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

#define START_BUTTON_PIN 33
#define STOP_BUTTON_PIN 32
#define RELAY_1_PIN 23
#define RELAY_2_PIN 25
#define RELAY_3_PIN 26
#define RELAY_4_PIN 27

LiquidCrystal_I2C lcd(0x27, 20, 4);
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {13, 12, 14, 15};
byte colPins[COLS] = {16, 17, 18, 19};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

String inputVolume = "";
int targetVolume = 0;
bool startEnabled = false;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("FillFlow System");
  pinMode(START_BUTTON_PIN, INPUT_PULLUP);
  pinMode(STOP_BUTTON_PIN, INPUT_PULLUP);

  pinMode(RELAY_1_PIN, OUTPUT);
  pinMode(RELAY_2_PIN, OUTPUT);
  pinMode(RELAY_3_PIN, OUTPUT);
  pinMode(RELAY_4_PIN, OUTPUT);

  digitalWrite(RELAY_1_PIN, LOW);
  digitalWrite(RELAY_2_PIN, LOW);
  digitalWrite(RELAY_3_PIN, LOW);
  digitalWrite(RELAY_4_PIN, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
  char key = keypad.getKey();
  if (key) {
    if (key >= '0' && key <= '9') {
      inputVolume += key;
      lcd.setCursor(0, 1);
      lcd.print(inputVolume);
    } else if (key == '#') {
      targetVolume = inputVolume.toInt();
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Volume: ");
      lcd.print(targetVolume);
      lcd.print(" ml");
    } else if (key == '*') {
      inputVolume = "";
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Enter volume:");
    }
  }

  if (digitalRead(START_BUTTON_PIN) == LOW && startEnabled) {
    digitalWrite(RELAY_1_PIN, HIGH);
    lcd.setCursor(0, 1);
    lcd.print("memulai pengisian");
  }
  delay(10); // this speeds up the simulation
}