// 3 úrovňové menu (stránka, podstránka, hodnoty)

#include <LiquidCrystal.h>

LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

unsigned long buttontime = 0;
byte value = 0;
byte page = 0;
byte subpage = 0;
byte isinmenupage = 0;
byte value2 = 0;
bool state = 0;
byte alter = 0;
String item1 = "NULL";
String item2 = "NULL";
unsigned long present = 0;
unsigned long past = 0;
unsigned long past2 = 0;
byte amps = 10;
byte kw = 10;
byte poles = 4;
byte rpm = 2000;
byte nm = 10;

void setup() {

pinMode(8, INPUT_PULLUP);  // up
pinMode(9, INPUT_PULLUP);  // down
pinMode(10, INPUT_PULLUP);  // enter
pinMode(11, INPUT_PULLUP);  // back

lcd.begin(16, 2);
lcd.print("Liquid Crystal");
lcd.setCursor(0, 1);
lcd.print("Display Menu");
delay(2000);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Powered by:");
lcd.setCursor(0, 1);
lcd.print("Arduino Nano");
delay(2000);
lcd.clear();
lcd.setCursor(0, 0);

}

void loop() {

present = millis();

buttontime = present - past2;

if(digitalRead(8) == LOW && value < 255) {
  delay(500);
  value = value - 1;

if(isinmenupage == 2) {
  value2 = value2 + 1;
}

if(isinmenupage == 1) {
  value2 = 0;
  subpage = 0;
}

}

if(digitalRead(9) == LOW && value < 5) {
  delay(500);
  value = value + 1;

if(isinmenupage == 2) {
  value2 = value2 - 1;
}

}

if(digitalRead(10) == LOW) {
  delay(200);
  past2 = present;
  isinmenupage = isinmenupage + 1;
}

if(digitalRead(11) == LOW) {
  delay(200);
  isinmenupage = isinmenupage - 1;
}

if(value >= 5 && value < 200) {
  value = 0;
}

if(value >= 255 && value >= 5) {
  value = 4;
}

if(isinmenupage == 0) {
  page = value;
}

if(isinmenupage == 1) {
  subpage = value;
}


if(isinmenupage >= 3) {
  isinmenupage = 2;
}

if(page == 0) {

  item1 = "Motor configs:";

if(buttontime < 700) {
  switch(subpage) {

    case 0:
      item2 = "Max Speed: RPM";
      value2 = rpm;
      break;

    case 1:
      item2 = "Max Torque: NM";
      value2 = nm;
      break;

    case 2:
      item2 = "Max Power: kW";
      value2 = kw;
      break;

    case 3:
      item2 = "Pole count:";
      value2 = poles;
      break;

    case 4:
      item2 = "Max Current: A";
      value2 = amps;
      break;

  }
}

if(buttontime > 700) {
  switch(subpage) {

    case 0:
      item2 = "Max Speed: RPM";
      rpm = value2;
      break;

    case 1:
      item2 = "Max Torque: NM";
      nm = value2;
      break;

    case 2:
      item2 = "Max Power: kW";
      kw = value2;
      break;

    case 3:
      item2 = "Pole count:";
      poles = value2;
      break;

    case 4:
      item2 = "Max Current: A";
      amps = value2;
      break;

  }
}

}

if(isinmenupage == 2 && present - past >= 100) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(item2);
  lcd.setCursor(0, 1);
  lcd.print(value2);
  past = present;
}

if(present - past >= 100 && isinmenupage <= 1) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(item1);
  lcd.setCursor(0, 1);
  lcd.print(item2);
  past = present;
}

}