#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

#define nextBtn 12
#define selectBtn 3

struct Relay {
  const char* name;
  int pin;
};
Relay relays[] = {
  {"Relay1", 13},
  {"Relay2", 11},
};

unsigned long lastPress = 0;
const unsigned long pressDelay = 200;

const char* menuItems[] = {"Relay-1", "Relay-2"};
const char* subMenuItems[] = {"Relay-1 State", "Relay-2 State"};
int menulength = 1;
int currentitem = 0;
int currentSubitem = 0;
bool onSub = false;

void setup() {
  pinMode(nextBtn, INPUT_PULLUP);
  pinMode(selectBtn, INPUT_PULLUP);
  digitalWrite(relays[0].pin, 1);
  digitalWrite(relays[1].pin, 0);
  lcd.init();
  lcd.backlight();
  lcd.clear();
  drawmenu();

}
void loop() {
  unsigned long currentMillis = millis();
  
 if (digitalRead(nextBtn) == LOW && onSub == false) {
  if (currentMillis - lastPress >= pressDelay) {
    lastPress = currentMillis;
  if (currentitem < menulength) {
    currentitem++;
    drawmenu();
  }
  else {
  currentitem = 0;
  drawmenu();
     }
    }
   }
  if (digitalRead(selectBtn) == LOW) {
    if (currentMillis - lastPress >= pressDelay) {
    lastPress = currentMillis;
    if (onSub == false) {
      drawSubMenu();
      onSub = true;
    }
     else {
      drawmenu();
      onSub = false;
    }
   }
  }
}

void drawmenu() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(">");
  lcd.setCursor(1, 0);
  lcd.print(menuItems[currentitem]);
  if (currentitem < menulength) {
  lcd.setCursor(1, 1);
  lcd.print(menuItems[currentitem+1]);
  }
}
void drawSubMenu() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(subMenuItems[currentitem]);
  lcd.setCursor(0, 1);
  lcd.print(relayCheck(relays[currentitem].pin));

}

const char* relayCheck(int relayPin) {
     return digitalRead(relayPin) ? "ON" : "OFF";
}