/*
 * © 2009 ROBO Design
 * http://www.robodesign.ro
 */

(function () {
  if (!window.welcome_headers || !window.welcome_header) {
    return;
  }

  var file = '../images/welcome-headers/header',
      delay_fade = 50,
      delay_img = 3500,
      opacity = 1.0,
      opacity_step = 0.05;
      step = 'fadeout',
      pos = welcome_header,
      n = welcome_headers,
      header = document.getElementById('welcome-header' + pos),
      img = document.createElement('img');

  if (!header || !img) {
    return;
  }

  img.alt = '';
  img.src = file + pos + '.jpg';

  // preload the headers
  for (var i = 1, preload = []; i <= n; i++) {
    preload[i] = new Image();
    preload[i].src = file + i + '.jpg';
  }

myAddEvent(window, 'load', function () {
  header.appendChild(img);

  var timerfn = function () {
    if (opacity == 1 && step == 'fadein') {
      pos++;
      if (pos > n) {
        pos = 1;
      }
      header.style.backgroundImage = 'url("' + file + pos + '.jpg")';

      step = 'fadeout';
      setTimeout(timerfn, delay_img);

    } else {
      if (step == 'fadeout') {
        opacity -= opacity_step;
      } else {
        opacity += opacity_step;
      }
      if (opacity > 1) {
        opacity = 1;
      } else if (opacity < 0) {
        opacity = 0;
        step = 'fadein';
        img.src = file + pos + '.jpg';
      }

      if (window.RD_IE_ver && window.RD_IE_ver <= 8) {
        img.style.filter = 'alpha(opacity=' + parseInt(opacity*100) + ')';
      } else {
        img.style.opacity = opacity;
      }

      setTimeout(timerfn, delay_fade);
    }
  };

  setTimeout(timerfn, delay_fade);
});
})();