/* =============================================================
 * bootstrap-scrollspy.js v2.0.1
 * 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"

  /* 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.data-api', process)
    this.selector = (this.options.target
      || ((href = $(element).attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) //strip for ie7
      || '') + ' .nav li > a'
    this.$body = $('body').on('click.scroll.data-api', this.selector, process)
    this.refresh()
    this.process()
  }

  scrollspy.prototype = {

      constructor: scrollspy

    , refresh: function () {
        this.targets = this.$body
          .find(this.selector)
          .map(function () {
            var href = $(this).attr('href')
            return /^#\w/.test(href) && $(href).length ? href : null
          })

        this.offsets = $.map(this.targets, function (id) {
          return $(id).position().top
        })
      }

    , process: function () {
        var scrolltop = this.$scrollelement.scrolltop() + this.options.offset
          , offsets = this.offsets
          , targets = this.targets
          , activetarget = this.activetarget
          , 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

        this.activetarget = target

        this.$body
          .find(this.selector).parent('.active')
          .removeclass('active')

        active = this.$body
          .find(this.selector + '[href="' + target + '"]')
          .parent('li')
          .addclass('active')

        if ( active.parent('.dropdown-menu') )  {
          active.closest('li.dropdown').addclass('active')
        }
      }

  }


 /* scrollspy plugin definition
  * =========================== */

  $.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 data-api
  * ================== */

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

}( window.jquery );