(function ($) {

/**

 * Attaches the autocomplete behavior to all required fields.

 */

Drupal.behaviors.autocomplete = {

  attach: function (context, settings) {

    var acdb = [];

    $('input.autocomplete', context).once('autocomplete', function () {

      var uri = this.value;

      if (!acdb[uri]) {

        acdb[uri] = new Drupal.ACDB(uri);

      }

      var $input = $('#' + this.id.substr(0, this.id.length - 13))

        .attr('autocomplete', 'OFF')

        .attr('aria-autocomplete', 'list');

      $($input[0].form).submit(Drupal.autocompleteSubmit);

      $input.parent()

        .attr('role', 'application')

        .append($('<span class="element-invisible" aria-live="assertive"></span>')

          .attr('id', $input.attr('id') + '-autocomplete-aria-live')

        );

      new Drupal.jsAC($input, acdb[uri]);

    });

  }

};

/**

 * Prevents the form from submitting if the suggestions popup is open

 * and closes the suggestions popup when doing so.

 */

Drupal.autocompleteSubmit = function () {

  return $('#autocomplete').each(function () {

    this.owner.hidePopup();

  }).length == 0;

};

/**

 * An AutoComplete object.

 */

Drupal.jsAC = function ($input, db) {

  var ac = this;

  this.input = $input[0];

  this.ariaLive = $('#' + this.input.id + '-autocomplete-aria-live');

  this.db = db;

  $input

    .keydown(function (event) { return ac.onkeydown(this, event); })

    .keyup(function (event) { ac.onkeyup(this, event); })

    .blur(function () { ac.hidePopup(); ac.db.cancel(); });

};

/**

 * Handler for the "keydown" event.

 */

Drupal.jsAC.prototype.onkeydown = function (input, e) {

  if (!e) {

    e = window.event;

  }

  switch (e.keyCode) {

    case 40: // down arrow.

      this.selectDown();

      return false;

    case 38: // up arrow.

      this.selectUp();

      return false;

    default: // All other keys.

      return true;

  }

};

/**

 * Handler for the "keyup" event.

 */

Drupal.jsAC.prototype.onkeyup = function (input, e) {

  if (!e) {

    e = window.event;

  }

  switch (e.keyCode) {

    case 16: // Shift.

    case 17: // Ctrl.

    case 18: // Alt.

    case 20: // Caps lock.

    case 33: // Page up.

    case 34: // Page down.

    case 35: // End.

    case 36: // Home.

    case 37: // Left arrow.

    case 38: // Up arrow.

    case 39: // Right arrow.

    case 40: // Down arrow.

      return true;

    case 9:  // Tab.

    case 13: // Enter.

    case 27: // Esc.

      this.hidePopup(e.keyCode);

      return true;

    default: // All other keys.

      if (input.value.length > 0 && !input.readOnly) {

        this.populatePopup();

      }

      else {

        this.hidePopup(e.keyCode);

      }

      return true;

  }

};

/**

 * Puts the currently highlighted suggestion into the autocomplete field.

 */

Drupal.jsAC.prototype.select = function (node) {

  this.input.value = $(node).data('autocompleteValue');

  $(this.input).trigger('autocompleteSelect', [node]);

};

/**

 * Highlights the next suggestion.

 */

Drupal.jsAC.prototype.selectDown = function () {

  if (this.selected && this.selected.nextSibling) {

    this.highlight(this.selected.nextSibling);

  }

  else if (this.popup) {

    var lis = $('li', this.popup);

    if (lis.length > 0) {

      this.highlight(lis.get(0));

    }

  }

};

/**

 * Highlights the previous suggestion.

 */

Drupal.jsAC.prototype.selectUp = function () {

  if (this.selected && this.selected.previousSibling) {

    this.highlight(this.selected.previousSibling);

  }

};

/**

 * Highlights a suggestion.

 */

Drupal.jsAC.prototype.highlight = function (node) {

  if (this.selected) {

    $(this.selected).removeClass('selected');

  }

  $(node).addClass('selected');

  this.selected = node;

  $(this.ariaLive).html($(this.selected).html());

};

/**

 * Unhighlights a suggestion.

 */

Drupal.jsAC.prototype.unhighlight = function (node) {

  $(node).removeClass('selected');

  this.selected = false;

  $(this.ariaLive).empty();

};

/**

 * Hides the autocomplete suggestions.

