#include <mongoc/mongoc.h>

int
main(void)
{
   mongoc_init();
   bson_t *to_insert = BCON_NEW("_id", BCON_INT32(1));
   bson_t *selector = BCON_NEW("_id", "{", "$gt", BCON_INT32(0), "}");
   bson_t *update = BCON_NEW("$set", "{", "x", BCON_INT32(1), "}");
   const bson_t *next_doc;
   char *to_str;
   bson_error_t error = {0};
   mongoc_cursor_t *cursor;
   mongoc_client_t *client;
   mongoc_collection_t *coll;
   const char *uri_string = "mongodb://localhost:27017/?appname=example-update";
   mongoc_uri_t *uri = mongoc_uri_new_with_error(uri_string, &error);

   if (!uri) {
      fprintf(stderr,
              "failed to parse URI: %s\n"
              "error message:       %s\n",
              uri_string,
              error.message);
      return EXIT_FAILURE;
   }

   client = mongoc_client_new_from_uri(uri);
   if (!client) {
      return EXIT_FAILURE;
   }

   coll = mongoc_client_get_collection(client, "db", "example_coll");

   mongoc_client_set_error_api(client, 2);
   /* insert a document */
   if (!mongoc_collection_insert_one(coll, to_insert, NULL, NULL, &error)) {
      fprintf(stderr, "insert failed: %s\n", error.message);
      return EXIT_FAILURE;
   }

   if (!mongoc_collection_update_one(coll, selector, update, NULL, NULL, &error)) {
      fprintf(stderr, "update failed: %s\n", error.message);
      return EXIT_FAILURE;
   }

   to_str = bson_as_relaxed_extended_json(to_insert, NULL);
   printf("inserted: %s\n", to_str);
   bson_free(to_str);

   cursor = mongoc_collection_find_with_opts(coll, selector, NULL, NULL);
   BSON_ASSERT(mongoc_cursor_next(cursor, &next_doc));
   printf("after update, collection has the following document:\n");

   to_str = bson_as_relaxed_extended_json(next_doc, NULL);
   printf("%s\n", to_str);
   bson_free(to_str);

   BSON_ASSERT(mongoc_collection_drop(coll, NULL));

   bson_destroy(to_insert);
   bson_destroy(update);
   bson_destroy(selector);
   mongoc_collection_destroy(coll);
   mongoc_uri_destroy(uri);
   mongoc_client_destroy(client);
   mongoc_cleanup();
   return EXIT_SUCCESS;
}
