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

#define FAN        26
#define GLED       18
#define RLED       21
#define DUST       5
#define MQ7        33
#define DHTPIN     23
#define TESTP      35

LiquidCrystal_I2C lcd(0x27, 16, 2);
DHT dht(DHTPIN, DHT22, 15);

char notification[50] = "";
float coAmount = 0, dustAmount = 0, Humidity = 0, Temperature = 0;
const int maxTemperature = 50, maxcoAmount = 50, maxdustAmount = 50;

unsigned long duration = 0;
unsigned long starttime = 0;
unsigned long endtime = 0;
unsigned long sampletime_ms = 30000;
unsigned long lowpulseoccupancy = 0;
float ratio = 0;
float concentration = 0;

void setup() {
  lcd.init();
  lcd.backlight();
  dht.begin();
  Serial.begin(115200);

  pinMode(GLED, OUTPUT);
  pinMode(RLED, OUTPUT);
  pinMode(FAN, OUTPUT);
  pinMode(DUST, INPUT);

  digitalWrite(FAN, LOW);
  digitalWrite(GLED, HIGH);
  digitalWrite(RLED, LOW);

  starttime = millis();
}

void loop() {
  checkCO();
  checkDust();
  tempHum();

  // Check for dangerous conditions
  bool danger = false;
  if (coAmount > maxcoAmount) {
    handleDanger("CO GAS DETECTED");
    danger = true;
  } 
  if (dustAmount > maxdustAmount) {
    handleDanger("DUST DETECTED");
    danger = true;
  } 
  if (Temperature > maxTemperature) {
    handleDanger("HIGH TEMPERATURE");
    danger = true;
  }

  if (!danger) {
    resetLEDs();
  }

  homedisplay();
}

void handleDanger(const char* alertMessage) {
  digitalWrite(GLED, LOW);
  digitalWrite(RLED, HIGH);
  digitalWrite(FAN, HIGH);
  snprintf(notification, sizeof(notification), "%s", alertMessage);
  alert_display(alertMessage);
}

void resetLEDs() {
  digitalWrite(FAN, LOW);
  digitalWrite(RLED, LOW);
  digitalWrite(GLED, HIGH);
}

void homedisplay() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("TEMP:");
  lcd.print(Temperature, 1);
  lcd.setCursor(7, 0);
  lcd.print("HUMID:");
  lcd.print(Humidity, 1);
  lcd.setCursor(0, 1);
  lcd.print("DUST:");
  lcd.print(dustAmount, 1);
  lcd.setCursor(7, 1);
  lcd.print("GAS:");
  lcd.print(coAmount, 1);
}

void alert_display(const char* textAlert) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("EMERGENCY ALERT");
  lcd.setCursor(0, 1);
  lcd.print(textAlert);
}

void checkDust() {
  duration = pulseIn(DUST, LOW);
  lowpulseoccupancy += duration;
  endtime = millis();

  if ((endtime - starttime) > sampletime_ms) {
    ratio = (lowpulseoccupancy / (sampletime_ms * 10.0));
    concentration = 1.1 * pow(ratio, 3) - 3.8 * pow(ratio, 2) + 520 * ratio + 0.62;
    dustAmount = map(analogRead(TESTP), 0, 4095, 0, 100);
    Serial.print("Dust Amount: ");
    Serial.println(dustAmount);
    lowpulseoccupancy = 0;
    starttime = millis();
  }
}

void checkCO() {
  int sensorValue = analogRead(MQ7);
  coAmount = map(sensorValue, 0, 4095, 0, 100);
  Serial.print("CO Amount: ");
  Serial.println(coAmount);
}

void tempHum() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  Temperature = t;
  Humidity = h;
  Serial.print("Temperature: ");
  Serial.print(Temperature);
  Serial.print(" °C, Humidity: ");
  Serial.print(Humidity);
  Serial.println(" %");
}