        priv->use_foreign_display = TRUE;
    }
    else {
        priv->x11_display = XOpenDisplay(get_display_name(display));
        if (!priv->x11_display)
            return FALSE;
        priv->use_foreign_display = FALSE;
    }
    priv->x11_screen = DefaultScreen(priv->x11_display);

    check_xrandr(display);
    return TRUE;
}

static void
gst_vaapi_display_x11_close_display(GstVaapiDisplay *display)
{
    GstVaapiDisplayX11Private * const priv =
        GST_VAAPI_DISPLAY_X11_PRIVATE(display);

    if (priv->x11_display) {
        if (!priv->use_foreign_display)
            XCloseDisplay(priv->x11_display);
        priv->x11_display = NULL;
    }

    if (priv->display_name) {
        g_free(priv->display_name);
        priv->display_name = NULL;
    }
}

static void
gst_vaapi_display_x11_sync(GstVaapiDisplay *display)
{
    GstVaapiDisplayX11Private * const priv =
        GST_VAAPI_DISPLAY_X11_PRIVATE(display);

    if (priv->x11_display) {
        GST_VAAPI_DISPLAY_LOCK(display);
        XSync(priv->x11_display, False);
        GST_VAAPI_DISPLAY_UNLOCK(display);
    }
}

static void
gst_vaapi_display_x11_flush(GstVaapiDisplay *display)
{
    GstVaapiDisplayX11Private * const priv =
        GST_VAAPI_DISPLAY_X11_PRIVATE(display);

    if (priv->x11_display) {
        GST_VAAPI_DISPLAY_LOCK(display);
        XFlush(priv->x11_display);
        GST_VAAPI_DISPLAY_UNLOCK(display);
    }
}

static gboolean
gst_vaapi_display_x11_get_display_info(
    GstVaapiDisplay     *display,
    GstVaapiDisplayInfo *info
)
{
    GstVaapiDisplayX11Private * const priv =
        GST_VAAPI_DISPLAY_X11_PRIVATE(display);
    GstVaapiDisplayCache *cache;
    const GstVaapiDisplayInfo *cached_info;

    /* Return any cached info even if child has its own VA display */
    cache = gst_vaapi_display_get_cache();
    if (!cache)
        return FALSE;
    cached_info = gst_vaapi_display_cache_lookup_by_native_display(
        cache, priv->x11_display, GST_VAAPI_DISPLAY_TYPES(display));
    if (cached_info) {
        *info = *cached_info;
        return TRUE;
    }

    /* Otherwise, create VA display if there is none already */
    info->native_display = priv->x11_display;
    info->display_name   = priv->display_name;
    if (!info->va_display) {
        info->va_display = vaGetDisplay(priv->x11_display);
        if (!info->va_display)
            return FALSE;
        info->display_type = GST_VAAPI_DISPLAY_TYPE_X11;
    }
    return TRUE;
}

static void
gst_vaapi_display_x11_get_size(
    GstVaapiDisplay *display,
    guint           *pwidth,
    guint           *pheight
)
{
    GstVaapiDisplayX11Private * const priv =
        GST_VAAPI_DISPLAY_X11_PRIVATE(display);

    if (!priv->x11_display)
        return;

    if (pwidth)
        *pwidth = DisplayWidth(priv->x11_display, priv->x11_screen);

    if (pheight)
        *pheight = DisplayHeight(priv->x11_display, priv->x11_screen);
}

static void
gst_vaapi_display_x11_get_size_mm(
    GstVaapiDisplay *display,
    guint           *pwidth,
    guint           *pheight
)
{
    GstVaapiDisplayX11Private * const priv =
        GST_VAAPI_DISPLAY_X11_PRIVATE(display);
    guint width_mm, height_mm;

    if (!priv->x11_display)
        return;

    width_mm  = DisplayWidthMM(priv->x11_display, priv->x11_screen);
    height_mm = DisplayHeightMM(priv->x11_display, priv->x11_screen);

#ifdef HAVE_XRANDR
    /* XXX: fix up physical size if the display is rotated */
    if (priv->use_xrandr) {
        XRRScreenConfiguration *xrr_config = NULL;
        XRRScreenSize *xrr_sizes;
        Window win;
        int num_xrr_sizes, size_id, screen;
        Rotation rotation;

        do {
            win    = DefaultRootWindow(priv->x11_display);
            screen = XRRRootToScreen(priv->x11_display, win);

            xrr_config = XRRGetScreenInfo(priv->x11_display, win);
            if (!xrr_config)
                break;

            size_id = XRRConfigCurrentConfiguration(xrr_config, &rotation);
            if (rotation == RR_Rotate_0 || rotation == RR_Rotate_180)
                break;

            xrr_sizes = XRRSizes(priv->x11_display, screen, &num_xrr_sizes);
            if (!xrr_sizes || size_id >= num_xrr_sizes)
                break;

            width_mm  = xrr_sizes[size_id].mheight;
            height_mm = xrr_sizes[size_id].mwidth;
        } while (0);
        if (xrr_config)
            XRRFreeScreenConfigInfo(xrr_config);
    }
#endif

