/**
 * Owl Carousel v2 Accessibility Plugin
 * Version 0.2.1
 *
 * https://github.com/rtrvrtg/owlcarousel2-a11ylayer
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Geoffrey Roberts
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 *
 * © Geoffrey Roberts 2016
 */

;
(function($) {

  var Owl2A11y = function(carousel) {
    this._core = carousel
    this._initialized = false

    this._core._options = $.extend(Owl2A11y.defaults, this._core.options)

    this.$element = this._core.$element

    var setCurrent = $.proxy(function(e) {
      this.setCurrent(e)
    }, this)

    this._handlers = {
      'initialized.owl.carousel': $.proxy(function(e) {
        this.setupRoot()
        if (e.namespace && !this._initialized) {
          this.setupFocus()
          this.setupKeyboard()
        }
        this.setCurrent(e)
      }, this),
      'changed.owl.carousel': setCurrent,
      'translated.owl.carousel': setCurrent,
      'refreshed.owl.carousel': setCurrent,
      'resized.owl.carousel': setCurrent
    }
    this.$element.on(this._handlers)
  }


  /* PREFERENCES */

  /**
   * Contains default parameters, if there were any.
   */
  Owl2A11y.defaults = {}


  /* EVENT HANDLERS */

  /**
   * Adds support for things that don't map nicely to the root object
   * such as event handlers.
   */
  Owl2A11y.eventHandlers = {}

  /**
   * Get a callback for keyup events within this carousel.
   *
   * @return callback
   *   An event callback that takes an Event as an argument.
   */
  Owl2A11y.prototype.getDocumentKeyUp = function() {
    var self = this
    return function(e) {
      var eventTarg = $(e.target),
        targ = self.focused(eventTarg),
        action = null

      if (!!targ) {
        if (e.keyCode == 37 || e.keyCode == 38) {
          action = 'prev.owl.carousel'
        } else if (e.keyCode == 39 || e.keyCode == 40) {
          action = 'next.owl.carousel'
        } else if (e.keyCode == 13) {
          if (eventTarg.hasClass('owl-prev')) action = 'prev.owl.carousel'
          else if (eventTarg.hasClass('owl-next')) action = 'next.owl.carousel'
          else if (eventTarg.hasClass('owl-dot')) action = 'click'
        }

        if (!!action) targ.trigger(action)

      }
    }
  }


  /* SETUP AND TEAR DOWN */

  /**
   * Assign attributes to the root element.
   */
  Owl2A11y.prototype.setupRoot = function() {
     this.$element.attr({
       // @FIXME
       //   role: 'listbox',
       tabindex: '0'
    })
  }

  /**
   * Setup keyboard events for this carousel.
   */
  Owl2A11y.prototype.setupKeyboard = function() {
    // Only needed to initialise once for the entire document
    if (!this.$element.attr('data-owl-access-keyup')) {
      this.$element.bind('keyup', this.getDocumentKeyUp())
        .attr('data-owl-access-keyup', '1')
    }
    this.$element.attr('data-owl-carousel-focusable', '1')
  }

  /**
   * Setup focusing behaviour for the carousel.
   */
  Owl2A11y.prototype.setupFocus = function() {
    // Only needed to initialise once for the entire document
    if (this._core.options.autoplay) {
      this.$element.bind('focusin', function() {
        $(this).attr({
            'data-owl-carousel-focused': '1',
            'aria-live': 'polite'
          }).trigger('stop.owl.autoplay')
        }).bind('focusout', function() {
        $(this).attr({
          'data-owl-carousel-focused': '0',
          'aria-live': 'off'
        }).trigger('play.owl.autoplay')
      })
    } else {
      this.$element.bind('focusin', function() {
        $(this).attr({
            'data-owl-carousel-focused': '1',
          })
        }).bind('focusout', function() {
        $(this).attr({
          'data-owl-carousel-focused': '0',
        })
      })
    }

    // Add tabindex to allow navigation to be focused.
    if (!!this._core._plugins.navigation) {
      var navPlugin = this._core._plugins.navigation,
        toFocus = []
      if (!!navPlugin._controls.$previous) {
        toFocus.push(navPlugin._controls.$previous)
      }
      if (!!navPlugin._controls.$next) {
        toFocus.push(navPlugin._controls.$next)
      }
      if (!!navPlugin._controls.$indicators) {
        toFocus.push(navPlugin._controls.$indicators.children())
      }
      $.each(toFocus, function() {
        this.attr('tabindex', '0')
      })
    }
  }

