#include <WiFi.h>
#include "DHTesp.h"
#include "ThingSpeak.h"
#include <MQUnifiedsensor.h>  // Include MQUnifiedsensor library

// Pin settings
const int DHT_PIN = 15;
const int LED_PIN = 13;
const int MQ2_PIN = 34;  // Pin connected to MQ2 sensor
const char* WIFI_NAME = "Wokwi-GUEST";
const char* WIFI_PASSWORD = "";
const int myChannelNumber = 2780341;
const char* myApiKey = "7L60HZYCQQSBWG4K";
const char* server = "api.thingspeak.com";

// MQ2 sensor setup
#define         Board                   ("ESP-32")
#define         Pin                     (MQ2_PIN)  // Pin connected to MQ2 sensor
#define         Type                    ("MQ-2") // MQ2 Gas sensor type
#define         Voltage_Resolution      (3.3)
#define         ADC_Bit_Resolution      (12) // 12-bit ADC resolution
#define         RatioMQ2CleanAir        (9.83) // Clean air ratio for calibration

MQUnifiedsensor MQ2(Board, Voltage_Resolution, ADC_Bit_Resolution, Pin, Type);

DHTesp dhtSensor;
WiFiClient client;

void setup() {
  Serial.begin(115200);
  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);
  pinMode(LED_PIN, OUTPUT);
  pinMode(MQ2_PIN, INPUT);  // Initialize MQ2 as an analog input

  WiFi.begin(WIFI_NAME, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED){
    delay(1000);
    Serial.println("Wifi not connected");
  }
  Serial.println("Wifi connected!");
  Serial.println("Local IP: " + String(WiFi.localIP()));
  WiFi.mode(WIFI_STA);
  ThingSpeak.begin(client);

  // Initialize MQ2 sensor
  MQ2.init();
  MQ2.setRegressionMethod(1);  // PPM = a * ratio^b
  MQ2.setA(574.25); 
  MQ2.setB(-2.222);  // Set the constants for LPG

  // Calibrate the sensor (ratio in clean air)
  MQ2.calibrate(RatioMQ2CleanAir);  // Pass the ratio value for clean air
}

void loop() {
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  ThingSpeak.setField(1, data.temperature);  // Set temperature to field 1
  ThingSpeak.setField(2, data.humidity);     // Set humidity to field 2

  // Read MQ2 value and calculate PPM concentration
  MQ2.update();  // Read new data from the sensor

  float mq2Value = MQ2.readSensor();  // Returns the raw value of the sensor
  float gasPPM = MQ2.calibrate(RatioMQ2CleanAir);  // Calibrate and get PPM value

  // Update the Smoke field with the MQ2 value
  ThingSpeak.setField(3, gasPPM);  // Set MQ2 value to field 3 (Smoke field)

  // If MQ2 value is high, turn on the LED
  if (data.temperature > 35 || data.temperature < 12 || data.humidity > 70 || data.humidity < 40 || gasPPM > 400) {
    digitalWrite(LED_PIN, HIGH);  // Turn on the LED if conditions are met
  } else {
    digitalWrite(LED_PIN, LOW);   // Otherwise, turn off the LED
  }

  int x = ThingSpeak.writeFields(myChannelNumber, myApiKey);

  Serial.println("Temp: " + String(data.temperature, 2) + "°C");
  Serial.println("Humidity: " + String(data.humidity, 1) + "%");
  Serial.println("MQ2 Value: " + String(gasPPM));

  if (x == 200) {
    Serial.println("Data pushed successfully");
  } else {
    Serial.println("Push error" + String(x));
  }
  Serial.println("---");

  delay(10000);  // Wait for 10 seconds before the next loop
}