#include "FastLED.h"

#define NUM_LEDS 38
#define LED_DATA_PIN 3
#define NUM_BYTES (NUM_LEDS*3) // 3 colors  

#define BRIGHTNESS 100
#define UPDATES_PER_SECOND 100

#define TIMEOUT 3000

#define MODE_ANIMATION 0
#define MODE_AMBILIGHT 1
uint8_t mode = MODE_ANIMATION;

byte MESSAGE_PREAMBLE[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09 };
uint8_t PREAMBLE_LENGTH = 10;
uint8_t current_preamble_position = 0;

unsigned long last_serial_available = -1L;

uint8_t led_counter = 0;
uint8_t byte_counter = 0;

CRGB leds[NUM_LEDS];
byte buffer[NUM_BYTES];


// Filler animation attributes
CRGBPalette16 currentPalette = RainbowColors_p;
TBlendType    currentBlending = LINEARBLEND;
uint8_t startIndex = 0;

void setup()
{
  Serial.begin(115200);
  FastLED.clear(true);
  FastLED.addLeds<WS2811, LED_DATA_PIN, GRB>(leds, NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);
}

void loop()
{
	switch (mode) {
		case MODE_ANIMATION: 
			fillLEDsFromPaletteColors();
			break;
		
		case MODE_AMBILIGHT:
			processIncomingData();
			break;
	}
	
}

void processIncomingData()
{
	if (waitForPreamble(TIMEOUT))
	{
		Serial.readBytes(buffer, NUM_BYTES);

		/* DEBUG
		for (int i = 0; i < NUM_BYTES; i++)
		{
			Serial.write((char)buffer[i]);
		}
		*/

		while (byte_counter < NUM_BYTES)
		{
			byte green = buffer[byte_counter++];
      byte blue = buffer[byte_counter++];
			byte red = buffer[byte_counter++];

			leds[led_counter++] = CRGB(red, green, blue);
		}

		FastLED.show();

		byte_counter = 0;
		led_counter = 0;
	}
	else
	{
		mode = MODE_ANIMATION;
	}
}

bool waitForPreamble(int timeout)
{
	last_serial_available = millis();
	while (current_preamble_position < PREAMBLE_LENGTH)
	{
		if (Serial.available() > 0)
		{
			last_serial_available = millis();

			if (Serial.read() == MESSAGE_PREAMBLE[current_preamble_position])
			{
				current_preamble_position++;
			}
			else
			{
				current_preamble_position = 0;
			}
		}

		if (millis() - last_serial_available > timeout)
		{
			return false;
		}
	}
	current_preamble_position = 0;
	return true;
}

void fillLEDsFromPaletteColors()
{
	startIndex++; // speed

	uint8_t colorIndex = startIndex;
	for( int i = 0; i < NUM_LEDS; i++) {
        leds[i] = ColorFromPalette(currentPalette, colorIndex, BRIGHTNESS, currentBlending);
		colorIndex += 3;
    }

	FastLED.delay(1000 / UPDATES_PER_SECOND);

	if (Serial.available() > 0)
	{
		mode = MODE_AMBILIGHT;
	}
}