/*

 * Copyright © 2013 Lars Uebernickel

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * 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, see <http://www.gnu.org/licenses/>.

 *

 * Authors: Lars Uebernickel <lars@uebernic.de>

 */

#include "config.h"

#include "gnotificationbackend.h"

#include "gapplication.h"

#include "giomodule-priv.h"

#include "gnotification-private.h"

#include "gdbusconnection.h"

#include "gdbusnamewatching.h"

#include "gactiongroup.h"

#include "gaction.h"

#include "gthemedicon.h"

#include "gfileicon.h"

#include "gfile.h"

#include "gdbusutils.h"

#define G_TYPE_FDO_NOTIFICATION_BACKEND  (g_fdo_notification_backend_get_type ())

#define G_FDO_NOTIFICATION_BACKEND(o)    (G_TYPE_CHECK_INSTANCE_CAST ((o), G_TYPE_FDO_NOTIFICATION_BACKEND, GFdoNotificationBackend))

typedef struct _GFdoNotificationBackend GFdoNotificationBackend;

typedef GNotificationBackendClass       GFdoNotificationBackendClass;

struct _GFdoNotificationBackend

{

  GNotificationBackend parent;

  guint   bus_name_id;

  guint   notify_subscription;

  GSList *notifications;

};

GType g_fdo_notification_backend_get_type (void);

G_DEFINE_TYPE_WITH_CODE (GFdoNotificationBackend, g_fdo_notification_backend, G_TYPE_NOTIFICATION_BACKEND,

  _g_io_modules_ensure_extension_points_registered ();

  g_io_extension_point_implement (G_NOTIFICATION_BACKEND_EXTENSION_POINT_NAME,

                                 g_define_type_id, "freedesktop", 0))

typedef struct

{

  GFdoNotificationBackend *backend;

  gchar *id;

  guint32 notify_id;

  gchar *default_action;  /* (nullable) (owned) */

  GVariant *default_action_target;  /* (nullable) (owned), not floating */

} FreedesktopNotification;

static void

freedesktop_notification_free (gpointer data)

{

  FreedesktopNotification *n = data;

  g_object_unref (n->backend);

  g_free (n->id);

  g_free (n->default_action);

  if (n->default_action_target)

    g_variant_unref (n->default_action_target);

  g_slice_free (FreedesktopNotification, n);

}

static FreedesktopNotification *

freedesktop_notification_new (GFdoNotificationBackend *backend,

                              const gchar             *id,

                              GNotification           *notification)

{

  FreedesktopNotification *n;

  n = g_slice_new0 (FreedesktopNotification);

  n->backend = g_object_ref (backend);

  n->id = g_strdup (id);

  n->notify_id = 0;

  g_notification_get_default_action (notification,

                                     &n->default_action,

                                     &n->default_action_target);

  return n;

}

static FreedesktopNotification *

g_fdo_notification_backend_find_notification (GFdoNotificationBackend *backend,

                                              const gchar             *id)

{

  GSList *it;

  for (it = backend->notifications; it != NULL; it = it->next)

    {

      FreedesktopNotification *n = it->data;

      if (g_str_equal (n->id, id))

        return n;

    }

  return NULL;

}

static FreedesktopNotification *

g_fdo_notification_backend_find_notification_by_notify_id (GFdoNotificationBackend *backend,

                                                           guint32                  id)

{

  GSList *it;

  for (it = backend->notifications; it != NULL; it = it->next)

    {

      FreedesktopNotification *n = it->data;

      if (n->notify_id == id)

        return n;

    }

  return NULL;

}

static gboolean

activate_action (GFdoNotificationBackend *backend,

                 const gchar             *name,

                 GVariant                *parameter)

{

  GNotificationBackend *g_backend = G_NOTIFICATION_BACKEND (backend);

  /* Callers should not provide a floating variant here */

  g_assert (parameter == NULL || !g_variant_is_floating (parameter));

  if (name != NULL &&

      g_str_has_prefix (name, "app."))