  /**
   * Assign attributes to the root element.
   */
  Owl2A11y.prototype.destroy = function() {
    this.$element.unbind('keyup', this.eventHandlers.documentKeyUp)
      .removeAttr('data-owl-access-keyup data-owl-carousel-focusable')
      .unbind('focusin focusout')
  }


  /* HELPER FUNCTIONS */

  /**
   * Identifies all focusable elements within a given element.
   *
   * @param DOMElement elem
   *   A DOM element.
   *
   * @return jQuery
   *   A jQuery object that may refer to zero or more focusable elements.
   */
  Owl2A11y.prototype.focusableElems = function(elem) {
    return $(elem).find('a, input, select, button, *[tabindex]')
  }

  /**
   * Identifies all focusable elements within a given element.
   *
   * @param jQeury elems
   *   A jQuery object that may refer to zero or more focusable elements.
   * @param boolean enable
   *   Whether focus is to be enabled on these elements or not.
   */
  Owl2A11y.prototype.adjustFocus = function(elems, enable) {
    elems.each(function() {
      var item = $(this)
      var newTabIndex = '0',
        storeTabIndex = '0',
        currentTabIndex = item.attr('tabindex'),
        storedTabIndex = item.attr('data-owl-temp-tabindex')

      if (enable) {
        newTabIndex = (
          typeof(storedTabIndex) != 'undefined' && (storedTabIndex != '-1') ?
          item.attr('data-owl-temp-tabindex') :
          '0'
        )
        storedTabIndex = newTabIndex
      } else {
        newTabIndex = '-1'
        storedTabIndex = (
          (typeof(currentTabIndex) != 'undefined') || (currentTabIndex != '-1') ?
          currentTabIndex :
          '0'
        )
      }

      item.attr({
        tabindex: newTabIndex,
        'data-owl-temp-tabindex': storeTabIndex
      })
    })
  }

  /**
   * Get the root element if we are focused within it.
   *
   * @param DOMElement targ
   *   An element that might be within this carousel.
   *
   * @return mixed
   *   Either the jQuery element containing the root element, or NULL.
   */
  Owl2A11y.prototype.focused = function(targ) {
    var targ = $(targ)
    if (targ.attr('data-owl-carousel-focused') == 1) {
      return targ
    }
    var closest = targ.closest('[data-owl-carousel-focused="1"]')
    if (closest.length > 0) return closest
    return null
  }


  /* UPDATE FUNCTIONS */

  /**
   * Identify active elements, set WAI-ARIA sttributes accordingly,
   * scroll to show element if we need to, and set up focusing.
   *
   * @param Event e
   *   The triggering event.
   */
  Owl2A11y.prototype.setCurrent = function() {
    var targ = this.focused($(':focus')),
      element = this._core.$element,
      stage = this._core.$stage,
      focusableElems = this.focusableElems,
      adjustFocus = this.adjustFocus

    if (!!stage) {
//      var offs = stage.offset()
//      if (!!targ) {
//        window.scrollTo(
//          offs.left,
//          offs.top - parseInt($('body').css('padding-top'), 10)
//        )
//      }

      this._core.$stage.children().each(function() {
        var item = $(this)
        var focusable = focusableElems(this)

        // Use the active class to determine if we can see it or not.
        // Pretty lazy, but the Owl API doesn't make it easy to tell
        // from indices alone.
        if (item.hasClass('active')) {
          item.attr('aria-hidden', 'false')
          adjustFocus(focusable, true)
        } else {
          item.attr('aria-hidden', 'true')
          adjustFocus(focusable, false)
        }
      })

      if (!!targ) {
        // Focus on the root element after we're done moving,
        // but only if we're not using the controls.
        setTimeout(function() {
          var newFocus = element
          if ($(':focus').closest('.owl-controls').length) {
            newFocus = $(':focus')
          }
          newFocus.focus()
        }, 250)
      }
    }
  }

  $.fn.owlCarousel.Constructor.Plugins['Owl2A11y'] = Owl2A11y

})(window.Zepto || window.jQuery, window)