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

#define BUTTON_DOT 2
#define BUTTON_DASH 3
#define BUTTON_ENTER 4
#define TRIG_PIN 10
#define ECHO_PIN 11

String PASSWORD = "-.-.";
const int redd = 6;
const int greenn = 5;
const int bluee = 7;

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

String inputPassword = "";
bool standbyMode = true;

void setup() {
  lcd.begin(16, 2);
  lcd.backlight();
  pinMode(BUTTON_DOT, INPUT_PULLUP);
  pinMode(BUTTON_DASH, INPUT_PULLUP);
  pinMode(BUTTON_ENTER, INPUT_PULLUP);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(redd, OUTPUT);
  pinMode(greenn, OUTPUT);
  pinMode(bluee, OUTPUT);
  doorServo.attach(9);
  doorServo.write(0);
}

void loop() {
  long distance = measureDistance();

  if (distance > 50) {
    if (!standbyMode) {
      lcd.clear();
      delay(1000);
      lcd.print("Smart Door Lock");
      setRGB(0, 0, 0);
      standbyMode = true;
    }
  } else { 
    if (standbyMode) {
      lcd.clear();
      delay(1000);
      lcd.print("Enter Password:");
      setRGB(0, 0, 255);
      standbyMode = false;
    }
    handleButtonInput();
    if (digitalRead(BUTTON_ENTER) == LOW) {
      checkPassword();
      delay(500);
    }
  }
}

long measureDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

void handleButtonInput() {
  if (digitalRead(BUTTON_DOT) == LOW) {
    inputPassword += ".";
    lcd.setCursor(0, 1);
    lcd.print(inputPassword);
    delay(200);
  }
  if (digitalRead(BUTTON_DASH) == LOW) {
    inputPassword += "-";
    lcd.setCursor(0, 1);
    lcd.print(inputPassword);
    delay(200);
  }
}

void checkPassword() {
  if (inputPassword == PASSWORD) {
    lcd.clear();
    lcd.print("Correct!");
    setRGB(0, 255, 0);
    doorServo.write(180); 
    delay(3000);
    doorServo.write(0);
    lcd.clear();
    lcd.print("Smart Door Lock");
    setRGB(0, 0, 0);
  } else {
    lcd.clear();
    lcd.print("Incorrect!");
    setRGB(255, 0, 0);
    delay(2000);
    lcd.clear();
    delay(1000);
    lcd.print("Enter Password:");
    setRGB(0, 0, 255);
  }
  inputPassword = "";
  standbyMode = true;
}

void setRGB(int red, int green, int blue) {
  analogWrite(redd, red);
  analogWrite(greenn, green);
  analogWrite(bluee, blue);
}