#include <Arduino.h>
#include <WiFi.h>

// --- European Timezones ---
const char* TZ_BERLIN      = "CET-1CEST,M3.5.0/2:00,M10.5.0/3:00";   // Central European Time (UTC+1/+2)
const char* TZ_LONDON      = "GMT0BST,M3.5.0/1:00,M10.5.0/2:00";   // Greenwich Mean Time (UTC+0/+1)
const char* TZ_MOSCOW      = "MSK-3";                               // Moscow Standard Time (UTC+3, No DST)
const char* TZ_PARIS       = "CET-1CEST,M3.5.0/2:00,M10.5.0/3:00";   // Central European Time (UTC+1/+2)

// --- North American Timezones ---
const char* TZ_NEW_YORK    = "EST5EDT,M3.2.0/2:00,M11.1.0/2:00";   // Eastern Time (UTC-5/-4)
const char* TZ_CHICAGO     = "CST6CDT,M3.2.0/2:00,M11.1.0/2:00";   // Central Time (UTC-6/-5)
const char* TZ_LOS_ANGELES = "PST8PDT,M3.2.0/2:00,M11.1.0/2:00";   // Pacific Time (UTC-8/-7)
const char* TZ_PHOENIX     = "MST7";                               // Mountain Time (UTC-7, No DST)

// --- Asian / Oceania Timezones ---
const char* TZ_SINGAPORE   = "SGT-8";                               // Singapore Time (UTC+8, No DST)
const char* TZ_BEIJING     = "CST-8";                               // China Standard Time (UTC+8, No DST)
const char* TZ_TOKYO       = "JST-9";                               // Japan Standard Time (UTC+9, No DST)
const char* TZ_NEW_DELHI   = "IST-5:30";                            // Indian Standard Time (UTC+5:30, No DST)
const char* TZ_SYDNEY      = "AEST-10AEDT,M10.1.0/2:00,M4.1.0/3:00"; // Australian Eastern Time with DST

// --- Africa / South America Timezones ---
const char* TZ_JOHANNESBURG = "SAST-2";                             // South Africa Standard Time (UTC+2, No DST)
const char* TZ_BUENOS_AIRES = "ART3";                               // Argentina Time (UTC-3, No DST)

// choose your timezone here:
const char* TIMEZONE = TZ_BERLIN;

const char* NTPSERVER = "pool.ntp.org";

void setupWiFi() {
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(100);
  }
  Serial.println("connected");
  Serial.println(WiFi.localIP());
}

void setupNTP() {
  configTzTime(TIMEZONE, NTPSERVER);
}

void setup() {
  Serial.begin(115200);
  setupWiFi();
  setupNTP();
}

void printTime() {
  static time_t last_now;
  time_t now;
  time(&now);
  if (last_now == now) return;
  last_now = now;

  Serial.printf("UTC Timestamp: %d - " , now);
  Serial.print(ctime(&now));
}

void loop() {
  printTime();
  delay(10); // this speeds up the simulation
}