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

// Defining pins in ESP32
#define FLAME_SENSOR_PIN 5
#define GAS_SENSOR_PIN 34   // Analog pin for gas sensor
#define LED_PIN 2
#define BUZZER_PIN 4

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

// ThingSpeak settings
const char* writeAPIKey = "RAJ7W6B3G23BD3A9"; 
const char* server = "http://api.thingspeak.com";

// Twilio credentials
const char* accountSID = "ACad1af54adb440a915506228c2b050eeb";
const char* authToken = "712e76d434d0c5f813a1bcd8d3a3bb3b";
const char* twilioNumber = "+15677087640"; 
const char* userPhoneNumber = "+919385967737"; 

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

  pinMode(FLAME_SENSOR_PIN, INPUT_PULLUP);
  pinMode(GAS_SENSOR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  WiFi.begin(ssid, password);
  Serial.println("Connecting to Wi-Fi...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Attempting to connect to Wi-Fi...");
  }
  Serial.println("Connected to Wi-Fi");
}

void loop() {
  // Reading sensor values
  int flameStatus = digitalRead(FLAME_SENSOR_PIN);
  int gasLevel = analogRead(GAS_SENSOR_PIN);  // Directly read from the custom gas sensor

  Serial.print("Flame Status: ");
  Serial.println(flameStatus);
  Serial.print("Gas Level: ");
  Serial.println(gasLevel);

  // Trigger alerts if gas leak is detected based on threshold value
  if (flameStatus == LOW || gasLevel > 500) { 
    digitalWrite(LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, HIGH);
    sendSMSAlert(" Alert: Fire or Gas Leak detected! Take immediate action.");
  } else {
    digitalWrite(LED_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
  }

  // Send data to ThingSpeak
  sendDataToThingSpeak(flameStatus, gasLevel);

  delay(10000);  // Delay for 10 seconds before the next reading
}


void sendDataToThingSpeak(int flame, int gas) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String(server) + "/update?api_key=" + writeAPIKey + "&field1=" + flame + "&field2=" + gas;

    http.begin(url);
    int httpResponseCode = http.GET();

    if (httpResponseCode > 0) {
      Serial.println("Data sent to ThingSpeak successfully.");
    } else {
      Serial.print("Error sending data to ThingSpeak: ");
      Serial.println(httpResponseCode);
    }

    http.end();
  } else {
    Serial.println("Wi-Fi not connected. Data not sent to ThingSpeak.");
  }
}

void sendSMSAlert(String message) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = "https://api.twilio.com/2010-04-01/Accounts/" + String(accountSID) + "/Messages.json";
    String postData = "To=" + String(userPhoneNumber) + "&From=" + String(twilioNumber) + "&Body=" + message;

    http.begin(url);
    http.setAuthorization(accountSID, authToken);
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");

    int httpResponseCode = http.POST(postData);

    if (httpResponseCode > 0) {
      Serial.println(" SMS Alert Sent Successfully!");
    } else {
      Serial.print(" Error sending SMS: ");
      Serial.println(httpResponseCode);
    }

    http.end();
  } else {
    Serial.println("Wi-Fi not connected. Unable to send SMS.");
  }
}