/*
 * Copyright © 2016 Red Hat, Inc
 *
 * This program 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 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:
 *       Alexander Larsson <alexl@redhat.com>
 *       Matthias Clasen <mclasen@redhat.com>
 */

#include "config.h"

#include <locale.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <gio/gio.h>
#include <gio/gunixfdlist.h>

#include "file-chooser.h"
#include "request.h"
#include "documents.h"
#include "xdp-dbus.h"
#include "xdp-impl-dbus.h"
#include "xdp-utils.h"

typedef struct _FileChooser FileChooser;
typedef struct _FileChooserClass FileChooserClass;

struct _FileChooser
{
  XdpFileChooserSkeleton parent_instance;
};

struct _FileChooserClass
{
  XdpFileChooserSkeletonClass parent_class;
};

static XdpImplLockdown *lockdown;
static XdpImplFileChooser *impl;
static FileChooser *file_chooser;

GType file_chooser_get_type (void) G_GNUC_CONST;
static void file_chooser_iface_init (XdpFileChooserIface *iface);

G_DEFINE_TYPE_WITH_CODE (FileChooser, file_chooser, XDP_TYPE_FILE_CHOOSER_SKELETON,
                         G_IMPLEMENT_INTERFACE (XDP_TYPE_FILE_CHOOSER, file_chooser_iface_init));

static void
send_response_in_thread_func (GTask        *task,
                              gpointer      source_object,
                              gpointer      task_data,
                              GCancellable *cancellable)
{
  Request *request = task_data;
  GVariantBuilder results;
  GVariantBuilder ruris;
  guint response;
  GVariant *options;
  gboolean writable = TRUE;
  const char **uris;
  GVariant *choices;
  gboolean for_save;

  g_variant_builder_init (&results, G_VARIANT_TYPE_VARDICT);
  g_variant_builder_init (&ruris, G_VARIANT_TYPE_STRING_ARRAY);

  REQUEST_AUTOLOCK (request);

  for_save = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (request), "for-save"));
  response = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (request), "response"));
  options = (GVariant *)g_object_get_data (G_OBJECT (request), "options");

  if (response != 0)
    goto out;

  if (!g_variant_lookup (options, "writable", "b",  &writable))
    writable = FALSE;

  choices = g_variant_lookup_value (options, "choices", G_VARIANT_TYPE ("a(ss)"));
  if (choices)
    g_variant_builder_add (&results, "{sv}", "choices", choices);

  if (g_variant_lookup (options, "uris", "^a&s", &uris))
    {
      int i;

      for (i = 0; uris && uris[i]; i++)
        {
          g_autofree char *ruri = NULL;
          g_autoptr(GError) error = NULL;

          ruri = register_document (uris[i], xdp_app_info_get_id (request->app_info), for_save, writable, &error);
          if (ruri == NULL)
            {
              g_warning ("Failed to register %s: %s", uris[i], error->message);
              continue;
            }
          g_debug ("convert uri %s -> %s\n", uris[i], ruri);
          g_variant_builder_add (&ruris, "s", ruri);
        }
    }

out:
  g_variant_builder_add (&results, "{sv}", "uris", g_variant_builder_end (&ruris));

  if (request->exported)
    {
      xdp_request_emit_response (XDP_REQUEST (request),
                                 response,
                                 g_variant_builder_end (&results));
      request_unexport (request);
    }
}

static void
open_file_done (GObject *source,
                GAsyncResult *result,
                gpointer data)
{
  g_autoptr(Request) request = data;
  guint response = 2;
  g_autoptr(GVariant) options = NULL;
  g_autoptr(GError) error = NULL;
  g_autoptr(GTask) task = NULL;

  if (!xdp_impl_file_chooser_call_open_file_finish (XDP_IMPL_FILE_CHOOSER (source),
                                                    &response,
                                                    &options,
                                                    result,
                                                    &error))
    {
      g_warning ("Backend call failed: %s", error->message);
    }

  g_object_set_data (G_OBJECT (request), "response", GINT_TO_POINTER (response));
  if (options)
    g_object_set_data_full (G_OBJECT (request), "options", g_variant_ref (options), (GDestroyNotify)g_variant_unref);

  task = g_task_new (NULL, NULL, NULL, NULL);
  g_task_set_task_data (task, g_object_ref (request), g_object_unref);
  g_task_run_in_thread (task, send_response_in_thread_func);
}

static gboolean
check_value_type (const char *key,
                  GVariant *value,
                  const GVariantType *type,
                  GError **error)
{
  if (g_variant_is_of_type (value, type))
    return TRUE;

