#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <stdlib.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#define Password_Length 4
int buzzer = 13;
char Data[Password_Length];
char Master[Password_Length];
byte data_count = 0;
byte master_count = 0;
char customKey;
bool Boom = false;
bool Stop = false;
bool isSet = false;
const byte ROWS = 4;
const byte COLS = 4;

char hexaKeys[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 customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS);

long previousTime;
long interval = 1000;
unsigned long startTime = 0;
unsigned long elapsedTime;
unsigned long currentTimee;

long hour = 0, minute = 0, second = 10;
long countdown_time = (hour * 3600) + (minute * 60) + second;
long countdown_sec = 0;
long countdown_hour = 0;
long countdown_minute = 0;

void setup() {
  Serial.begin(9600);
  pinMode(buzzer, OUTPUT);
  pinMode(12, OUTPUT);
  //pinMode(1, OUTPUT); reset
  lcd.init();
  lcd.backlight();

  digitalWrite(11, HIGH);

  //lcd.print("HH:MM:SS");
}

void loop() {
  while (!isSet)
  {
    customKey = customKeypad.getKey();
    lcd.setCursor(1, 0);
    lcd.print("Set Password:)");
    if (customKey) {
      if (customKey == 'D')
      {
        startTime = millis();
        lcd.clear();
        Serial.println(2);
        isSet = true;
        return;
      }
      else {
        Master[master_count] = customKey;
        lcd.setCursor(master_count + 4, 1);
        lcd.print(Master[master_count]);
        master_count++;
      }
    }
  }

  if (!Stop && isSet)
  {
    currentTimee = millis();
    elapsedTime = currentTimee - startTime;
    customKey = customKeypad.getKey();
    long countdowntime_seconds = countdown_time - (elapsedTime / 1000);
    if (!Stop)
    {
      if (countdowntime_seconds >= 0) {
        countdown_hour = countdowntime_seconds / 3600;
        countdown_minute = ((countdowntime_seconds / 60) % 60);
        countdown_sec = countdowntime_seconds % 60;
        lcd.setCursor(2, 0);

        if (countdown_hour < 10) {
          lcd.print("0");
        }
        lcd.print(countdown_hour);
        lcd.print(":");
        if (countdown_minute < 10) {
          lcd.print("0");
        }
        lcd.print(countdown_minute);
        lcd.print(":");
        if (countdown_sec < 10) {
          lcd.print("0");
        }
        lcd.print(countdown_sec);
        lcd.print(":");
        lcd.print((elapsedTime / 100) % 10);
        lcd.print((elapsedTime / 10) % 10);

        if (countdown_hour == 0 && countdown_minute == 0 && countdown_sec == 0)
        {
          lcd.clear();
          lcd.print("BOOM");
          Stop = true;
          Boom = true;
        }
      }
    }

    if (!Stop)
    {
      if (customKey) {
        Data[data_count] = customKey;
        lcd.setCursor(data_count + 4, 1);
        lcd.print(Data[data_count]);
        data_count++;
      }

      if (data_count == master_count) {
        lcd.clear();

        if (!strcmp(Data, Master)) {
          lcd.setCursor(2, 0);
          lcd.print("Bomb  Defused");
          Stop = true;
          return;
        }
        else {
          lcd.print("Incorrect");
          delay(1000);
        }
        lcd.clear();
        clearData();
      }
    }

    long currentTime = elapsedTime;
    if (!Stop)
    {
      if (currentTime - previousTime >= interval) {
        if (countdown_hour == 0 && countdown_minute == 0 && countdown_sec < 40 && countdown_sec >= 20)
        {
          interval -=  20 ; //* 1.000999
        }
        else if (countdown_sec < 20)
        {
          interval -= 5;
        }
        //Serial.println(interval);
        previousTime = currentTime;
        digitalWrite(12, HIGH);
        tone(buzzer, 4200, 100);
      }
      digitalWrite(12, LOW);
    }
    while (Boom)
    {
      if (elapsedTime <= 17000)
      {
        currentTimee = millis();
        elapsedTime = currentTimee - startTime;
        Serial.println(elapsedTime);
        digitalWrite(10, HIGH);
      }
      else {
        digitalWrite(10, LOW);
      }
    }
  }
}



void clearData() {
  while (data_count != 0) {
    Data[data_count--] = 0;
  }
  return;
}