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

#define MQ2_PIN 34
#define PIR_PIN 27
#define BUZZER_PIN 25

const char* ssid = "Wokwi-GUEST";
const char* password = "";

String apiKey = "93GE1UU25BKIOK1U"; // Your ThingSpeak Write API Key

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

  pinMode(MQ2_PIN, INPUT);
  pinMode(PIR_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  digitalWrite(BUZZER_PIN, LOW);

  Serial.print("Connecting to WiFi");

  WiFi.begin(ssid, password);

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

  Serial.println("\nWiFi Connected");
}

void loop() {

  int gasValue = analogRead(MQ2_PIN);
  int motionValue = digitalRead(PIR_PIN);

  Serial.println("--------------------");
  Serial.print("Gas Value: ");
  Serial.println(gasValue);

  Serial.print("Motion: ");
  Serial.println(motionValue);

  // Alarm Condition
  if (gasValue > 2000 || motionValue == 0) {

    Serial.println("ALERT! Buzzer ON");

    digitalWrite(BUZZER_PIN, HIGH);
    delay(500);

    digitalWrite(BUZZER_PIN, LOW);
    delay(500);

  } else {

    digitalWrite(BUZZER_PIN, LOW);
    Serial.println("System Normal");
  }

  // Send Data to ThingSpeak
  HTTPClient http;

  String url =
    "https://api.thingspeak.com/update?api_key=" + apiKey +
    "&field1=" + String(gasValue) +
    "&field2=" + String(motionValue);

  http.begin(url);

  int httpCode = http.GET();

  Serial.print("ThingSpeak Response: ");
  Serial.println(httpCode);

  String payload = http.getString();
  Serial.print("Entry Number: ");
  Serial.println(payload);

  http.end();

  delay(15000); // ThingSpeak minimum update interval
}