// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  Serial.begin(9600);
  pinMode(6, INPUT);
  pinMode(13, INPUT);
  pinMode(9, OUTPUT);
}
int mainMenu = 1;
int ustMenu = 0;
int menu = 0;
int tempMenu = 0;
int jasnosc = 100;

#define up 6
#define down 7
#define select 13
#define back 8

void loop() {

  lcd.setCursor(0, 1);
  if (mainMenu == 1) {
    if(menu < 0) { menu = 1; }
    if(menu == 0) { lcd.print("1. Temperatura"); }
    if(menu == 1) { lcd.print("2. Ustawienia"); }
    if(menu > 1) { menu = 0; }
  }
  if (ustMenu == 1) {
    if(menu < 0) { menu = 1; }
    if(menu == 0) { lcd.print("1. Jasnosc"); }
    if(menu == 1) { lcd.print("2. Kontrast"); }
    if(menu > 1) { menu = 0; }
  }
  if (tempMenu == 1) {
    lcd.setCursor(0,0);
    lcd.print("Jasnosc: ");
    lcd.setCursor(0,1);
    lcd.print(jasnosc);
  }

  if(digitalRead(up) == HIGH) {
    upKey();
  }
  if(digitalRead(down) == HIGH) {
    downKey();
  }
  if(digitalRead(select) == HIGH) {
    selectKey();
  }
  if(digitalRead(back) == HIGH) {
    backKey();
  }
}
int upKey() {
  lcd.clear();
  while(digitalRead(up) == HIGH) {
  }
  menu++;
}
int downKey() {
  lcd.clear();
  while(digitalRead(down) == HIGH) {
  }
  menu--;
}
int selectKey() {
  lcd.clear();
  while(digitalRead(select) == HIGH) {
  }
  if(menu == 0) {
    lcd.setCursor(0,0);
    lcd.print(analogRead(0));
  }
  if(mainMenu == 1 && menu == 1) {
    ustMenu = 1;
    mainMenu = 0;
  }
  if(ustMenu == 1 && menu == 0) {
    tempMenu = 1;
    ustMenu = 0;
  }
  menu = 0;
}
int backKey() {
  lcd.clear();
  while(digitalRead(back) == HIGH) {
  }
  if (ustMenu == 1) {
    ustMenu = 0;
    mainMenu = 1;
  }
}
int resMenu(int x) {
  tempMenu = 0;
  mainMenu = 0;
  ustMenu = 0;
  x = 1;
}