# define button1  2
# define button2  3

# define b1State  4
# define b2State  5

void setup() {
  Serial.begin(115200);
  Serial.println("\TEST\n");

  pinMode(button1, INPUT_PULLUP);
  pinMode(button2, INPUT_PULLUP);

  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
}

# define WINDOW 1000

static unsigned long counter;

void loop() {
  static unsigned char pst;
  static bool waiting;
  static unsigned long start;

  unsigned long now = millis();

  unsigned char was = pst;
  pst |= oneButtonK() ? 0x1 : 0;
  pst |= twoButtonK() ? 0x2 : 0;

  if (!was && pst) {
    start = now;
    digitalWrite(9, HIGH);
  }

  if (pst == 0x3) {
    Serial.println("both edges seen in time");

    // set act flag and reset mechanism
    pst = 0;
    digitalWrite(9, LOW);
  }
  else if (pst) {
    if (now - start > WINDOW) {
      Serial.print("          "); Serial.println(pst);
      Serial.println("t o o  s l o w");

      pst = 0;
      digitalWrite(9, LOW);
    }
  }

  delay(20);
}


void loopTHE() {
  static bool one = false;
  bool two = false;

  counter++;
  
  one |= oneButtonK();

  if (one) {
    digitalWrite(8, HIGH);
    two = twoButtonK();
    while (!two)
      two = twoButtonK();
  }
  digitalWrite(8, LOW);

  if (two) {
   Serial.println(" temporal congruence ");
   one = false;
  }

  delay(10);
}

bool oneButtonK()
{
  static bool lastButton;
  bool isPressed = false;

  digitalWrite(b1State, lastButton ? HIGH : LOW);

  bool thisButton = digitalRead(button1) == LOW;    // true = pressed
  if (lastButton != thisButton) {
    lastButton = thisButton;
    if (thisButton) isPressed = true;
  }

  return isPressed;
}

bool twoButtonK_()
{
  static bool lastButton;
  bool isPressed = false;

  digitalWrite(b2State, lastButton ? HIGH : LOW);

  bool thisButton = digitalRead(button2) == LOW;    // true = pressed
  if (lastButton != thisButton) {
    lastButton = thisButton;
    if (thisButton) isPressed = true;
  }

  return isPressed;
}

bool twoButtonK()  // delay the second button press by N loop cycles
{
  static bool buffer[8];
  static byte readI;
  static byte writeI;

  static bool lastButton;
  bool isPressed = false;

  bool thisButton = digitalRead(button2) == LOW;    // true = pressed
  if (lastButton != thisButton) {
    lastButton = thisButton;
    if (thisButton) isPressed = true;
  }

  buffer[writeI++] = isPressed;
  writeI &= 0x7;
  isPressed = buffer[readI++];
  readI &= 0x7;

  return isPressed;
}












// test fragments and functions
// test button handling
void loopTEST() {
  counter++;

  bool one = oneButtonK();
  bool two = twoButtonK();

  if (one) {
    Serial.print(counter);
    Serial.println(" [] one got pressed?");
  }

  if (two) {
    Serial.print(counter);
    Serial.println("                 two got pressed?");
  }

  delay(20);
}

void loop0() {
  bool one = digitalRead(2) == LOW;
  bool two = digitalRead(3) == LOW;

  if (one != two) Serial.println("mismatch");
}