/*
 * SCREENSAVER: bounces a nice little text over the screen
 */

// for some reason the OLED screen needs this timeout
setTimeout(function() {
  // offsets must be defined for correct display on screen!
  const Xoffset = 8;
  const Yoffset = 8;

  // define the function first, before using it below
  function displayText(textString, x, y) {
    // write some text
    scrn.drawString(textString, Xoffset + x, Yoffset + y);
    // write to the screen
    scrn.flip();
    // clear a bit of the screen in preparation before next update
    scrn.clearRect(Xoffset + x, Yoffset + y, Xoffset + x + 30, Yoffset + y + 8);
  }

  // MAIN: flash LED (D8)
  let on = false;
  let x = 0;
  let y = 0;
  let ix = 1;
  let iy = 1;
  const txt = 'HELLO';
  function go() {
    setInterval(function() {
      on = !on;
      digitalWrite("D8",on);
      y += iy;
      x += ix;
      if (x > (72-(txt.length*8))) ix = -ix;
      if (y > 34) iy = -iy;
      if (x < 1) ix = -ix;
      if (y < 1) iy = -iy;
      displayText(txt, x, y);
    }, 100);
  }

  //
  // required modules/libraries (in Espruino must be included at the end due to needing functions)
  //
  I2C1.setup({scl:"D6",sda:"D5"}); // I2C setup
  // initialize the screen and its dimensions (null can be replaced by a callback)
  const scrn = require("SSD1306").connect(I2C1, main, { width:72, height:48 }); // for 72x48 LCD
}, 5000);