#include <OneWire.h>
#include <DallasTemperature.h>
#include <TimerOne.h>

#define ONE_WIRE_BUS 2
#define BUFFER_SIZE 10

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

float buffer[BUFFER_SIZE];
volatile int head = 0;
volatile int tail = 0;
volatile int count = 0;

// Overflow counter
volatile int overflowCount = 0;

unsigned long lastSend = 0;

void setup() {
  Serial.begin(9600);
  sensors.begin();
  Timer1.initialize(200000);  // Interrupt setiap 200 ms
  Timer1.attachInterrupt(readTemperatureISR);
  Serial.println("System started...");
}

void loop() {
  unsigned long now = millis();

  // Simulasi sistem sibuk: buffer terus penuh
  if (now > 5000 && now < 12000) {
    // Tampilkan pesan full SECEPAT mungkin
    if (overflowCount > 0) {
      Serial.println("BUFFER FULL");
      overflowCount--;       // kurangi, sehingga muncul sering
    }
    return;
  }

  // Saat tidak sibuk, juga tampilkan overflow yg tersisa
  if (overflowCount > 0) {
    Serial.println("BUFFER FULL");
    overflowCount--;
  }

  // Kirim data tiap 1 detik
  if (now - lastSend >= 1000) {
    lastSend = now;

    if (count == 0) {
      Serial.println("Buffer empty");
    } else {
      noInterrupts();
      while (count > 0) {
        float value = buffer[tail];
        tail = (tail + 1) % BUFFER_SIZE;
        count--;
        interrupts();
        Serial.println(value);
        noInterrupts();
      }
      interrupts();
    }
  }
}

void readTemperatureISR() {
  sensors.requestTemperatures();
  float tempC = sensors.getTempCByIndex(0);

  if (count < BUFFER_SIZE) {
    buffer[head] = tempC;
    head = (head + 1) % BUFFER_SIZE;
    count++;
  } else {
    overflowCount++;  // Tambah counter setiap overflow
  }
}