// @ts-check
const dataAttrHelpers = (() => {
  /** @type {Record<string, (value: string) => boolean>} */
  const typesTesters = {
    string: value => true,
    number: value => /^-?\d+(\.\d+)?$/.test(value),
    boolean: value => value === "false" || value === "true"
  };
  /** @type {Record<string, (value: string) => any>} */  const typesParsers = {
    string: value => value,
    number: value => parseFloat(value),
    boolean: value => value !== "false"
  };
  /**
     *
     * @param {string} dataAttr
     * @param {Record<string, string[]>} types
     */  const parseDataAttr = (dataAttr, types = {}) => {
    const options = {};
    for (const row of dataAttr.split(";")) {
      const match = row.trim().match(/^(.*?):([\s\S]*)$/);
      if (!match) continue;
      let [key, value] = [ match[1], match[2] ].map(a => a.trim());
      for (const type in types) {
        if (types[type].includes(key) && typesTesters[type](value)) {
          value = typesParsers[type](value);
          break;
        }
      }
      options[key] = value;
    }
    return options;
  };
  /**
     * @param {string} dataAttrName 
     * @param {(el: Element) => void} runDataAttr 
     */  const watchDataAttr = (dataAttrName, runDataAttr) => {
    const callback = /** @type {Element} */ el => {
      if (!el.hasAttribute(dataAttrName)) return;
      const key = "--data-attr-" + dataAttrName + "--";
      if (el[key]) return;
      el[key] = true;
      runDataAttr(el);
    };
    document.querySelectorAll("[" + dataAttrName + "]").forEach(callback);
    const observer = new MutationObserver(mutationList => {
      for (const mutation of mutationList) {
        if (mutation.target instanceof Element) {
          callback(mutation.target);
          mutation.target.querySelectorAll("[" + dataAttrName + "]").forEach(callback);
        }
      }
    });
    observer.observe(document.body, {
      attributes: true,
      childList: true,
      subtree: true,
      attributeFilter: [ dataAttrName ]
    });
  };
  return {
    typesTesters: typesTesters,
    typesParsers: typesParsers,
    watchDataAttr: watchDataAttr,
    parseDataAttr: parseDataAttr
  };
})();
// document.addEventListener('DOMContentLoaded', () => {
//     // Run all.
//     dataAttrHelpers.watchDataAttr('data-feather', el => {
//         // @ts-ignore
//         if (typeof feather !== 'undefined') feather.replace();
//     });
// });