#define upButton 2
#define downButton 3
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 4);
const int ArrayLength = 15;
String menuItems[ArrayLength] = {"Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6", "Item 7", "Item 8", "Item 9", "Item 10", "Item 11", "Item 12", "Item 13", "Item 14", "Item 15"};

int currIndex = 0;
int currDisolayRow = 0;
bool currsorMode = 0;
void setup() {
  pinMode(upButton, INPUT_PULLUP);
  pinMode(downButton, INPUT_PULLUP);


  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Welcome....");
  delay(1000);
  lcd.clear();
  clearArrow();
  lcd.setCursor(0, 0);
  lcd.print(">");
  drawMenu(0);
  Serial.begin(115200);
  Serial.println(currIndex);

}
void clearArrow() {
  //  column,row
  lcd.setCursor(0, 0);
  lcd.print(" ");
  lcd.setCursor(0, 1);
  lcd.print(" ");
  lcd.setCursor(0, 2);
  lcd.print(" ");
  lcd.setCursor(0, 3);
  lcd.print(" ");


}

void drawMenu(int startItem) {

  for (int i = 0; i < 4; i++) {
    lcd.setCursor(1, i);
    lcd.print(menuItems[i + startItem]);
    if (currIndex == ArrayLength - 1 and currsorMode == 1) {
      currIndex = 0;
      currDisolayRow = 0;

    }


  }

}

void loop() {

  bool upState = digitalRead(upButton) ;
  bool downState = digitalRead(downButton);

  if (downState == LOW  and currIndex < ArrayLength - 1) {
    currsorMode = 0;
    if ( currDisolayRow > 2 ) {
      currIndex ++;
      //currDisolayRow++;
      lcd.clear();
      lcd.setCursor( 0, currDisolayRow);
      lcd.print(">");
      drawMenu(currIndex - 3);

      Serial.println(currIndex);
      delay(250);
    } else {
      currIndex ++;
      currDisolayRow++;
      clearArrow();
      lcd.setCursor( 0, currDisolayRow);
      lcd.print(">");
      //Serial.println(currIndex);
      delay(250);
    }
  }





  if (upState == LOW  ) {
    Serial.println(currIndex);
    currsorMode = 1;
    if ( currDisolayRow < 0 ) {
      Serial.println("Display Last Item");
      currIndex = ArrayLength - 1;
      lcd.clear();
      lcd.setCursor( 0, currDisolayRow);
      lcd.print(">");
      drawMenu(ArrayLength - 1);

      //Serial.println(currIndex);
      delay(250);
    } else {
      currIndex --;
      currDisolayRow--;
      clearArrow();
      lcd.setCursor( 0, currDisolayRow);
      lcd.print(">");
      //Serial.println(currIndex);
      delay(250);
    }
  }


}