#include <WiFi.h>
#include <HTTPClient.h>
#include <HX711.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <SPI.h>
#include <MFRC522.h>

// ====================== WIFI =====================
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ====================== SERVER =====================
const char* serverName = "http://iot.informatika-unes.com/api/timbang"; // Ganti dengan URL server kamu

// ====================== HX711 (Timbangan) =====================
#define DT 32
#define SCK 33
HX711 scale;

// ====================== RFID =====================
#define RST_PIN 22
#define SS_PIN 21
MFRC522 rfid(SS_PIN, RST_PIN); // SDA, RST

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

// ====================== PIN =====================
const int tombolPin = 15;
const int ledHijau = 26;
const int ledMerah = 27;

// ====================== UID → Nama Dummy =====================
String getNamaByUID(String uid) {
  uid.toUpperCase();
  if (uid == "A1B2C3D4") return "Andi";
  if (uid == "11223344") return "Siti";
  return "Tidak Dikenal";
}

void setup() {
    Wire.begin(21, 22); // Wokwi default I2C

  Serial.begin(115200);
  pinMode(tombolPin, INPUT_PULLUP);
  pinMode(ledHijau, OUTPUT);
  pinMode(ledMerah, OUTPUT);
 while (!Serial);
  Serial.println("\nI2C Scanner");
  // LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Timbangan IoT");

  // RFID
  SPI.begin(); 
  rfid.PCD_Init();

  // Load Cell
  scale.begin(DT, SCK);
  scale.set_scale(420.0);  // Sesuaikan hasil kalibrasi
  scale.tare();

  // WiFi
  lcd.setCursor(0, 1);
  lcd.print("Menghubungkan...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi Terhubung");
  lcd.clear();
  lcd.print("WiFi Terhubung!");
  delay(1000);
  lcd.clear();
}

void loop() {
  lcd.setCursor(0, 0);
  lcd.print("Scan Kartu...   ");

  // Cek kartu RFID
  if (!rfid.PICC_IsNewCardPresent() || !rfid.PICC_ReadCardSerial()) {
    delay(100);
    return;
  }

  // Baca UID
  String uid = "";
  for (byte i = 0; i < rfid.uid.size; i++) {
    uid += String(rfid.uid.uidByte[i], HEX);
  }
  uid.toUpperCase();
  Serial.println("UID: " + uid);

  // Cek nama pengguna
  String nama = getNamaByUID(uid);
  Serial.println("Nama: " + nama);

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Nama:");
  lcd.setCursor(0, 1);
  lcd.print(nama);
  delay(2000);

  // Timbang
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Timbang...");
  scale.tare();
  delay(2000);
  float berat = scale.get_units(10);
  Serial.print("Berat: ");
  Serial.println(berat);

  lcd.setCursor(0, 1);
  lcd.print("Berat: " + String(berat, 2) + " kg");

  // Tunggu tombol kirim
  lcd.setCursor(0, 0);
  lcd.print("Tekan Kirim...");

  while (digitalRead(tombolPin) == HIGH) {
    delay(100);
  }

  // Kirim ke server
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin(serverName);
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");

    String postData = "uid=" + uid + "&nama=" + nama + "&berat=" + String(berat, 2);
    Serial.println("Mengirim: " + postData);

    int httpResponseCode = http.POST(postData);
    String response = http.getString();

    lcd.clear();
    if (httpResponseCode == 200) {
      Serial.println("✅ Terkirim");
      lcd.print("Data Terkirim!");
      digitalWrite(ledHijau, HIGH);
      digitalWrite(ledMerah, LOW);
    } else {
      Serial.println("❌ Gagal Kirim");
      Serial.println(response);
      lcd.print("Gagal Kirim!");
      digitalWrite(ledMerah, HIGH);
      digitalWrite(ledHijau, LOW);
    }

    http.end();
  } else {
    Serial.println("❌ Tidak Terhubung ke WiFi");
    lcd.clear();
    lcd.print("Koneksi Gagal");
    digitalWrite(ledMerah, HIGH);
    digitalWrite(ledHijau, LOW);
  }

  delay(3000);
  digitalWrite(ledHijau, LOW);
  digitalWrite(ledMerah, LOW);
  lcd.clear();

  // Reset RFID
  rfid.PICC_HaltA();
  rfid.PCD_StopCrypto1();
}