/* GIO - GLib Input, Output and Streaming Library
 *
 * Copyright 2017 Red Hat, Inc.
 *
 * 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/>.
 */

#include "config.h"

#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <glib/gstdio.h>

#include "gopenuriportal.h"
#include "xdp-dbus.h"
#include "gtkwindowprivate.h"

#ifdef G_OS_UNIX
#include <gio/gunixfdlist.h>
#endif

#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#else
#define HAVE_O_CLOEXEC 1
#endif


static GXdpOpenURI *openuri;

static gboolean
init_openuri_portal (void)
{
  static gsize openuri_inited = 0;

  if (g_once_init_enter (&openuri_inited))
    {
      GError *error = NULL;
      GDBusConnection *connection = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);

      if (connection != NULL)
        {
          openuri = gxdp_open_uri_proxy_new_sync (connection, 0,
                                                  "org.freedesktop.portal.Desktop",
                                                  "/org/freedesktop/portal/desktop",
                                                  NULL, &error);
          if (openuri == NULL)
            {
              g_warning ("Cannot create document portal proxy: %s", error->message);
              g_error_free (error);
            }

          g_object_unref (connection);
        }
      else
        {
          g_warning ("Cannot connect to session bus when initializing document portal: %s",
                     error->message);
          g_error_free (error);
        }

      g_once_init_leave (&openuri_inited, 1);
    }

  return openuri != NULL;
}

enum {
  XDG_DESKTOP_PORTAL_SUCCESS   = 0,
  XDG_DESKTOP_PORTAL_CANCELLED = 1,
  XDG_DESKTOP_PORTAL_FAILED    = 2
};

static void
response_received (GDBusConnection *connection,
                   const char      *sender_name,
                   const char      *object_path,
                   const char      *interface_name,
                   const char      *signal_name,
                   GVariant        *parameters,
                   gpointer         user_data)
{
  GTask *task = user_data;
  guint32 response;
  guint signal_id;

  signal_id = GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (task), "signal-id"));
  g_dbus_connection_signal_unsubscribe (connection, signal_id);

  g_variant_get (parameters, "(u@a{sv})", &response, NULL);

  switch (response)
    {
    case XDG_DESKTOP_PORTAL_SUCCESS:
      g_task_return_boolean (task, TRUE);
      break;
    case XDG_DESKTOP_PORTAL_CANCELLED:
      g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_CANCELLED, "Launch cancelled");
      break;
    case XDG_DESKTOP_PORTAL_FAILED:
    default:
      g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_FAILED, "Launch failed");
      break;
    }

  g_object_unref (task);
}

static void
open_call_done (GObject      *source,
                GAsyncResult *result,
                gpointer      user_data)
{
  GXdpOpenURI *portal = GXDP_OPEN_URI (source);
  GDBusConnection *connection;
  GTask *task = user_data;
  GError *error = NULL;
  gboolean open_file;
  gboolean res;
  char *path = NULL;
  const char *handle;
  guint signal_id;

  connection = g_dbus_proxy_get_connection (G_DBUS_PROXY (portal));
  open_file = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (task), "open-file"));

  if (open_file)
    res = gxdp_open_uri_call_open_file_finish (portal, &path, NULL, result, &error);
  else
    res = gxdp_open_uri_call_open_uri_finish (portal, &path, result, &error);

  if (!res)
    {
      g_task_return_error (task, error);
      g_object_unref (task);
      g_free (path);
      return;
    }

  handle = (const char *)g_object_get_data (G_OBJECT (task), "handle");
  if (g_strcmp0 (handle, path) != 0)
    {
      signal_id = GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (task), "signal-id"));
      g_dbus_connection_signal_unsubscribe (connection, signal_id);

      signal_id = g_dbus_connection_signal_subscribe (connection,
                                                      "org.freedesktop.portal.Desktop",
                                                      "org.freedesktop.portal.Request",
                                                      "Response",
                                                      path,
                                                      NULL,
                                                      G_DBUS_SIGNAL_FLAGS_NO_MATCH_RULE,
                                                      response_received,
                                                      task,
                                                      NULL);
      g_object_set_data (G_OBJECT (task), "signal-id", GINT_TO_POINTER (signal_id));
    }
}

static void
open_uri (GFile               *file,
          const char          *parent_window,
          GCancellable        *cancellable,
          GAsyncReadyCallback  callback,
          gpointer             user_data)
{
  GTask *task;
  GVariant *opts = NULL;
  int i;
  guint signal_id;

  if (callback)
    {
      GDBusConnection *connection;
      GVariantBuilder opt_builder;
      char *token;
      char *sender;
      char *handle;

      connection = g_dbus_proxy_get_connection (G_DBUS_PROXY (openuri));

      task = g_task_new (NULL, cancellable, callback, user_data);

