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

LiquidCrystal_I2C lcd(0x27, 16, 2);
char password[4];
char initial_password[4], new_password[4];
char master_password[4] = {'2', '4', '6', '8'}; // Password master
int vcc = 11;
int push_button_pin = 11;
int i = 0;
int relay_pin = 10;
char key_pressed = 0;
const byte rows = 4;
const byte columns = 4;
char hexaKeys[rows][columns] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte row_pins[rows] = {2, 3, 4, 5};
byte column_pins[columns] = {6, 7, 8, 9};
Keypad keypad_key = Keypad(makeKeymap(hexaKeys), row_pins, column_pins, rows, columns);

int failedAttempts = 0; // Jumlah percobaan gagal
unsigned long lastFailedAttemptTime = 0; // Waktu terakhir percobaan gagal
const unsigned long cooldownPeriod = 10000; // Waktu cooldown (10 detik)

void setup() {
  lcd.begin(16, 2);
  lcd.backlight();
  pinMode(relay_pin, OUTPUT);
  pinMode(vcc, OUTPUT);
  pinMode(push_button_pin, INPUT_PULLUP);

  lcd.print("Electronic Lock ");
  lcd.setCursor(0, 1);
  lcd.print("By Excel Zona");
  delay(3000);
  lcd.clear();
  lcd.print("Masukkan PIN:");
  lcd.setCursor(0, 1);
  initialpassword();
}

void loop() {
  digitalWrite(relay_pin, LOW);
  key_pressed = keypad_key.getKey();
  if (digitalRead(push_button_pin) == LOW) { // Cek jika tombol push ditekan
    digitalWrite(relay_pin, HIGH); // Aktifkan relay
    delay(3000); // Tunda selama 3 detik
    digitalWrite(relay_pin, LOW); // Matikan relay setelah 3 detik
  }

  if (key_pressed == '#')
    change();
  if (key_pressed) {
    password[i++] = key_pressed;
    lcd.print('*');
  }

  if (i == 4) {
    delay(200);
    for (int j = 0; j < 4; j++)
      initial_password[j] = EEPROM.read(j);
    if (!(strncmp(password, initial_password, 4))) {
      lcd.clear();
      lcd.print("Sandi Benar");
      digitalWrite(relay_pin, HIGH);
      failedAttempts = 0; // Reset jumlah percobaan gagal
      delay(3000);
      lcd.clear();
      lcd.print("Masukkan PIN:");
      lcd.setCursor(0, 1);
      i = 0;
    } else {
      if (isCooldownActive()) {
        lcd.clear();
        lcd.print("Cooldown Aktif");
        delay(2000);
        lcd.clear();
        lcd.print("Masukkan PIN:");
        lcd.setCursor(0, 1);
      } else {
        lcd.clear();
        lcd.print("Sandi Salah");
        delay(2000);
        lcd.clear();
        lcd.print("Masukkan PIN:");
        lcd.setCursor(0, 1);
        i = 0;
        failedAttempts++;

        if (failedAttempts >= 3) {
          // Jika percobaan gagal lebih dari 3 kali, mulai waktu cooldown
          lastFailedAttemptTime = millis();
        }
      }
    }
  }
}

void change() {
  int j = 0;
  lcd.clear();
  lcd.print("Sandi Saat ini:");
  lcd.setCursor(0, 1);
  while (j < 4) {
    char key = keypad_key.getKey();
    if (key) {
      new_password[j++] = key;
      lcd.print('*');
    }
    key = 0;
  }
  delay(500);

  if ((strncmp(new_password, initial_password, 4)) && (strncmp(new_password, master_password, 4))) {
    lcd.clear();
    lcd.print("Sandi Salah");
    lcd.setCursor(0, 1);
    lcd.print("Coba Lagi");
    delay(1000);
  } else {
    j = 0;
    lcd.clear();
    lcd.print("Sandi Baru:");
    lcd.setCursor(0, 1);

    while (j < 4) {
      char key = keypad_key.getKey();
      if (key) {
        initial_password[j] = key;
        lcd.print(key);
        EEPROM.write(j, key);
        j++;
      }
    }
    lcd.clear();
    lcd.print("Sandi Diubah");
    delay(1000);
  }

  lcd.clear();
  lcd.print("Masukkan PIN:");
  lcd.setCursor(0, 1);
  key_pressed = 0;
}

void initialpassword() {
  int j;
  for (j = 0; j < 4; j++) {
    initial_password[j] = EEPROM.read(j);
    if (initial_password[j] == 255) { // Cek apakah EEPROM kosong
      EEPROM.write(j, '1'); // Jika kosong, atur password awal
      initial_password[j] = '1';
    }
  }
}

bool isCooldownActive() {
  return millis() - lastFailedAttemptTime < cooldownPeriod;
}