 */

Drupal.jsAC.prototype.hidePopup = function (keycode) {

  // Select item if the right key or mousebutton was pressed.

  if (this.selected && ((keycode && keycode != 46 && keycode != 8 && keycode != 27) || !keycode)) {

    this.select(this.selected);

  }

  // Hide popup.

  var popup = this.popup;

  if (popup) {

    this.popup = null;

    $(popup).fadeOut('fast', function () { $(popup).remove(); });

  }

  this.selected = false;

  $(this.ariaLive).empty();

};

/**

 * Positions the suggestions popup and starts a search.

 */

Drupal.jsAC.prototype.populatePopup = function () {

  var $input = $(this.input);

  var position = $input.position();

  // Show popup.

  if (this.popup) {

    $(this.popup).remove();

  }

  this.selected = false;

  this.popup = $('<div id="autocomplete"></div>')[0];

  this.popup.owner = this;

  $(this.popup).css({

    top: parseInt(position.top + this.input.offsetHeight, 10) + 'px',

    left: parseInt(position.left, 10) + 'px',

    width: $input.innerWidth() + 'px',

    display: 'none'

  });

  $input.before(this.popup);

  // Do search.

  this.db.owner = this;

  this.db.search(this.input.value);

};

/**

 * Fills the suggestion popup with any matches received.

 */

Drupal.jsAC.prototype.found = function (matches) {

  // If no value in the textfield, do not show the popup.

  if (!this.input.value.length) {

    return false;

  }

  // Prepare matches.

  var ul = $('<ul></ul>');

  var ac = this;

  for (key in matches) {

    $('<li></li>')

      .html($('<div></div>').html(matches[key]))

      .mousedown(function () { ac.hidePopup(this); })

      .mouseover(function () { ac.highlight(this); })

      .mouseout(function () { ac.unhighlight(this); })

      .data('autocompleteValue', key)

      .appendTo(ul);

  }

  // Show popup with matches, if any.

  if (this.popup) {

    if (ul.children().length) {

      $(this.popup).empty().append(ul).show();

      $(this.ariaLive).html(Drupal.t('Autocomplete popup'));

    }

    else {

      $(this.popup).css({ visibility: 'hidden' });

      this.hidePopup();

    }

  }

};

Drupal.jsAC.prototype.setStatus = function (status) {

  switch (status) {

    case 'begin':

      $(this.input).addClass('throbbing');

      $(this.ariaLive).html(Drupal.t('Searching for matches...'));

      break;

    case 'cancel':

    case 'error':

    case 'found':

      $(this.input).removeClass('throbbing');

      break;

  }

};

/**

 * An AutoComplete DataBase object.

 */

Drupal.ACDB = function (uri) {

  this.uri = uri;

  this.delay = 300;

  this.cache = {};

};

/**

 * Performs a cached and delayed search.

 */

Drupal.ACDB.prototype.search = function (searchString) {

  var db = this;

  this.searchString = searchString;

  // See if this string needs to be searched for anyway. The pattern ../ is

  // stripped since it may be misinterpreted by the browser.

  searchString = searchString.replace(/^\s+|\.{2,}\/|\s+$/g, '');

  // Skip empty search strings, or search strings ending with a comma, since

  // that is the separator between search terms.

  if (searchString.length <= 0 ||

    searchString.charAt(searchString.length - 1) == ',') {

    return;

  }

  // See if this key has been searched for before.

  if (this.cache[searchString]) {

    return this.owner.found(this.cache[searchString]);

  }

  // Initiate delayed search.

  if (this.timer) {

    clearTimeout(this.timer);

  }

  this.timer = setTimeout(function () {

    db.owner.setStatus('begin');

    // Ajax GET request for autocompletion. We use Drupal.encodePath instead of

    // encodeURIComponent to allow autocomplete search terms to contain slashes.

    $.ajax({

      type: 'GET',

      url: db.uri + '/' + Drupal.encodePath(searchString),

      dataType: 'json',

      success: function (matches) {

        if (typeof matches.status == 'undefined' || matches.status != 0) {

          db.cache[searchString] = matches;

          // Verify if these are still the matches the user wants to see.

          if (db.searchString == searchString) {

            db.owner.found(matches);

          }

          db.owner.setStatus('found');

        }

      },

      error: function (xmlhttp) {

        Drupal.displayAjaxError(Drupal.ajaxError(xmlhttp, db.uri));

      }

    });

  }, this.delay);

};

/**

 * Cancels the current autocomplete request.

 */

Drupal.ACDB.prototype.cancel = function () {

  if (this.owner) this.owner.setStatus('cancel');

  if (this.timer) clearTimeout(this.timer);

  this.searchString = '';

};

})(jQuery);