#include <WiFi.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// LCD Setup
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);

// NTP Setup
#define NTP_SERVER     "pool.ntp.org"
#define UTC_OFFSET     8   // UTC+8
#define UTC_OFFSET_DST 0   // No DST

// Simulated GPS data
const char* simulatedGPSLatitude = "22.3964 N";   // Simulated Latitude
const char* simulatedGPSLongitude = "114.1095 E"; // Simulated Longitude
int simulatedGPSHour = 12;   // Simulated GPS time: Hour
int simulatedGPSMinute = 34; // Simulated GPS time: Minute
int simulatedGPSSecond = 56; // Simulated GPS time: Second

// Modes
enum Mode { WIFI_MODE, GPS_MODE };
Mode currentMode = WIFI_MODE; // Start in WiFi mode

unsigned long lastSwitchTime = 0; // Time of the last mode switch
const unsigned long switchInterval = 10000; // Switch every 10 seconds

void connectToWiFi() {
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.print("Connecting WiFi...");
  WiFi.begin("Wokwi-GUEST", ""); // Replace with your WiFi credentials
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    LCD.print(".");
  }
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.print("WiFi Connected");
  delay(1000);
}

void printWiFiTime() {
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) {
    LCD.setCursor(0, 1);
    LCD.print("Time Error");
    return;
  }

  // Display time
  LCD.setCursor(0, 0);
  LCD.printf("%02d:%02d:%02d", timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec);

  // Display mode
  LCD.setCursor(0, 1);
  LCD.print("WiFi Mode");
}

void printSimulatedGPSTime() {
  // Display simulated GPS time
  LCD.setCursor(0, 0);
  LCD.printf("%02d:%02d:%02d", simulatedGPSHour, simulatedGPSMinute, simulatedGPSSecond);

  // Display simulated GPS coordinates
  static bool showLat = true;
  LCD.setCursor(0, 1);
  if (showLat) {
    LCD.printf("Lat: %s", simulatedGPSLatitude);
  } else {
    LCD.printf("Lon: %s", simulatedGPSLongitude);
  }
  showLat = !showLat; // Toggle between latitude and longitude
}

void setup() {
  Serial.begin(115200);
  LCD.init();
  LCD.backlight();

  // Connect to WiFi
  connectToWiFi();
  configTime(UTC_OFFSET, UTC_OFFSET_DST, NTP_SERVER); // Configure NTP
  LCD.clear();
}

void loop() {
  // Automatically switch modes every 10 seconds
  if (millis() - lastSwitchTime > switchInterval) {
    currentMode = (currentMode == WIFI_MODE) ? GPS_MODE : WIFI_MODE; // Toggle mode
    lastSwitchTime = millis();
    LCD.clear();
  }

  // Update display based on the current mode
  if (currentMode == WIFI_MODE) {
    printWiFiTime();
  } else if (currentMode == GPS_MODE) {
    printSimulatedGPSTime();
  }

  delay(1000); // Update every second
}