#include <stdbool.h>
#include <stdint.h>

/* The state of a healthcheck. */
enum sk_health_state {
  /* The check is in an unknown state, probably due to an internal error. */
  SK_HEALTH_STATE_UNKNOWN = 0,
  /* The check is healthy. */
  SK_HEALTH_STATE_OK = 1,
  /* The check is healthy but will soon reach unhealthy level; preventive
   * action should be taken. */
  SK_HEALTH_STATE_WARN = 2,
  /* The check is unhealthy; action needs to be taken immediately. */
  SK_HEALTH_STATE_CRITICAL = 3,
};

/* Healthcheck interface.
 */
typedef enum sk_health_state (*sk_healthcheck_cb_t)(
    const void* opaque, sk_buf_t* err_msg);

enum {
  SK_HEALTHCHECK_ENABLED = 1,
};

typedef struct sk_healtcheck {
  /* The name of the healthcheck. */
  const char* name;
  /* A brief description of the healthcheck. */
  const char* description;

  uint64_t flags;

  /* User provided callback that implements the healthcheck. */
  sk_healthcheck_cb_t callback;
  /* User provided data given to the callback. */
  void* opaque;
} sk_healthcheck_t;