#include "Adafruit_ILI9341.h"
#include "Adafruit_GFX.h"
#include "SPI.h"

//#include "lib/draw.h"
void drawCircleInShells(Adafruit_ILI9341 &tft, int16_t x, int16_t y, uint16_t color, int16_t r, int16_t ri);

#define TFT_SCLK 5 // Clock line, "SCK" or "CLK"
#define TFT_MOSI 6 // Master In Slave Out, "SDI", "SDA", "SI", "DIN"
#define TFT_RST 7  // RESET
#define TFT_DC 8   // Data/Command
#define TFT_CS 9   // Chip Select
#define TFT_BL 10  // Backlight

// Cyan
// #define LIGHT GC9A01A_CYAN
// #define DARK GC9A01A_DARKCYAN

// Pink
#define GC9A01A_LIGHT_PINK 0xFC18
#define GC9A01A_PINK 0xFDB8
#define LIGHT GC9A01A_PINK
#define DARK GC9A01A_LIGHT_PINK

// Green
// #define LIGHT GC9A01A_GREEN
// #define DARK GC9A01A_DARKGREEN

// Grey
// #define LIGHT GC9A01A_LIGHTGREY
// #define DARK GC9A01A_DARKGREY

#define WHITE 0xFFFF
#define BLACK 0x0000

//Adafruit_GC9A01A tft(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST);

// Screen
#define SCREEN_DC 9
#define SCREEN_CS 10
Adafruit_ILI9341 tft = Adafruit_ILI9341(SCREEN_CS, SCREEN_DC);

void setup() {
  // Turn on backlight.
//  pinMode(TFT_BL, OUTPUT);
//  digitalWrite(TFT_BL, HIGH);

  // Initialize the display.
  tft.begin();

  // Get size.
  int w = tft.width(), h = tft.height();

  // Draw eye color.
  drawCircleDownwardsFast(tft, w / 2, h / 2, w * 0.5, DARK);
  drawCircleDownwardsFast(tft, w / 2, h / 2, w * 0.4, LIGHT);

  // Cover bottom third with black.
  tft.fillRect(0, 0.9 * h, w, h, BLACK);

  // Draw a white circle in the upper left corner.
  drawCircleInShells(tft, w / 3, h / 3, WHITE, w / 16, 0);

  // Draws a big pupil in the center.
  drawCircleDownwardsFast(tft, w / 2, h / 2, w / 8, WHITE);

  // Draw a white circle in the upper left corner.
  drawCircleInShells(tft, w * 2 / 3, h * 2 / 3, WHITE, w / 24, 0);
}

void loop(void) {
  // Get size.
  int w = tft.width(), h = tft.height();

  // Wait.
  delay(random(2000, 10000));

  // Take a random action.
  int action = random(3);
  if (action == 0) {
    // Blink upper circle.
    drawCircleInShells(tft, w / 3, h / 3, LIGHT, w / 32, w / 16);
    drawCircleInShells(tft, w / 3, h / 3, WHITE, w / 16, w / 32);
  } else if (action == 1) {
    // Blink lower circle.
    drawCircleInShells(tft, w * 2 / 3, h * 2 / 3, LIGHT, 0, w / 24);
    delay(random(50, 150));
    drawCircleInShells(tft, w * 2 / 3, h * 2 / 3, WHITE, w / 24, 0);
  } else {
    // Blink center circle.
    drawCircleDownwardsFast(tft, w / 2, h / 2, w / 8 + 1, LIGHT);
    delay(random(100, 500));
    drawCircleUpwardsFast(tft, w / 2, h / 2, w / 8, WHITE);
  }
}


void drawCircle(Adafruit_ILI9341 &tft, int16_t x0, int16_t y0, uint16_t color, int16_t r) {
  int16_t x = 0;
  int16_t y = r;

  tft.writePixel(x0, y0 + r, color);
  tft.writePixel(x0, y0 - r, color);
  tft.writePixel(x0 + r, y0, color);
  tft.writePixel(x0 - r, y0, color);

  while (x < y) {
    if (x * x + y * y >= r * r) {
      y--;
    } else {
      x++;
    }

    tft.writePixel(x0 + x, y0 + y, color);
    tft.writePixel(x0 - x, y0 + y, color);
    tft.writePixel(x0 + x, y0 - y, color);
    tft.writePixel(x0 - x, y0 - y, color);
    tft.writePixel(x0 + y, y0 + x, color);
    tft.writePixel(x0 - y, y0 + x, color);
    tft.writePixel(x0 + y, y0 - x, color);
    tft.writePixel(x0 - y, y0 - x, color);
  }
}

void drawCircleInShells(Adafruit_ILI9341 &tft, int16_t x, int16_t y,
                        uint16_t color, int16_t r, int16_t ri = 0) {
  // Draws a circle with a radius of `r`, centered at `(x, y)`, in a spiral
  // pattern, starting from radius `ri`. If `ri` is bigger than `r`, then
  // the circle will be drawn inward, resulting in an outer circle with the
  // specified color and an inner circle with the background color.
  tft.startWrite();
  if (ri > r) {
    while (ri > r) {
      drawCircle(tft, x, y, color, ri);
      ri--;
    }
  } else {
    while (ri < r) {
      drawCircle(tft, x, y, color, ri);
      ri++;
    }
  }
  tft.endWrite();
}

void drawCircleDownwardsFast(Adafruit_ILI9341 &tft, int16_t x, int16_t y,
                             int16_t r, uint16_t color) {
  tft.startWrite();
  int16_t x0 = 1;

  for (int16_t y0 = -r; y0 < 0; y0++) {
    while (x0 * x0 + y0 * y0 <= r * r) {
      x0++;
    }
    tft.writeFastHLine(x - x0, y + y0, 2 * x0, color);
  }

  for (int16_t y0 = 0; y0 < r; y0++) {
    while (x0 * x0 + y0 * y0 > r * r) {
      x0--;
    }
    tft.writeFastHLine(x - x0, y + y0, 2 * x0, color);
  }

  tft.endWrite();
}

void drawCircleUpwardsFast(Adafruit_ILI9341 &tft, int16_t x, int16_t y,
                           int16_t r, uint16_t color) {
  tft.startWrite();
  int16_t x0 = 1;

  for (int16_t y0 = r; y0 > 0; y0--) {
    while (x0 * x0 + y0 * y0 <= r * r) {
      x0++;
    }
    tft.writeFastHLine(x - x0, y + y0, 2 * x0, color);
  }

  for (int16_t y0 = 0; y0 >= -r; y0--) {
    while (x0 * x0 + y0 * y0 > r * r) {
      x0--;
    }
    tft.writeFastHLine(x - x0, y + y0, 2 * x0, color);
  }

  tft.endWrite();
}