/* CONSTANTS */
/* RED */
const int ledPinR = 2;
const int bttnPinR = 6;
const int cR = 0;
const int tR = 310;
/* GREEN */
const int ledPinG = 3;
const int bttnPinG = 7;
const int cG = 1;
const int tG = 415;
/* BLUE */
const int ledPinB = 4;
const int bttnPinB = 8;
const int cB = 2;
const int tB = 209;
/* YELLOW */
const int ledPinY = 5;
const int bttnPinY = 9;
const int cY = 3;
const int tY = 252;
/* TONES */
const int lose = 5;
const int toneOff = 6;
/* SPEAKER */
const int spkrPin = 11;
/* BUTTON */
const int no_bttn = 24;
const int ok_bttn = 23;
/* RNG */
int sequence [32];

/* SETUP */
void setup() {
  /* Defines outputs and inputs */
  pinMode(ledPinR, OUTPUT);
  pinMode(bttnPinR, INPUT_PULLUP);
  pinMode(ledPinG, OUTPUT);
  pinMode(bttnPinG, INPUT_PULLUP);
  pinMode(ledPinB, OUTPUT);
  pinMode(bttnPinB, INPUT_PULLUP);
  pinMode(ledPinY, OUTPUT);
  pinMode(bttnPinY, INPUT_PULLUP);
  pinMode(spkrPin, OUTPUT);
  /* Makes sure all lights are initially off */
  digitalWrite(ledPinR, HIGH);
  digitalWrite(ledPinG, HIGH);
  digitalWrite(ledPinB, HIGH);
  digitalWrite(ledPinY, HIGH);
}

/* RNG */
void fillSequence() {
  int index = 0;
  while (index < 32) {
    sequence[index] = random(4);
    index++;
  }
}

/* Initial Loop */
void loop() {
  executeSimon();
}

/* Turns on LED */
void ledOn(int color) {
  if (color == cR) {
    digitalWrite(ledPinR, LOW);
  }
  else if (color == cG) {
    digitalWrite(ledPinG, LOW);
  }
  else if (color == cB) {
    digitalWrite(ledPinB, LOW);
  }
  else if (color == cY) {
    digitalWrite(ledPinY, LOW);
  }
}

/* Turns off LED */
void ledOff(int color) {
  if (color == cR) {
    digitalWrite(ledPinR, HIGH);
  }
  else if (color == cG) {
    digitalWrite(ledPinG, HIGH);
  }
  else if (color == cB) {
    digitalWrite(ledPinB, HIGH);
  }
  else if (color == cY) {
    digitalWrite(ledPinY, HIGH);
  }
}

/* Plays the given tone */
void playTone(int givenTone) {
  if (givenTone == cR) {
    tone(spkrPin, 310);
  }
  else if (givenTone == cG) {
    tone(spkrPin, 415);
  }
  else if (givenTone == cB) {
    tone(spkrPin, 209);
  }
  else if (givenTone == cY) {
    tone(spkrPin, 252);
  }
  else if (givenTone == lose) {
    tone(spkrPin, 42);
  }
  else if (givenTone == toneOff) {
    noTone(spkrPin);
  }
}

/* Winning sequence execution */
void onWin(int color) {
  int x = 6;
  while (x>0) {
    playTone(color);
    ledOn(color);
    delay(70);
    playTone(toneOff);
    ledOff(color);
    delay(20);
    x = x - 1;
  }
}

/* Losing sequence execution */
void onLose(int color) {
  int x = 6;
  while (x>0) {
    playTone(color);
    ledOn(color);
    delay(70);
    playTone(toneOff);
    ledOff(color);
    delay(20);
    x = x - 1;
  }
}

/* Special Win Condition */
void onWinExtra(int color) {
  playTone(color);
  ledOn(color);
  delay(200);
  playTone(toneOff);
  ledOff(color);
  delay(200);
  playTone(color);
  ledOn(color);
  delay(200);
  playTone(toneOff);
  ledOff(color);
  delay(200);
  playTone(color);
  ledOn(color);
  delay(200);
  playTone(toneOff);
  ledOff(color);
  delay(200);
  ledOn(cR);
  playTone(cR);
  delay(200);
  ledOff(cR);
  playTone(cG);
  ledOn(cG);
  delay(200);
  ledOff(cG);
  ledOn(cY);
  playTone(cY);
  delay(200);
  ledOff(cY);
  ledOn(cB);
  playTone(cB);
  delay(200);
  ledOff(cB);
  playTone(toneOff);
  delay(200);
  ledOn(cY);
  ledOn(cB);
  ledOn(cR);
  ledOn(cG);
  playTone(cY);
  playTone(cR);
  playTone(cG);
  playTone(cB);
  delay(200);
  playTone(toneOff);
  ledOff(cY);
  ledOff(cB);
  ledOff(cR);
  ledOff(cG);
}

