/*
 * Copyright (c) 2009, The Mozilla Foundation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of the Mozilla Foundation nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY The Mozilla Foundation ''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 The Mozilla Foundation 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.
 *
 * Contributors:
 *   Ted Mielczarek <ted.mielczarek@gmail.com>
 *   Karl Tomlinson <karlt+@karlt.net>
 */
/*
 * gdk-screenshot.cpp: Save a screenshot of the root window in .png format.
 *  If a filename is specified as the first argument on the commandline,
 *  then the image will be saved to that filename. Otherwise, the image will
 *  be written to stdout.
 */
#include <gdk/gdk.h>
#ifdef MOZ_WAYLAND
#  include <gdk/gdkwayland.h>
#endif

#include <errno.h>
#include <stdio.h>
#include <unistd.h>

#if defined(MOZ_ENABLE_DBUS)
#  include <glib.h>
#  include <glib/gstdio.h>
#  include <dlfcn.h>
#endif

gboolean save_to_stdout(const gchar* buf, gsize count, GError** error,
                        gpointer data) {
  size_t written = fwrite(buf, 1, count, stdout);
  if (written != count) {
    g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(errno),
                "Write to stdout failed: %s", g_strerror(errno));
    return FALSE;
  }

  return TRUE;
}

#if defined(MOZ_ENABLE_DBUS) && defined(MOZ_WAYLAND)
static GdkPixbuf* get_screenshot_dbus() {
  char *path = nullptr, *filename = nullptr, *tmpname = nullptr;
  GdkPixbuf* screenshot = nullptr;
  const char* method_name;
  GVariant* method_params;
  GDBusConnection* connection;

  auto sGApplicationGetDbusConnection = (GDBusConnection * (*)(GApplication*))
      dlsym(RTLD_DEFAULT, "g_application_get_dbus_connection");
  if (!sGApplicationGetDbusConnection) {
    return nullptr;
  }

  path =
      g_build_filename(g_get_user_cache_dir(), "mozilla-screenshot", nullptr);
  g_mkdir_with_parents(path, 0700);

  tmpname = g_strdup_printf("mozilla-screen-%d.png", g_random_int());
  filename = g_build_filename(path, tmpname, nullptr);

  method_name = "Screenshot";
  method_params = g_variant_new("(bbs)", FALSE, /* include pointer */
                                FALSE,          /* flash */
                                filename);

  GApplication* app = g_application_new(nullptr, G_APPLICATION_NON_UNIQUE);
  g_application_register(app, nullptr, nullptr);
  connection = sGApplicationGetDbusConnection(app);
  if (g_dbus_connection_call_sync(
          connection, "org.gnome.Shell.Screenshot",
          "/org/gnome/Shell/Screenshot", "org.gnome.Shell.Screenshot",
          method_name, method_params, nullptr, G_DBUS_CALL_FLAGS_NONE, -1,
          nullptr, nullptr)) {
    screenshot = gdk_pixbuf_new_from_file(filename, nullptr);
    unlink(filename);
  }

  g_free(path);
  g_free(tmpname);
  g_free(filename);

  return screenshot;
}
#endif

int main(int argc, char** argv) {
  gdk_init(&argc, &argv);

  GdkPixbuf* screenshot = nullptr;

#if defined(MOZ_ENABLE_DBUS) && defined(MOZ_WAYLAND)
  GdkDisplay* display = gdk_display_get_default();
  if (display && GDK_IS_WAYLAND_DISPLAY(display)) {
    screenshot = get_screenshot_dbus();
  }
#endif
  if (!screenshot) {
    GdkWindow* window = gdk_get_default_root_window();
    screenshot =
        gdk_pixbuf_get_from_window(window, 0, 0, gdk_window_get_width(window),
                                   gdk_window_get_height(window));
  }

  if (!screenshot) {
    fprintf(stderr, "%s: failed to create screenshot GdkPixbuf\n", argv[0]);
    return 1;
  }

  GError* error = nullptr;
  if (argc > 1) {
    gdk_pixbuf_save(screenshot, argv[1], "png", &error, nullptr);
  } else {
    gdk_pixbuf_save_to_callback(screenshot, save_to_stdout, nullptr, "png",
                                &error, nullptr);
  }
  if (error) {
    fprintf(stderr, "%s: failed to write screenshot as png: %s\n", argv[0],
            error->message);
    return error->code;
  }

  return 0;
}

// These options are copied from mozglue/build/AsanOptions.cpp
#ifdef MOZ_ASAN
extern "C" const char* __asan_default_options() {
  return "allow_user_segv_handler=1:alloc_dealloc_mismatch=0:detect_leaks=0";
}
#endif