#include <WiFi.h>

#define NTP_SERVER     "pool.ntp.org"

#define ntpUpdateDelay 20000 // 60 * 1000
#define connectRetryDelay 5000

uint32_t curMillis = 0;
bool timeUpdated = false;
uint32_t lastTimeUpdate = 0;
uint32_t lastConnectAttempt = 0;
bool wifiStatus = WL_STOPPED; // 254

void setup() {
  Serial.begin(115200);
  Serial.println("");
  Serial.println("==> Start! <==");
  Serial.println("");
  
  Serial.print("WiFi status: ");
  Serial.println(WiFi.status());
}

void loop() {
  curMillis = millis();
  wifiStatus = WiFi.status();
  Serial.print("WiFi status: ");
  Serial.print(wifiStatus);
  Serial.print(" ==? ");
  Serial.println(WL_CONNECTED);

  if (wifiStatus != WL_CONNECTED) {
    connectWifi();
  } else {
    updateClock();
  }

  delay(300);
}

void updateClock() {
  if (lastTimeUpdate + ntpUpdateDelay < curMillis) {
    Serial.println("The time has come!");
    getNtpTime();
  }
}

void setClockTime() {
  Serial.println("set clock");
  lastTimeUpdate = curMillis;
}

void getNtpTime() {
  if (wifiStatus == WL_CONNECTED) {
    Serial.println("Get ntp time");
    setClockTime();
  }
}

void connectWifi() {
  if (wifiStatus == WL_CONNECTED) {
    return;
  };

  if (lastConnectAttempt == 0) {
    Serial.println("Try to connect on start");
    WiFi.begin("Wokwi-GUEST", "", 6);
    lastConnectAttempt = curMillis;
  }

  if (lastConnectAttempt + connectRetryDelay < curMillis) {
    Serial.println("Try to reconnect");
    lastConnectAttempt = curMillis;
    WiFi.disconnect();
    WiFi.reconnect();
  }
}