#include <Arduino.h>
#include <U8g2lib.h>

U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(
  U8G2_R0,
  /* clock=*/ 9,
  /* data=*/ 8,
  /* reset=*/ U8X8_PIN_NONE
);

#define TOUCH_LEFT  4
#define TOUCH_RIGHT 5

const char* facts[] = {
  "Loves Gilda",
  "New To BCN",
  "From India",
  "FAB LAB Noob",
  "Loves Emotional Design",
  "Built This Board with sweat blood and tears",
  "Created Whiff",
  "Has Congenital Anosmia",
  "She/ Her/ A11y"
};

const int factCount = 8;

int currentFact = 0;
int xPos = 95;

long readTouch(int pin) {

  pinMode(pin, OUTPUT);
  digitalWrite(pin, LOW);
  delay(1);

  pinMode(pin, INPUT_PULLUP);

  long count = 0;

  while (digitalRead(pin) == LOW && count < 300) {
    count++;
  }

  return count;
}

void setup() {

  delay(1000);

  u8g2.begin();

  u8g2.setFont(u8g2_font_6x12_tf);
}

void loop() {

  long left  = readTouch(TOUCH_LEFT);
  long right = readTouch(TOUCH_RIGHT);

  bool touched =
    (left > 10) &&
    (right > 10);

  u8g2.clearBuffer();

  if (touched) {

    const char* message = facts[currentFact];

    u8g2.drawStr(xPos, 40, message);

    // speed
    xPos -= 14;

    int textWidth = strlen(message) * 6;

    // next fact
    if (xPos < -textWidth + 31) {

      currentFact++;

      if (currentFact >= factCount) {
        currentFact = 0;
      }

      xPos = 95;
    }

  } else {

    u8g2.drawStr(40, 40, "Hold Me");
  }

  u8g2.sendBuffer();

  delay(20);
}