/*

 * fprintd example to verify a fingerprint

 * Copyright (C) 2008 Daniel Drake <dsd@gentoo.org>

 * Copyright (C) 2020 Marco Trevisan <marco.trevisan@canonical.com>

 *

 * 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, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <locale.h>

#include <gio/gio.h>

#include "fprintd-dbus.h"

static FprintDBusManager *manager = NULL;

static GDBusConnection *connection = NULL;

static char *finger_name = NULL;

static gboolean g_fatal_warnings = FALSE;

static char **usernames = NULL;

static void

create_manager (void)

{

  g_autoptr(GError) error = NULL;

  connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM, NULL, &error);

  if (connection == NULL)

    {

      g_print ("Failed to connect to session bus: %s\n", error->message);

      exit (1);

    }

  manager = fprint_dbus_manager_proxy_new_sync (connection,

                                                G_DBUS_PROXY_FLAGS_NONE,

                                                "net.reactivated.Fprint",

                                                "/net/reactivated/Fprint/Manager",

                                                NULL, &error);

  if (manager == NULL)

    {

      g_print ("Failed to get Fprintd manager: %s\n", error->message);

      exit (1);

    }

}

static FprintDBusDevice *

open_device (const char *username)

{

  g_autoptr(FprintDBusDevice) dev = NULL;

  g_autoptr(GError) error = NULL;

  g_autofree char *path = NULL;

  if (!fprint_dbus_manager_call_get_default_device_sync (manager, &path,

                                                         NULL, &error))

    {

      g_print ("Impossible to verify: %s\n", error->message);

      exit (1);

    }

  g_print ("Using device %s\n", path);

  dev = fprint_dbus_device_proxy_new_sync (connection,

                                           G_DBUS_PROXY_FLAGS_NONE,

                                           "net.reactivated.Fprint",

                                           path, NULL, &error);

  if (error)

    {

      g_print ("failed to connect to device: %s\n", error->message);

      exit (1);

    }

  if (!fprint_dbus_device_call_claim_sync (dev, username, NULL, &error))

    {

      g_print ("failed to claim device: %s\n", error->message);

      exit (1);

    }

  return g_steal_pointer (&dev;;

}

static void

find_finger (FprintDBusDevice *dev, const char *username)

{

  g_autoptr(GError) error = NULL;

  g_auto(GStrv) fingers = NULL;

  guint i;

  if (!fprint_dbus_device_call_list_enrolled_fingers_sync (dev, username,

                                                           &fingers,

                                                           NULL, &error))

    {

      g_print ("ListEnrolledFingers failed: %s\n", error->message);

      exit (1);

    }

  if (fingers == NULL || g_strv_length (fingers) == 0)

    {

      g_print ("No fingers enrolled for this device.\n");

      exit (1);

    }

  g_print ("Listing enrolled fingers:\n");

  for (i = 0; fingers[i] != NULL; i++)

    g_print (" - #%d: %s\n", i, fingers[i]);

  if (finger_name && !g_str_equal (finger_name, "any") &&

      !g_strv_contains ((const char **) fingers, finger_name))

    {

      g_print ("Finger '%s' not enrolled for user %s.\n", finger_name,

               username);

      g_free (finger_name);

      exit (1);

    }

  if (finger_name == NULL)

    finger_name = g_strdup (fingers[0]);

}

struct VerifyState

{

  GError  *error;

  gboolean started;

  gboolean completed;

};

static void

verify_result (GObject *object, const char *result, gboolean done, void *user_data)

{

  struct VerifyState *verify_state = user_data;

  g_print ("Verify result: %s (%s)\n", result, done ? "done" : "not done");

  if (done != FALSE)

    verify_state->completed = TRUE;

}

static void

verify_finger_selected (GObject *object, const char *name, void *user_data)

{

  g_print ("Verifying: %s\n", name);

}

static void

verify_started_cb (GObject      *obj,

                   GAsyncResult *res,

                   gpointer      user_data)

{

  struct VerifyState *verify_state = user_data;

  if (fprint_dbus_device_call_verify_start_finish (FPRINT_DBUS_DEVICE (obj), res, &verify_state->error))

    {

      g_print ("Verify started!\n");

      verify_state->started = TRUE;

