/************************************************************************//**
 * RTC time keeping and synchronization using SNTP for esp-open-rtos.
 * Uses SNTP lwIP contribution.
 *
 * 2016, Jesus Alonso (doragasu)
 ****************************************************************************/

#ifndef _SNTP_H_
#define _SNTP_H_

#include <stdint.h>
#include <time.h>

/// Update SNTP RTC timer
void sntp_update_rtc(time_t t, uint32_t us);

/// Function used to update the date/time, with microseconds resolution.
#define SNTP_SET_SYSTEM_TIME_US(sec, us) sntp_update_rtc(sec, us)

/// For the lwIP implementation of SNTP to allow using names for NTP servers.
#define SNTP_SERVER_DNS             1

/// Number of supported NTP servers
#define SNTP_NUM_SERVERS_SUPPORTED 	4

/// Initialize the module, and start requesting SNTP updates. This function
/// must be called only once.
void sntp_initialize(int time_zone, int day_light);

/// Sets time zone. Allowed values are in the range [-11, 13].
/// NOTE: Settings do not take effect until SNTP time is updated. It is
void sntp_set_timezone(int time_zone);

/// Sets daylight.
/// NOTE: Settings do not take effect until SNTP time is updated.
void sntp_set_daylight(int day_light);

/// Returns the time read from RTC counter, in seconds from Epoch. If
/// us is not null, it will be filled with the microseconds.
time_t sntp_get_rtc_time(int32_t *us);

/// Set SNTP servers. Up to SNTP_NUM_SERVERS_SUPPORTED can be set.
/// Returns 0 if OK, less than 0 if error.
/// NOTE: This function must NOT be called before sntp_initialize().
int sntp_set_servers(char *server_url[], int num_servers);

/// Sets the update delay in ms. If requested value is less than 15s,
/// a 15s update interval will be set.
void sntp_set_update_delay(uint32_t ms);

#endif /* _SNTP_H_ */