/*
 * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>
 * Copyright (C) 2011-2013 Richard Hughes <richard@hughsie.com>
 * Copyright (C) 2020 NVIDIA CORPORATION
 * Copyright (C) 2021 Red Hat Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include "backends/x11/meta-color-manager-x11.h"

#include <colord.h>
#include <X11/Xatom.h>

#include "backends/meta-color-device.h"
#include "backends/meta-color-profile.h"
#include "backends/meta-monitor.h"
#include "backends/x11/meta-backend-x11.h"
#include "backends/x11/meta-output-xrandr.h"

struct _MetaColorManagerX11
{
  MetaColorManager parent;
};

G_DEFINE_TYPE (MetaColorManagerX11, meta_color_manager_x11,
               META_TYPE_COLOR_MANAGER)

/* see http://www.oyranos.org/wiki/index.php?title=ICC_Profiles_in_X_Specification_0.3 */
#define ICC_PROFILE_IN_X_VERSION_MAJOR 0
#define ICC_PROFILE_IN_X_VERSION_MINOR 3

static void
update_root_window_atom (MetaColorManager *color_manager,
                         MetaColorDevice  *color_device)
{
  MetaBackend *backend = meta_color_manager_get_backend (color_manager);
  MetaBackendX11 *backend_x11 = META_BACKEND_X11 (backend);
  Display *xdisplay = meta_backend_x11_get_xdisplay (backend_x11);
  Window xroot = meta_backend_x11_get_root_xwindow (backend_x11);
  Atom icc_profile_atom;
  Atom icc_profile_version_atom;
  MetaMonitor *monitor;
  MetaColorProfile *color_profile;
  const uint8_t *profile_contents = NULL;
  size_t profile_size;

  monitor = meta_color_device_get_monitor (color_device);
  if (!meta_monitor_is_primary (monitor))
    return;

  color_profile = meta_color_device_get_assigned_profile (color_device);
  if (color_profile)
    {
      profile_contents = meta_color_profile_get_data (color_profile);
      profile_size = meta_color_profile_get_data_size (color_profile);
    }

  icc_profile_atom = XInternAtom (xdisplay, "_ICC_PROFILE", False);
  icc_profile_version_atom = XInternAtom (xdisplay,
                                          "_ICC_PROFILE_IN_X_VERSION", False);
  if (profile_contents)
    {
      unsigned int version_data;

      XChangeProperty (xdisplay, xroot,
                       icc_profile_atom,
                       XA_CARDINAL, 8,
                       PropModeReplace,
                       profile_contents, profile_size);

      version_data =
        ICC_PROFILE_IN_X_VERSION_MAJOR * 100 +
        ICC_PROFILE_IN_X_VERSION_MINOR * 1;

      XChangeProperty (xdisplay, xroot,
                       icc_profile_version_atom,
                       XA_CARDINAL, 8,
                       PropModeReplace,
                       (uint8_t *) &version_data, 1);
    }
  else
    {
      XDeleteProperty (xdisplay, xroot, icc_profile_atom);
      XDeleteProperty (xdisplay, xroot, icc_profile_version_atom);
    }
}

static uint64_t
double_to_ctmval (double value)
{
  uint64_t sign = value < 0;
  double integer, fractional;

  if (sign)
    value = -value;

  fractional = modf (value, &integer);

  return
    sign << 63 |
    (uint64_t) integer << 32 |
    (uint64_t) (fractional * 0xffffffffUL);
}

static MetaOutputCtm
mat33_to_ctm (const CdMat3x3 *matrix)
{
  MetaOutputCtm ctm;

  /*
   * libcolord generates a matrix containing double values. RandR's CTM
   * property expects values in S31.32 fixed-point sign-magnitude format
   */
  ctm.matrix[0] = double_to_ctmval (matrix->m00);
  ctm.matrix[1] = double_to_ctmval (matrix->m01);
  ctm.matrix[2] = double_to_ctmval (matrix->m02);
  ctm.matrix[3] = double_to_ctmval (matrix->m10);
  ctm.matrix[4] = double_to_ctmval (matrix->m11);
  ctm.matrix[5] = double_to_ctmval (matrix->m12);
  ctm.matrix[6] = double_to_ctmval (matrix->m20);
  ctm.matrix[7] = double_to_ctmval (matrix->m21);
  ctm.matrix[8] = double_to_ctmval (matrix->m22);

  return ctm;
}

static void
update_device_ctm (MetaColorDevice *color_device)
{
  MetaMonitor *monitor;
  MetaColorProfile *color_profile;
  const MetaColorCalibration *color_calibration;
  MetaOutputCtm ctm;
  MetaOutput *output;
  MetaOutputXrandr *output_xrandr;

  monitor = meta_color_device_get_monitor (color_device);
  if (!meta_monitor_supports_color_transform (monitor))
    return;

  color_profile = meta_color_device_get_assigned_profile (color_device);
  if (!color_profile)
    return;

  color_calibration = meta_color_profile_get_calibration (color_profile);

  if (!color_calibration->has_adaptation_matrix)
    return;

  ctm = mat33_to_ctm (&color_calibration->adaptation_matrix);

  output = meta_monitor_get_main_output (monitor);
  output_xrandr = META_OUTPUT_XRANDR (output);
  meta_output_xrandr_set_ctm (output_xrandr, &ctm);
}

static void
on_color_device_calibration_changed (MetaColorManager *color_manager,
                                     MetaColorDevice  *color_device)
{
  update_root_window_atom (color_manager, color_device);
  update_device_ctm (color_device);
}

static void
meta_color_manager_x11_constructed (GObject *object)
{
  MetaColorManager *color_manager = META_COLOR_MANAGER (object);

  g_signal_connect (color_manager, "device-calibration-changed",
                    G_CALLBACK (on_color_device_calibration_changed), NULL);

  G_OBJECT_CLASS (meta_color_manager_x11_parent_class)->constructed (object);
}

static void
meta_color_manager_x11_class_init (MetaColorManagerX11Class *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->constructed = meta_color_manager_x11_constructed;
}

static void
meta_color_manager_x11_init (MetaColorManagerX11 *color_manager_x11)
{
}