/* Special Lose Condition */
void onLoseExtra(int color) {
  playTone(color);
  ledOn(color);
  delay(200);
  playTone(toneOff);
  ledOff(color);
  delay(200);
  playTone(color);
  ledOn(color);
  delay(200);
  playTone(toneOff);
  ledOff(color);
  delay(200);
  playTone(color);
  ledOn(color);
  delay(200);
  playTone(toneOff);
  ledOff(color);
  delay(200);
  ledOn(cR);
  playTone(cR);
  ledOn(cY);
  playTone(cY);
  delay(200);
  ledOff(cR);
  ledOff(cY);
  ledOn(cG);
  playTone(cG);
  ledOn(cB);
  playTone(cB);
  delay(200);
  ledOff(cG);
  ledOff(cB);
  ledOn(cR);
  playTone(cR);
  ledOn(cY);
  playTone(cY);
  delay(200);
  ledOff(cR);
  ledOff(cY);
  ledOn(cG);
  playTone(cG);
  ledOn(cB);
  playTone(cB);
  delay(200);
  ledOff(cG);
  ledOff(cB);
  playTone(toneOff);
}

/*Returns the pressed button */
int getButton() {
  int isPressedR = digitalRead(bttnPinR);
  int isPressedG = digitalRead(bttnPinG);
  int isPressedB = digitalRead(bttnPinB);
  int isPressedY = digitalRead(bttnPinY);
  int button = no_bttn;
  if (isPressedR == LOW) {
    button = cR;
  }
  else if (isPressedG == LOW) {
    button = cG;
  }
  else if (isPressedB == LOW) {
    button = cB;
  }
  else if (isPressedY == LOW) {
    button = cY;
  }
  return button;
}

/* Attracts the player / Difficulty Screen */
int attract() {
  int button = no_bttn;
  long int oldTime = millis();
  long int newTime;
  while (button == no_bttn) {
    newTime = millis();
    if (newTime > (oldTime + 2500)) {
      ledOff(cR);
      ledOff(cB);
      ledOff(cG);
      ledOff(cY);
      oldTime = millis();
    }
    else if (newTime > (oldTime + 2000)) {
      ledOn(cG);
    }
    else if (newTime > (oldTime + 1500)) {
      ledOn(cR);
    }
    else if (newTime > (oldTime + 1000)) {
      ledOn(cB);
    }
    else if (newTime > (oldTime + 500)) {
      ledOn(cY);
    }
    button = getButton();
  }
  ledOff(cR);
  ledOff(cG);
  ledOff(cB);
  ledOff(cY);
  return button;
}

/* Correct Button Pressed Checker */
int getButtonPlay(int correctColor) {
  int button = no_bttn;
  long int startTime = millis();
  long int elapsedTime = 0;
  while (elapsedTime < 3000) {
    int buttonPress = getButton();
    if (buttonPress != no_bttn) {
      if (correctColor == buttonPress) {
        ledOn(correctColor);
        playTone(correctColor);
        while (getButton() == correctColor) {
        }
        ledOff(correctColor);
        playTone(toneOff);
        button = ok_bttn;
        break;
        }
        else {
          break;
        }
      }

    elapsedTime = millis() - startTime;
    }
  return button;
}

/* Plays the LED that gradually speeds up */
void ledPlay(int color, int sequence) {
  ledOn(color);
  playTone(color);
  if (sequence < 6) {
    delay(420);
  }
  else if (sequence > 5 && sequence < 14) {
    delay(320);
  }
  else if (sequence > 13) {
    delay(220);
  }
  ledOff(color);
  playTone(toneOff);
}

/* Plays the sequence in order */
void playSequence(int colorsToPlay) {
  int index = 0;
  while (index <colorsToPlay) {
    ledPlay(sequence[index], colorsToPlay);
    delay(50);
    index++;
  }
  return;
}

/* Obtains information regarding the button press of the player */
int getButtonSequence(int colorsToPlay) {
  int index = 0;
  while (index < colorsToPlay) {
    int button = getButtonPlay(sequence [index]);
    if (button == no_bttn) {
      break;
    }
    index = index + 1;
  }
  return index;
}
/* Plays the game */
void playSimon(int size) {
  int colorsToPlay = 1;
  int lastButton;
  while (colorsToPlay <= size) {
    playSequence(colorsToPlay);
    lastButton = getButtonSequence(colorsToPlay);
    if (lastButton != colorsToPlay) {
      onLoseExtra(sequence[lastButton]);
      delay(1000);
      return;
    }
    colorsToPlay++;
    delay(800);
  }
  onWinExtra(sequence[size-1]);
  delay(1000);
}

/* Skill Level */
void executeSimon() {
  int skill = attract();
  delay(1000);
  int size = (skill + 1) * 8;
  fillSequence();
  playSimon(size);
  delay(1000);
}