#include <FastLED.h>

#define NUM_LEDS 50
#define DATA_PIN 4
#define INTR_PIN 2
#define VIZUALIZATIONS 3

CRGB pixels[NUM_LEDS];
unsigned char offset = 0;
void (*viz[VIZUALIZATIONS])(unsigned char);
volatile unsigned char currentViz = 0;

void sineRed(unsigned char offset)
{
	for (unsigned char i = 0; i < NUM_LEDS; i++)
		pixels[(i + offset) % NUM_LEDS] = CRGB(128 + floor(127 * sin(
		        2 * 3.1415926 * i / NUM_LEDS)), 0, 0);
}
void falloffRed(unsigned char offset)
{
	// Alles aus
	memset(pixels, 0, NUM_LEDS * sizeof(CRGB));

	pixels[offset % NUM_LEDS]        = CRGB(0x0F, 0xF, 0xF);
	pixels[(offset + 1) % NUM_LEDS]  = CRGB(0x1F, 0xE, 0xE);
	pixels[(offset + 2) % NUM_LEDS]  = CRGB(0x2F, 0xD, 0xD);
	pixels[(offset + 3) % NUM_LEDS]  = CRGB(0x3F, 0xC, 0xC);
	pixels[(offset + 4) % NUM_LEDS]  = CRGB(0x4F, 0xB, 0xB);
	pixels[(offset + 5) % NUM_LEDS]  = CRGB(0x5F, 0xA, 0xA);
	pixels[(offset + 6) % NUM_LEDS]  = CRGB(0x6F, 0x9, 0x9);
	pixels[(offset + 7) % NUM_LEDS]  = CRGB(0x7F, 0x8, 0x8);
	pixels[(offset + 8) % NUM_LEDS]  = CRGB(0x8F, 0x7, 0x7);
	pixels[(offset + 9) % NUM_LEDS]  = CRGB(0x9F, 0x6, 0x6);
	pixels[(offset + 10) % NUM_LEDS] = CRGB(0xAF, 0x5, 0x5);
	pixels[(offset + 11) % NUM_LEDS] = CRGB(0xBF, 0x4, 0x4);
	pixels[(offset + 12) % NUM_LEDS] = CRGB(0xCF, 0x3, 0x3);
	pixels[(offset + 13) % NUM_LEDS] = CRGB(0xDF, 0x2, 0x2);
	pixels[(offset + 14) % NUM_LEDS] = CRGB(0xEF, 0x1, 0x1);
	pixels[(offset + 15) % NUM_LEDS] = CRGB(0xFF, 0x0, 0x0);
}

void halfSineOverlap(unsigned char offset)
{
	const unsigned char sine[NUM_LEDS] = {0, 87, 163, 220, 251, 251, 220, 163, 87};
	for (unsigned char i = 0; i < NUM_LEDS; i++)
		pixels[NUM_LEDS - i] = CRGB(sine[(i + offset) % NUM_LEDS],
		                            sine[(i + 2 * offset) % NUM_LEDS], sine[(i + 3 * offset) % NUM_LEDS]);
}

void changeViz(void)
{
	currentViz = (currentViz + 1) % VIZUALIZATIONS;
}

void setup()
{
	FastLED.addLeds<WS2812B, DATA_PIN>(pixels, NUM_LEDS);
	FastLED.setBrightness(0);
	// Alles aus
	memset(pixels, 0, NUM_LEDS * sizeof(CRGB));
	FastLED.show();

	viz[0] = &sineRed;
	viz[1] = &falloffRed;
	viz[2] = &halfSineOverlap;

	pinMode(INTR_PIN, INPUT_PULLUP);
	attachInterrupt(digitalPinToInterrupt(INTR_PIN), changeViz, FALLING);
}

void loop()
{
	unsigned char brightness = 16 + floor(239.0 * analogRead(A0) / 1024.0);
	unsigned int sleep = 100 + floor(900.0 * analogRead(A1) / 1024.0);
	(*viz[currentViz])(offset);
	FastLED.setBrightness(brightness);
	FastLED.show();
	delay(sleep);
	offset++;
}