//ttps://wokwi.com/projects/416730474971197441
#include <Keypad.h>
const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
//define the cymbols on the buttons of the keypads
char hexaKeys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {13,12,14,27}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {26,25,33,32}; //connect to the column pinouts of the keypad

//initialize an instance of class NewKeypad
Keypad keypad = Keypad( makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 
#define redLed 22
#define piezo 23  //D23
#define passLed 21
#define greenLed 19
#define relay1 18 



bool x=false;
bool lockStatus = false;
int otp =1432;
int keyIndex= 0;
String pressedKeys = "";
String passwordChanged = "";
String passwordString = "1432";



void setup()
{
  Serial.begin(9600);
  Serial.println("\nOTP Project");
  pinMode(redLed,OUTPUT);
  pinMode(relay1, OUTPUT);
  pinMode(piezo,OUTPUT);
  pinMode(passLed, OUTPUT);
  pinMode(greenLed, OUTPUT);
  digitalWrite(redLed,x);
  digitalWrite(relay1, HIGH);
  digitalWrite(greenLed, HIGH);
}
  
void loop()
{
  char key = keypad.getKey();
  
  if(key){
    digitalWrite(piezo, HIGH);
    delay(100);
    digitalWrite(piezo, LOW);
    if (keyIndex == 5){
      String temp =pressedKeys+=(key);
      String lastTwo = temp.substring(temp.length() - 2);
      Serial.println("Last two characters: " + lastTwo);
      if (lastTwo == "CA") 
      {
        digitalWrite(passLed, HIGH);
        passwordChanged = temp.substring(0,4);
        Serial.println("passwordChanged: " + passwordChanged);
        passwordString = passwordChanged; 
        delay(1000);
        digitalWrite(passLed, LOW);
      }
      keyIndex= 0;
      pressedKeys = "";
    }
    else if(keyIndex == 4 && key=='D'){
      Serial.print("keyIndex:");
      Serial.println(keyIndex);
      String temp = pressedKeys+=(key);
      String lastOne = temp.substring(temp.length() - 1);
      Serial.println("Last One characters is: " + lastOne);
      if (lastOne == "D") 
      { 
        if(passwordString == temp.substring(0,4) &&  lockStatus == false)
        {
          Serial.println("Safe opened Successfully");
          keyIndex= 0;
          pressedKeys = "";
          lockStatus = true;
          digitalWrite(relay1, HIGH);
          digitalWrite(redLed, HIGH);
          digitalWrite(greenLed, LOW);
        }
        else if(passwordString == temp.substring(0,4) &&  lockStatus == true){
          Serial.println("Safe closed Successfully");
          keyIndex= 0;
          pressedKeys = "";
          lockStatus = false;
          digitalWrite(relay1, LOW);
          digitalWrite(redLed, LOW);
          digitalWrite(greenLed, HIGH);
        }
      }
      return;
    }
    else{

      keyIndex++;
      pressedKeys +=(key);
      //Serial.print("keyIndex:");
      //Serial.println(keyIndex);
      Serial.print("pressedKeys:");
      Serial.println(pressedKeys);
    }
  }


  
  
 
}

void Error_OTP()
{
  Serial.println("OTP Error. !!! Warning");
 
}