/* ========================================================================

   * Bootstrap: scrollspy.js v3.3.7

   * http://getbootstrap.com/javascript/#scrollspy
   * ========================================================================

   * Copyright 2011-2016 Twitter, Inc.
   * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)

   * ======================================================================== */

  +function ($) {
    'use strict';

  
    // SCROLLSPY CLASS DEFINITION
    // ==========================
  
    function ScrollSpy(element, options) {

      this.$body          = $(document.body)
      this.$scrollElement = $(element).is(document.body) ? $(window) : $(element)

      this.options        = $.extend({}, ScrollSpy.DEFAULTS, options)

      this.selector       = (this.options.target || '') + ' .nav li > a'
      this.offsets        = []
      this.targets        = []

      this.activeTarget   = null

      this.scrollHeight   = 0

      this.$scrollElement.on('scroll.bs.scrollspy', $.proxy(this.process, this))

      this.refresh()
      this.process()
    }

    ScrollSpy.VERSION  = '3.3.7'

    ScrollSpy.DEFAULTS = {
      offset: 10
    }

    ScrollSpy.prototype.getScrollHeight = function () {
      return this.$scrollElement[0].scrollHeight || Math.max(this.$body[0].scrollHeight, document.documentElement.scrollHeight)
    }

    ScrollSpy.prototype.refresh = function () {

      var that          = this
      var offsetMethod  = 'offset'
      var offsetBase    = 0
  
      this.offsets      = []
      this.targets      = []
      this.scrollHeight = this.getScrollHeight()

      if (!$.isWindow(this.$scrollElement[0])) {
        offsetMethod = 'position'
        offsetBase   = this.$scrollElement.scrollTop()
      }

      this.$body

        .find(this.selector)
        .map(function () {
          var $el   = $(this)
          var href  = $el.data('target') || $el.attr('href')

          var $href = /^#./.test(href) && $(href)

  
          return ($href
            && $href.length

            && $href.is(':visible')
            && [[$href[offsetMethod]().top + offsetBase, href]]) || null

        })
        .sort(function (a, b) { return a[0] - b[0] })
        .each(function () {

          that.offsets.push(this[0])
          that.targets.push(this[1])

        })
    }
  
    ScrollSpy.prototype.process = function () {
      var scrollTop    = this.$scrollElement.scrollTop() + this.options.offset

      var scrollHeight = this.getScrollHeight()
      var maxScroll    = this.options.offset + scrollHeight - this.$scrollElement.height()

      var offsets      = this.offsets
      var targets      = this.targets
      var activeTarget = this.activeTarget
      var i

      if (this.scrollHeight != scrollHeight) {
        this.refresh()
      }

      if (scrollTop >= maxScroll) {

        return activeTarget != (i = targets[targets.length - 1]) && this.activate(i)
      }
  
      if (activeTarget && scrollTop < offsets[0]) {
        this.activeTarget = null
        return this.clear()

      }
  
      for (i = offsets.length; i--;) {
        activeTarget != targets[i]
          && scrollTop >= offsets[i]

          && (offsets[i + 1] === undefined || scrollTop < offsets[i + 1])
          && this.activate(targets[i])

      }
    }
  
    ScrollSpy.prototype.activate = function (target) {
      this.activeTarget = target

      this.clear()

      var selector = this.selector +
        '[data-target="' + target + '"],' +
        this.selector + '[href="' + target + '"]'

  
      var active = $(selector)
        .parents('li')
        .addClass('active')

      if (active.parent('.dropdown-menu').length) {

        active = active
          .closest('li.dropdown')
          .addClass('active')
      }
  
      active.trigger('activate.bs.scrollspy')
    }

    ScrollSpy.prototype.clear = function () {
      $(this.selector)
        .parentsUntil(this.options.target, '.active')
        .removeClass('active')
    }

  
    // SCROLLSPY PLUGIN DEFINITION
    // ===========================

    function Plugin(option) {

      return this.each(function () {
        var $this   = $(this)
        var data    = $this.data('bs.scrollspy')
        var options = typeof option == 'object' && option
  
        if (!data) $this.data('bs.scrollspy', (data = new ScrollSpy(this, options)))
        if (typeof option == 'string') data[option]()
      })
    }

    var old = $.fn.scrollspy
  
    $.fn.scrollspy             = Plugin

    $.fn.scrollspy.Constructor = ScrollSpy
  
  
    // SCROLLSPY NO CONFLICT
    // =====================
  
    $.fn.scrollspy.noConflict = function () {
      $.fn.scrollspy = old
      return this
    }
  
  
    // SCROLLSPY DATA-API
    // ==================

    $(window).on('load.bs.scrollspy.data-api', function () {

      $('[data-spy="scroll"]').each(function () {
        var $spy = $(this)

        Plugin.call($spy, $spy.data())

      })
    })
  
  }(jQuery);