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

 * bootstrap-scrollspy.js v2.3.1

 * http://twitter.github.com/bootstrap/javascript.html#scrollspy

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

 * Copyright 2012 Twitter, Inc.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

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

!function ($) {

  "use strict"; // jshint ;_;

 /* SCROLLSPY CLASS DEFINITION

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

  function ScrollSpy(element, options) {

    var process = $.proxy(this.process, this)

      , $element = $(element).is('body') ? $(window) : $(element)

      , href

    this.options = $.extend({}, $.fn.scrollspy.defaults, options)

    this.$scrollElement = $element.on('scroll.scroll-spy.data-api', process)

    this.selector = (this.options.target

      || ((href = $(element).attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) //strip for ie7

      || '') + ' .nav li > a'

    this.$body = $('body')

    this.refresh()

    this.process()

  }

  ScrollSpy.prototype = {

      constructor: ScrollSpy

    , refresh: function () {

        var self = this

          , $targets

        this.offsets = $([])

        this.targets = $([])

        $targets = this.$body

          .find(this.selector)

          .map(function () {

            var $el = $(this)

              , href = $el.data('target') || $el.attr('href')

              , $href = /^#\w/.test(href) && $(href)

            return ( $href

              && $href.length

              && [[ $href.position().top + (!$.isWindow(self.$scrollElement.get(0)) && self.$scrollElement.scrollTop()), href ]] ) || null

          })

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

          .each(function () {

            self.offsets.push(this[0])

            self.targets.push(this[1])

          })

      }

    , process: function () {

        var scrollTop = this.$scrollElement.scrollTop() + this.options.offset

          , scrollHeight = this.$scrollElement[0].scrollHeight || this.$body[0].scrollHeight

          , maxScroll = scrollHeight - this.$scrollElement.height()

          , offsets = this.offsets

          , targets = this.targets

          , activeTarget = this.activeTarget

          , i

        if (scrollTop >= maxScroll) {

          return activeTarget != (i = targets.last()[0])

            && this.activate ( i )

        }

        for (i = offsets.length; i--;) {

          activeTarget != targets[i]

            && scrollTop >= offsets[i]

            && (!offsets[i + 1] || scrollTop <= offsets[i + 1])

            && this.activate( targets[i] )

        }

      }

    , activate: function (target) {

        var active

          , selector

        this.activeTarget = target

        $(this.selector)

          .parent('.active')

          .removeClass('active')

        selector = this.selector

          + '[data-target="' + target + '"],'

          + this.selector + '[href="' + target + '"]'

        active = $(selector)

          .parent('li')

          .addClass('active')

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

          active = active.closest('li.dropdown').addClass('active')

        }

        active.trigger('activate')

      }

  }

 /* SCROLLSPY PLUGIN DEFINITION

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

  var old = $.fn.scrollspy

  $.fn.scrollspy = function (option) {

    return this.each(function () {

      var $this = $(this)

        , data = $this.data('scrollspy')

        , options = typeof option == 'object' && option

      if (!data) $this.data('scrollspy', (data = new ScrollSpy(this, options)))

      if (typeof option == 'string') data[option]()

    })

  }

  $.fn.scrollspy.Constructor = ScrollSpy

  $.fn.scrollspy.defaults = {

    offset: 10

  }

 /* SCROLLSPY NO CONFLICT

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

  $.fn.scrollspy.noConflict = function () {

    $.fn.scrollspy = old

    return this

  }

 /* SCROLLSPY DATA-API

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

  $(window).on('load', function () {

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

      var $spy = $(this)

      $spy.scrollspy($spy.data())

    })

  })

}(window.jQuery);