/*!
Deck JS - deck.goto
Copyright (c) 2011-2014 Caleb Troughton
Dual licensed under the MIT license.
https://github.com/imakewebthings/deck.js/blob/master/MIT-license.txt
*/

/*
This module adds the necessary methods and key bindings to show and hide a form
for jumping to any slide number/id in the deck (and processes that form
accordingly). The form-showing state is indicated by the presence of a class on
the deck container.
*/
(function($, undefined) {
  var $document = $(document);
  var rootCounter;

  var bindKeyEvents = function() {
    $document.unbind('keydown.deckgoto');
    $document.bind('keydown.deckgoto', function(event) {
      var key = $.deck('getOptions').keys.goto;
      if (event.which === key || $.inArray(event.which, key) > -1) {
        event.preventDefault();
        $.deck('toggleGoTo');
      }
    });
  };

  var populateDatalist = function() {
    var options = $.deck('getOptions');
    var $datalist = $(options.selectors.gotoDatalist);

    $.each($.deck('getSlides'), function(i, $slide) {
      var id = $slide.attr('id');
      if (id) {
        $datalist.append('<option value="' + id + '">');
      }
    });
  };

  var markRootSlides = function() {
    var options = $.deck('getOptions');
    var slideTest = $.map([
      options.classes.before,
      options.classes.previous,
      options.classes.current,
      options.classes.next,
      options.classes.after
    ], function(el, i) {
      return '.' + el;
    }).join(', ');

    rootCounter = 0;
    $.each($.deck('getSlides'), function(i, $slide) {
      var $parentSlides = $slide.parentsUntil(
        options.selectors.container,
        slideTest
      );

      if ($parentSlides.length) {
        $slide.removeData('rootIndex');
      }
      else if (!options.countNested) {
        ++rootCounter;
        $slide.data('rootIndex', rootCounter);
      }
    });
  };

  var handleFormSubmit = function() {
    var options = $.deck('getOptions');
    var $form = $(options.selectors.gotoForm);

    $form.unbind('submit.deckgoto');
    $form.bind('submit.deckgoto', function(event) {
      var $field = $(options.selectors.gotoInput);
      var indexOrId = $field.val();
      var index = parseInt(indexOrId, 10);

      if (!options.countNested) {
        if (!isNaN(index) && index >= rootCounter) {
          return false;
        }
        $.each($.deck('getSlides'), function(i, $slide) {
          if ($slide.data('rootIndex') === index) {
            index = i + 1;
            return false;
          }
        });
      }

      $.deck('go', isNaN(index) ? indexOrId : index - 1);
      $.deck('hideGoTo');
      $field.val('');
      event.preventDefault();
    });
  };

  /*
  Extends defaults/options.

  options.classes.goto
    This class is added to the deck container when showing the Go To Slide
    form.

  options.selectors.gotoDatalist
    The element that matches this selector is the datalist element that will
    be populated with options for each of the slide ids.  In browsers that
    support the datalist element, this provides a drop list of slide ids to
    aid the user in selecting a slide.

  options.selectors.gotoForm
    The element that matches this selector is the form that is submitted
    when a user hits enter after typing a slide number/id in the gotoInput
    element.

  options.selectors.gotoInput
    The element that matches this selector is the text input field for
    entering a slide number/id in the Go To Slide form.

  options.keys.goto
    The numeric keycode used to show the Go To Slide form.

  options.countNested
    If false, only top level slides will be counted when entering a
    slide number.
  */
  $.extend(true, $.deck.defaults, {
    classes: {
      goto: 'deck-goto'
    },

    selectors: {
      gotoDatalist: '#goto-datalist',
      gotoForm: '.goto-form',
      gotoInput: '#goto-slide'
    },

    keys: {
      goto: 71 // g
    },

    countNested: true
  });

  /*
  jQuery.deck('showGoTo')

  Shows the Go To Slide form by adding the class specified by the goto class
  option to the deck container.
  */
  $.deck('extend', 'showGoTo', function() {
    var options = $.deck('getOptions');
    $.deck('getContainer').addClass(options.classes.goto);
    $(options.selectors.gotoForm).attr('aria-hidden', false);
    $(options.selectors.gotoInput).focus();
  });

  /*
  jQuery.deck('hideGoTo')

  Hides the Go To Slide form by removing the class specified by the goto class
  option from the deck container.
  */
  $.deck('extend', 'hideGoTo', function() {
    var options = $.deck('getOptions');
    $(options.selectors.gotoInput).blur();
    $.deck('getContainer').removeClass(options.classes.goto);
    $(options.selectors.gotoForm).attr('aria-hidden', true);
  });

  /*
  jQuery.deck('toggleGoTo')

  Toggles between showing and hiding the Go To Slide form.
  */
  $.deck('extend', 'toggleGoTo', function() {
    var options = $.deck('getOptions');
    var hasGotoClass = $.deck('getContainer').hasClass(options.classes.goto);
    $.deck(hasGotoClass ? 'hideGoTo' : 'showGoTo');
  });

  $document.bind('deck.init', function() {
    bindKeyEvents();
    populateDatalist();
    markRootSlides();
    handleFormSubmit();
  });
})(jQuery);