#include <WiFi.h>
#include <Firebase_ESP_Client.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>

// Provide the token generation process info.
#include "addons/TokenHelper.h"
// Provide the RTDB payload printing info and other helper functions.
#include "addons/RTDBHelper.h"

// WiFi credentials
#define WIFI_SSID "YOUR_WIFI_SSID"
#define WIFI_PASSWORD "YOUR_WIFI_PASSWORD"

// Firebase project API Key
#define API_KEY "YOUR_FIREBASE_API_KEY"

// Firebase Realtime Database URL
#define DATABASE_URL "YOUR_FIREBASE_DATABASE_URL"

// Firebase email and password
#define USER_EMAIL "YOUR_FIREBASE_EMAIL"
#define USER_PASSWORD "YOUR_FIREBASE_PASSWORD"

// Define Firebase objects
FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;

// MQ2 sensor pin
#define MQ2PIN 34  // Analog pin for MQ2 sensor

// Variables
float gasValue = 0.0;
unsigned long sendDataPrevMillis = 0;
bool signupOK = false;

void setup() {
  // Initialize serial communication
  Serial.begin(115200);
  
  // Connect to WiFi
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(300);
  }
  Serial.println();
  Serial.print("Connected with IP: ");
  Serial.println(WiFi.localIP());
  
  // Initialize Firebase
  config.api_key = API_KEY;
  config.database_url = DATABASE_URL;
  
  // Assign user credentials
  auth.user.email = USER_EMAIL;
  auth.user.password = USER_PASSWORD;
  
  // Assign the callback function for the long running token generation task
  config.token_status_callback = tokenStatusCallback;
  
  Firebase.begin(&config, &auth);
  Firebase.reconnectWiFi(true);
  
  // Wait for Firebase to authenticate
  Serial.print("Authenticating with Firebase");
  while (!Firebase.ready()) {
    Serial.print(".");
    delay(300);
  }
  Serial.println();
  Serial.println("Firebase authentication successful");
  signupOK = true;
}

void loop() {
  // Send data to Firebase every 15 seconds
  if (Firebase.ready() && signupOK && (millis() - sendDataPrevMillis > 15000 || sendDataPrevMillis == 0)) {
    sendDataPrevMillis = millis();
    
    // Read MQ2 sensor value
    gasValue = analogRead(MQ2PIN);
    gasValue = map(gasValue, 0, 4095, 0, 100); // Convert to percentage (adjust as needed)
    
    Serial.printf("Gas Value: %.2f%%\n", gasValue);
    
    // Send to Firebase
    if (Firebase.RTDB.setFloat(&fbdo, "/MQ2/GasValue", gasValue)) {
      Serial.println("Data sent to Firebase successfully");
    } else {
      Serial.println("Failed to send data");
      Serial.println("REASON: " + fbdo.errorReason());
    }
  }
}