$(function() { // onload
  var comment_form = $('#new_comment');
  var input_elements = comment_form.find(':text, textarea');
  var fetch_comment_preview = function() {
    var dest = window.location.href;
    dest = dest.split('#')[0];
    dest = dest.split('?')[0];

    if (!dest.endsWith('comments')) {
      dest += '/comments';
    }

    jQuery.ajax({
      data: comment_form.serialize(),
      url:  dest + '/new',
      dataType: 'html',
      timeout: 2000,
      error: function() {
        if ($('#comment-preview').length === 0) {
          comment_form.after('<div id="comment-preview"></div>');
        }
        $('#comment-preview').text("Failed to submit");
      },
      success: function(r) {
        if ($('#comment-preview').length === 0) {
          comment_form.after('<h2>Your comment will look like this:</h2><div id="comment-preview"></div>');
        }
        $('#comment-preview').html(r);
      }
    });
  };

  input_elements.keyup(function () {
    fetch_comment_preview.only_every(1000);
  });

  if (input_elements.any(function() {
    return $(this).val().length > 0;
  })) {
    fetch_comment_preview();
  }
});