"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.extractCssFromStyleNode = extractCssFromStyleNode;
exports.isAmpBoilerplate = isAmpBoilerplate;
exports.isComment = isComment;
exports.isConditionalComment = isConditionalComment;
exports.isEventHandler = isEventHandler;
exports.isStyleNode = isStyleNode;
exports.optionalImport = optionalImport;
function _getRequireWildcardCache(e) { if ("function" != typeof WeakMap) return null; var r = new WeakMap(), t = new WeakMap(); return (_getRequireWildcardCache = function (e) { return e ? t : r; })(e); }
function _interopRequireWildcard(e, r) { if (!r && e && e.__esModule) return e; if (null === e || "object" != typeof e && "function" != typeof e) return { default: e }; var t = _getRequireWildcardCache(r); if (t && t.has(e)) return t.get(e); var n = { __proto__: null }, a = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var u in e) if ("default" !== u && Object.prototype.hasOwnProperty.call(e, u)) { var i = a ? Object.getOwnPropertyDescriptor(e, u) : null; i && (i.get || i.set) ? Object.defineProperty(n, u, i) : n[u] = e[u]; } return n.default = e, t && t.set(e, n), n; }
function __transformExtension(filepath, extMapping) {
  if (!filepath.startsWith('./') && !filepath.startsWith('../')) {
    // Package import
    return filepath;
  }
  const idx = filepath.lastIndexOf('.');
  if (idx === -1 || filepath.includes('/', idx)) {
    // No extension
    const newExt = extMapping[''];
    if (newExt) {
      return filepath + newExt;
    }
    return filepath;
  }
  for (let [origExt, newExt] of Object.entries(extMapping).sort((a, b) => b[0].length - a[0].length)) {
    if (filepath.endsWith(origExt)) {
      return filepath.slice(0, -origExt.length) + newExt;
    }
  }
  return filepath;
}
const ampBoilerplateAttributes = ['amp-boilerplate', 'amp4ads-boilerplate', 'amp4email-boilerplate'];
function isAmpBoilerplate(node) {
  if (!node.attrs) {
    return false;
  }
  for (const attr of ampBoilerplateAttributes) {
    if (attr in node.attrs) {
      return true;
    }
  }
  return false;
}
function isComment(content) {
  if (typeof content === 'string') {
    return content.trim().startsWith('<!--');
  }
  return false;
}
function isConditionalComment(content) {
  return (content || '').trim().startsWith('<!--[if');
}
function isStyleNode(node) {
  return node.tag === 'style' && !isAmpBoilerplate(node) && 'content' in node && node.content.length > 0;
}
function extractCssFromStyleNode(node) {
  return Array.isArray(node.content) ? node.content.join(' ') : node.content;
}
function isEventHandler(attributeName) {
  return attributeName && attributeName.slice && attributeName.slice(0, 2).toLowerCase() === 'on' && attributeName.length >= 5;
}
async function optionalImport(moduleName) {
  try {
    const module = await (specifier => new Promise(r => r(`${specifier}`)).then(s => _interopRequireWildcard(require(s))))(__transformExtension(moduleName, {
      ".mjs": ".cjs"
    }));
    return module.default || module;
  } catch (e) {
    if (e.code === 'MODULE_NOT_FOUND' || e.code === 'ERR_MODULE_NOT_FOUND') {
      return null;
    }
    throw e;
  }
}