// https://github.com/esp8266/Arduino/commit/a05a71fa9d2e6b143cb34f01b47e22c4b66b80a1

void debugSNTP() {
  // lwIP v2 is able to list more details about the currently configured SNTP servers
  for (int i = 0; i < SNTP_MAX_SERVERS; i++) {
    IPAddress sntp = *sntp_getserver(i);
    const char* name = sntp_getservername(i);
    if (sntp.isSet()) {
      Serial.printf("sntp%d:     ", i);
      if (name) {
        Serial.printf("%s (%s) ", name, sntp.toString().c_str());
      } else {
        Serial.printf("%s ", sntp.toString().c_str());
      }
      Serial.printf("- IPv6: %s - Reachability: %o\n", sntp.isV6() ? "Yes" : "No", sntp_getreachability(i));
    }
  }
}

String printLocalTime() {
  if (!getLocalTime(&timeinfo, 200)) {
    return "N/A";
  }
  //Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");
  char timeStringBuff[50]; //50 chars should be enough
  strftime(timeStringBuff, sizeof(timeStringBuff), "%A, %B %d %Y %H:%M:%S", &timeinfo);
  return timeStringBuff;

}

/*
 * Check for DHCP supplied NTP
 */
void ntpReachableCheckCallback() {
  // lwIP v2 is able to list more details about the currently configured SNTP servers
  int usuableServer = 0;
  int serverCount = 0;
  for (int i = 0; i < SNTP_MAX_SERVERS; i++) {    
    IPAddress sntp = *sntp_getserver(i);
    const char* name = sntp_getservername(i);
    if (sntp.isSet()) {
      serverCount++;
      if (sntp_getreachability(i) > 0) {
        NTPreachable = true;
        usuableServer++;
        getLocalTime(&timeinfo, 200);
        Serial.println("NTP reachable");
        currentNTP=sntp.toString();
      }
      else {
        NTPreachable = false;
        Serial.println("ntp NOT reachable");
      }
    }
    if (serverCount == 0) {
      setFallbackNTP();
    }
  }
}
/*
    refresh the internal time struct
*/
void timeRefreshCallback( bool from_sntp ) {
  getLocalTime(&timeinfo, 200);
  Serial.print(asctime(&timeinfo));
  Serial.printf("timezone:  %s\n", getenv("TZ") ? : "(none)");

  //set new time only when from sntp
  //no manual way to set time
  if (!from_sntp) {
    Serial.println("Not SNTP time");
  }
  else {
    debugSNTP();
    Serial.println("SNTP time used");
    if (clockwiseRing) {
      currentSec = timeinfo.tm_sec;
      currentMin = timeinfo.tm_min;
      currentHour = MOD(timeinfo.tm_hour, 12);
    }
    else {
      //inverted logic - remaining time
      currentSec = 60 - timeinfo.tm_sec;
      currentMin = 60 - timeinfo.tm_min;
      currentHour = 12 - MOD(timeinfo.tm_hour, 12);
    }
    Serial.println("timestruct mapped: " + String(int(currentHour * NUM_LEDS / 12)) + ":" + String(int(currentMin * NUM_LEDS / 60)) + ":" + String(int(currentSec * NUM_LEDS / 60)));
    bootAnim.disable();
    //iotWebConfConfigSaved(); //ToDo why?
    ledRefresh.enableIfNot();
#ifdef LDR_PIN
    brightnessFading.enableIfNot();
#endif
    clockTick.enableIfNot();
    brightnessAdjustment.enableIfNot();
  }
}

void setTimeZone() {
  //init and get the time
#ifdef ESP8266
  //sntp_servermode_dhcp(0); // 0: disable obtaining SNTP servers from DHCP (enabled by default)
  configTime(MYTZ,currentNTP);
  yield();
#endif
#ifdef ESP32
  setenv("TZ", "AEST-10", 1);
  tzset(); // save the TZ variable
#endif
  yield();
}
/*
   function to set NTP server
   maybe not needed
*/
void setFallbackNTP() {
  //init and get the time
#ifdef ESP8266
  //sntp_servermode_dhcp(0); // 0: disable obtaining SNTP servers from DHCP (enabled by default)
  //configTime(int timezone, int daylightOffset_sec, const char* server1, const char* server2, const char* server3 )
  configTime(MYTZ, "pool.ntp.org"); //ToDo skip TZ
  //setTZ(MYTZ);
#endif
#ifdef ESP32
  configTime(0, 0, "pool.ntp.org");
#endif
  yield();
}

/*
   Callback to handle the separate
   loose time structure for the mapping
   to the analog representation of a clock

*/
void clockTickCallback() {
#ifdef LDR_PIN
  ldrValue = (ldrValue + analogRead(LDR_PIN));
#endif
  if (clockwiseRing) {
    if (currentSec >= 60) {
      currentSec = 0;
      currentMin++;
      if (currentMin >= 60) {
        currentMin = 0;
        currentHour++;
        if (currentHour >= 12) {
          currentHour = 0;
        }
      }
      if (followingHour) {
        hourOffset = int(currentMin * NUM_LEDS / 60 / 12);
        //Serial.println("clockwise hourOffset: " + String(hourOffset));
      }
      //Serial.println(String(interruptCounter) + " | Ring Index: " + String(currentHour / (12 / NUM_LEDS)) + ":" + String(currentMin / (60 / NUM_LEDS)) + ":" + String(currentSec / (60 / NUM_LEDS)));
    }
    currentSec++;

  }
  else {
    if (currentSec < 0) {
      currentSec = 59;
      currentMin--;
      if (currentMin < 0) {
        currentMin = 59;
        currentHour--;
        if (currentHour < 0) {
          currentHour = 11;
        }
      }
      if (followingHour) {
        hourOffset = 0 - int((60 - currentMin * NUM_LEDS / 60) / 12); //negative value
        //Serial.println("Anticlockwise hourOffset: " + String(hourOffset));
      }
      //Serial.println(String(interruptCounter) + " | Ring Index: " + String(currentHour / (12 / NUM_LEDS)) + ":" + String(currentMin / (60 / NUM_LEDS)) + ":" + String(currentSec / (60 / NUM_LEDS)));
    }
    currentSec--;
  }
}