#include <avr/interrupt.h>
#include <avr/io.h> //include to get access to port defenitions
#include <Robostix.h>
#include <timer0.h>
#include <led.h>

/* Definitions and globals */
typedef enum { SCROLLING, MORSE_CODE } Mode;
Mode led_mode;
int num_passes;
ticks_t next_event;

// Scrolling
int scroll_count;
#define SCROLL_PASSES 2
#define SCROLL_LED_DELAY 15
#define SCROLL_SPACE_DELAY 3

// Morse code
typedef enum {DASH, DOT, SPACE} MorseState;

#define MORSE_SYMBOL_DELAY 35
#define MORSE_INTRA_CHAR_DELAY 25

#define MORSE_PASSES 2
#define NUM_MORSE_STATES 18
MorseState three_four_nine[NUM_MORSE_STATES] =
  {DOT, DOT, DOT, DASH, DASH, SPACE,
   DOT, DOT, DOT, DOT, DASH, SPACE,
   DASH, DASH, DASH, DASH, DOT, SPACE};
int morse_count;

typedef enum {SYMBOL, INTRACHAR} MorseMode;
MorseMode morse_mode;

/* Prototypes */
void timer_handler(ticks_t ticks);
void update_next_event(ticks_t ticks, ticks_t delay);
void display_morse(MorseState m);

void display_morse(MorseState m) {
  switch (m) {
  case DOT:
    LED_OFF(RED);
    LED_ON(BLUE);
    LED_OFF(YELLOW);
    break;
  case DASH:
    LED_ON(RED);
    LED_ON(BLUE);
    LED_ON(YELLOW);
    break;
  case SPACE:
    leds_off();
    break;
  }
}

void update_next_event(ticks_t ticks, ticks_t delay) {
  next_event = ticks + delay;
}

void timer_handler(ticks_t ticks) {
  if (ticks == next_event) {
    switch (led_mode) {
    case SCROLLING:
      leds_off();

      switch (scroll_count) {
      case 0:
	LED_ON(RED);
	update_next_event(ticks, SCROLL_LED_DELAY);
	break;
      case 2:
	LED_ON(BLUE);
	update_next_event(ticks, SCROLL_LED_DELAY);
	break;
      case 4:
	LED_ON(YELLOW);
	update_next_event(ticks, SCROLL_LED_DELAY);
	break;
      case 6:
	LED_ON(RED);
	update_next_event(ticks, SCROLL_LED_DELAY);
	break;
      default:
	update_next_event(ticks, SCROLL_SPACE_DELAY);
	break;
      }

      scroll_count++;

      if (scroll_count > 7) {
	scroll_count = 0;

	num_passes++;
	if (num_passes >= SCROLL_PASSES) {
	  num_passes = 0;
	  led_mode = MORSE_CODE;
	  morse_count = 0;
	  update_next_event(ticks, SCROLL_SPACE_DELAY*10);
	}
      }
      break;

    case MORSE_CODE:
      switch (morse_mode) {
      case SYMBOL:
	display_morse(three_four_nine[morse_count]);
	morse_mode = INTRACHAR;
	update_next_event(ticks, MORSE_SYMBOL_DELAY);
	break;
      case INTRACHAR:
	leds_off();
	morse_mode = SYMBOL;
	update_next_event(ticks, MORSE_INTRA_CHAR_DELAY);
	morse_count++;
	break;
      }

      if (morse_count >= NUM_MORSE_STATES) {
	num_passes++;
	morse_count = 0;

	if (num_passes >= MORSE_PASSES) {
	  num_passes = 0;
	  led_mode = SCROLLING;
	  update_next_event(ticks, MORSE_INTRA_CHAR_DELAY*2);
	}
      }
      break;
    }
  }
}

int main(void) {
  led_init();
  init_timer0(timer_handler);

  next_event = 1;
  led_mode = SCROLLING;
  num_passes = 0;
  scroll_count = 0;
  morse_count = 0;
  morse_mode = SYMBOL;

  sei();

  while (1);
}