#include <Keypad.h>

// Pin declaration
const int ROWS = 4;
const int COLS = 4;
int doorPin = 12;
int buzzerPin = 13;
int checkingFlag = 0;
int ENABLEPIN=0;
int ENABLE;
char enteredPasscode[5]; // Buffer to store entered passcode
int passcodeIndex = 0;
const char passcode[] = "1234";
char keys[ROWS][COLS] = {
    {'1', '2', '3', 'A'},
    {'4', '5', '6', 'B'},
    {'7', '8', '9', 'C'},
    {'*', '0', '#', 'D'}
};

byte rowPins[ROWS] = {3, 4, 5, 6}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {7, 8, 9, 10}; // Connect to the cols input of the keypad

// Object declaration of keypad
Keypad myKeypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// State of door and alarm
boolean doorOpen = false;
boolean alarmOn = false;

// Times
unsigned long doorOpenTime = 0;
const unsigned long maxTime = 10000;

void setup() {
    pinMode(doorPin, INPUT);
    pinMode(buzzerPin, OUTPUT);
    pinMode(ENABLEPIN,INPUT);
    Serial.begin(9600);
}

void loop() {
    ENABLE=digitalRead(ENABLEPIN);
    doorOpen = digitalRead(doorPin) == HIGH;
    checkingFlag = 0;

    if (doorOpen&&ENABLE==LOW) {
        checkingFlag = 1;
        doorOpenTime = millis(); // Start the clock
    }

    // Looping
    while (checkingFlag == 1 && millis() - doorOpenTime < maxTime) {
        char key = myKeypad.getKey();

        if (key != NO_KEY) {
            if (key == '#') {
                // Check if the entered passcode matches
                if (strcmp(enteredPasscode, passcode) == 0) {
                    Serial.println("Access Granted");
                    // Turn off the buzzer
                    digitalWrite(buzzerPin, LOW);
                    checkingFlag = 0; // Exit loop
                } else {
                    Serial.println("Access Denied");
                }
                // Reset entered passcode
                passcodeIndex = 0;
                memset(enteredPasscode, 0, sizeof(enteredPasscode));
            } else if (key == '*') {
                // Clear entered passcode
                passcodeIndex = 0;
                memset(enteredPasscode, 0, sizeof(enteredPasscode));
            } else {
                // Add key to entered passcode
                if (passcodeIndex < 4) { // Avoid buffer overflow
                    enteredPasscode[passcodeIndex++] = key;
                    Serial.print("Entered Passcode: ");
                    Serial.println(enteredPasscode);
                }
            }
        }
    }

    // Alarm activated if door open for too long
    if (millis() - doorOpenTime >= maxTime&&checkingFlag==1) {
      while(true){
        alarmOn = true;
        Serial.println("Alarm activated.");
        digitalWrite(buzzerPin, HIGH);
    }
    }
}