  g_set_error (error,
               XDG_DESKTOP_PORTAL_ERROR,
               XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
               "expected type for key %s is %s, found %s",
               key, (const char *)type, (const char *)g_variant_get_type (value));

  return FALSE;
}

static gboolean
check_filter (GVariant *filter,
              GError **error)
{
  const char *name;
  g_autoptr(GVariant) list = NULL;
  int i;

  g_variant_get (filter, "(&s@a(us))", &name, &list);

  if (name[0] == 0)
    {
      g_set_error_literal (error,
                           XDG_DESKTOP_PORTAL_ERROR,
                           XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                           "name is empty");
      return FALSE;
    }

  if (g_variant_n_children (list) == 0)
    {
      g_set_error_literal (error,
                           XDG_DESKTOP_PORTAL_ERROR,
                           XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                           "no filters");
      return FALSE;
    }

  for (i = 0; i < g_variant_n_children (list); i++)
    {
      guint32 type;
      const char *string;

      g_variant_get_child (list, i, "(u&s)", &type, &string);
      if (type == 0)
        {
          /* TODO: validate glob */
          if (string[0] == 0)
            {
              g_set_error_literal (error,
                                   XDG_DESKTOP_PORTAL_ERROR,
                                   XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                                   "invalid glob pattern");
              return FALSE;
            }
        }
      else if (type == 1)
        {
          /* TODO: validate content type */
          if (string[0] == 0)
            {
              g_set_error_literal (error,
                                   XDG_DESKTOP_PORTAL_ERROR,
                                   XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                                   "invalid content type");
              return FALSE;
            }
        }
      else
        {
          g_set_error (error,
                       XDG_DESKTOP_PORTAL_ERROR,
                       XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                       "invalid filter type: %u", type);
          return FALSE;
        }
    }

  return TRUE;
}

static gboolean
validate_filters (const char *key,
                  GVariant *value,
                  GVariant *options,
                  GError **error)
{
  gsize i;

  if (!check_value_type ("filters", value, G_VARIANT_TYPE ("a(sa(us))"), error))
    return FALSE;

  for (i = 0; i < g_variant_n_children (value); i++)
    {
      g_autoptr(GVariant) filter = g_variant_get_child_value (value, i);

      if (!check_filter (filter, error))
        {
          g_prefix_error (error, "invalid filter: ");
          return FALSE;
        }
    }

  return TRUE;
}

static gboolean
validate_current_filter (const char *key,
                         GVariant *value,
                         GVariant *options,
                         GError **error)
{
  g_autoptr(GVariant) filters = NULL;
  gsize i, n_children;

  if (!check_value_type ("current_filter", value, G_VARIANT_TYPE ("(sa(us))"), error))
    return FALSE;

  if (!check_filter (value, error))
    {
      g_prefix_error (error, "invalid filter: ");
      return FALSE;
    }

  /* If the filters list is nonempty and current_filter is specified,
   * then the list must contain current_filter. But if the list is
   * empty, current_filter may be anything.
   */
  filters = g_variant_lookup_value (options, "filters", G_VARIANT_TYPE ("a(sa(us))"));
  if (!filters)
    return TRUE;

  if (!check_value_type ("filters", filters, G_VARIANT_TYPE ("a(sa(us))"), error))
    {
      g_prefix_error (error, "filters list is invalid: ");
      return FALSE;
    }

  n_children = g_variant_n_children (filters);
  if (n_children == 0)
    return TRUE;

  for (i = 0; i < n_children; i++)
    {
      g_autoptr(GVariant) filter = g_variant_get_child_value (filters, i);
      if (g_variant_equal (filter, value))
        return TRUE;
    }

  g_set_error_literal (error,
                       XDG_DESKTOP_PORTAL_ERROR,
                       XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                       "current_filter, if specified, must be present in filters list if list is nonempty");
  return FALSE;
}

static gboolean
check_choice (GVariant *choice,
              GError **error)
{
  const char *id;
  const char *label;
  g_autoptr(GVariant) options = NULL;
  const char *option;
  int i;
  gboolean seen_option;

  g_variant_get (choice, "(&s&s@a(ss)&s)", &id, &label, &options, &option);

  if (id[0] == 0)
    {
      g_set_error_literal (error,
                           XDG_DESKTOP_PORTAL_ERROR,
                           XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                           "id is empty");
      return FALSE;
    }

  if (label[0] == 0)
    {
      g_set_error_literal (error,
                           XDG_DESKTOP_PORTAL_ERROR,
                           XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                           "label is empty");
      return FALSE;
    }

  if (g_variant_n_children (options) == 0)
    {
      const char *values[] = { "", "true", "false", NULL };
      if (!g_strv_contains (values, option))
        {
          g_set_error (error,
                       XDG_DESKTOP_PORTAL_ERROR,
                       XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                       "bad current option: %s", option);
          return FALSE;
        }

