#include <Adafruit_NeoPixel.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED width,  in pixels
#define SCREEN_HEIGHT 64 // OLED height, in pixels

// create an OLED display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);


#define AIN 4
#define NPpin 5
#define NUMPIXELS 24
Adafruit_NeoPixel NPring = Adafruit_NeoPixel(NUMPIXELS, NPpin, NEO_GRB + NEO_KHZ800);

const int MID_AVAL = 2047;
const int MAX_AVAL = 4095;
int avalue = 0;  // analog value
float speed = 0; // rotation speed 0 - 100%
bool direction = 0; // direction 0 = CW, 1 = CCW
bool rotate = 0;  // 0 = still, 1 = rotate
int pixel_idx = 0;  // pixel index
int finish = 0;

 void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  NPring.begin();
  NPring.show();  // initialize all pixels to 'off'

  // initialize OLED display with I2C address 0x3C
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }

  delay(2000);         // wait two seconds for initializing
  oled.clearDisplay(); // clear display

  oled.setTextSize(1);         // set text size
  oled.setTextColor(WHITE);    // set text color  
  // oled.setCursor(0, 2);       // set position to display (x,y)
  // oled.println("Robotronix"); // set text
  // oled.display();              // display on OLED  
}

void loop() {
  if (!finish) clear_pixel(pixel_idx);  // clear previous pixel 
  
  if(analogRead(AIN) != 0) {
    if (speed != 0) {
        speed -= 5;
        pxl_run();
        if (speed < 2) {
          speed = 0;
          finish = 1;
          direction = !direction;
          Serial.print("Lucky");
          Serial.println(pixel_idx);
        }
    }
  }else{
    clear_pixel(pixel_idx);
    speed = 100;
    pxl_run();
    finish = 0;
  }
  set_color_pixel(pixel_idx);
  oled_display();
  delay((int)(1000 - 9.7*speed)); 
}

void clear_pixel(int i)   {
  NPring.setPixelColor(i,0,0,0);
  NPring.show();
}

void set_color_pixel(int i)   {
  int rval = (int)(speed+100);
  int gval = (int)direction*2*(120 - speed);
  int bval = (int)(1-direction)*2*(120 - speed);
  NPring.setPixelColor(i, rval,gval,bval);
  NPring.show();
}

void oled_display()  {
  oled.clearDisplay();
  oled.setCursor(0,0);
  oled.print("Speed : ");
  oled.println(speed);
  oled.setCursor(0,20);
  oled.print("Dir : ");
  if (direction) oled.println("CCW");
  else oled.println("CW");
  if(finish != 0) {
    oled.setCursor(0,40);
    oled.print("Lucky : ");
    if (finish) oled.println(pixel_idx);
    else oled.println(" ");
  }
  oled.display();

}
void pxl_run()  {
  if (direction == 0) { //run in cw
    pixel_idx--;
    if (pixel_idx<0) pixel_idx = 23;
  }
  if (direction == 1) { // run in ccw
    pixel_idx++;
    if (pixel_idx>23) pixel_idx = 0;
  }
}