enum {
  IDLE,
  ALLON,
  ALLOFF,
  ZEROONE,
  ZEROTWOFOUR,
  ONETHREE,
  PROGRAMMED,
  TOGGLE1,
  TOGGLE2
} BlinkType;

int BlinkState = IDLE;

struct LEDType {
  unsigned long LastMillis = 0;
  unsigned long interval   = 500;
  boolean       isOn = false;
  boolean       letBlink = true;
  int           Pin;
};

const int NoOfLEDs = 5;

LEDType LED[NoOfLEDs];

void SetLED(int No, int State) {
  LED[No].isOn = State;
  digitalWrite(LED[No].Pin, LED[No].isOn);
}


void BlinkLedNo(int No) {
  if (LED[No].letBlink) {
    if (millis() - LED[No].LastMillis > LED[No].interval) {
      LED[No].LastMillis = millis();
      LED[No].isOn = !LED[No].isOn;
      SetLED(No, LED[No].isOn);
    }
  } else {
    if (LED[No].isOn) SetLED(No, LOW);
  }
}

void BlinkLEDs() {
  for (int i = 0; i < NoOfLEDs; i++) {
    BlinkLedNo(i);
  }
}

void AllLEDs(int Value) {
  for (int i = 0; i < NoOfLEDs; i++) {
    SetLED(i, Value);
  }
}

void StateMachine() {
  switch (BlinkState) {
    case IDLE  :
      break;
    case ALLOFF :
      AllLEDs(LOW);
      BlinkState = IDLE;
      break;
    case ALLON :
      AllLEDs(HIGH);
      BlinkState = IDLE;
      break;
    case ZEROONE :
      AllLEDs(LOW);
      SetLED(0, HIGH);
      SetLED(1, HIGH);
      BlinkState = IDLE;
      break;
    case ZEROTWOFOUR :
      AllLEDs(LOW);
      SetLED(0, HIGH);
      SetLED(2, HIGH);
      SetLED(4, HIGH);
      BlinkState = IDLE;
      break;
    case ONETHREE :
      AllLEDs(LOW);
      SetLED(1, HIGH);
      SetLED(3, HIGH);
      BlinkState = IDLE;
      break;
    case TOGGLE1 :

      break;
    case PROGRAMMED :
      BlinkLEDs();
      break;
    default : break;
  }
}

void AllowAllToBlink() {
  for (int i = 0; i < NoOfLEDs; i++ ) {
    LED[i].letBlink = true;
  };
}

void DisableToBlink(int No) {
  LED[No].letBlink = false;
}


void getSerialCommand() {
  if (Serial.available()) {
    char c = Serial.read();
    switch (c) {
      case 'A' :
        BlinkState = ALLON;
        break;
      case 'a' :
        BlinkState = ALLOFF;
        break;
      case 'P' :
        AllowAllToBlink();
        BlinkState = PROGRAMMED;
        break;
      case 'I' :
        BlinkState = IDLE;  // Leaves LED states as they are at time of key pressure
        break;
      case '0' :
        BlinkState = ZEROONE;
        break;
      case '1' :
        BlinkState = ZEROTWOFOUR;
        break;
      case '2' :
        BlinkState = ONETHREE;
        break;
      case 'T' :
        AllowAllToBlink();
        DisableToBlink(0);
        DisableToBlink(2);
        DisableToBlink(4);
        BlinkState = PROGRAMMED;
        break;
      case 't' :
        AllowAllToBlink();
        DisableToBlink(1);
        DisableToBlink(3);
        BlinkState = PROGRAMMED;
        break;
      default : break;
    }
    c = ' ';
  }

}

void setup() {
  Serial.begin(115200);
  // Just a quick initialization
  for (int i = 0; i < NoOfLEDs; i++ ) {
    LED[i].interval = 300 * (i + 1);
    LED[i].Pin = 9 + i; // Do this only in this case as 9 + 4 = 13 !!!
    pinMode(LED[i].Pin, OUTPUT);
  }
  AllLEDs(HIGH);
  delay(500);
  AllLEDs(LOW);
  Serial.println("Use keys A,a, P, I, 0, 1 ,2 , T, t on Serial to switch LED control");
}


void loop() {
  getSerialCommand();
  StateMachine();
}