#include <LiquidCrystal_I2C.h>
#include <Servo.h>

LiquidCrystal_I2C lcd(0x027, 20,4);
Servo servo;

int number1=0;
int number2=0;

int pot1=A0;
int pot2 = A1;

int led1 =13;
int led2 =12;

void setup() {
  // put your setup code here, to run once:
  lcd.begin(20,4);
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("- [+] - = ");
  lcd.setCursor(0,1);
  lcd.print("- [-] - = ");
  lcd.setCursor(0,2);
  lcd.print("- [x] - = ");
  lcd.setCursor(0,3);
  lcd.print("- [/] - = ");

  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);

  servo.attach(10);
}

void loop() {
                    calculate(0, 0," [+] ");
                    calculate(0, 1," [-] ");
                    calculate(0, 2," [x] ");
                    calculate(0, 3," [/] ");
}





void calculate(int column, int row,char* operation ){
  number1 = map(analogRead(pot1), 0,1023,0,10);
  number2 = map(analogRead(pot2), 0,1023,0,10);
  lcd.setCursor(column,row);
  lcd.print(number1);
  lcd.print(operation);
  lcd.print(number2);
  lcd.print(" = ");
  if(operation == " [+] "){
    lcd.print(number1+number2);
  }
  else if(operation == " [-] "){
    int result =number1-number2;
    lcd.print(result);
    if(result<0){
      blink(led2);
    }
  }
  else if(operation == " [x] "){
    lcd.print(number1*number2);
  }
  else{
    lcd.print((float)number1/number2);
    if(number2==0){
      blink(led1);
      noNoNo();
    }
  }
  lcd.print("       ");
}

void blink(int led){
  for(int x=1; x<=5; x++){
    digitalWrite(led, HIGH);
    delay(100);
    digitalWrite(led, LOW);
    delay(100);
  }
}

void noNoNo(){
  for(int y=1; y<=5;y++){
    for(int x=0; x<=180; x++){
        servo.write(x);
        delay(5);
      }
      for(int z=180; z>=0; z--){
        servo.write(z);
        delay(5);
      }
  }
  
}