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

// PIN DEFINITIONS
#define BUZZER 18
#define G_LED 5
#define R_LED 17

// WIFI & DATABASE SETTINGS
const char* ssid = "Wokwi-GUEST";
const char* password = "";
// YOUR LIVE URL
String scriptURL = "https://script.google.com/macros/s/AKfycbyJRSciKLgf9YpHhKeU58o0uFY3WRANKzx5krJWgv-liKIBPNg0tOEtjErcL0ZZjB_3/exec"; 

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  Serial.begin(115200);
  pinMode(BUZZER, OUTPUT);
  pinMode(G_LED, OUTPUT);
  pinMode(R_LED, OUTPUT);

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Connecting...");

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  lcd.clear();
  lcd.print("System Ready");
  Serial.println("WiFi Connected!");
}

void loop() {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    
    // 1. Check the Google Script for updates
    http.begin(scriptURL);
    http.setFollowRedirects(HTTPC_STRICT_FOLLOW_REDIRECTS);
    
    int httpCode = http.GET();
    if (httpCode > 0) {
      String payload = http.getString();
      Serial.println("Current Status: " + payload);

      // 2. If a name (not "Waiting") is found
      if (payload != "Waiting") {
        processAttendance(payload);
      }
    }
    http.end();
  }
  delay(3000); // Check every 3 seconds
}

void processAttendance(String name) {
  // Visual and Audio Feedback
  lcd.clear();
  lcd.print("Welcome:");
  lcd.setCursor(0, 1);
  lcd.print(name);

  digitalWrite(G_LED, HIGH);
  tone(BUZZER, 1000, 500); // 1kHz beep for 0.5s
  delay(4000); // Keep name on screen for 4 seconds
  digitalWrite(G_LED, LOW);

  // 3. Reset the Google Script to "Waiting" so it doesn't repeat
  HTTPClient resetHttp;
  String resetURL = scriptURL + "?name=Waiting";
  resetHttp.begin(resetURL);
  resetHttp.setFollowRedirects(HTTPC_STRICT_FOLLOW_REDIRECTS);
  resetHttp.GET();
  resetHttp.end();

  lcd.clear();
  lcd.print("Ready to Scan");
}