      return TRUE;
    }

  seen_option = FALSE;
  for (i = 0; i < g_variant_n_children (options); i++)
    {
      const char *o_id;
      const char *o_label;

      g_variant_get_child (options, i, "(&s&s)", &o_id, &o_label);

      if (o_id[0] == 0)
        {
          g_set_error_literal (error,
                               XDG_DESKTOP_PORTAL_ERROR,
                               XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                               "option id is empty");
          return FALSE;
        }
      if (o_label[0] == 0)
        {
          g_set_error_literal (error,
                               XDG_DESKTOP_PORTAL_ERROR,
                               XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                               "option label is empty");
          return FALSE;
        }

      if (strcmp (o_id, option) == 0)
        seen_option = TRUE;
    }

  if (!seen_option && option[0] != 0)
    {
      g_set_error (error,
                   XDG_DESKTOP_PORTAL_ERROR,
                   XDG_DESKTOP_PORTAL_ERROR_INVALID_ARGUMENT,
                   "bad current option: %s", option);
      return FALSE;
    }

  return TRUE;
}

static gboolean
validate_choices (const char *key,
                  GVariant *value,
                  GVariant *options,
                  GError **error)
{
  int i;

  if (!check_value_type ("choices", value, G_VARIANT_TYPE ("a(ssa(ss)s)"), error))
    return FALSE;

  for (i = 0; i < g_variant_n_children (value); i++)
    {
      g_autoptr(GVariant) choice = g_variant_get_child_value (value, i);

      if (!check_choice (choice, error))
        {
          g_prefix_error (error, "invalid choice: ");
          return FALSE;
        }
    }

  return TRUE;
}

static XdpOptionKey open_file_options[] = {
  { "accept_label", G_VARIANT_TYPE_STRING, NULL },
  { "modal", G_VARIANT_TYPE_BOOLEAN, NULL },
  { "multiple", G_VARIANT_TYPE_BOOLEAN, NULL },
  { "filters", (const GVariantType *)"a(sa(us))", validate_filters },
  { "current_filter", (const GVariantType *)"(sa(us))", validate_current_filter },
  { "choices", (const GVariantType *)"a(ssa(ss)s)", validate_choices }
};

static gboolean
handle_open_file (XdpFileChooser *object,
                  GDBusMethodInvocation *invocation,
                  const gchar *arg_parent_window,
                  const gchar *arg_title,
                  GVariant *arg_options)
{
  Request *request = request_from_invocation (invocation);
  const char *app_id = xdp_app_info_get_id (request->app_info);
  g_autoptr(GError) error = NULL;
  g_autoptr(XdpImplRequest) impl_request = NULL;
  GVariantBuilder options;
  g_autoptr(GVariant) value = NULL;

  REQUEST_AUTOLOCK (request);

  g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
  if (!xdp_filter_options (arg_options, &options,
                           open_file_options, G_N_ELEMENTS (open_file_options),
                           &error))
    {
      g_dbus_method_invocation_return_gerror (invocation, error);
      return TRUE;
    }

  impl_request = xdp_impl_request_proxy_new_sync (g_dbus_proxy_get_connection (G_DBUS_PROXY (impl)),
                                                  G_DBUS_PROXY_FLAGS_NONE,
                                                  g_dbus_proxy_get_name (G_DBUS_PROXY (impl)),
                                                  request->id,
                                                  NULL, &error);
  if (!impl_request)
    {
      g_dbus_method_invocation_return_gerror (invocation, error);
      return TRUE;
    }

  request_set_impl_request (request, impl_request);
  request_export (request, g_dbus_method_invocation_get_connection (invocation));

  xdp_impl_file_chooser_call_open_file (impl,
                                        request->id,
                                        app_id,
                                        arg_parent_window,
                                        arg_title,
                                        g_variant_builder_end (&options),
                                        NULL,
                                        open_file_done,
                                        g_object_ref (request));

  xdp_file_chooser_complete_open_file (object, invocation, request->id);

  return TRUE;
}

static XdpOptionKey save_file_options[] = {
  { "accept_label", G_VARIANT_TYPE_STRING, NULL },
  { "modal", G_VARIANT_TYPE_BOOLEAN, NULL },
  { "filters", (const GVariantType *)"a(sa(us))", validate_filters },
  { "current_filter", (const GVariantType *)"(sa(us))", validate_current_filter },
  { "current_name", G_VARIANT_TYPE_STRING, NULL },
  { "current_folder", G_VARIANT_TYPE_BYTESTRING, NULL },
  { "current_file", G_VARIANT_TYPE_BYTESTRING, NULL },
  { "choices", (const GVariantType *)"a(ssa(ss)s)", validate_choices  }
};

