#include "FastLED.h"

#define NUM_STRIPS 2
#define NUM_LEDS_PER_STRIP 180

#define NUM_LEDS_PER_SQUARE 12
#define NUM_SQUARES_PER_STRIP 15

#define PIN_0 12
#define PIN_1 13

CRGB leds[NUM_STRIPS][NUM_LEDS_PER_STRIP];

void setup() {
  FastLED.addLeds<NEOPIXEL, PIN_0>(leds[0], NUM_LEDS_PER_STRIP);
  FastLED.addLeds<NEOPIXEL, PIN_1>(leds[1], NUM_LEDS_PER_STRIP);

  Serial.begin(9600);
  FastLED.show();
}

uint8_t hex;
uint8_t stored[3];

int rgb;
int led;

void loop() {
  if (Serial.available() > 0) {
    int data;
    switch (data = Serial.read()) {
      case 'r':
        resetState();
        break;
      case 'q':
        complete();
        break;
      case 'l': // end of LED
        nextLed();
        break;
      case 'n':
        nextColour();
        break;
      default:
        hex = (hex << 4) + charMap(data);
        break;
    }
  }
}

void nextColour() {
  stored[rgb++] = hex;
  hex = 0;
}

void nextLed() {
  CRGB color = CRGB(stored[0], stored[1], stored[2]);

  int strip = led / NUM_SQUARES_PER_STRIP;
  int start = (led * NUM_LEDS_PER_SQUARE) - (strip * NUM_LEDS_PER_STRIP);

  for (int i = start; i < start + NUM_LEDS_PER_SQUARE; i++) {
    leds[strip][i] = color;
  }

  led++;
  rgb = hex = 0;
}

void complete() {
  FastLED.show();
  led = rgb = hex = 0;
}

void resetState() {
  led = rgb = hex = 0;
}

uint8_t charMap(char c) {
  switch (c) {
    case '0':
      return 0;
    case '1':
      return 1;
    case '2':
      return 2;
    case '3':
      return 3;
    case '4':
      return 4;
    case '5':
      return 5;
    case '6':
      return 6;
    case '7':
      return 7;
    case '8':
      return 8;
    case '9':
      return 9;
    case 'a':
      return 10;
    case 'b':
      return 11;
    case 'c':
      return 12;
    case 'd':
      return 13;
    case 'e':
      return 14;
    case 'f':
      return 15;
    default:
      return 0;
  }
}