#include <WiFi.h>
#include <NTPClient.h>
#include <WiFiUdp.h>
#include <RTClib.h>

// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// NTP server and time offset
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "pool.ntp.org", 8 * 3600, 60000); // GMT+8 (Kuala Lumpur)

// RTC DS3231
RTC_DS3231 rtc;

void setup() {
    Serial.begin(115200);

    // Connect to WiFi
    WiFi.begin(ssid, password);
    Serial.print("Connecting to WiFi");
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("\nWiFi connected!");

    // Start the NTP client
    timeClient.begin();
    timeClient.update();

    // Initialize RTC
    if (!rtc.begin()) {
        Serial.println("Couldn't find RTC");
        while (1);
    }

    // Set RTC time from NTP
    updateRTCFromNTP();
}

void loop() {
    // Print RTC time every 5 seconds
    printRTCTime();
    delay(5000);
}

void updateRTCFromNTP() {
    timeClient.update();

    time_t epochTime = timeClient.getEpochTime();
    struct tm *timeinfo = gmtime(&epochTime);

    DateTime now(timeinfo->tm_year + 1900, timeinfo->tm_mon + 1, timeinfo->tm_mday,
                 timeinfo->tm_hour, timeinfo->tm_min, timeinfo->tm_sec);

    rtc.adjust(now);
    Serial.println("RTC updated with NTP time.");
}

void printRTCTime() {
    DateTime now = rtc.now();
    Serial.printf("RTC Date & Time: %04d-%02d-%02d %02d:%02d:%02d\n",
                  now.year(), now.month(), now.day(),
                  now.hour(), now.minute(), now.second());
}