#include <LiquidCrystal_I2C.h>
#include <DHT.h>

#define ADC_REF 3.3
#define ADC_RESOLUTION 4095

#define DHT_PIN 4
#define DHT_TYP DHT22
#define MQD_PIN 3
#define MQA_PIN A0
#define BUZ_PIN 5

DHT dht(DHT_PIN, DHT_TYP);
LiquidCrystal_I2C lcd(0x27, 16, 2);

uint32_t previousMillis = 0;
const uint16_t interval = 1000;

float ppm;  //Stores parts per million value for gas concentration.
//long previous_millis = 0;  //previous_millis: Used for timing the main loop operations.
//int interval = 1000;  //interval: Defines the delay between consecutive gas checks in milliseconds.

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

  lcd.init();
  lcd.backlight();
  lcd.print("Hello, World!");
}

void loop() {
  //uint32_t currentMillis = millis();
  //if (currentMillis - previousMillis <= interval) return;
  //previousMillis = currentMillis;

  // Membaca kelembapan dan suhu
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Gagal membaca dari sensor DHT!");
    delay(2000);
    return;
  }

  lcd.setCursor(0, 0);
  lcd.print("Suhu : " + String(temperature) + "      ");

  GASLevel();
}


// GASLevel Function
// Function to convert ADC value to ppm (assuming a linear relationship for demonstration)
// You may need to adjust the calibration values based on your sensor's datasheet and environment.
float convertToPPM(int sensorValue)  {
  float voltage = sensorValue * (ADC_REF / ADC_RESOLUTION);
  // Assuming a linear relationship: ppm = k * voltage (you should calibrate this properly)
  float ppm = voltage * 1000; // Adjust the factor based on calibration
  return ppm;
}

// Function to read gas level, update the LCD, and handle MQTT communication
void GASLevel() {
  int sensorValue = analogRead(MQA_PIN);
  int gasLevel = map(sensorValue, 0, 4095, 0, 100);
  //adc_value = analogRead(POT_PIN);  // Read the analog value from the potentiometer
  //Serial.print("ADC Value: ");  // Print the ADC value for debugging
  //Serial.println(sensorValue);
  ppm = convertToPPM(sensorValue);
  //Serial.print("PPM Value:");  // Print the PPM value for debugging
  //Serial.println(ppm);

//  lcd.clear();  // Clear the LCD
  lcd.setCursor(0, 1);
  lcd.print("Gas  : ");
  lcd.print(ppm);
  lcd.print("ppm     ");

  if (ppm >= 1800) { //it will trigger alarm at 55%
    // Adjust threshold as needed
    digitalWrite(BUZ_PIN, HIGH);
    tone(BUZ_PIN, 200);
//    lcd.setCursor(0, 1);
//    lcd.print("Gas detected!!!");
    //Serial.println("Gas detected");
//    client.publish("IOT/group5/project", "Gas detected");
    //Red_Led_state = HIGH;
    //Green_Led_state = LOW;
    //Yellow_Led_state = LOW;
  } else if ((ppm >= 900) && (ppm  <= 1800)) { //28% - 55% under normal
    digitalWrite(BUZ_PIN, LOW);
    noTone(BUZ_PIN);
//    lcd.setCursor(0, 1);
//    lcd.print("Warning ! ! !       ");
    //Serial.println("Normal");
//    client.publish("IOT/group5/project", "Warning");
    //Red_Led_state = LOW;
    //Green_Led_state = LOW;
    //Yellow_Led_state = HIGH;
  } else { // 0% - 27% is safe and will trigger Green Led
    digitalWrite(BUZ_PIN, LOW);
    noTone(BUZ_PIN);
//    lcd.setCursor(0, 1);
//    lcd.print("Safe           ");
    //Serial.println("Safe");
//    client.publish("IOT/group5/project", "Safe");
    //Red_Led_state = LOW;
    //Green_Led_state = HIGH;
    //Yellow_Led_state = LOW;
  }
}