#define NumberInGroup 18

#define button 0

#define SEG1 5
#define SEG2 4
#define SEG3 3
#define SEG4 2

#define SEGA 6
#define SEGB 7
#define SEGC 8
#define SEGD 9
#define SEGE 10
#define SEGF 12
#define SEGG 11
#define SEGDOT 13

#define Buzzer A0

#define FPS 250 //max for millis 250Hz
#define FT 1000/(FPS*4) //Delay for each segment

int secondsCount = 0;
unsigned long previousTime = 0;
unsigned long button_timer_prev = 0;
unsigned long display_timer_prev = 0;
bool modeState = false; //false == 0, show NumberInGroup; true == 1, show timer

void updateDisplay(int);
void bin2SEG(byte);
void runStopwatch();
bool scanButton();
void doBuzz();

int main()
{
  init(); //to make millis() and other built-in functions work
  // DDRD0 - Button, PORTD0 = 0 when pressed
  // DDRD2-5 -> segments 1-4
  // SEG4-1: HIGH == OFF, LOW == ON
  // A-H: HIGH == ON, LOW == OFF
  // DDRD6-7 -> A, B
  // DDRB0-5 -> C, D, E, G, F, Dot

  pinMode(button, INPUT_PULLUP);

  pinMode(SEG1, OUTPUT);
  pinMode(SEG2, OUTPUT);
  pinMode(SEG3, OUTPUT);
  pinMode(SEG4, OUTPUT);

  digitalWrite(SEG1, HIGH);
  digitalWrite(SEG2, HIGH);
  digitalWrite(SEG3, HIGH);
  digitalWrite(SEG4, HIGH);

  pinMode(SEGA, OUTPUT);
  pinMode(SEGB, OUTPUT);
  pinMode(SEGC, OUTPUT);
  pinMode(SEGD, OUTPUT);
  pinMode(SEGE, OUTPUT);
  pinMode(SEGF, OUTPUT);
  pinMode(SEGG, OUTPUT);

  pinMode(SEGDOT, OUTPUT);
  digitalWrite(SEGDOT, LOW);

  pinMode(Buzzer, OUTPUT);
//  Serial.begin(19200);

  while(true)
  {
    if (modeState == false)
      updateDisplay(NumberInGroup);
    else if (modeState == true)
    {
      updateDisplay(secondsCount);
      runStopwatch();
    }
  }
  return 0;
}

void updateDisplay (int number)
{
  byte num[4];
  num[0] = number / 1000;
  num[1] = (number / 100) % 10;
  num[2] = (number / 10) % 10;
  num[3] = number % 10;

  digitalWrite(SEG1, HIGH);
  digitalWrite(SEG2, HIGH);
  digitalWrite(SEG3, HIGH);
  digitalWrite(SEG4, HIGH);
  for(byte i = 0; i < FPS; i++) //byte since 250 FPS max
  {
    if(number >= 1000 && ((millis() - display_timer_prev) >= FT) )
    {
      digitalWrite(SEG1, HIGH);
      digitalWrite(SEG2, HIGH);
      digitalWrite(SEG3, HIGH);
      bin2SEG(num[0]);
      digitalWrite(SEG4, LOW);
      display_timer_prev = millis();
    }
    if(number >= 100 && ((millis() - display_timer_prev) >= FT) )
    {
      digitalWrite(SEG1, HIGH);
      digitalWrite(SEG2, HIGH);
      digitalWrite(SEG4, HIGH);
      bin2SEG(num[1]);
      digitalWrite(SEG3, LOW);
      display_timer_prev = millis();
    }
    if(number >= 10 && ((millis() - display_timer_prev) >= FT) )
    {
      digitalWrite(SEG1, HIGH);
      digitalWrite(SEG3, HIGH);
      digitalWrite(SEG4, HIGH);
      bin2SEG(num[2]);
      digitalWrite(SEG2, LOW);
      display_timer_prev = millis();
    }
    if(number >= 0 && ((millis() - display_timer_prev) >= FT) )
    {
      digitalWrite(SEG2, HIGH);
      digitalWrite(SEG3, HIGH);
      digitalWrite(SEG4, HIGH);
      bin2SEG(num[3]);
      digitalWrite(SEG1, LOW);
      display_timer_prev = millis();
    }
    if (scanButton())
      break;
  }
}

void runStopwatch()
{
  if ( (millis() - previousTime) >= 1000)
  {
    secondsCount++;
//    Serial.print(secondsCount);
//    Serial.println('s');
    previousTime = millis();
  }
}

bool scanButton()
{
  if ((millis() - button_timer_prev) >= 50)
  {
    if (digitalRead(button))
    {
      modeState = modeState;
      button_timer_prev = millis();
    }
    else if (!digitalRead(button)) // button pressed -> switch modes
    {
      modeState = !modeState;
//      if (modeState == false)
//        Serial.println("Number mode");
//      else if(modeState == true)
      if(modeState)
      {
        secondsCount = 0;
        previousTime = millis();
//        Serial.println("Timer mode");
      }
      doBuzz();
      button_timer_prev = millis();
      return true; //Switched state
    }
  }
  return false; //Stays the same
}

void doBuzz()
{
  tone(Buzzer, 440, 150);
}

void bin2SEG(byte number)
{
  switch(number)
  {
    case 0:
      //ABCDEF
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, HIGH);
      digitalWrite(SEGE, HIGH);
      digitalWrite(SEGF, HIGH);
      digitalWrite(SEGG, LOW);
    break;
    case 1:
      //BC
      digitalWrite(SEGA, LOW);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, LOW);
      digitalWrite(SEGE, LOW);
      digitalWrite(SEGF, LOW);
      digitalWrite(SEGG, LOW);
    break;
    case 2:
      //ABDEG
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, LOW);
      digitalWrite(SEGD, HIGH);
      digitalWrite(SEGE, HIGH);
      digitalWrite(SEGF, LOW);
      digitalWrite(SEGG, HIGH);
    break;
    case 3:
      //ABCDG
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, HIGH);
      digitalWrite(SEGE, LOW);
      digitalWrite(SEGF, LOW);
      digitalWrite(SEGG, HIGH);
    break;
    case 4:
      //BCFG
      digitalWrite(SEGA, LOW);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, LOW);
      digitalWrite(SEGE, LOW);
      digitalWrite(SEGF, HIGH);
      digitalWrite(SEGG, HIGH);
    break;
    case 5:
      //ACDFG
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, LOW);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, HIGH);
      digitalWrite(SEGE, LOW);
      digitalWrite(SEGF, HIGH);
      digitalWrite(SEGG, HIGH);
    break;
    case 6:
      //ACDEFG
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, LOW);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, HIGH);
      digitalWrite(SEGE, HIGH);
      digitalWrite(SEGF, HIGH);
      digitalWrite(SEGG, HIGH);
    break;
    case 7:
      //ABC
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, LOW);
      digitalWrite(SEGE, LOW);
      digitalWrite(SEGF, LOW);
      digitalWrite(SEGG, LOW);
    break;
    case 8:
      //ABCDEFG
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, HIGH);
      digitalWrite(SEGE, HIGH);
      digitalWrite(SEGF, HIGH);
      digitalWrite(SEGG, HIGH);
    break;
    case 9:
      //ABCFG
      digitalWrite(SEGA, HIGH);
      digitalWrite(SEGB, HIGH);
      digitalWrite(SEGC, HIGH);
      digitalWrite(SEGD, LOW);
      digitalWrite(SEGE, LOW);
      digitalWrite(SEGF, HIGH);
      digitalWrite(SEGG, HIGH);
    break;
  }
}