    {

      const GVariantType *parameter_type = NULL;

      const gchar *action_name = name + strlen ("app.");

      /* @name and @parameter come as untrusted input over D-Bus, so validate them first */

      if (g_action_group_query_action (G_ACTION_GROUP (g_backend->application),

                                       action_name, NULL, &parameter_type,

                                       NULL, NULL, NULL) &&

          ((parameter_type == NULL && parameter == NULL) ||

           (parameter_type != NULL && parameter != NULL && g_variant_is_of_type (parameter, parameter_type))))

        {

          g_action_group_activate_action (G_ACTION_GROUP (g_backend->application), action_name, parameter);

          return TRUE;

        }

    }

  else if (name == NULL)

    {

      g_application_activate (g_backend->application);

      return TRUE;

    }

  return FALSE;

}

static void

notify_signal (GDBusConnection *connection,

               const gchar     *sender_name,

               const gchar     *object_path,

               const gchar     *interface_name,

               const gchar     *signal_name,

               GVariant        *parameters,

               gpointer         user_data)

{

  GFdoNotificationBackend *backend = user_data;

  guint32 id = 0;

  const gchar *action = NULL;

  FreedesktopNotification *n;

  gboolean notification_closed = TRUE;

  if (g_str_equal (signal_name, "NotificationClosed") &&

      g_variant_is_of_type (parameters, G_VARIANT_TYPE ("(uu)")))

    {

      g_variant_get (parameters, "(uu)", &id, NULL);

    }

  else if (g_str_equal (signal_name, "ActionInvoked") &&

           g_variant_is_of_type (parameters, G_VARIANT_TYPE ("(us)")))

    {

      g_variant_get (parameters, "(u&s)", &id, &action);

    }

  else

    return;

  n = g_fdo_notification_backend_find_notification_by_notify_id (backend, id);

  if (n == NULL)

    return;

  if (action)

    {

      if (g_str_equal (action, "default"))

        {

          if (!activate_action (backend, n->default_action, n->default_action_target))

            notification_closed = FALSE;

        }

      else

        {

          gchar *name = NULL;

          GVariant *target = NULL;

          if (!g_action_parse_detailed_name (action, &name, &target, NULL) ||

              !activate_action (backend, name, target))

            notification_closed = FALSE;

          g_free (name);

          g_clear_pointer (&target, g_variant_unref);

        }

    }

  /* Remove the notification, as it’s either been explicitly closed

   * (`NotificationClosed` signal) or has been closed as a result of activating

   * an action successfully. GLib doesn’t currently support the `resident` hint

   * on notifications which would allow them to stay around after having an

   * action invoked on them (see

   * https://specifications.freedesktop.org/notification-spec/notification-spec-latest.html#idm45877717456448)

   *

   * First, get the notification again in case the action redrew it */

  if (notification_closed)

    {

      n = g_fdo_notification_backend_find_notification_by_notify_id (backend, id);

      if (n != NULL)

        {

          backend->notifications = g_slist_remove (backend->notifications, n);

          freedesktop_notification_free (n);

        }

    }

}

static void

name_vanished_handler_cb (GDBusConnection *connection,

                          const gchar     *name,

                          gpointer         user_data)

{

  GFdoNotificationBackend *backend = user_data;

  if (backend->notifications)

    {

      g_slist_free_full (backend->notifications, freedesktop_notification_free);

      backend->notifications = NULL;

    }

}

/* Converts a GNotificationPriority to an urgency level as defined by

 * the freedesktop spec (0: low, 1: normal, 2: critical).

 */

static guchar

urgency_from_priority (GNotificationPriority priority)

{

  switch (priority)

    {

    case G_NOTIFICATION_PRIORITY_LOW:

      return 0;

    default:

    case G_NOTIFICATION_PRIORITY_NORMAL:

    case G_NOTIFICATION_PRIORITY_HIGH:

      return 1;

    case G_NOTIFICATION_PRIORITY_URGENT:

      return 2;

    }

}

static void

call_notify (GDBusConnection     *con,

             GApplication        *app,

             guint32              replace_id,

             GNotification       *notification,

             GAsyncReadyCallback  callback,

             gpointer             user_data)

{

  GVariantBuilder action_builder;

  guint n_buttons;

  guint i;

  GVariantBuilder hints_builder;

  GIcon *icon;

  GVariant *parameters;

  const gchar *app_name;

  const gchar *body;

  guchar urgency;

  g_variant_builder_init (&action_builder, G_VARIANT_TYPE_STRING_ARRAY);

  if (g_notification_get_default_action (notification, NULL, NULL))

