#include <HX711.h>
#include <Servo.h>
#include <Keypad.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Load Cell
#define DT A1
#define SCK A0
HX711 scale;

// Servo
Servo myServo;
int servoPin = 9;

// Buzzer & Limit Switch
const int buzzerPin = 10;
const int limitSwitchPin = 8;

// LCD I2C
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Keypad 4x4
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},  // ← tombol 'C' sebagai HAPUS
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {2, 3, 4, 5};
byte colPins[COLS] = {6, 7, A2, A3}; // Tambahan A3 untuk kolom ke-4
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// Variabel Input
String inputBerat = "";
float targetBerat = 0;

void setup() {
  Serial.begin(9600);
  scale.begin(DT, SCK);
  scale.set_scale();
  scale.tare();

  myServo.attach(servoPin);
  myServo.write(0);

  pinMode(buzzerPin, OUTPUT);
  pinMode(limitSwitchPin, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Sistem Penakar");
  lcd.setCursor(0, 1);
  lcd.print("Teh Siap...");
  delay(1500);
  lcd.clear();
}

void loop() {
  if (digitalRead(limitSwitchPin) == LOW) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Teh Habis!");
    lcd.setCursor(0, 1);
    lcd.print("Isi Wadah Dulu");
    digitalWrite(buzzerPin, HIGH);
    delay(1000);
    digitalWrite(buzzerPin, LOW);
    delay(1000);
    return;
  }

  char key = keypad.getKey();
  if (key) {
    if (key >= '0' && key <= '9') {
      if (inputBerat.length() < 4) {
        inputBerat += key;
        lcd.setCursor(0, 0);
        lcd.print("Input Berat:");
        lcd.setCursor(0, 1);
        lcd.print(inputBerat + "g   ");
      }
    } else if (key == '*') { // Enter
      if (inputBerat.length() > 0) {
        targetBerat = inputBerat.toFloat();
        inputBerat = ""; // reset input

        scale.tare();
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Menakar: ");
        lcd.print(targetBerat, 0);
        lcd.print("g");
        Serial.print("Menakar: ");
        Serial.print(targetBerat);
        Serial.println(" gram");

        bukaWadah();

        while (scale.get_units() < targetBerat) {
          float berat = scale.get_units();
          Serial.print("Berat sekarang: ");
          Serial.print(berat, 2);
          Serial.println(" g");

          lcd.setCursor(0, 1);
          lcd.print("Berat: ");
          lcd.print(berat, 2);
          lcd.print("g     ");
          delay(300);
        }

        tutupWadah();

        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Penakaran");
        lcd.setCursor(0, 1);
        lcd.print("Selesai!");
        Serial.println("Penakaran selesai!");
        delay(1500);
        lcd.clear();
      }
    } else if (key == '#') { // Tare manual
      scale.tare();
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Timbangan");
      lcd.setCursor(0, 1);
      lcd.print("direset ke 0");
      Serial.println("Timbangan direset ke 0");
      delay(1500);
      lcd.clear();
    } else if (key == 'C') { // Hapus karakter terakhir
      if (inputBerat.length() > 0) {
        inputBerat.remove(inputBerat.length() - 1);
        lcd.setCursor(0, 0);
        lcd.print("Input Berat:");
        lcd.setCursor(0, 1);
        lcd.print(inputBerat + "g    ");
      }
    }
  }
}

void bukaWadah() {
  myServo.write(90);
  delay(500);
}

void tutupWadah() {
  myServo.write(0);
  delay(500);
}