(function ($) {

  //The timeout has to live in this scope
  var timeout;

  function LiveSearch($elem, options) {
    this.$elem = $elem;
    this.$form = $elem.closest('form');
    this.options = $.extend({
      delay: 400,
      minimum_characters: 3,
      serialize: this.$form,
      client_side_cache: true,
      process_data: false
    }, options);
    if (this.options.file_extension) {
      this.ajax_url = this.ensure_file_extension(this.options.file_extension);
    } else {
      this.ajax_url = this.url;
    }
    this.last_search = false;
    this.search_xhr = false;
    if (this.options.client_side_cache) {
      this.cache = {};
    } else {
      this.cache = false;
    }
    this.active = true;
    this._attach();
  }

  $.fn.livesearch = function (options) {
    options = options || {};
    return $(this).each(function () {
      var livesearch = $(this).data('livesearch');
      if (!livesearch) {
        livesearch = new LiveSearch($(this), options);
        $(this).data('livesearch', livesearch);
      }
    });
  };


  $.extend(LiveSearch.prototype, {
    _attach: function () {
      var _this = this;
      
      this.$elem.attr('autocomplete', 'off'); //we got this, yall

      this.$elem.bind("keypress cut paste input", function () {
        if (!_this.active) { return; }

        clearTimeout(timeout);
        timeout = setTimeout(function () {
          _this.search();
        }, _this.options.delay);
      });
      this.options.serialize.bind('change', function () {
        _this.search();
      });
      this.$elem.bind('livesearch:suspend', function () {
        _this.active = false;
      });
      this.$elem.bind('livesearch:activate', function () {
        _this.active = true;
      });
      this.$elem.bind('livesearch:cancel', function () {
        if (_this.search_xhr) {
          _this.search_xhr.abort();
        }
        _this.last_search = false;
      });
    },

    ensure_file_extension: function (extension) {
      var
        host_regexp_string = window.location.host.replace(/[^\w\d]/g, function (m) { return '\\' + m; }),
        file_extension_regexp = new RegExp("((?:" + host_regexp_string + ")?[^\\.$#\\?]+)(\\.\\w*|)($|#|\\?)");

      return this.url.replace(file_extension_regexp, function (m, _1, _2, _3) { return _1 + '.' + extension + _3; });
    },

    suspend_while: function (func) {
      this.active = false;
      func();
      // TODO: this timeout is to to allow events to bubble before re-enabling,
      // but I'm not sure why bubbling doesn't occur synchronously.
      var _this = this;
      setTimeout(function () {
        _this.active = true;
      }, 100);
    },

    search: function () {
      var _this = this,
        form_data = this.options.serialize.serialize();


      if (this.options.process_data) {
        form_data = this.options.process_data.apply(this, [form_data]);
        if (typeof form_data === 'object') {
          form_data = $.param(form_data);
        }
      }

      if (form_data === this.last_search) { return; }
      if (this.$elem.val().length < this.options.minimum_characters) { return; }

      if (this.search_xhr) {
        this.search_xhr.abort();
      }

      if (this.cache && this.cache[form_data] && typeof (this.cache[form_data]) !== 'function') {
        this.$elem.trigger('livesearch:results', [this.cache[form_data]]);
      } else {
        this.$elem.trigger('livesearch:searching');
        this.$elem.addClass('searching');

        this.search_xhr = $.ajax({
          type: 'get',
          url: this.options.url || this.$form.attr('action'),
          dataType: 'json',
          data: form_data,
          global: false,
          success: function (data, textStatus, xhr) {
            // this is the best workaround I can think of for
            // http://dev.jquery.com/ticket/6173
            if (data === null) { return; }

            _this.$elem.trigger('livesearch:results', [data]);
            _this.$elem.removeClass('searching');
            if (_this.cache) {
              _this.cache[form_data] = data;
            }
          },
          error: function () {
            _this.$elem.trigger('livesearch:ajax_error');
            _this.$elem.removeClass('searching');
          }
        });
      }

      this.last_search = form_data;
    }

  });

}(jQuery));