#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>
#include <Servo.h> // For servo control

// Pin configuration
#define DHTPIN 2
#define MQ2PIN A1 // Analog pin for MQ2 sensor
#define BUZZERPIN 3
#define ROTARY_A_PIN 4  // Rotary Encoder A pin
#define ROTARY_B_PIN 5  // Rotary Encoder B pin
#define ROTARY_BTN_PIN 6  // Rotary Encoder button pin
#define BUTTON_2_PIN 7 // Second button for opening/closing the menu

// DHT setup
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// LCD setup (20x40 LCD)
#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

// Servo setup
#define SERVOPIN 11 // Define the pin for the servo motor
Servo myServo; // Create a Servo object

// Variables
int currentPage = 1;
bool tempControlOn = false;  // Temp Control toggle
bool buzzerOn = false;       // Buzzer toggle
bool motorOn = false;        // Motor toggle
bool fanOn = false;          // Fan toggle
int rotaryPosition = 0;      // Rotary encoder position
int previousRotaryPosition = 0; // To track position changes
bool menuOpen = false;       // Track if menu is open

// Thresholds for controlling temp and MQ2
const int temperatureThresholds[] = {85, 95, 90}; // Example thresholds

// Function declarations
void updateDisplay(float temperature = NAN, float humidity = NAN, int mq2Value = -1);
void openMenu();
void closeMenu();
void manageBuzzer(float temperature, int mq2Value);
void manageServo(float temperature, int mq2Value);
void readRotaryEncoder();

// Initialize setup()
void setup() {
  // Initialize the LCD
  lcd.init();
  lcd.backlight();

  // Initialize the DHT sensor
  dht.begin();

  // Set pin modes
  pinMode(MQ2PIN, INPUT);
  pinMode(BUZZERPIN, OUTPUT);
  pinMode(ROTARY_A_PIN, INPUT);
  pinMode(ROTARY_B_PIN, INPUT);
  pinMode(ROTARY_BTN_PIN, INPUT_PULLUP);  // Button on rotary encoder
  pinMode(BUTTON_2_PIN, INPUT_PULLUP);    // Second button for menu

  // Attach interrupt for rotary encoder
  attachInterrupt(digitalPinToInterrupt(ROTARY_A_PIN), readRotaryEncoder, CHANGE);

  myServo.attach(SERVOPIN); // Attach the servo to pin

  // Display welcome message
  lcd.setCursor(0, 0);
  lcd.print("Welcome to your");
  lcd.setCursor(0, 1);
  lcd.print("Smart Enclosure");
  lcd.setCursor(0, 2);
  lcd.print("Version 3.0.0");
  delay(5000); // Display for 5 seconds
  lcd.clear();

  // Display initial page
  updateDisplay();
}

void loop() {
  unsigned long currentMillis = millis();
  static unsigned long lastDHTRead = 0;
  
  // Read DHT sensor only if interval passed
  if (currentMillis - lastDHTRead >= 1000) {
    lastDHTRead = currentMillis;
    float temperature = dht.readTemperature(true); // Temperature in Fahrenheit
    float humidity = dht.readHumidity();
    int mq2Value = analogRead(MQ2PIN);

    // Update display based on rotary encoder position
    updateDisplay(temperature, humidity, mq2Value);

    // Check and manage buzzer & servo motor
    manageBuzzer(temperature, mq2Value);
    manageServo(temperature, mq2Value);
  }

  // Check if the second button (BUTTON_2) is pressed to open/close the menu
  if (digitalRead(BUTTON_2_PIN) == LOW) {
    delay(200);  // Debounce delay
    if (menuOpen) {
      closeMenu(); // Close the menu
    } else {
      openMenu();  // Open the menu
    }
  }

  // Check if the rotary button is pressed to enter selected option
  if (digitalRead(ROTARY_BTN_PIN) == LOW) {
    delay(200);  // Debounce delay
    // If menu is open, process the selection
    if (menuOpen) {
      if (rotaryPosition == 0) {
        openTempControlPage();  // Open Temp Control settings
      } else if (rotaryPosition == 1) {
        buzzerOn = !buzzerOn;   // Toggle Buzzer
      } else if (rotaryPosition == 2) {
        motorOn = !motorOn;     // Toggle Motor
      } else if (rotaryPosition == 3) {
        fanOn = !fanOn;         // Toggle Fan
      }

      while (digitalRead(ROTARY_BTN_PIN) == LOW) { // Wait for button release
        delay(10);
      }

      rotaryPosition = 0;  // Reset rotary position after selection
    }
  }

  delay(100); // Short delay for stability
}

void openMenu() {
  menuOpen = true;  // Mark menu as open

  // Update display for menu
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Menu");

  // Show menu options (scroll through with rotary encoder)
  lcd.setCursor(0, 1);
  lcd.print("1. Temp Control");
  lcd.setCursor(0, 2);
  lcd.print("2. Buzzer");
  lcd.setCursor(0, 3);
  lcd.print("3. Motor");
  lcd.setCursor(0, 4);
  lcd.print("4. Fan");

  // Scroll through menu options using rotary encoder
  if (rotaryPosition == 0) {
    lcd.setCursor(0, 1);
    lcd.print("> Temp Control");
  } else if (rotaryPosition == 1) {
    lcd.setCursor(0, 2);
    lcd.print("> Buzzer");
  } else if (rotaryPosition == 2) {
    lcd.setCursor(0, 3);
    lcd.print("> Motor");
  } else if (rotaryPosition == 3) {
    lcd.setCursor(0, 4);
    lcd.print("> Fan");
  }
}

void closeMenu() {
  menuOpen = false;  // Mark menu as closed
  updateDisplay();   // Return to main page
}

void openTempControlPage() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp Control");
  lcd.setCursor(0, 1);
  lcd.print("Thresholds:");

  // Display the current temperature thresholds
  for (int i = 0; i < 3; i++) {
    lcd.setCursor(0, i + 2);
    lcd.print("T" + String(i + 1) + ": " + String(temperatureThresholds[i]));
  }

  // Wait for user input to change or exit
  while (digitalRead(ROTARY_BTN_PIN) == LOW) {
    delay(10);
  }
  closeMenu();  // Close the menu after adjusting settings
}

void updateDisplay(float temperature, float humidity, int mq2Value) {
  if (!menuOpen) {
    if (currentPage == 1) {
      lcd.setCursor(0, 0);
      lcd.print("Temp: ");
      if (isnan(temperature)) {
        lcd.print("NA");
      } else {
        lcd.print(temperature);
        lcd.print(" F");
      }

      lcd.setCursor(0, 1);
      lcd.print("Hum: ");
      if (isnan(humidity)) {
        lcd.print("NA");
      } else {
        lcd.print(humidity);
        lcd.print(" %");
      }

      lcd.setCursor(0, 2);
      lcd.print("MQ2: ");
      if (mq2Value == -1) {
        lcd.print("NA");
      } else {
        lcd.print(mq2Value);
      }

      lcd.setCursor(0, 3);
      lcd.print("Page: 1");
    }
  }
}

void manageBuzzer(float temperature, int mq2Value) {
  // Add buzzer logic based on temperature and MQ2 value
}

void manageServo(float temperature, int mq2Value) {
  // Add servo control logic based on temperature
}

void readRotaryEncoder() {
  int A = digitalRead(ROTARY_A_PIN);
  int B = digitalRead(ROTARY_B_PIN);

  if (A == B) {
    rotaryPosition++;
  } else {
    rotaryPosition--;
  }

  if (rotaryPosition > 3) rotaryPosition = 0;
  if (rotaryPosition < 0) rotaryPosition = 3;
}