#include <Arduino.h>

#define LED_BLINK   D10
#define LED_BUTTON  D11
#define LED_FIBO    D12

#define BUTTON_PIN  A3

int fibIndex = 1;

// =====================================================
// FIBONACCI
// =====================================================

unsigned long fibonacci(int n) {

  if (n <= 1)
    return n;

  unsigned long a = 0;
  unsigned long b = 1;
  unsigned long c;

  for (int i = 2; i <= n; i++) {
    c = a + b;
    a = b;
    b = c;
  }

  return b;
}

// =====================================================
// TIMING VARIABLES
// =====================================================

unsigned long lastBlink = 0;
unsigned long lastFibo = 0;

bool blinkState = false;

// =====================================================
// SETUP
// =====================================================

void setup() {

  Serial.begin(115200);

  pinMode(LED_BLINK, OUTPUT);
  pinMode(LED_BUTTON, OUTPUT);
  pinMode(LED_FIBO, OUTPUT);

  pinMode(BUTTON_PIN, INPUT_PULLUP);
}

// =====================================================
// LOOP (ALL TASK IN ONE LOOP)
// =====================================================

void loop() {

  unsigned long now = millis();

  // =====================================================
  // 1. LED BLINK 1 Hz
  // =====================================================
  if (now - lastBlink >= 500) {

    lastBlink = now;

    blinkState = !blinkState;
    digitalWrite(LED_BLINK, blinkState);
  }

  // =====================================================
  // 2. BUTTON LED
  // =====================================================
  if (digitalRead(BUTTON_PIN) == LOW) {
    digitalWrite(LED_BUTTON, HIGH);
  } else {
    digitalWrite(LED_BUTTON, LOW);
  }

  // =====================================================
  // 3. FIBONACCI TASK (0.1 detik)
  // =====================================================
  if (now - lastFibo >= 100) {

    lastFibo = now;

    digitalWrite(LED_FIBO, LOW);

    unsigned long startTime = micros();

    unsigned long result = fibonacci(fibIndex);

    unsigned long endTime = micros();

    // =================================================
    // PULSE LED FIBO (SOLUSI SETARA RTOS VERSION)
    // =================================================
    digitalWrite(LED_FIBO, HIGH);
    delay(30);
    digitalWrite(LED_FIBO, LOW);

    // =================================================
    // SERIAL OUTPUT
    // =================================================
    Serial.print("Fib(");
    Serial.print(fibIndex);
    Serial.print(") = ");
    Serial.print(result);

    Serial.print(" | Time = ");
    Serial.print(endTime - startTime);
    Serial.println(" us");

    fibIndex++;

    if (fibIndex > 45)
      fibIndex = 1;
  }
}