// Define the number of tasks
#define NUM_TASKS 3

// Define task state
typedef void (*Task)();
Task tasks[NUM_TASKS];  // Array to hold tasks
int currentTask = 0;    // Index of the currently running task

// Task 1: Blink LED on pin 13
void task1() {
  static unsigned long lastRun = 0;
  unsigned long now = millis();
  if (now - lastRun >= 500) {  // Task runs every 500ms
    lastRun = now;
    digitalWrite(13, !digitalRead(13));  // Toggle LED
    Serial.println("Task 1: Toggling LED");
  }
}

// Task 2: Print a message every 1 second
void task2() {
  static unsigned long lastRun = 0;
  unsigned long now = millis();
  if (now - lastRun >= 1000) {  // Task runs every 1000ms
    lastRun = now;
    Serial.println("Task 2: Printing message");
  }
}

// Task 3: Check a button press (on pin 2)
void task3() {
  static unsigned long lastRun = 0;
  unsigned long now = millis();
  if (now - lastRun >= 200) {  // Task runs every 200ms
    lastRun = now;
    if (digitalRead(2) == HIGH) {  // Assuming active LOW button
      Serial.println("Task 3: Button Pressed");
    }
  }
}

// Function to switch tasks (round-robin)
void switchTask() {
  currentTask++;
  if (currentTask >= NUM_TASKS) {
    currentTask = 0;
  }
}

// Scheduler loop that calls the current task
void scheduler() {
  tasks[currentTask]();
  switchTask();
}

void setup() {
  Serial.begin(9600);

  // Initialize hardware
  pinMode(13, OUTPUT);  // LED pin
  pinMode(2, INPUT);  // Button pin

  // Register tasks
  tasks[0] = task1;
  tasks[1] = task2;
  tasks[2] = task3;
}

void loop() {
  scheduler();  // Run the scheduler in the main loop
}