    if (pwidth)
        *pwidth = width_mm;

    if (pheight)
        *pheight = height_mm;
}

void
gst_vaapi_display_x11_class_init(GstVaapiDisplayX11Class *klass)
{
    GstVaapiMiniObjectClass * const object_class =
        GST_VAAPI_MINI_OBJECT_CLASS(klass);
    GstVaapiDisplayClass * const dpy_class = GST_VAAPI_DISPLAY_CLASS(klass);

    gst_vaapi_display_class_init(&klass->parent_class);

    object_class->size          = sizeof(GstVaapiDisplayX11);
    dpy_class->display_types    = g_display_types;
    dpy_class->bind_display     = gst_vaapi_display_x11_bind_display;
    dpy_class->open_display     = gst_vaapi_display_x11_open_display;
    dpy_class->close_display    = gst_vaapi_display_x11_close_display;
    dpy_class->sync             = gst_vaapi_display_x11_sync;
    dpy_class->flush            = gst_vaapi_display_x11_flush;
    dpy_class->get_display      = gst_vaapi_display_x11_get_display_info;
    dpy_class->get_size         = gst_vaapi_display_x11_get_size;
    dpy_class->get_size_mm      = gst_vaapi_display_x11_get_size_mm;
}

static inline const GstVaapiDisplayClass *
gst_vaapi_display_x11_class(void)
{
    static GstVaapiDisplayX11Class g_class;
    static gsize g_class_init = FALSE;

    if (g_once_init_enter(&g_class_init)) {
        gst_vaapi_display_x11_class_init(&g_class);
        g_once_init_leave(&g_class_init, TRUE);
    }
    return GST_VAAPI_DISPLAY_CLASS(&g_class);
}

/**
 * gst_vaapi_display_x11_new:
 * @display_name: the X11 display name
 *
 * Opens an X11 #Display using @display_name and returns a newly
 * allocated #GstVaapiDisplay object. The X11 display will be cloed
 * when the reference count of the object reaches zero.
 *
 * Return value: a newly allocated #GstVaapiDisplay object
 */
GstVaapiDisplay *
gst_vaapi_display_x11_new(const gchar *display_name)
{
    return gst_vaapi_display_new(gst_vaapi_display_x11_class(),
        GST_VAAPI_DISPLAY_INIT_FROM_DISPLAY_NAME, (gpointer)display_name);
}

/**
 * gst_vaapi_display_x11_new_with_display:
 * @x11_display: an X11 #Display
 *
 * Creates a #GstVaapiDisplay based on the X11 @x11_display
 * display. The caller still owns the display and must call
 * XCloseDisplay() when all #GstVaapiDisplay references are
 * released. Doing so too early can yield undefined behaviour.
 *
 * Return value: a newly allocated #GstVaapiDisplay object
 */
GstVaapiDisplay *
gst_vaapi_display_x11_new_with_display(Display *x11_display)
{
    g_return_val_if_fail(x11_display, NULL);

    return gst_vaapi_display_new(gst_vaapi_display_x11_class(),
        GST_VAAPI_DISPLAY_INIT_FROM_NATIVE_DISPLAY, x11_display);
}

/**
 * gst_vaapi_display_x11_get_display:
 * @display: a #GstVaapiDisplayX11
 *
 * Returns the underlying X11 #Display that was created by
 * gst_vaapi_display_x11_new() or that was bound from
 * gst_vaapi_display_x11_new_with_display().
 *
 * Return value: the X11 #Display attached to @display
 */
Display *
gst_vaapi_display_x11_get_display(GstVaapiDisplayX11 *display)
{
    g_return_val_if_fail(GST_VAAPI_IS_DISPLAY_X11(display), NULL);

    return GST_VAAPI_DISPLAY_XDISPLAY(display);
}

/**
 * gst_vaapi_display_x11_get_screen:
 * @display: a #GstVaapiDisplayX11
 *
 * Returns the default X11 screen that was created by
 * gst_vaapi_display_x11_new() or that was bound from
 * gst_vaapi_display_x11_new_with_display().
 *
 * Return value: the X11 #Display attached to @display
 */
int
gst_vaapi_display_x11_get_screen(GstVaapiDisplayX11 *display)
{
    g_return_val_if_fail(GST_VAAPI_IS_DISPLAY_X11(display), -1);

    return GST_VAAPI_DISPLAY_XSCREEN(display);
}

/**
 * gst_vaapi_display_x11_set_synchronous:
 * @display: a #GstVaapiDisplayX11
 * @synchronous: boolean value that indicates whether to enable or
 *   disable synchronization
 *
 * If @synchronous is %TRUE, gst_vaapi_display_x11_set_synchronous()
 * turns on synchronous behaviour on the underlying X11
 * display. Otherwise, synchronous behaviour is disabled if
 * @synchronous is %FALSE.
 */
void
gst_vaapi_display_x11_set_synchronous(GstVaapiDisplayX11 *display,
    gboolean synchronous)
{
    g_return_if_fail(GST_VAAPI_IS_DISPLAY_X11(display));

    set_synchronous(display, synchronous);
}