    {

      g_variant_builder_add (&action_builder, "s", "default");

      g_variant_builder_add (&action_builder, "s", "");

    }

  n_buttons = g_notification_get_n_buttons (notification);

  for (i = 0; i < n_buttons; i++)

    {

      gchar *label;

      gchar *action;

      GVariant *target;

      gchar *detailed_name;

      g_notification_get_button (notification, i, &label, &action, &target);

      detailed_name = g_action_print_detailed_name (action, target);

      /* Actions named 'default' collide with libnotify's naming of the

       * default action. Rewriting them to something unique is enough,

       * because those actions can never be activated (they aren't

       * prefixed with 'app.').

       */

      if (g_str_equal (detailed_name, "default"))

        {

          g_free (detailed_name);

          detailed_name = g_dbus_generate_guid ();

        }

      g_variant_builder_add_value (&action_builder, g_variant_new_take_string (detailed_name));

      g_variant_builder_add_value (&action_builder, g_variant_new_take_string (label));

      g_free (action);

      if (target)

        g_variant_unref (target);

    }

  g_variant_builder_init (&hints_builder, G_VARIANT_TYPE ("a{sv}"));

  g_variant_builder_add (&hints_builder, "{sv}", "desktop-entry",

                         g_variant_new_string (g_application_get_application_id (app)));

  urgency = urgency_from_priority (g_notification_get_priority (notification));

  g_variant_builder_add (&hints_builder, "{sv}", "urgency", g_variant_new_byte (urgency));

  if (g_notification_get_category (notification))

    {

      g_variant_builder_add (&hints_builder, "{sv}", "category",

                             g_variant_new_string (g_notification_get_category (notification)));

    }

  icon = g_notification_get_icon (notification);

  if (icon != NULL)

    {

      if (G_IS_FILE_ICON (icon))

        {

           GFile *file;

           file = g_file_icon_get_file (G_FILE_ICON (icon));

           g_variant_builder_add (&hints_builder, "{sv}", "image-path",

                                  g_variant_new_take_string (g_file_get_path (file)));

        }

      else if (G_IS_THEMED_ICON (icon))

        {

           const gchar* const* icon_names = g_themed_icon_get_names(G_THEMED_ICON (icon));

           /* Take first name from GThemedIcon */

           g_variant_builder_add (&hints_builder, "{sv}", "image-path",

                                  g_variant_new_string (icon_names[0]));

        }

    }

  app_name = g_get_application_name ();

  body = g_notification_get_body (notification);

  parameters = g_variant_new ("(susssasa{sv}i)",

                              app_name ? app_name : "",

                              replace_id,

                              "",           /* app icon */

                              g_notification_get_title (notification),

                              body ? body : "",

                              &action_builder,

                              &hints_builder,

                              -1);          /* expire_timeout */

  g_dbus_connection_call (con, "org.freedesktop.Notifications", "/org/freedesktop/Notifications",

                          "org.freedesktop.Notifications", "Notify",

                          parameters, G_VARIANT_TYPE ("(u)"),

                          G_DBUS_CALL_FLAGS_NONE, -1, NULL,

                          callback, user_data);

}

static void

notification_sent (GObject      *source_object,

                   GAsyncResult *result,

                   gpointer      user_data)

{

  FreedesktopNotification *n = user_data;

  GVariant *val;

  GError *error = NULL;

  static gboolean warning_printed = FALSE;

  val = g_dbus_connection_call_finish (G_DBUS_CONNECTION (source_object), result, &error);

  if (val)

    {

      GFdoNotificationBackend *backend = n->backend;

      FreedesktopNotification *match;

      g_variant_get (val, "(u)", &n->notify_id);

      g_variant_unref (val);

      match = g_fdo_notification_backend_find_notification_by_notify_id (backend, n->notify_id);

      if (match != NULL)

        {

          backend->notifications = g_slist_remove (backend->notifications, match);

          freedesktop_notification_free (match);

        }

      backend->notifications = g_slist_prepend (backend->notifications, n);

    }

  else

    {

      if (!warning_printed)

        {

          g_warning ("unable to send notifications through org.freedesktop.Notifications: %s",

                     error->message);

          warning_printed = TRUE;

