/* iridium-remote.c
 *
 * Copyright 2018 Matthias Vogelgesang
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <json-glib/json-glib.h>
#include <libsoup/soup.h>
#include "iridium-remote.h"

struct _IridiumRemote {
  GObject parent_instance;

  SoupSession       *session;
  SoupURI           *base_uri;
  gchar             *password;
  IridiumAuthParams  params;
};

G_DEFINE_TYPE (IridiumRemote, iridium_remote, G_TYPE_OBJECT)

IridiumRemote *
iridium_remote_new (void)
{
  return g_object_new (IRIDIUM_TYPE_REMOTE, NULL);
}

static void
on_auth_params_response_parsed (GObject *object,
                                GAsyncResult *result,
                                gpointer user_data)
{
  GTask *task;
  IridiumRemote *self;
  JsonParser *parser;
  JsonObject *root;
  const gchar *version;
  GError *error = NULL;

  task = user_data;
  self = g_task_get_task_data (task);
  parser = JSON_PARSER (object);

  if (!json_parser_load_from_stream_finish (parser, result, &error)) {
    g_task_return_error (task, error);
    return;
  }

  root = json_node_get_object (json_parser_get_root (parser));

  self->params.func = IRIDIUM_CRYPTO_SF_FUNC_PBKDF2;
  self->params.hash = IRIDIUM_CRYPTO_SF_HASH_SHA512;
  self->params.cost = json_object_get_int_member (root, "pw_cost");
  self->params.key_size = json_object_get_int_member (root, "pw_key_size");
  self->params.salt = g_strdup (json_object_get_string_member (root, "pw_salt"));

  if (g_strcmp0 (json_object_get_string_member (root, "pw_alg"), "sha512")) {
    g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
                         "Hash algorithm other than sha512 is not supported");
    g_task_return_error (task, error);
    return;
  }

  if (g_strcmp0 (json_object_get_string_member (root, "pw_func"), "pbkdf2")) {
    g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
                         "Password derivative function other than PBKDF2 is not supported");
    g_task_return_error (task, error);
    return;
  }

  version = json_object_get_string_member (root, "version");

  if (!g_strcmp0 (version, "001"))
    self->params.version = IRIDIUM_CRYPTO_SF_VERSION_001;
  else if (!g_strcmp0 (version, "002"))
    self->params.version = IRIDIUM_CRYPTO_SF_VERSION_002;
  else {
    g_set_error_literal (&error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
                         "StandardFile protocols other than 001 and 002 are not supported");
    g_task_return_error (task, error);
    return;
  }

  iridium_crypto_derive_keys (&self->params, self->password);

  g_debug ("StandardFile parameters: version=%i func=%i hash=%i key_size=%u iterations=%u",
           self->params.version,
           self->params.func,
           self->params.hash,
           self->params.key_size,
           self->params.cost);

  g_object_unref (parser);
}

static void
on_send_auth_params_message (GObject *object,
                             GAsyncResult *result,
                             gpointer user_data)
{
  GInputStream *stream;
  GTask *task;
  JsonParser *parser;
  GError *error = NULL;

  task = user_data;
  stream = soup_request_send_finish (SOUP_REQUEST (object), result, &error);

  if (stream == NULL) {
    g_task_return_error (task, error);
    return;
  }

  parser = json_parser_new ();
  json_parser_load_from_stream_async (parser, stream, g_task_get_cancellable (task),
                                      on_auth_params_response_parsed, task);
  /* g_object_unref (object); */
  g_object_unref (stream);
}

void
iridium_remote_get_auth_params_async (IridiumRemote *remote,
                                      const gchar *server,
                                      const gchar *email,
                                      const gchar *password,
                                      GCancellable *cancellable,
                                      GAsyncReadyCallback callback,
                                      gpointer user_data)
{
  SoupURI *uri;
  SoupRequestHTTP *request;
  GTask *task;
  GError *error = NULL;

  if (remote->base_uri)
    soup_uri_free (remote->base_uri);

  remote->base_uri = soup_uri_new (server);
  remote->password = g_strdup (password);

  uri = soup_uri_new_with_base (remote->base_uri, "api/auth/params");
  soup_uri_set_query_from_fields (uri, "email", email, NULL);
  task = g_task_new (remote, cancellable, callback, user_data);
  /* TODO: what happens to request? */
  request = soup_session_request_http_uri (remote->session, "GET", uri, &error);

  if (request == NULL) {
    g_task_return_error (task, error);
    return;
  }

  g_task_set_task_data (task, remote, NULL);
  soup_request_send_async (SOUP_REQUEST (request), cancellable, on_send_auth_params_message, task);
  soup_uri_free (uri);
}

const IridiumAuthParams *
iridium_remote_get_auth_params_finish (IridiumRemote *remote,
                                       GAsyncResult *result,
                                       GError **error)
{
  g_return_val_if_fail (g_task_is_valid (result, remote), NULL);
  return &remote->params;
}

static void
iridium_remote_dispose (GObject *object)
{
  IridiumRemote *self;

  self = IRIDIUM_REMOTE (object);
  g_object_unref (self->session);

  if (self->base_uri)
    soup_uri_free (self->base_uri);

  G_OBJECT_CLASS (iridium_remote_parent_class)->dispose (object);
}

static void
iridium_remote_class_init (IridiumRemoteClass *klass)
{
  GObjectClass *oclass;

  oclass = G_OBJECT_CLASS (klass);
  oclass->dispose = iridium_remote_dispose;
}

static void
iridium_remote_init (IridiumRemote *self)
{
  self->base_uri = NULL;
  self->session = soup_session_new ();
}