var $filterCheckboxes = $('input[type="checkbox"]');
var filterFunc = function() {
  
  var selectedFilters = {};

  $filterCheckboxes.filter(':checked').each(function() {

    if (!selectedFilters.hasOwnProperty(this.name)) {
      selectedFilters[this.name] = [];
    }

    selectedFilters[this.name].push(this.value);
  });

  // create a collection containing all of the filterable elements
  var $filteredResults = $('.flower');

  // loop over the selected filter name -> (array) values pairs
  $.each(selectedFilters, function(name, filterValues) {

    // filter each .flower element
    $filteredResults = $filteredResults.filter(function() {

      var matched = false,
        currentFilterValues = $(this).data('category').split(' ');

      // loop over each category value in the current .flower's data-category
      $.each(currentFilterValues, function(_, currentFilterValue) {

        // if the current category exists in the selected filters array
        // set matched to true, and stop looping. as we're ORing in each
        // set of filters, we only need to match once

        if ($.inArray(currentFilterValue, filterValues) != -1) {
          matched = true;
          return false;
        }
      });

      // if matched is true the current .flower element is returned
      return matched;

    });
  });

  $('.flower').hide().filter($filteredResults).show();
}

$filterCheckboxes.on('change', filterFunc);