#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2
#define VERT_PIN A0
#define HORZ_PIN A1
#define SEL_PIN  10
#define ledPin 12
int mainMenuCounter = 3, buttonCounter = 0, ledMenuCounter = 2, exitValue = 0;
int vert, oldVert;
bool selPressed, oldSelPressed = 1;

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.begin(16, 2);
  pinMode(VERT_PIN, INPUT);
  pinMode(HORZ_PIN, INPUT);
  pinMode(SEL_PIN, INPUT_PULLUP);
  Serial.begin(9600);

}

void loop() {
  vert = analogRead(VERT_PIN);

  ReadButton();
  if (vert == 1023 && oldVert < 600)
  {
    lcd.clear();
    if (mainMenuCounter < 4)
    {
      mainMenuCounter++;

      if (buttonCounter > 0 && ledMenuCounter < 3)
      {
        ledMenuCounter++;
      }
    }
  }
  if (vert == 0 && oldVert > 400)
  {
    lcd.clear();
    if (mainMenuCounter > 0)
    {
      mainMenuCounter--;
      if (buttonCounter > 0 && ledMenuCounter > 0)
      {
        ledMenuCounter--;
      }
    }
  }
  oldVert = vert;

  if (buttonCounter == exitValue)
  {
    if (mainMenuCounter >= 3)
    {
      MainMenu1();
    }

    if (mainMenuCounter == 2)
    {
      MainMenu2();
    }

    if (mainMenuCounter <= 1)
    {
      MainMenu3();
    }
  }
  else
  {
    if (ledMenuCounter >= 2)
    {
      ledMenu1();
      if (buttonCounter % 2 == 0)
      {
        digitalWrite(ledPin, HIGH);
      }
      else {
        digitalWrite(ledPin, LOW);
      }
    }
    if (ledMenuCounter <= 1)
    {
      ledMenu2();
      if (buttonCounter % 2 == digitalRead(ledPin))
      {
        exitValue = buttonCounter;
        mainMenuCounter = 3;
      }
    }
  }
  Serial.print(buttonCounter);
  Serial.print("  ");
  Serial.println(exitValue);
}

void MainMenu1()
{
  lcd.setCursor(0, 0);
  lcd.print("LED control   <-");
  lcd.setCursor(0, 1);
  lcd.print("Temperature");
}
void MainMenu2()
{
  lcd.setCursor(0, 0);
  lcd.print("Temperature   <-");
  lcd.setCursor(0, 1);
  lcd.print("Win. Ctrl");
}
void MainMenu3()
{

  lcd.setCursor(0, 0);
  lcd.print("Win. Ctrl     <-");
}

void ledMenu1()
{
  lcd.setCursor(0, 0);
  lcd.print("ON/OFF   <-");
  lcd.setCursor(0, 1);
  lcd.print("Exit");
}

void ledMenu2()
{
  lcd.setCursor(0, 0);
  lcd.print("ON/OFF");
  lcd.setCursor(0, 1);
  lcd.print("Exit     <-");
}

void ReadButton()
{
  selPressed = digitalRead(SEL_PIN) == LOW;
  if (selPressed == 1  && oldSelPressed == 0)
  {
    buttonCounter++;
    lcd.clear();
  }
  else
  {
    delay(50);
  }

  oldSelPressed = selPressed;
}