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

void checkPassword();
void openLock();
void triggerAlarm();
void beep(int times, int msOn);

const byte ROWS = 4; 
const byte COLS = 4; 
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {9, 8, 7, 6};   
byte colPins[COLS] = {5, 4, 3, 2};   
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);


Servo lockServo;
const int servoPin = 10;
const int buzzerPin = 11;


LiquidCrystal_I2C lcd(0x27, 16, 2);

String inputPassword = "";
const String correctPassword = "1234";
int attempts = 0;
const int maxAttempts = 4;

const int openAngle = 180;  
const int closedAngle = 0;   
const unsigned long openDuration = 3000; 
const unsigned long alarmDuration = 5000; 

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

  
  lockServo.attach(servoPin);
  lockServo.write(closedAngle); 
  pinMode(buzzerPin, OUTPUT);
  digitalWrite(buzzerPin, LOW);

  
  lcd.init();     
  lcd.backlight();    
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Smart Lock Ready");
  lcd.setCursor(0,1);
  lcd.print("Enter 4 digits");
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    if (key == '*') {               // مسح الإدخال
      inputPassword = "";
      lcd.setCursor(0,1);
      lcd.print("                "); // مسح السطر الثاني بالكامل
      lcd.setCursor(0,1);
      lcd.print("Cleared");
      Serial.println("Cleared input");
      delay(500);
      lcd.setCursor(0,1);
      lcd.print("Enter 4 digits");
    } else if (key == '#') {        // مثال: يمكنك استخدام # لإرسال/تأكيد يدويا — هنا نتجاهله لأن نتحقق تلقائياً بعد 4 أرقام
      // يمكنك تخصيص سلوك لزر #
    } else {
      inputPassword += key;
    
      lcd.setCursor(0,1);
      
      lcd.print("Input:");
      lcd.print(inputPassword);
      
      int rem = 16 - (6 + inputPassword.length()); 
      for (int i=0;i<rem;i++) lcd.print(' ');

      Serial.print("Current: ");
      Serial.println(inputPassword);

      if (inputPassword.length() == 4) {
        checkPassword();
        inputPassword = ""; 
        delay(300); 
        lcd.setCursor(0,1);
        lcd.print("Enter 4 digits   ");
      }
    }
  }
}

void checkPassword() {
  if (inputPassword == correctPassword) {
    Serial.println("Password correct — Opening lock.");
    lcd.setCursor(0,0);
    lcd.print("Correct! Unlocking ");
    lcd.setCursor(0,1);
    lcd.print("Please wait...     ");
    openLock();
    attempts = 0;
    lcd.setCursor(0,0);
    lcd.print("Smart Lock Ready   ");
  } else {
    attempts++;
    Serial.print("Wrong password. Attempts: ");
    Serial.println(attempts);
    lcd.setCursor(0,0);
    lcd.print("Wrong Password     ");
    lcd.setCursor(0,1);
    lcd.print("Attempts:");
    lcd.print(attempts);
    if (attempts >= maxAttempts) {
      Serial.println("Max attempts reached! Alarm!");
      lcd.setCursor(0,0);
      lcd.print("!! ALARM !!        ");
      lcd.setCursor(0,1);
      lcd.print("Locked...          ");
      triggerAlarm();
      attempts = 0;
      lcd.setCursor(0,0);
      lcd.print("Smart Lock Ready   ");
      lcd.setCursor(0,1);
      lcd.print("Enter 4 digits     ");
    } else {
      beep(1, 200);
      delay(800);
      lcd.setCursor(0,0);
      lcd.print("Smart Lock Ready   ");
    }
  }
}

// فتح وغلق السيرفو
void openLock() {
  lockServo.write(openAngle);
  delay(openDuration);
  lockServo.write(closedAngle);
  Serial.println("Lock closed again.");
}

// تفعيل البازر عند المحاولات الخاطئة
void triggerAlarm() {
  unsigned long start = millis();
  while (millis() - start < alarmDuration) {
    digitalWrite(buzzerPin, HIGH);
    delay(200);
    digitalWrite(buzzerPin, LOW);
    delay(100);
  }
  digitalWrite(buzzerPin, LOW);
}

// صفارة بسيطة
void beep(int times, int msOn) {
  for (int i = 0; i < times; i++) {
    digitalWrite(buzzerPin, HIGH);
    delay(msOn);
    digitalWrite(buzzerPin, LOW);
    delay(100);
  }
}