#include <LiquidCrystal_I2C.h>     // if you don´t have I2C version of the display, use LiquidCrystal.h library instead
#include <Keypad.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); // set the LCD address to 0x27 for a 16 chars and 2 line display
//LiquidCrystal_I2C lcd(0x3f,16,2);    // set the LCD address to 0x3f for a 16 chars and 2 line display
// if you don´t know the I2C address of the display, use I2C scanner first (https://playground.arduino.cc/Main/I2cScanner/)


/* Keypad setup */
const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {5, 4, 3, 2};
byte colPins[KEYPAD_COLS] = {A3, A2, A1, A0};
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);

//===============================
//GLOBAL VARIABLES
//===============================

String permText = "Enter Code:";
String codeEntered = "";

const int finalCode = 1234;
const int code1 = 5555;

void setup() {
  Serial.begin(9600);
  lcd.begin(16, 2);
  lcd.backlight();                  // enable backlight for the LCD module

  //showSpalshScreen();
  lcd.clear();
  lcd.cursor();

  codeEnterScreen();
}




void loop() {
  updateCursor();

  char key = keypad.getKey();
  if (key) {
    processInput(key);
  }
}

//========================================
//EVERYTHING OTHER THAN LOOP AND SETUP
//========================================



//char operation = 0;
//String memory = "";
String current = "";
//uint64_t currentDecimal;
//bool decimalPoint = false;



void showSpalshScreen() {
  lcd.print("GoodArduinoCode");
  lcd.setCursor(3, 1);
  String message = "Calculator";
  for (byte i = 0; i < message.length(); i++) {
    lcd.print(message[i]);
    delay(50);
  }
  delay(250);
}


void codeEnterScreen() {
  lcd.clear();
  lcd.setCursor(2, 0);
  lcd.print(permText);
  lcd.setCursor(5, 1);
  lcd.print("****");
  lcd.setCursor(5,1);
  codeEntered = ""; //Clear Code
}

//===========================
//MAKE CURSOR FLASH
//===========================

void updateCursor() {
  if (millis() / 250 % 2 == 0 ) {
    lcd.cursor();
  } else {
    lcd.noCursor();
  }
}

//================================
//PROCESS KEY INPUT
//================================

void processInput(char key) {

  if (key == '#') {
    lcd.clear();
    lcd.print(codeEntered);
    lcd.noCursor();
    delay(2000);
    codeEnterScreen();
  }

  if ('A' != key && 'B' != key && 'C' != key && 'D' != key && '#' != key && '*' != key) {
    codeEntered += String(key);
    lcd.print(key);
    Serial.println(codeEntered);
    Serial.println(codeEntered.length());
    if (codeEntered.length() >= 4) {

      switch(codeEntered.toInt()){
        case finalCode:
         lcd.clear();
         lcd.print("Code success");
         lcd.noCursor();
         delay(2000);
         codeEnterScreen();
         break;
        case code1:
         lcd.clear();
         lcd.print("code 1");
         lcd.noCursor();
         delay(2000);
         codeEnterScreen();
         break;
        default:
         lcd.clear();
         lcd.print("you suck!");
         lcd.noCursor();
         delay(2000);
         codeEnterScreen();
         break;
      }
/*
      if (finalCode == codeEntered.toInt()) {
        lcd.clear();
        lcd.print("You WIN");
        lcd.noCursor();
        delay(2000);
        codeEnterScreen();
      } else {
        lcd.clear();
        lcd.print("You Suck!");
        lcd.noCursor();
        delay(2000);
        codeEnterScreen();
      }
      */
    }
  }


  //lcd.print(key);
}