      token = g_strdup_printf ("gtk%d", g_random_int_range (0, G_MAXINT));
      sender = g_strdup (g_dbus_connection_get_unique_name (connection) + 1);
      for (i = 0; sender[i]; i++)
        if (sender[i] == '.')
          sender[i] = '_';

      handle = g_strdup_printf ("/org/freedesktop/portal/desktop/request/%s/%s", sender, token);
      g_object_set_data_full (G_OBJECT (task), "handle", handle, g_free);
      g_free (sender);

      signal_id = g_dbus_connection_signal_subscribe (connection,
                                                      "org.freedesktop.portal.Desktop",
                                                      "org.freedesktop.portal.Request",
                                                      "Response",
                                                      handle,
                                                      NULL,
                                                      G_DBUS_SIGNAL_FLAGS_NO_MATCH_RULE,
                                                      response_received,
                                                      task,
                                                      NULL);
      g_object_set_data (G_OBJECT (task), "signal-id", GINT_TO_POINTER (signal_id));

      g_variant_builder_init (&opt_builder, G_VARIANT_TYPE_VARDICT);
      g_variant_builder_add (&opt_builder, "{sv}", "handle_token", g_variant_new_string (token));
      g_free (token);

      opts = g_variant_builder_end (&opt_builder);
    }
  else
    task = NULL;

  if (g_file_is_native (file))
    {
      const char *path = NULL;
      GUnixFDList *fd_list = NULL;
      int fd, fd_id, errsv;

      if (task)
        g_object_set_data (G_OBJECT (task), "open-file", GINT_TO_POINTER (TRUE));

      path = g_file_peek_path (file);
      fd = g_open (path, O_RDONLY | O_CLOEXEC);
      errsv = errno;
      if (fd == -1)
        {
          g_task_report_new_error (NULL, callback, user_data, NULL,
                                   G_IO_ERROR, g_io_error_from_errno (errsv),
                                   "OpenURI portal is not available");
          return;
        }

#ifndef HAVE_O_CLOEXEC
      fcntl (fd, F_SETFD, FD_CLOEXEC);
#endif
      fd_list = g_unix_fd_list_new_from_array (&fd, 1);
      fd = -1;
      fd_id = 0;

      gxdp_open_uri_call_open_file (openuri,
                                    parent_window ? parent_window : "",
                                    g_variant_new ("h", fd_id),
                                    opts,
                                    fd_list,
                                    cancellable,
                                    task ? open_call_done : NULL,
                                    task);
      g_object_unref (fd_list);
    }
  else
    {
      char *uri = g_file_get_uri (file);

      gxdp_open_uri_call_open_uri (openuri,
                                   parent_window ? parent_window : "",
                                   uri,
                                   opts,
                                   cancellable,
                                   task ? open_call_done : NULL,
                                   task);

      g_free (uri);
    }
}

typedef struct {
  GtkWindow *parent;
  GFile *file;
  GTask *task;
} OpenUriData;

static void
open_uri_data_free (OpenUriData *data)
{
  if (data->parent)
    gtk_window_unexport_handle (data->parent);
  g_clear_object (&data->parent);
  g_clear_object (&data->file);
  g_clear_object (&data->task);
  g_free (data);
}

static void
open_uri_done (GObject      *source,
               GAsyncResult *result,
               gpointer      user_data)
{
  OpenUriData *data = user_data;
  GError *error = NULL;

  if (!g_task_propagate_boolean (G_TASK (result), &error))
    g_task_return_error (data->task, error);
  else
    g_task_return_boolean (data->task, TRUE);

  open_uri_data_free (data);
}

static void
window_handle_exported (GtkWindow  *window,
                        const char *handle,
                        gpointer    user_data)
{
  OpenUriData *data = user_data;

  open_uri (data->file, handle, g_task_get_cancellable (data->task), open_uri_done, data);
}

void
g_openuri_portal_open_async (GFile               *file,
                             GtkWindow           *parent,
                             GCancellable        *cancellable,
                             GAsyncReadyCallback  callback,
                             gpointer             user_data)
{
  OpenUriData *data;

  if (!init_openuri_portal ())
    {
      g_task_report_new_error (NULL, callback, user_data, NULL,
                               G_IO_ERROR, G_IO_ERROR_NOT_INITIALIZED,
                               "OpenURI portal is not available");
      return;
    }

  data = g_new0 (OpenUriData, 1);
  data->parent = parent ? g_object_ref (parent) : NULL;
  data->file = g_object_ref (file);
  data->task = g_task_new (parent, cancellable, callback, user_data);
  g_task_set_source_tag (data->task, g_openuri_portal_open_async);

  if (!parent || !gtk_window_export_handle (parent, window_handle_exported, data))
    window_handle_exported (parent, NULL, data);
}

gboolean
g_openuri_portal_open_finish (GAsyncResult  *result,
                              GError       **error)
{
  return g_task_propagate_boolean (G_TASK (result), error);
}