/* Global Variables and Functions */
int led[] = {0, 1, 2, 3, 4, 5, 6}; // LED Pins
int button[] = {7, 8, 9}; // Button Pins
int ledCount = 7;
int buttonCount = 3; 
int time = 200; // Delay Time

// Turning all the LEDs on or off at once
void globalLEDState(char state) { 
  for (int i = 0; i < ledCount; i++) { 
    digitalWrite(led[i], state); 
  } 
}

// Turning LEDs on and off one by one
void sequentialLighting() {
  for (int i = 0; i < ledCount; i++) { digitalWrite(led[i], HIGH); delay(time); } // On in order
  for (int i = ledCount; i >= 0; i--) { digitalWrite(led[i], LOW); delay(time); } // Off in reverse order
}

// Alternate Blinking
void alternateBlink() { 
  for (int j = 0; j < 6; j+=1) {
    for (int i = j % 2; i < ledCount; i+=2) { digitalWrite(led[i], HIGH); }  delay(time*2);
    for (int i = j % 2; i < ledCount; i+=2) { digitalWrite(led[i], LOW); }
  }
}

/* Arduino Setup and Loop */
void setup() {
  // Setting led pins to output
  for (int i = 0; i < ledCount; i++) { pinMode(led[i], OUTPUT); }
  // Setting button pins to input
  for (int i = 0; i < buttonCount; i++) { pinMode(button[i], INPUT_PULLUP); }
}

void loop() {
  // Sequential on-off - Blue Button
  if (digitalRead(button[0]) == LOW)  { sequentialLighting(); }

  // Rapid Blinking - Green Button
  if (digitalRead(button[1]) == LOW)  {
    for (int j = 0; j < 5; j++) {
      globalLEDState(HIGH); delay(time);
      globalLEDState(LOW); delay(time);
    }
  }

  // Alternate Blinking - Yellow Button
  if (digitalRead(button[2]) == LOW) {
      alternateBlink();
      globalLEDState(LOW);
  }  
}