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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define SEED 420
#define bobSize 8
#define wait 2000


bool bob[bobSize];
unsigned int pos = 0;
unsigned int a;
unsigned int b = 12;

void setup() {
  Serial.begin(9600);
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  for (int i = 0; i < SEED; i++){
    random(64);
  }

  display.display();
  display.setTextSize(1);
  display.setTextColor(1);
  delay(200);
  display.clearDisplay();


}

void loop() {
  display.clearDisplay();
  shuffleBob();
  int d = select(bob);
  display.setCursor(80, 0);
  display.println(d);
  display.display();
  delay(wait);
  


}

void shuffleBob() {
  for (int i = 0; i < bobSize; i++) {
    bob[i] = random(2);
  }
  display.setCursor(0, 0);
  for (int i = 0; i < bobSize; i++) {
    display.print("bob item:");
    display.print(i);
    display.print(" ");
    display.println(bob[i]);
  }
}

int select(bool pow[]){
  unsigned int a = 0;
  unsigned int b = 12;
  unsigned int pos = 0;
  for (int i = 0; i < bobSize; i++) {
    if (pow[i]) {
      pos++;
    }
  }
  a = random(pos);

  for (int i = 0; i < bobSize; i++) {
    if (b == 12) {
      if (pow[i]) {
        if (a == 0) {
          b = i;
        }
        a--;
      }
    }
  }
  return b;
}