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

LiquidCrystal_I2C lcd(0x27, 16, 2);
HX711 scale;

// Pin
#define DT 4
#define SCK 5
#define TRIG 6
#define ECHO 7
#define BTN_NEXT 8
#define BTN_OK   9
#define BUZZ 11

int gender = 0;
int usia = 1;
float berat, tinggi;

// ambang aktifasi
const float BEBAN_MIN = 0.1;  // 100 gram

void setup() {
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(BTN_NEXT, INPUT_PULLUP);
  pinMode(BTN_OK, INPUT_PULLUP);
  pinMode(BUZZ, OUTPUT);

  scale.begin(DT, SCK);
  scale.set_scale(2150.f);
  scale.tare();

  lcd.init();
  lcd.noBacklight();   // LCD awal kondisi mati
  lcd.clear();
}

float bacaTinggi() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(5);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  long dur = pulseIn(ECHO, HIGH);
  return dur * 0.034 / 2;
}

void buzzerNormal(){
  for(int i=0;i<2;i++){
    tone(BUZZ,1000); delay(200);
    noTone(BUZZ); delay(200);
  }
}

void buzzerBahaya(){
  tone(BUZZ, 1000); delay(2000);
  noTone(BUZZ);
}

void tungguAdaBayi() {
  // LCD dimatikan
  lcd.noBacklight();
  lcd.clear();

  // Tunggu sampai berat >= 100 gram
  while (scale.get_units(5) < BEBAN_MIN) {
    delay(50);
  }

  lcd.backlight();
}

void loop() {

  // ==========================
  // WAIT FOR BABY (LCD OFF)
  // ==========================
  tungguAdaBayi();

  // ==========================
  // PILIH GENDER
  // ==========================
  lcd.clear();
  lcd.setCursor(0,0); lcd.print("Pilih Gender");

  while (digitalRead(BTN_OK) == HIGH) {
    if (digitalRead(BTN_NEXT) == LOW) {
      gender = !gender;
      delay(250);
    }
    lcd.setCursor(0,1);
    lcd.print(gender == 0 ? "Laki-laki   " : "Perempuan  ");
  }
  delay(300);

  // ==========================
  // PILIH USIA
  // ==========================
  lcd.clear();
  lcd.setCursor(0,0); lcd.print("Pilih Usia");

  while (digitalRead(BTN_OK) == HIGH) {
    if (digitalRead(BTN_NEXT) == LOW) {
      usia++;
      if (usia > 24) usia = 1;
      delay(250);
    }
    lcd.setCursor(0,1);
    lcd.print("Usia: ");
    lcd.print(usia);
    lcd.print(" bln ");
  }
  delay(300);

  // ==========================
  // BACA SENSOR
  // ==========================
  berat = scale.get_units(10);
  tinggi = bacaTinggi();

  lcd.clear();
  lcd.setCursor(0,0); lcd.print("BB:");
  lcd.print(berat,1); lcd.print("kg");

  lcd.setCursor(0,1); lcd.print("TB:");
  lcd.print(tinggi,1); lcd.print("cm");

  delay(1500);

  // ==========================
  // DIAGNOSE
  // ==========================
  float bb_min = 3;
  float bb_max = 10;
  float tb_min = 40;
  float tb_max = 100;

  lcd.clear();
  lcd.setCursor(0,0);

  if(berat>=bb_min && berat<=bb_max && tinggi>=tb_min && tinggi<=tb_max){
    lcd.print("Status NORMAL");
    buzzerNormal();
  }
  else if(berat < bb_min){
    lcd.print("Under/Stunting");
    buzzerBahaya();
  }
  else{
    lcd.print("Over/Obesitas");
    buzzerBahaya();
  }

  delay(2000);

  // ==========================
  // TUNGGU BAYI DIANGKAT
  // ==========================
  while (scale.get_units(5) >= BEBAN_MIN) {
    delay(100);
  }

  // LCD mati lagi → standby
  lcd.noBacklight();
  lcd.clear();
}