        }

      freedesktop_notification_free (n);

      g_error_free (error);

    }

}

static void

g_fdo_notification_backend_dispose (GObject *object)

{

  GFdoNotificationBackend *backend = G_FDO_NOTIFICATION_BACKEND (object);

  if (backend->bus_name_id)

    {

      g_bus_unwatch_name (backend->bus_name_id);

      backend->bus_name_id = 0;

    }

  if (backend->notify_subscription)

    {

      GDBusConnection *session_bus;

      session_bus = G_NOTIFICATION_BACKEND (backend)->dbus_connection;

      g_dbus_connection_signal_unsubscribe (session_bus, backend->notify_subscription);

      backend->notify_subscription = 0;

    }

  if (backend->notifications)

    {

      g_slist_free_full (backend->notifications, freedesktop_notification_free);

      backend->notifications = NULL;

    }

  G_OBJECT_CLASS (g_fdo_notification_backend_parent_class)->dispose (object);

}

static gboolean

g_fdo_notification_backend_is_supported (void)

{

  /* This is the fallback backend with the lowest priority. To avoid an

   * unnecessary synchronous dbus call to check for

   * org.freedesktop.Notifications, this function always succeeds. A

   * warning will be printed when sending the first notification fails.

   */

  return TRUE;

}

static void

g_fdo_notification_backend_send_notification (GNotificationBackend *backend,

                                              const gchar          *id,

                                              GNotification        *notification)

{

  GFdoNotificationBackend *self = G_FDO_NOTIFICATION_BACKEND (backend);

  FreedesktopNotification *n, *tmp;

  if (self->bus_name_id == 0)

    {

      self->bus_name_id = g_bus_watch_name_on_connection (backend->dbus_connection,

                                                          "org.freedesktop.Notifications",

                                                          G_BUS_NAME_WATCHER_FLAGS_NONE,

                                                          NULL,

                                                          name_vanished_handler_cb,

                                                          backend,

                                                          NULL);

    }

  if (self->notify_subscription == 0)

    {

      self->notify_subscription =

        g_dbus_connection_signal_subscribe (backend->dbus_connection,

                                            "org.freedesktop.Notifications",

                                            "org.freedesktop.Notifications", NULL,

                                            "/org/freedesktop/Notifications", NULL,

                                            G_DBUS_SIGNAL_FLAGS_NONE,

                                            notify_signal, backend, NULL);

    }

  n = freedesktop_notification_new (self, id, notification);

  tmp = g_fdo_notification_backend_find_notification (self, id);

  if (tmp)

    n->notify_id = tmp->notify_id;

  call_notify (backend->dbus_connection, backend->application, n->notify_id, notification, notification_sent, n);

}

static void

g_fdo_notification_backend_withdraw_notification (GNotificationBackend *backend,

                                                  const gchar          *id)

{

  GFdoNotificationBackend *self = G_FDO_NOTIFICATION_BACKEND (backend);

  FreedesktopNotification *n;

  n = g_fdo_notification_backend_find_notification (self, id);

  if (n)

    {

      if (n->notify_id > 0)

        {

          g_dbus_connection_call (backend->dbus_connection,

                                  "org.freedesktop.Notifications",

                                  "/org/freedesktop/Notifications",

                                  "org.freedesktop.Notifications", "CloseNotification",

                                  g_variant_new ("(u)", n->notify_id), NULL,

                                  G_DBUS_CALL_FLAGS_NONE, -1, NULL, NULL, NULL);

        }

      self->notifications = g_slist_remove (self->notifications, n);

      freedesktop_notification_free (n);

    }

}

static void

g_fdo_notification_backend_init (GFdoNotificationBackend *backend)

{

}

static void

g_fdo_notification_backend_class_init (GFdoNotificationBackendClass *class)

{

  GObjectClass *object_class = G_OBJECT_CLASS (class);

  GNotificationBackendClass *backend_class = G_NOTIFICATION_BACKEND_CLASS (class);

  object_class->dispose = g_fdo_notification_backend_dispose;

  backend_class->is_supported = g_fdo_notification_backend_is_supported;

  backend_class->send_notification = g_fdo_notification_backend_send_notification;

  backend_class->withdraw_notification = g_fdo_notification_backend_withdraw_notification;

}