#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

#define SWPIN 4

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


//#define AIN 34
#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
bool finish = 0;  // finish flag
bool start = 0;  // start flag
bool printed = 0;  // print flag

int pixel_idx = 0;  // pixel index

void setup() {
  // put your setup code here, to run once:
  pinMode(SWPIN, INPUT_PULLUP);
  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 
  //avalue = analogRead(AIN);  // 0 - 4095
  // Serial.println(avalue);
  if (digitalRead(SWPIN))   {
    if (speed != 0)   {
      speed -= random(3,5);
      if (speed<2.0)  {
        speed = 0;
        finish = 1;
        direction = !direction; // switch direction for next time
      }
    }
  }
  else   {
    clear_pixel(pixel_idx);
    speed = 100;
    finish = 0;
    printed = 0;
  }

  if (!finish)  {
    if (direction)  {
      pixel_idx--;
      if (pixel_idx<0) pixel_idx = 23;
    }  else {
      pixel_idx++;
      if (pixel_idx>24) pixel_idx = 0;      
    }
  }
  else   {
    if (!printed)   {
      Serial.print("Lucky number = ");
      Serial.println(pixel_idx);
      printed = 1;
    }
  }
  // if (rotate)   {
  //   if (avalue > MID_AVAL)   {
  //     direction = 0;
  //     speed = (float)(avalue-MID_AVAL)/20; 
  //     pixel_idx++;
  //     if (pixel_idx>24) pixel_idx = 0;
  //   } else   {
  //     direction = 1;
  //     speed = (float)(MID_AVAL - avalue)/20;
  //     pixel_idx--;
  //     if (pixel_idx<0) pixel_idx = 23;
  //   }  
  set_color_pixel(pixel_idx);  // display pixel

  // if (abs(MID_AVAL-avalue)<20)  {
  //   rotate = 0;  // stop rotation around zero speed cmd
  // }  else   {
  //   rotate = 1;
  // }
  // Serial.println(rotate);
  // Serial.print("Speed = ");
  // Serial.println(speed);
  // Serial.print("Direction = ");
  // Serial.println(direction);
  oled_display();
  delay((int)(1000 - 9.9*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) {
    oled.setCursor(0,40);
    oled.print("Lucky number = ");
    oled.println(pixel_idx);
  }
  oled.display();

}