static void
save_file_done (GObject *source,
                GAsyncResult *result,
                gpointer data)
{
  g_autoptr(Request) request = data;
  guint response = 2;
  g_autoptr(GVariant) options = NULL;
  g_autoptr(GError) error = NULL;
  g_autoptr(GTask) task = NULL;

  if (!xdp_impl_file_chooser_call_save_file_finish (XDP_IMPL_FILE_CHOOSER (source),
                                                    &response,
                                                    &options,
                                                    result,
                                                    &error))
    {
      g_warning ("Backend call failed: %s", error->message);
    }

  g_object_set_data (G_OBJECT (request), "response", GINT_TO_POINTER (response));
  if (options)
    g_object_set_data_full (G_OBJECT (request), "options", g_variant_ref (options), (GDestroyNotify)g_variant_unref);

  task = g_task_new (NULL, NULL, NULL, NULL);
  g_task_set_task_data (task, g_object_ref (request), g_object_unref);
  g_task_run_in_thread (task, send_response_in_thread_func);
}

static gboolean
handle_save_file (XdpFileChooser *object,
                  GDBusMethodInvocation *invocation,
                  const gchar *arg_parent_window,
                  const gchar *arg_title,
                  GVariant *arg_options)
{
  Request *request = request_from_invocation (invocation);
  const char *app_id = xdp_app_info_get_id (request->app_info);
  g_autoptr(GError) error = NULL;
  XdpImplRequest *impl_request;
  GVariantBuilder options;

  if (xdp_impl_lockdown_get_disable_save_to_disk (lockdown))
    {
      g_debug ("File saving disabled");
      g_dbus_method_invocation_return_error (invocation,
                                             XDG_DESKTOP_PORTAL_ERROR,
                                             XDG_DESKTOP_PORTAL_ERROR_NOT_ALLOWED,
                                             "File saving disabled");
      return TRUE;
    }

  REQUEST_AUTOLOCK (request);

  g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
  if (!xdp_filter_options (arg_options, &options,
                           save_file_options, G_N_ELEMENTS (save_file_options),
                           &error))
    {
      g_dbus_method_invocation_return_gerror (invocation, error);
      return TRUE;
    }

  impl_request = xdp_impl_request_proxy_new_sync (g_dbus_proxy_get_connection (G_DBUS_PROXY (impl)),
                                                  G_DBUS_PROXY_FLAGS_NONE,
                                                  g_dbus_proxy_get_name (G_DBUS_PROXY (impl)),
                                                  request->id,
                                                  NULL, &error);
  if (!impl_request)
    {
      g_dbus_method_invocation_return_gerror (invocation, error);
      return TRUE;
    }

  g_object_set_data (G_OBJECT (request), "for-save", GINT_TO_POINTER (TRUE));

  request_set_impl_request (request, impl_request);
  request_export (request, g_dbus_method_invocation_get_connection (invocation));

  xdp_impl_file_chooser_call_save_file (impl,
                                        request->id,
                                        app_id,
                                        arg_parent_window,
                                        arg_title,
                                        g_variant_builder_end (&options),
                                        NULL,
                                        save_file_done,
                                        g_object_ref (request));

  xdp_file_chooser_complete_open_file (object, invocation, request->id);

  return TRUE;
}

static void
file_chooser_iface_init (XdpFileChooserIface *iface)
{
  iface->handle_open_file = handle_open_file;
  iface->handle_save_file = handle_save_file;
}

static void
file_chooser_init (FileChooser *fc)
{
  xdp_file_chooser_set_version (XDP_FILE_CHOOSER (fc), 1);
}

static void
file_chooser_class_init (FileChooserClass *klass)
{
}

GDBusInterfaceSkeleton *
file_chooser_create (GDBusConnection *connection,
                     const char      *dbus_name,
                     gpointer         lockdown_proxy)
{
  g_autoptr(GError) error = NULL;

  lockdown = lockdown_proxy;

  impl = xdp_impl_file_chooser_proxy_new_sync (connection,
                                               G_DBUS_PROXY_FLAGS_NONE,
                                               dbus_name,
                                               DESKTOP_PORTAL_OBJECT_PATH,
                                               NULL,
                                               &error);

  if (impl == NULL)
    {
      g_warning ("Failed to create file chooser proxy: %s", error->message);
      return NULL;
    }

  g_dbus_proxy_set_default_timeout (G_DBUS_PROXY (impl), G_MAXINT);

  file_chooser = g_object_new (file_chooser_get_type (), NULL);

  return G_DBUS_INTERFACE_SKELETON (file_chooser);
}