/*
 * Minimal smoke test for libprom + libpromhttp.
 *
 *   smoke_test            -> register metrics, print exposition text, exit
 *   smoke_test <port> <s> -> additionally serve /metrics on <port> for <s> seconds
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "microhttpd.h"
#include "prom.h"
#include "promhttp.h"

int main(int argc, char **argv) {
  if (prom_collector_registry_default_init() != 0) return 1;

  prom_counter_t *requests = prom_collector_registry_must_register_metric(
      prom_counter_new("smoke_requests_total", "Requests handled by the smoke test", 1, (const char *[]){"path"}));
  prom_gauge_t *temperature =
      prom_collector_registry_must_register_metric(prom_gauge_new("smoke_temperature", "A test gauge", 0, NULL));

  if (prom_counter_add(requests, 3, (const char *[]){"/api"})) return 1;
  if (prom_gauge_set(temperature, 21.5, NULL)) return 1;

  const char *text = prom_collector_registry_bridge(PROM_COLLECTOR_REGISTRY_DEFAULT);
  if (text == NULL) return 1;
  printf("%s", text);
  free((void *)text);

  if (argc == 3) {
    promhttp_set_active_collector_registry(NULL);
    struct MHD_Daemon *daemon =
        promhttp_start_daemon(MHD_USE_SELECT_INTERNALLY, (unsigned short)atoi(argv[1]), NULL, NULL);
    if (daemon == NULL) {
      fprintf(stderr, "failed to start HTTP daemon on port %s\n", argv[1]);
      return 1;
    }
    sleep((unsigned int)atoi(argv[2]));
    MHD_stop_daemon(daemon);
  }

  prom_collector_registry_destroy(PROM_COLLECTOR_REGISTRY_DEFAULT);
  return 0;
}