#include <FastLED.h>

#define LED_PIN     7
#define SENSOR1_PIN 2
#define SENSOR2_PIN 3
#define NUM_LEDS    32
#define LED_TYPE    WS2811
#define COLOR_ORDER GRB
CRGB leds[NUM_LEDS];

#define UPDATES_PER_SECOND 50

const uint8_t PROGMEM gamma8[] = {
  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  1,  1,
  1,  1,  1,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  2,  2,  2,
  2,  3,  3,  3,  3,  3,  3,  3,  4,  4,  4,  4,  4,  5,  5,  5,
  5,  6,  6,  6,  6,  7,  7,  7,  7,  8,  8,  8,  9,  9,  9, 10,
  10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16,
  17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 24, 24, 25,
  25, 26, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 34, 35, 35, 36,
  37, 38, 39, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 50,
  51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68,
  69, 70, 72, 73, 74, 75, 77, 78, 79, 81, 82, 83, 85, 86, 87, 89,
  90, 92, 93, 95, 96, 98, 99, 101, 102, 104, 105, 107, 109, 110, 112, 114,
  115, 117, 119, 120, 122, 124, 126, 127, 129, 131, 133, 135, 137, 138, 140, 142,
  144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 167, 169, 171, 173, 175,
  177, 180, 182, 184, 186, 189, 191, 193, 196, 198, 200, 203, 205, 208, 210, 213,
  215, 218, 220, 223, 225, 228, 231, 233, 236, 239, 241, 244, 247, 249, 252, 255
};

const CHSV hsv_colour = CHSV(25, 2, 200);


void setup() {
  Serial.begin(115200);
  //FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS).setCorrection( 0xFF7040 );

  pinMode(SENSOR1_PIN, INPUT);
  pinMode(SENSOR2_PIN, INPUT);

}


// how quickly the gradient moves along the strip, in 1/256ths of a pixel per frame
int16_t gradientspeed;// = 0;
// position of gradient at power up
static int32_t gradientval;// = 0;

void loop()
{
  static int8_t state;
  static int8_t oldState;

  // smaller numbers give wider gradients
  uint16_t gradientslope = 1800;

  if ((gradientval < 65536 + NUM_LEDS * gradientslope) && gradientval > -1) {
    // accumulate the gradient along the strip of LEDs
    int32_t ledval = gradientval;
    for (uint16_t ledno = 0; ledno < NUM_LEDS; ledno++) {
      // clamp the brightness to the range 0-255
      uint8_t brightness = 0;
      if (ledval > 0) {
        brightness = ledval < 65536 ? ledval / 256 : 255;
      }
      uint8_t currentLed = (state == -1 || (state == 0 && oldState == 1)) ? NUM_LEDS - ledno - 1 : (state == 1 || (state == 0 && oldState == -1)) ? ledno : ledno;
      // set this LED to the chosen colour for this point on the gradient
      leds[currentLed] = CHSV(hsv_colour.h, hsv_colour.s, pgm_read_byte(&gamma8[brightness]));
      // move to next position in the gradient
      ledval -= gradientslope;
    }
    // move the gradient by some amount
    gradientval += gradientspeed;
  }

  if (digitalRead(SENSOR1_PIN)) {
    if (state != 1) {
      if (state == 0) {
        gradientval = 0;
        gradientspeed = 150;
      }

      state = 1;
    }
  }

  else if (digitalRead(SENSOR2_PIN)) {
    if (state != -1) {
      if (state == 0) {
        gradientval = 0;
        gradientspeed = 150;
      }

      state = -1;
    }

  } else {
    if (state != 0) {
      gradientspeed = -150;

      oldState = state;
      state = 0;
    }

    gradientval = constrain(gradientval--, 0, 65536 + NUM_LEDS * gradientslope);
  }

  FastLED.show();
}