// Thelissa Levana Zheng 00000075569

// Establish the I/O registers' memory locations.
#define DDRB_REG (*((volatile uint8_t*)0x24))  // PORTB Data Direction Register
#define PORTB_REG (*((volatile uint8_t*)0x25)) // PORTB Data Register

#define PINC_REG (*((volatile uint8_t*)0x26))  // Input Pins Register or PINC

#define LEDS_MASK 0xFF // The LED pin mask (pins 0 through 7)
#define SWITCH1_MASK 0x04 // Switch 1 mask (pin 10)
#define SWITCH2_MASK 0x02 // Switch 2 mask(pin 9)
#define SWITCH_START_MASK 0x01 // switch_start mask (pin 8)

// Function to initialize ports and pins
void setup() {
  DDRB_REG |= LEDS_MASK; // Plot LED pins as output
  PORTB_REG &= ~LEDS_MASK; // All LEDs are turn off initially

  DDRB_REG &= ~SWITCH_START_MASK; // Plot switch_start pin as input
  PORTB_REG |= SWITCH_START_MASK; // Pull-up resistor been enabled for switch_start pin

  DDRB_REG &= ~(SWITCH1_MASK | SWITCH2_MASK); // Plot switch pins as input
  PORTB_REG |= (SWITCH1_MASK | SWITCH2_MASK); // Pull-up resistors been enabled for switch pins
}

// Function to run LEDs in running mode
void runMode() {
  uint8_t ledState = 0x80; // Begin with LED at Digital Pin 7
  while (!(PINC_REG & SWITCH_START_MASK)) { // Will be done continously until switch_start is pressed
    PORTB_REG = ledState; // LED was turned on corresponding to the current state
    ledState >>= 1; // Jump to the next LED
    if (ledState == 0) // If it reached the end, it will come back from Pin 7
      ledState = 0x80;
    _delay_ms(100); // Delay for smooth transition (adjust if needed)
  }
}

// Function to run LEDs in bouncing mode
void bounceMode() {
  uint8_t ledState = 0x80; // Begin with LED at Digital Pin 7
  bool direction = true; // Direction of LED motion
  while (!(PINC_REG & SWITCH_START_MASK)) { // Will be done continously until switch_start is pressed
    PORTB_REG = ledState; // LED was turned on corresponding to the current state
    if (direction) {
      ledState >>= 1; // Jump to the next LED
      if (ledState == 0) { // If reached the end, replace the direction
        ledState = 0x02;
        direction = false;
      }
    } else {
      ledState <<= 1; // Jump to the previous LED
      if (ledState == 0x80) { // If it reached the end, replace the direction
        ledState = 0x40;
        direction = true;
      }
    }
    _delay_ms(100); // Delay for smooth transition (adjust if needed)
  }
}

void loop() {
  // Verify which mode switch is pressed
  if (!(PINC_REG & SWITCH1_MASK)) {
    runMode(); //If switch_1 was hit, then run mode
  } else if (!(PINC_REG & SWITCH2_MASK)) {
    bounceMode(); // If switch_2 is pressed, bounce mode happens
  }
}