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

 * Bootstrap: scrollspy.js v3.3.5

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

 * ========================================================================

 * Copyright 2011-2015 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  = '3.3.5'

  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);