#include <Arduino.h>
#include "Keypad.h"
#include <Wire.h> 
#include <LiquidCrystal_I2C.h> 
#include <EEPROM.h>


LiquidCrystal_I2C LCD(0x27, A4, A5);

byte rowPins[n] = { 9, 8, 7, 6 };
byte colPins[n] = { 5, 4, 3, 2 };

char Keys[n*n] =
{
    '1', '2', '3', 'A',
    '4', '5', '6', 'B',
    '7', '8', '9', 'C',
    '*', '0', '#', 'D'
};

Keypad* key = new Keypad(Keys, colPins, rowPins, n, n);

void display_words(String str1, String str2)
{
  interrupts();
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.print(str1);

  LCD.setCursor(0, 1);
  LCD.print(str2);
  noInterrupts();
}

void display_words_int(int str1, int str2)
{
  interrupts();
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.print(str1);

  LCD.setCursor(0, 1);
  LCD.print(str2);
  noInterrupts();
}


void counter()
{ 
  char symbol = ' ';
  
  display_words("FROM MEM: 1","ENTER: 2");
  while(symbol == ' ')
  {
    symbol = key->getKey();
  }

  String res;
  int first;
  
  if(symbol == '2')
  {
    display_words("FIRST NUM:", "");
    res = "";
    symbol = '1';
    
    while(symbol != '*')
    {
      symbol = key->getKey();
      if(symbol >= '0' && symbol <= '9')
      {
        res += symbol;
        display_words("FIRST NUM:", res);
      }
    }
  
    first = res.toInt();
    Serial.println("FIRST NUM: ");   
    Serial.println(first);
  }
  else
  {
    EEPROM.get(0, first);
    display_words("FIRST NUM:", String(first));
    while(key->getKey() != '*')
    {
      
    }
  }

  symbol = ' ';
  display_words("FROM MEM: 1","ENTER: 2");
  while(symbol == ' ')
  {
    symbol = key->getKey();
  }

  int second_;
  if(symbol == '2') 
  {
    display_words("SECOND NUM:", "");
    res = "";
    symbol = '1';
  
    while(symbol != '*')
    {
      symbol = key->getKey();
      if(symbol >= '0' && symbol <= '9')
      {
        res += symbol;
        display_words("SECOND NUM:", res);
      }
    }

    second_ = res.toInt();
  }
  else
  {
    EEPROM.get(0, second_);
    display_words("SECOND NUM:", String(second_));
    while(key->getKey() != '*')
    {
      
    }
  }
    int res_or = first & second_;
    display_words(String(first) + " OR " + String(second_) + " =", String(res_or));
    while(key->getKey() != '*')
    {
      
    }
    display_words("ADD to MEM?", "*-No  D-Yes");

    symbol = ' ';
    while(symbol != 'D' && symbol != '*')
    {
      symbol = key->getKey();
    }
    if(symbol == 'D')
    {
      EEPROM.put(0, res_or);
      display_words("SUCCESS!", "PRESS * to EXIT");
      while(key->getKey() != '*')
      {
      
      }
    }
    else
    {
      display_words("NOT SAVED, OK", "PRESS * to EXIT");
      while(key->getKey() != '*')
      {
      
      }
    }
}

void memory()
{
   int res;
   EEPROM.get(0, res);
   display_words(String(res), "PRESS * to EXIT");
   while(key->getKey() != '*')
   {
      
   }
   
}

void resetting()
{
  int address = 0;
  display_words("DELELE MEM?", "*-No  D-Yes");

  char symbol = ' ';
  while(symbol != 'D' && symbol != '*')
  {
    symbol = key->getKey();
  }
  if(symbol == 'D') 
  {
    EEPROM.put(0, 0);
  }
}

void menu()
{
    noInterrupts();
    char res = key->getKey();
    if(res == 'A')
      counter();
    else
      if(res == 'B')
        memory();
      else
        if(res == 'C')
          resetting();
    interrupts();
}

void setup() { 
  LCD.init(); 
  LCD.backlight(); 
  pinMode(2, INPUT_PULLUP);
  EEPROM.put(0, 0);
  attachInterrupt(digitalPinToInterrupt(2), menu, LOW);
}  
  
void loop() 
{  
  LCD.setCursor(0, 0);   
  LCD.print("OR: A, MEM:B");    

  LCD.setCursor(0, 1);   
  LCD.print("RESET: C");

  delay(1000);
  LCD.clear();
}