const int LEEG_DISPLAY = 1;
const int ROLLEN = 2;
const int UITROLLEN = 3;
const int TOON_WAARDE = 4;

int huidigeToestand = LEEG_DISPLAY;

const int SEQUENCES = 16;
byte LEDsequence[SEQUENCES] = { B11111100, // 0
                                B01100000, // 1
                                B11011010, // 2
                                B11110010, // 3
                                B01100110, // 4
                                B10110110, // 5
                                B10111110, // 6
                                B11100000, // 7
                                B11111110, // 8
                                B11110110, // 9
                                B11101110, // A
                                B00111110, // B
                                B10011100, // C
                                B01111010, // D
                                B10011110, // E
                                B10001110  // F
                              };

const int dataPin = 6;  // loopt naar 14 DS
const int latchPin = 8; // loopt naar 12 ST_CP
const int clockPin = 10; // loopt naar 11 SH_CP

unsigned long int previousMillis;
int INTERVAL = 1000;

void setup() {

  Serial.begin(9600);
  initializePins();
  previousMillis = 0 - INTERVAL;
  serialFlush();
}

void serialFlush() {
  while (Serial.available()  > 0)
  {
    Serial.read();
  }
}

void loop() {
  listenSerialPort();
  currentSeq();
}

void listenSerialPort() {
  if (Serial.available()) {
    checkEditInput(Serial.read());
  }
}

void initializePins() {

  pinMode(dataPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
}

void checkEditInput(char input) {
  Serial.print(input);
  switch (input) {
    case 'S':
      huidigeToestand = ROLLEN;
      loopThroughSequences();
      break;
    case 'H':
      huidigeToestand = UITROLLEN;
      loopThroughSequences();
      break;
    case 'E':
      huidigeToestand = LEEG_DISPLAY;
      turnOff();
      break;
  }
}

void currentSeq() {

  switch (huidigeToestand) {
    case LEEG_DISPLAY:
      turnOff();
      break;
    case ROLLEN:
      loopThroughSequences();
      break;
    case UITROLLEN:
      loopThroughSequences();
      break;
    case TOON_WAARDE:

      break;
  }
}

int index;

void loopThroughSequences() {

  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= INTERVAL) {
    if ( huidigeToestand == ROLLEN ) {
      int spd = -100;
      speedFix(spd);
    }

    if ( huidigeToestand == UITROLLEN | huidigeToestand == TOON_WAARDE) {
      int spd = 100;
      speedFix(spd);
      showRoll(LEDsequence[index]);
      previousMillis = 0;
    }

    myfnUpdateDisplay(LEDsequence[index]);
    index++;

    if (index >= SEQUENCES) {
      index = 0;
    }

    previousMillis = currentMillis;
  }

}

void showRoll (byte bits) {
  unsigned long currentMillis = millis();
  if ( currentMillis - previousMillis >= 3500) {
    myfnUpdateDisplay(bits);
  }
}


void speedFix(int spd) {
  if (INTERVAL + spd >= 100) {
    INTERVAL += spd;
  }
}

void turnOff() {
  INTERVAL = 1000;
  index = 0;
  int lampsOff = B00000000;
  myfnUpdateDisplay(lampsOff);
}

void myfnUpdateDisplay(byte eightBits) {

  digitalWrite(latchPin, LOW);  // prepare shift register for data
  shiftOut(dataPin, clockPin, LSBFIRST, eightBits); // send data
  digitalWrite(latchPin, HIGH); // update display
}