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

LiquidCrystal_I2C lcd(0x27, 20, 4);

const byte RIADOK_NUM = 4; 
const byte STLPEC_NUM = 4;

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

byte pin_riadok [RIADOK_NUM] = {13, 12, 14, 27}; 
byte pin_stlpec [STLPEC_NUM] = {26, 25, 33, 32};

Keypad keypad = Keypad(makeKeymap(tlacidla), pin_riadok , pin_stlpec , RIADOK_NUM, STLPEC_NUM);

int pocetA = 0;
int pocetB = 0;
int pocetC = 0;
int pocetD = 0;


#define led 5

void setup() {
  Serial.begin(9600);
  pinMode (led, OUTPUT);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Stlac A/B/C/D");
  lcd.setCursor(0, 1);
  lcd.print("Pre reset #");
}

void loop() {
  char key = keypad.getKey(); 

  if (key) { Serial.println(key);
    switch (key) {
      case 'A':
        pocetA++;
        if (pocetA > 20)
        {
          pocetA = 19;
        }
        break;
      case 'B':
        pocetB++;
        break;
      case 'C':
        pocetC++;
        break;
      case 'D':
        pocetD++;
        break;
      case '#':
        pocetA = 0;
        pocetB = 0;
        pocetC = 0;
        pocetD = 0;
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Stlac A/B/C/D");
        lcd.setCursor(0, 1);
        lcd.print("Pre reset #");
        delay(2000);
        break;
      default:
        break;
    }
    if (pocetA == pocetB && pocetB == pocetC && pocetC == pocetD)
    {
      digitalWrite(led, HIGH);
    }
    else
    {
      digitalWrite(led, LOW);
    }
    lcd.clear();
    lcd.setCursor(0, 0);
    for (int i = 0; i < pocetA; i++) lcd.print("X");
    
    lcd.setCursor(0, 1);
    for (int i = 0; i < pocetB; i++) lcd.print("X");

    lcd.setCursor(0, 2);
    for (int i = 0; i < pocetC; i++) lcd.print("X");

    lcd.setCursor(0, 3);
    for (int i = 0; i < pocetD; i++) lcd.print("X");
  }
}