#include <Keypad.h>
#include <ShiftedLCD.h>
#include <SPI.h>

//Define LCD Pin
LiquidCrystal lcd(10);


void writeLCD(int column, int row, String text, bool wait, double balance)
{
  // reset LCD
  lcd.clear();

  // set top row with balance tracking
  lcd.setCursor(0, 0);
  lcd.print("Balance: ");

  // print updated balance
  lcd.setCursor(10, 0);
  lcd.print(balance);

  // set bottom row with params
  lcd.setCursor(column, row);
  lcd.print(text);
  if (wait)
  {
    delay(2000);
  }
}


int checkPosition(String codeStr)
{
  // if first or 2nd position are x, they are empty so can have a value inserted
  if (codeStr[0] == 'x')
    return 0;
  else if (codeStr[1] == 'x')
    return 1;
  else
  // otherwise return 666 to signify full code selection
    return 666;
}



String calculate(double balance, double cost)
{
  Serial.println(balance);
  Serial.println(cost);
  // check balance is greater than or equal to the cost of the item
  if (balance >= cost or balance * 1.0001 > cost)
  {
    // calculate new balance
    double newBal = balance - cost;
    Serial.println("balance greater");
    return String(newBal);
  }
  else if (balance == cost)
  {
    Serial.println("equal");
    return "Balance too low";
  }
  else if (balance <= cost)
  {
    Serial.println("balance is less");
    return "Balance too low";
  }
}

void clearSelection(String code, double balance)
{
  code = "xx\0";
  Serial.println("Selection cleared.");

  // reset lcd
  writeLCD(0, 1, "Your choice:", false, balance);
}