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

// ---------- PIN CONNECTIONS ----------
#define INDOOR_PIN   2
#define OUTDOOR_PIN  3
#define RAIN_PIN     A0
#define DUST_PIN     A1
#define BUZZER_PIN   8
#define SERVO_PIN    9

#define DHTTYPE DHT22

// ---------- THRESHOLDS ----------
const float HOT_TEMP = 30.0;

// Wokwi potentiometers simulate rain and dust.
// Rain: value below 500 = rain
// Dust: value above 700 = dust/storm
const int RAIN_THRESHOLD = 500;
const int DUST_THRESHOLD = 700;

// ---------- COMPONENTS ----------
DHT indoorDHT(INDOOR_PIN, DHTTYPE);
DHT outdoorDHT(OUTDOOR_PIN, DHTTYPE);

LiquidCrystal_I2C lcd(0x27, 16, 2);
Servo windowServo;

// Servo positions
const int WINDOW_CLOSED = 0;
const int WINDOW_HALF   = 45;
const int WINDOW_OPEN   = 90;

int currentAngle = -1;

void setWindow(int angle) {
  if (currentAngle != angle) {
    currentAngle = angle;
    windowServo.write(angle);
  }
}

void setup() {
  Serial.begin(9600);

  indoorDHT.begin();
  outdoorDHT.begin();

  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);

  windowServo.attach(SERVO_PIN);
  setWindow(WINDOW_CLOSED);

  lcd.init();
  lcd.backlight();
  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("SMART WINDOW");
  lcd.setCursor(0, 1);
  lcd.print("Starting...");
  delay(1500);
}

void loop() {
  float indoor = indoorDHT.readTemperature();
  float outdoor = outdoorDHT.readTemperature();

  int rainValue = analogRead(RAIN_PIN);
  int dustValue = analogRead(DUST_PIN);

  // Check for invalid DHT readings
  if (isnan(indoor) || isnan(outdoor)) {
    setWindow(WINDOW_CLOSED);
    digitalWrite(BUZZER_PIN, LOW);

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("DHT READ ERROR");
    lcd.setCursor(0, 1);
    lcd.print("Window CLOSED");

    Serial.println("DHT error - window closed");
    delay(1000);
    return;
  }

  bool rainDetected = (rainValue < RAIN_THRESHOLD);
  bool dustDetected = (dustValue > DUST_THRESHOLD);

  // ---------- MAIN CONTROL LOGIC ----------
  // Priority 1: Dust/storm -> fully close
  if (dustDetected) {
    setWindow(WINDOW_CLOSED);
  }

  // Priority 2: Rain detected
  else if (rainDetected) {
    // Very hot inside + cooler outside -> half open
    if (indoor > HOT_TEMP && outdoor < indoor) {
      setWindow(WINDOW_HALF);
    } else {
      // All other rainy conditions -> fully close
      setWindow(WINDOW_CLOSED);
    }
  }

  // Priority 3: No rain and no dust -> temperature control
  else {
    if (indoor > HOT_TEMP && outdoor < indoor) {
      setWindow(WINDOW_OPEN);
    } else {
      setWindow(WINDOW_CLOSED);
    }
  }

  // Buzzer alerts for rain or dust/storm
  if (rainDetected || dustDetected) {
    digitalWrite(BUZZER_PIN, HIGH);
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }

  // ---------- LCD DISPLAY ----------
  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("In:");
  lcd.print(indoor, 1);
  lcd.print(" Out:");
  lcd.print(outdoor, 1);

  lcd.setCursor(0, 1);

  if (dustDetected) {
    lcd.print("DUST: CLOSED");
  } else if (rainDetected && currentAngle == WINDOW_HALF) {
    lcd.print("RAIN: HALF OPEN");
  } else if (rainDetected) {
    lcd.print("RAIN: CLOSED");
  } else if (currentAngle == WINDOW_OPEN) {
    lcd.print("Window: OPEN");
  } else {
    lcd.print("Window: CLOSED");
  }

  // ---------- SERIAL MONITOR ----------
  Serial.print("Indoor: ");
  Serial.print(indoor, 1);
  Serial.print(" C | Outdoor: ");
  Serial.print(outdoor, 1);
  Serial.print(" C | Rain ADC: ");
  Serial.print(rainValue);
  Serial.print(" | Dust ADC: ");
  Serial.print(dustValue);
  Serial.print(" | Servo: ");
  Serial.print(currentAngle);
  Serial.println(" degrees");

  delay(1000);
}