#include <LiquidCrystal.h>

const int password[8] = {1,1,1,1,1,1,1,1};
int entered[8];
int flag = 0;
int i = 0;
bool alarm = 1;
int attempts = 3;

const int rs=12, en=11, d4 =10, d5=9, d6 = 8, d7=7;

LiquidCrystal lcd(rs, en, d4, d5, d6, d7);




void setup() {
  Serial.begin(9600);
  lcd.begin(16,2);
  pinMode(A0, INPUT_PULLUP);
  pinMode(A1, INPUT_PULLUP);
  pinMode(A2, INPUT_PULLUP);
  pinMode(A3, INPUT_PULLUP);
  pinMode(A4, INPUT_PULLUP);
  pinMode(A5, INPUT_PULLUP);
  pinMode(6, INPUT_PULLUP);
  pinMode(4, INPUT_PULLUP);
  pinMode(5, INPUT_PULLUP);
  pinMode(2, INPUT_PULLUP);
  pinMode(3, INPUT_PULLUP);
  pinMode(13, OUTPUT);
  
  


  lcd.print("Password-Based");
  lcd.setCursor(0,1);
  lcd.print("Locking System");
  delay(2000);
  lcd.clear();
  
  digitalWrite(13, LOW);
}


void loop(){
  if(flag == 0)
  {
switch (alarm){
case 0:
lcd.setCursor(0,0);
lcd.print("UNLOCKED");
break;

case 1:
lcd.setCursor(0,0);
lcd.print("LOCKED");
break;
  }
  
bool enter = digitalRead(2);
bool k0 = digitalRead(A0);
bool k1 = digitalRead(A1);
bool k2 = digitalRead(A2);
bool k3 = digitalRead(A3);
bool k4 = digitalRead(A4);
bool k5 = digitalRead(A5);
bool k6 = digitalRead(3);
bool k7 = digitalRead(6);
bool k8 = digitalRead(5);
bool k9 = digitalRead(4);
bool match = 1;

if (i>7 || enter == LOW)
{
flag++;
}

//int input = k0*1 + k1*2 + k2*4 + k3*8 + k4*16 + k5*32 + k6*64 + k7*128 + k8*256 + k9*512;
if(flag == 1){
  lcd.setCursor(0,0);
  lcd.print("Enter  Password:");
  lcd.setCursor(0,1);
  //k9 LOW
  if(k9 == LOW){
  entered[i] = 9;
    lcd.setCursor(i,1);
    lcd.print(entered[i]);
    
  i++;
  delay(1000);}
  
  //k8 LOW
  if(k8 == LOW){
  entered[i] = 8;
  lcd.setCursor(i,1);
  lcd.print(entered[i]);
  
  i++; 
  delay(1000);
  }
  //k7 LOW
   if(k7 == LOW){
  entered[i] = 7;
     lcd.setCursor(i,1);
     lcd.print(entered[i]);
     
     i++;
     delay(1000);}
  
  //k6 LOW
   if(k6 == LOW){
    entered[i] = 6;
   lcd.setCursor(i,1);
     lcd.setCursor(i,1);
     lcd.print(entered[i]);
     i++; 
     delay(1000);
   }
  
  //k5 LOW
   if(k5 == LOW){
    entered[i] = 5;
     lcd.setCursor(i,1);
     lcd.print(entered[i]);
     i++; 
     delay(1000);
   }

  //k4 LOW
   if(k4 == LOW)
   {
    entered[i] = 4;
    lcd.setCursor(i,1);
    lcd.print(entered[i]);
    i++; 
    delay(1000);
   }

  //k3 LOW
   if(k3 == LOW){
    entered[i] = 3;
     lcd.setCursor(i,1);
    lcd.print(entered[i]);
    i++; 
    delay(1000);
   }
  //k2 LOW
   if(k2 == LOW)
   {
    entered[i] = 2;
    lcd.setCursor(i,1);
    lcd.print(entered[i]);
    i++; 
    delay(1000);
    }
  
  //k1 LOW
   if(k1 == LOW)
   {
  entered[i] = 1;
  lcd.setCursor(i,1);
    lcd.print(entered[i]);
    i++; 
    delay(1000);
   }

  //k0 LOW
   if(k0 == LOW){
    entered[i] = 0;
     lcd.setCursor(i,1);
     lcd.print(entered[i]);
     
  i++; 
  delay(1000);
   }}

   
// Processing and Output Phase
if(flag == 2){
  lcd.clear();
  match = 0;
//Verification loop
for(int a = 0; a < 8; a++){
  if(password[a] != entered[a])
  { 
  match++;
  delay(100);
  }}

//Result Output 
  if(match == 0){
    lcd.setCursor(0,0);
    lcd.print("Authorized");
    alarm = !alarm;
    lcd.setCursor(0,1);

    if(alarm == 0)
    {
     lcd.print("Alarm disabled");
     }
    
    else if(alarm == 1)
    {
      lcd.print("Alarm enabled");
      }
      flag = 0;
      match = 1;
      i = 0;
      attempts = 3;
      delay(5000);
      lcd.clear();
     }

  else if(match == 1){
    lcd.clear();
    lcd.print("Unauthorized");
    attempts--;
    match = 0;
    flag = 0;
    i = 0;
    lcd.setCursor(0,1);

    if(attempts > 0){
    lcd.print(attempts);
    lcd.print(" attempts left");
    delay(1000);
    lcd.clear();
    }
    else {
      lcd.clear();
      lcd.print("Access denied");
      lcd.setCursor(0,1);
      lcd.print("System locked");
      flag++;
      delay(1000);
      digitalWrite(13, HIGH);
  }}}

  if (flag>2){

    for(;;)
    {
    lcd.print("")
        }
  }
  
  }