const int  button = A0;    // the pin that the pushbutton is attached to
const int ledPin = 13;       // the pin that the LED is attached to
#include <LiquidCrystal.h>

//rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(12, 11, 5, 4, 3, 2); // input value
int buttonCounter = 12;   // number of fulled stock
int hole_detected = 0;         // current state of the button
int lasthole_detected = 0;     // previous state of the button

int checkHole(void) {
  static int state = 0; // private state variable
  int  sensorNow = analogRead(button);
  if ((state == 0) && (sensorNow > 750))
  { // have a hole
    state = 1;
    if(buttonCounter > 0){

      buttonCounter--; // decrease counting

    }
    else{

      // add more

    }
  }
  if ( (state == 1) && (sensorNow < 100))
  { // no hole
    state = 0;

  }
  return state;
}


void setup() {
  // initialize the button pin as a input:
  pinMode(button, INPUT);
  lcd.begin(16, 2); //size of display
  lcd.setCursor(4, 0);
  lcd.print("padcount");

  delay(200);
}

void loop() {
  static int lastCount = 0 ;

  checkHole();
  if (buttonCounter != lastCount) {
    lcd.setCursor(4, 0); // set a location of words (rows,column)
    lcd.println("Stock: "); //print text
    lcd.setCursor(6, 1);
    lcd.println(buttonCounter);
    lastCount = buttonCounter;
    if (lastCount < 1){ //condition when a stock is out.
      lcd.setCursor(1,1);
      lcd.println("pls refill :(");
      }

  else {
    // do something
    }
  }

  delay(10);
}