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

#define LCD_COLS 16
#define LCD_ROWS 2
#define LCD_ADDR 0x27
#define MICROWAVE_PIN 4
#define SERVO_PIN 9

// Define global variables
LiquidCrystal_I2C lcd(LCD_ADDR, LCD_COLS, LCD_ROWS);
Servo servo;

// Define variables for tracking door state and time of last trigger
bool door_open = false;
unsigned long last_trigger_time = 0;

// Define constants for door open and close durations
const unsigned long DOOR_OPEN_TIME = 5000;
const unsigned long DOOR_CLOSE_TIME = 5000;

void setup() {
  // Initialize the LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Door Closed");


  // Initialize the MICROWAVE sensor
  pinMode(MICROWAVE_PIN, INPUT);

  // Initialize the servo
  servo.attach(SERVO_PIN);
  servo.write(0);  // Start with door closed
}

void loop()
{
  // Check for MICROWAVE sensor trigger
  if (digitalRead(MICROWAVE_PIN) == HIGH)
   {
   // if (!door_open || (millis() - last_trigger_time) > DOOR_CLOSE_TIME)
     if ( (millis() - last_trigger_time) > DOOR_CLOSE_TIME)
     {
      // Door is closed or has been closed for more than DOOR_CLOSE_TIME
      // Set door state to open and record time of trigger
      door_open = true;
      last_trigger_time = millis();

      // Update LCD and servo position
      lcd.setCursor(0, 0);
      lcd.print("Door Open  ");
      lcd.setCursor(0, 1);
      lcd.print("closes in");
      servo.write(90);
     }
  }
   else
    {
      if (door_open && (millis() - last_trigger_time) > DOOR_OPEN_TIME)
      {
        // Door is open and has been open for more than DOOR_OPEN_TIME
        // Set door state to closed
        door_open = false;

        // Update LCD and servo position
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Door Closed");
        servo.write(0);
      }
    }  
      if (door_open)
      {
        // Door is open - update countdown timer on LCD
        unsigned long time_left = (last_trigger_time + DOOR_CLOSE_TIME) - millis();
        int seconds_left = time_left / 1000;
      // lcd.setCursor(10, 1);
      // lcd.print("     ");  // Clear old value
        lcd.setCursor(10, 1);
        lcd.print(seconds_left);
      }
  
    
}