#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

LiquidCrystal_I2C lcd();

const byte KEYPAD1_ROWS = 4;
const byte KEYPAD1_COLS = 4;
byte rowPins1[KEYPAD1_ROWS] = {7, 6, 5, 4};
byte colPins1[KEYPAD1_COLS] = {3, 2, 1, 0};
char keys1[KEYPAD1_ROWS][KEYPAD1_COLS] = {
  {'1', '2', '3', '+'},
  {'4', '5', '6', '-'},
  {'7', '8', '9', '*'},
  {'.', '0', '=', '/'}
};
Keypad keypad1 = Keypad(makeKeymap(keys1), rowPins1, colPins1, KEYPAD1_ROWS, KEYPAD1_COLS);

const byte KEYPAD2_ROWS = 4;
const byte KEYPAD2_COLS = 4;
byte rowPins2[KEYPAD2_ROWS] = {14, 15, 16, 17};
byte colPins2[KEYPAD2_COLS] = {18, 19, 20, 21};
char keys2[KEYPAD2_ROWS][KEYPAD2_COLS] = {
         {"^", "±", "!", "sin"};
         {"cos", "tg", "ctg", "1/x"};
         { "log","√","_","_"};
         {"_","_","_","_"}
};
Keypad keypad2 = Keypad(makeKeymap(keys2), rowPins2, colPins2, KEYPAD2_ROWS, KEYPAD2_COLS);

uint64_t value = 0;

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(500);
}

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

void setup() {
  Serial.begin(115200);
  lcd.begin(16, 2);

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

  lcd.setCursor(1, 0);
}

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

double calculate(char operation, double left, double right) {
  switch (operation) {
    case '+': return left + right;
    case '-': return left - right;
    case '*': return left * right;
    case '/': return left / right;
    case '^': return pow(left, right);
    case '!': return pow(left, right);
    case '^': return pow(left, right);
    case '^': return pow(left, right);
    "±", "!", "sin"
  }
}

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}