#include <LiquidCrystal_I2C.h>
#include <Button.h>

//Setting up the button pins
bool btnUpState, btnOkState, btnDnState;
Button btnUp(A1);
Button btnOk(A2);
Button btnDn(A3);

//Setting up the i2C LCD Screen
LiquidCrystal_I2C lcd(0x27, 16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display

String menu[4] = {
  "Auto Home",
  "Automatic Cut",
  "Manual Cut",
  "Settings"
};

String autoCut[5] = {
  "Long to Short",
  "Long to A4",
  "Long to 1/2",
  "Long to 1/4"
};

int selectVal = 0;

void setup() {
  // put your setup code here, to run once:
  //Initialize Serial
  Serial.begin(115200);

  //Initialize Initialize
  lcd.init();
  lcd.backlight();

  //Initialize all buttons
  btnUp.begin();
  btnOk.begin();
  btnDn.begin();
}

void loop() {
  // put your main code here, to run repeatedly:
  buttonRead();
  menuNav(selectVal);
  Serial.println(btnUp.pressed());
}

void menuNav(int selectVal) {
  static int x, y, z;
  static int menuNoItems = (sizeof(menu) / sizeof(menu[0]) - 1);
  static int autoCutNoItems = (sizeof(autoCut) / sizeof(autoCut[0]) - 1);
  //Serial.println(selectVal);
  //Main Menu
  if(selectVal == 0) {
    if(x <= menuNoItems && x >= 0) {
      lcdPrint(menu[x], 0);
      lcdPrint(menu[x+1], 1);
    }
  }
  //Auto Cut
  else if (selectVal == 20) {
    if(y <= autoCutNoItems && y >= 0) {
      lcdPrint("Please Select:", 0);
      lcdPrint(autoCut[y-1], 1);
    }
  }

  //Button selection
  if(btnUpState) {
    Serial.println(x);
    //If @ main menu
    if(selectVal == 0) {
      //checks if value exceeds total menu
      if(x > menuNoItems) {
        x = 0;
      }
      else {
        x+=1;
      }
    }
    else if (selectVal == 20) {
      //checks if value exceeds total menu
      if(y > autoCutNoItems) {
        y = 0;
      }
      else {
        y+=1;
      }
    }
  }
}

void buttonRead() {
  if(btnUp.pressed()) {
    btnUpState = true;
  }
  else if (btnUp.released()) {
    btnUpState = false;
  }

  if(btnOk.pressed()) {
    btnOkState = true;
  }
  else if (btnOk.released()) {
    btnOkState = false;
  }

  if(btnDn.pressed()) {
    btnDnState = true;
  }
  else if (btnDn.released()) {
    btnDnState = false;
  }
}

void lcdPrint(String text, int row) {
  int textLength = text.length();
  int startingCursor;
  static String lastTextRow1, lastTextRow2;

  //checks if value is an odd or even
  if (textLength % 2 == 0) {
    startingCursor = (16/2) - (textLength/2);
  }
  else {
    startingCursor = (16/2) - ((textLength + 1)/2);
  }
  
  //checks if text is below 16 characters
  if(textLength > 16) {
    Serial.println("Text Exceeded 15 characters, chopping other texts...");
  }
  else {
    //checks which row is it gonna be pasted
    if (row == 0) {
      if (text != lastTextRow1) {
        //lcd.clear();
        //clears the first the row,
        lcd.setCursor(0, row);
        lcd.print("                ");

        //and then, starts to print
        lcd.setCursor(startingCursor, row);
        lcd.print(text);

        //stores the last text to the string
        lastTextRow1 = text; 
      }
    }
    else {
      if (text != lastTextRow2) {
        //lcd.clear();
        //clears the first the row,
        lcd.setCursor(0, row);
        lcd.print("                ");

        //and then, starts to print
        lcd.setCursor(startingCursor, row);
        lcd.print(text);

        //stores the last text to the string
        lastTextRow2 = text; 
      }

    }
    
  }
}