#include <NeoPixelBus.h>

#define DOUBLE_SIDE 0
#define DOUBLE_SIDE_MIRROR 0
#define IMAGE_HEIGHT (7)
#define IMAGE_WIDTH (48)
#define N_ROT_SLICES (48)
#define WS_PIN (8)
#define WS_VCC (9)
#define WS_GND (7)
#define HALL_PIN (2)

static const RgbColor off(0,0,0);


#if DOUBLE_SIDE
#define WS_PIXEL_COUNT (2*IMAGE_HEIGHT)
#else
#define WS_PIXEL_COUNT (IMAGE_HEIGHT)
#endif


#define IMAGE_FAIRYDUST
//#define IMAGE_CYBER

#ifdef IMAGE_CYBER

#define SKEW_RATE (0)

static const __restrict__ RgbColor PALETTE[] = {
  RgbColor(0,0,0),  // black
  RgbColor(20,20,0)  // yellow
};

static const __restrict__ uint8_t IMAGE[IMAGE_WIDTH][IMAGE_HEIGHT] = {
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,0,1,0,0,1},
  {1,0,1,0,1,1,1},
  {1,0,0,0,0,0,1},
  {1,1,1,1,1,1,1},
  {1,0,1,0,1,0,1},
  {1,0,1,0,1,0,1},
  {1,0,0,0,0,0,1},
  {1,1,1,1,1,1,1},
  {1,1,0,1,0,1,1},
  {1,0,1,0,1,0,1},
  {1,0,0,0,0,0,1},
  {1,1,1,1,1,1,1},
  {1,0,0,1,1,1,1},
  {1,1,1,0,0,0,1},
  {1,0,0,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,0,1,1,1,0,1},
  {1,0,1,1,1,0,1},
  {1,1,0,0,0,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1},
  {1,1,1,1,1,1,1}
};

#elif defined(IMAGE_FAIRYDUST)

#define SKEW_RATE (100)

static const RgbColor PALETTE[] = {
  RgbColor(0,0,0),  // black
  RgbColor(0,128,0),  // green
  RgbColor(255,180,0),  // orange
  RgbColor(255,0,0)  // red
};

static const __restrict__ uint8_t IMAGE[IMAGE_WIDTH][IMAGE_HEIGHT] = {
  {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},
  {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},
  {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},
  
  {0,0,0,0,0,0,0},
  {0,0,0,1,0,0,0},
  {0,0,1,2,1,0,0},
  {0,1,2,1,1,1,0},
  {0,1,2,1,1,1,0},
  {1,2,2,2,1,1,1},
  {1,2,2,2,1,1,1},
  {0,1,2,1,1,1,0},
  {0,1,2,1,1,1,0},
  {0,0,1,2,1,0,0},
  {0,1,0,1,0,1,0},
  {1,1,0,3,0,1,1},
  {1,1,3,3,3,1,1},
  {1,0,3,3,3,0,1},
  {0,0,0,3,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0},
  {0,0,0,0,0,0,0}
};

#endif

static NeoPixelBus<NeoGrbFeature, Neo800KbpsMethod> ws2812(WS_PIXEL_COUNT, WS_PIN);

static volatile uint32_t last_hall = 0UL;
static volatile uint32_t last_hall_diff = 1000UL;

#if SKEW_RATE
static uint16_t skew = 0U;
static uint32_t last_skew = 0UL;
#endif

void update_hall_timestamp() {
  uint32_t now = millis();
  last_hall_diff = now - last_hall;
  last_hall = now;
}

void setup() {
  // Setup output pins
  pinMode(WS_PIN, OUTPUT);
  pinMode(HALL_PIN, INPUT);
  // Setup power supply for WS2812 strip
  // (Yes, I know I shouldn't supply power from the Arduino I/O pins,
  // but I'm running the LEDs at a fraction of their max power draw)
  pinMode(WS_VCC, OUTPUT);
  pinMode(WS_GND, OUTPUT);
  digitalWrite(WS_VCC, HIGH);
  digitalWrite(WS_GND, LOW);
  // Setup WS2812 strup
  ws2812.Begin();
  ws2812.Show();
  // Setup hall sensor interrupt
  attachInterrupt(
    digitalPinToInterrupt(HALL_PIN),
    update_hall_timestamp,
    FALLING
  );
}

void loop() {
  // Get the current time
  uint32_t now = millis();
  // Turn the LEDs off if no sensor input was received for 3s
  if ((now - last_hall) > 3000UL) {
    for (size_t i = 0; i < IMAGE_HEIGHT; ++i) {
      ws2812.SetPixelColor(i, off);
#if DOUBLE_SIDE
      ws2812.SetPixelColor(IMAGE_HEIGHT + i, off);
#endif
    }
    ws2812.Show();
    // Only re-check after a second
    delay(1000);
    return;
  }

  // Get the slice to show at the current time, based on the time between the last two sensor events
  uint16_t slice = (uint16_t) (((now - last_hall) * N_ROT_SLICES / last_hall_diff) % N_ROT_SLICES);
#if SKEW_RATE
  // Increment the skew offset when it's time for the next skew step
  if (now - last_skew > SKEW_RATE) {
    skew = (skew + 1) % N_ROT_SLICES;
    last_skew = now;
  }
  // Add the current skew offset to the slice index
  slice = (uint16_t) ((slice + skew) % N_ROT_SLICES);
#endif

  // Display the current slice (row) of the image
  for (size_t i = 0; i < IMAGE_HEIGHT; ++i) {
    ws2812.SetPixelColor(i, PALETTE[IMAGE[slice][i]]);
#if DOUBLE_SIDE
#if DOUBLE_SIDE_MIRROR
    ws2812.SetPixelColor(IMAGE_HEIGHT+i, PALETTE[IMAGE[N_ROT_SLICES-slice][i]]);
#else
    ws2812.SetPixelColor(IMAGE_HEIGHT+i, PALETTE[IMAGE[slice][i]]);
#endif
#endif
  }
  ws2812.Show();
}