// https://forum.arduino.cc/t/search-and-destroy-bomb-prop-for-paintball/1130728
// https://wokwi.com/projects/365754412965833729

# define disarmButton   2
# define armButton      3

# define disarmedLED    5
# define armedLED       6

# define boomLED        7

void setup() {
  Serial.begin(115200);
  Serial.println("Hello Search and Destroy World!\n");

  pinMode(armButton, INPUT_PULLUP);
  pinMode(disarmButton, INPUT_PULLUP);

  pinMode(armedLED, OUTPUT);
  pinMode(disarmedLED, OUTPUT);
}

enum {DISARMED, ARMED, BOOM};

unsigned char state = DISARMED;

# define RATE           100     // every 100 milliseconds

// life too short timing constants. adjust to taste (and tolerance)
# define TOARM          50      // 50 ticks is 5 seconds
# define TODISARM       50      // 5 seconds
# define TOBOOM         200     // 10 seconds

unsigned char armCount;
unsigned char disarmCount;
unsigned char boomCount;

unsigned long now;

void loop() {
  now = millis();   // time for all machines

  handleDevice();
  report();
}

void handleDevice()
{
// RATE mechanism
  static unsigned long lastTime;
  if (now - lastTime < RATE) return;    // not time yet to do any of the rest of this
  lastTime = now;

// INPUT
  unsigned char armIt = !digitalRead(armButton);
  unsigned char disarmIt = !digitalRead(disarmButton);

// PROCESS
  switch (state) {
  case DISARMED :
    disarmCount = 0;    // nephew presses all the button at once - who does that IRL?
    if (armIt) armCount++;
    else armCount = 0;

    if (armCount == TOARM) state = ARMED;
    break;

  case ARMED :
    armCount = 0;    // nephews, who needs them?
    if (disarmIt) disarmCount++;
    else disarmCount = 0;

    boomCount++;

    if (boomCount == TOBOOM) state = BOOM;
    if (disarmCount == TODISARM) {
      state = DISARMED;
      boomCount = 0;
    }

    break;

  case BOOM :
// boom is end of the world. no further state transitions
    break;
  }

// OUTPUT
  switch (state) {
  case DISARMED :
    digitalWrite(armedLED, LOW);
    digitalWrite(disarmedLED, HIGH);
    break;

  case ARMED :
    digitalWrite(armedLED, HIGH);
    digitalWrite(disarmedLED, LOW);
    break;

  case BOOM :
    digitalWrite(armedLED, LOW);
    digitalWrite(disarmedLED, LOW);

    digitalWrite(boomLED, HIGH);
    break;
  }
}

void report()
{
  static unsigned long lastTime;
  unsigned long now = millis();

  if (now - lastTime < 777) return;    // not time yet to do any of the rest of this
  lastTime = now;
 
  Serial.print("arm count "); Serial.println(armCount);
  Serial.print("disarm count "); Serial.println(disarmCount);
  Serial.print("boom count "); Serial.println(boomCount);
  Serial.println();
}