/**
 @author Oleg Krasnov (krasnov@artlebedev.ru)
 @created 2019.01.28
 @copyright Art. Lebedev Studio (http://www.artlebedev.ru/)

 This source code follows Formatting section of Google Javascript Style Guide
 https://google.github.io/styleguide/jsguide.html#formatting
 */


/**
 * @constructor
 */
PromoUniversity = function() {
  /**
   * @type {!jQuery}
   * @private
   */
  this.root_ = jQuery('#layout');

  /**
   * @type {!jQuery}
   * @private
   */
  this.courseSection_ = this.root_.find('.course');

  /**
   * @type {!jQuery}
   * @private
   */
  this.courseDescriptionSection_ = this.root_.find('.course_description');

  /**
   * @type {!jQuery}
   * @private
   */
  this.svgText_ = this.courseDescriptionSection_.find('.item');

  /**
   * @type {!jQuery}
   * @private
   */
  this.svgTextDescription_ = this.svgText_.find('.svg_description h3');


  this.init_();
  this.attachEvents_()
};


/**
 * @private
 */
PromoUniversity.prototype.init_ = function() {
  for (var i = 0; i < this.courseSection_.length; i++) {
    new VerticalFixer(
      this.courseSection_.eq(i).find('.holder'),
      this.courseSection_.eq(i).find('.details'),
      this.courseSection_.eq(i).find('.program'),
      this.courseSection_.eq(i).find('.details'),
      30);
  }
};


/**
 * @private
 */
PromoUniversity.prototype.attachEvents_ = function() {
  var that = this;
  var prevActive = 0;
  var currentActive = 0;

  jQuery(window).scroll(function() {
    // var windowHeight = jQuery(window).height();
    var windowWidth = jQuery(window).width();
    var windowScrollTop = jQuery(window).scrollTop();

    for (var i = 0; i < that.svgText_.length; i++) {
      var svgTextTopPosition =
        that.svgText_.eq(i).offset().top - 100;

      if (windowScrollTop > svgTextTopPosition) {
        currentActive = i;

        if ((currentActive === 0 || currentActive === 1) && windowWidth > 760) {
          that.svgTextDescription_.addClass('fixed');
        } else if (currentActive === 2) {
          that.svgTextDescription_.removeClass('fixed');
        }
      } else {
        if (i === 0 && currentActive === 0) {
          that.svgTextDescription_.removeClass('fixed');
        }
      }
    }

    if (prevActive !== currentActive) {
      that.svgText_.removeClass('active');
      that.svgText_.eq(currentActive).addClass('active');
      prevActive = currentActive;
    }
  });
};


jQuery(document).ready(function() {
  new PromoUniversity();
});