    }

}

static void

proxy_signal_cb (GDBusProxy  *proxy,

                 const gchar *sender_name,

                 const gchar *signal_name,

                 GVariant    *parameters,

                 gpointer     user_data)

{

  struct VerifyState *verify_state = user_data;

  if (!verify_state->started)

    return;

  if (g_str_equal (signal_name, "VerifyStatus"))

    {

      const gchar *result;

      gboolean done;

      g_variant_get (parameters, "(&sb)", &result, &done);

      verify_result (G_OBJECT (proxy), result, done, user_data);

    }

  else if (g_str_equal (signal_name, "VerifyFingerSelected"))

    {

      const gchar *name;

      g_variant_get (parameters, "(&s)", &name);

      verify_finger_selected (G_OBJECT (proxy), name, user_data);

    }

}

static void

do_verify (FprintDBusDevice *dev)

{

  g_autoptr(GError) error = NULL;

  struct VerifyState verify_state = { 0 };

  /* This one is funny. We connect to the signal immediately to avoid

   * race conditions. However, we must ignore any authentication results

   * that happen before our start call returns.

   * This is because the verify call itself may internally try to verify

   * against fprintd (possibly using a separate account).

   *

   * To do so, we *must* use the async version of the verify call, as the

   * sync version would cause the signals to be queued and only processed

   * after it returns.

   */

  g_signal_connect (dev, "g-signal", G_CALLBACK (proxy_signal_cb),

                    &verify_state);

  fprint_dbus_device_call_verify_start (dev, finger_name, NULL,

                                        verify_started_cb,

                                        &verify_state);

  /* Wait for verify start while discarding any VerifyStatus signals */

  while (!verify_state.started && !verify_state.error)

    g_main_context_iteration (NULL, TRUE);

  if (verify_state.error)

    {

      g_print ("VerifyStart failed: %s\n", verify_state.error->message);

      g_clear_error (&verify_state.error);

      exit (1);

    }

  /* VerifyStatus signals are processing, wait for completion. */

  while (!verify_state.completed)

    g_main_context_iteration (NULL, TRUE);

  g_signal_handlers_disconnect_by_func (dev, proxy_signal_cb,

                                        &verify_state);

  if (!fprint_dbus_device_call_verify_stop_sync (dev, NULL, &error))

    {

      g_print ("VerifyStop failed: %s\n", error->message);

      exit (1);

    }

}

static void

release_device (FprintDBusDevice *dev)

{

  g_autoptr(GError) error = NULL;

  if (!fprint_dbus_device_call_release_sync (dev, NULL, &error))

    {

      g_print ("ReleaseDevice failed: %s\n", error->message);

      exit (1);

    }

}

static const GOptionEntry entries[] = {

  { "finger", 'f',  0, G_OPTION_ARG_STRING, &finger_name, "Finger selected to verify (default is automatic)", NULL },

  {"g-fatal-warnings", 0, 0, G_OPTION_ARG_NONE, &g_fatal_warnings, "Make all warnings fatal", NULL},

  { G_OPTION_REMAINING, '\0', 0, G_OPTION_ARG_STRING_ARRAY, &usernames, NULL, "[username]" },

  { NULL }

};

int

main (int argc, char **argv)

{

  g_autoptr(FprintDBusDevice) dev = NULL;

  g_autoptr(GError) err = NULL;

  GOptionContext *context;

  const char *username = NULL;

  setlocale (LC_ALL, "");

  context = g_option_context_new ("Verify a fingerprint");

  g_option_context_add_main_entries (context, entries, NULL);

  if (g_option_context_parse (context, &argc, &argv, &err) == FALSE)

    {

      g_print ("couldn't parse command-line options: %s\n", err->message);

      return 1;

    }

  if (usernames == NULL)

    username = "";

  else

    username = usernames[0];

  if (g_fatal_warnings)

    {

      GLogLevelFlags fatal_mask;

      fatal_mask = g_log_set_always_fatal (G_LOG_FATAL_MASK);

      fatal_mask |= G_LOG_LEVEL_WARNING | G_LOG_LEVEL_CRITICAL;

      g_log_set_always_fatal (fatal_mask);

    }

  create_manager ();

  dev = open_device (username);

  find_finger (dev, username);

  do_verify (dev);

  release_device (dev);

  return 0;

}