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

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Alamat I2C untuk LCD 16x2
const byte ROW_NUM    = 4; //jumlah baris keypad
const byte COLUMN_NUM = 4; //jumlah kolom keypad
char keys[ROW_NUM][COLUMN_NUM] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte pin_rows[ROW_NUM] = {9, 8, 7, 6}; //pin baris keypad
byte pin_column[COLUMN_NUM] = {5, 4, 3, 2}; //pin kolom keypad
Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM);

const float PERTALITE_HARGA = 10000.0;  // Harga per liter Pertalite
float total_harga = 0.0;
float jumlah_bensin = 0.0;

void setup() {
  lcd.backlight();
  lcd.begin(16, 2);
  lcd.print("SPBU Pertamina");
  lcd.setCursor(0, 1);
  lcd.print("Pilih A B C D");
  delay(2000);
  
  lcd.clear();
}

void loop() {
  char key = keypad.getKey();
  
  if (key) {
    switch (key) {
      case 'A':
        beliBensin(1.0);  // Misalnya, beli 1 liter
        break;
      case 'B':
        beliBensin(2.0);  // Misalnya, beli 2 liter
        break;
      case 'C':
        beliBensin(3.0);  // Misalnya, beli 3 liter
        break;
      case 'D':
        selesaiTransaksi();
        break;
    }
    updateLCD();
  }
}

void beliBensin(float liter) {
  jumlah_bensin += liter;
  total_harga = jumlah_bensin * PERTALITE_HARGA;
}

void selesaiTransaksi() {
  lcd.clear();
  lcd.print("Terima Kasih!");
  lcd.setCursor(0, 1);
  lcd.print("Total: Rp");
  lcd.print(total_harga, 2);
  delay(5000);
  lcd.clear();
  total_harga = 0.0;
  jumlah_bensin = 0.0;
  lcd.print("SPBU Pertamina");
  lcd.setCursor(0, 1);
  lcd.print("Pilih A B C D");
  delay(2000);
  lcd.clear();
}

void updateLCD() {
  lcd.clear();
  lcd.print("Liter: ");
  lcd.print(jumlah_bensin, 2);
  lcd.setCursor(0, 1);
  lcd.print("Total: Rp");
  lcd.print(total_harga, 2);
}