var slug = require('github-slugid');
var editHTMLElement = require('./editHTMLElement');

/**
    Add ID to an heading

    @param {HTMLElement} heading
*/
function addId(heading) {
    if (heading.attr('id')) return;
    heading.attr('id', slug(heading.text()));
}

/**
    Add ID to all headings

    @param {HTMLDom} $
*/
function addHeadingId($) {
    return editHTMLElement($, 'h1,h2,h3,h4,h5,h6', addId);
}

module.exports = addHeadingId;