#include <WiFi.h>
#include <Firebase_ESP_Client.h>
#include <HX711_ADC.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#if defined(ESP8266)|| defined(ESP32) || defined(AVR)
#include <EEPROM.h>
#endif

// === WIFI & FIREBASE ===
#define WIFI_SSID "..."
#define WIFI_PASSWORD "12345678"
#define API_KEY "AIzaSyDQ0zYJrQqCMrAU0-iO0qtCmXCR3wnG0wc"
#define DATABASE_URL "https://timbangan-ae018-default-rtdb.firebaseio.com/"
#define LEGACY_TOKEN "svzBUSZ6M8ANPs1uGuI4sxNeU2MLq3pEaDiYalgB"

FirebaseData fbdo;
FirebaseAuth auth;
FirebaseConfig config;

// === SENSOR BERAT ===
const int HX711_dout = 23;
const int HX711_sck = 4;
HX711_ADC LoadCell(HX711_dout, HX711_sck);

// === SENSOR ULTRASONIK ===
#define TRIG_PIN 5
#define ECHO_PIN 18

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int calVal_eepromAdress = 0;
unsigned long t = 0;
float calibrationFactor = 21.69;
long customOffset = 0;

#define NUM_SAMPLES 5
float beratBuffer[NUM_SAMPLES];
int bufferIndex = 0;
bool isWeightLocked = false;

float getSmoothedWeight(float newReading) {
  beratBuffer[bufferIndex] = newReading;
  bufferIndex = (bufferIndex + 1) % NUM_SAMPLES;
  float total = 0;
  for (int i = 0; i < NUM_SAMPLES; i++) {
    total += beratBuffer[i];
  }
  return total / NUM_SAMPLES;
}

long readDistanceCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH, 30000); // timeout 30ms
  long distance = duration * 0.034 / 2;
  return distance;
}

double hitungBMI(double berat, double tinggi) {
  if (tinggi == 0) return 0;
  double tinggiMeter = tinggi / 100.0; // Konversi tinggi ke meter
  return berat / (tinggiMeter * tinggiMeter); // Rumus BMI
}

String kategoriBMI(double bmi) {
  if (bmi < 18.5) return "Kurus";
  if (bmi <= 24.9) return "Normal";
  if (bmi <= 29.9) return "Berlebih";
  return "Obesitas";
}

void setup() {
  Serial.begin(115200);
  Serial.println("Memulai...");

  // Inisialisasi pin ultrasonik
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  // LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Menghubungkan...");

  // WiFi
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  unsigned long start = millis();
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    if (millis() - start > 20000) {
      Serial.println("Gagal Koneksi WiFi!");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Gagal WiFi");
      return;
    }
  }
  Serial.println("WiFi Terhubung!");
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("WiFi Terhubung");

  // Firebase
  config.api_key = API_KEY;
  config.database_url = DATABASE_URL;
  config.signer.tokens.legacy_token = LEGACY_TOKEN;
  Firebase.begin(&config, &auth);
  Firebase.reconnectWiFi(true);

  // LoadCell
  LoadCell.begin();
  unsigned long stabilizingtime = 2000;
  boolean _tare = true;
  LoadCell.start(stabilizingtime, _tare);
  if (LoadCell.getTareTimeoutFlag() || LoadCell.getSignalTimeoutFlag()) {
    Serial.println("Timeout HX711");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("HX711 Error");
    while (1);
  }
  LoadCell.setCalFactor(calibrationFactor);
  while (!LoadCell.update());
}
void loop() {
  static boolean newDataReady = 0;
  const int serialPrintInterval = 3000;

  if (LoadCell.update()) newDataReady = true;

  if (newDataReady && millis() > t + serialPrintInterval && Firebase.ready()) {
    // ====== BACA BERAT ======
    float berat = LoadCell.getData();
    if (berat < 0) berat = 0;
    float beratKg = berat / 1000.0;
    float rataRataBerat = getSmoothedWeight(beratKg);
    if (!isWeightLocked && abs(rataRataBerat - beratKg) < 0.1) {
      isWeightLocked = true;
    }

      // ====== BACA TINGGI DARI ULTRASONIK ======
      long jarak = readDistanceCM();  // cm
      float tinggi = 201.0 - jarak;
      if (jarak > 201                                                            || tinggi < 0) {
        tinggi = 0;
      }

    // ====== HITUNG BMI ======
    double bmi = hitungBMI(rataRataBerat, tinggi);

    // ====== TAMPILKAN DI LCD ======
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("B: ");
    lcd.print(rataRataBerat, 1);
    lcd.print("kg T: ");
    lcd.print(tinggi, 0);
    lcd.print("cm");

    lcd.setCursor(0, 1);
    char output[10];
    dtostrf(bmi, 4, 1, output);  // Convert to string with 1 decimal point
    lcd.print("BMI: ");
    lcd.print(output);  // Display BMI on LCD

    Serial.printf("Berat: %.2f kg | Tinggi: %.0f cm (Jarak: %ld cm) | BMI: %.1f\n", rataRataBerat, tinggi, jarak, bmi);

    // ====== KIRIM KE FIREBASE ======
    Firebase.RTDB.setFloat(&fbdo, "/sensor/berat", rataRataBerat);
    Firebase.RTDB.setFloat(&fbdo, "/sensor/tinggi", tinggi);
    Firebase.RTDB.setFloat(&fbdo, "/sensor/bmi", bmi);  // Kirim BMI ke Firebase

    newDataReady = 0;
    t = millis();
  }

  if (Serial.available() > 0) {
    char inByte = Serial.read();
    if (inByte == 't') LoadCell.tareNoDelay();
    else if (inByte == 'r') calibrate();
    else if (inByte == 'c') changeSavedCalFactor();
  }

  if (LoadCell.getTareStatus() == true) {
    Serial.println("Tare complete");
  }
}

void calibrate() {
  Serial.println("* Start calibration... Kirim 't' untuk tare");
}

void changeSavedCalFactor() {
  float oldVal = LoadCell.getCalFactor();
  boolean _resume = false;
  Serial.print("Current: "); Serial.println(oldVal);
  Serial.println("Kirim nilai baru:");
  float newVal;
  while (!_resume) {
    if (Serial.available() > 0) {
      newVal = Serial.parseFloat();
      if (newVal != 0) {
        LoadCell.setCalFactor(newVal);
        _resume = true;
      }
    }
  }

  _resume = false;
  Serial.println("Simpan ke EEPROM? y/n");
  while (!_resume) {
    if (Serial.available() > 0) {
      char inByte = Serial.read();
      if (inByte == 'y') {
        EEPROM.begin(512);
        EEPROM.put(calVal_eepromAdress, newVal);
        EEPROM.commit();
        Serial.println("Disimpan.");
        _resume = true;
      } else if (inByte == 'n') {
        Serial.println("Tidak disimpan.");
        _resume = true;
      }
    }
  }
}