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function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }

var fs = require('fs');
var cssSelect = require('css-select');
var htmlparser2 = require('htmlparser2');
var domhandler = require('domhandler');
var render = _interopDefault(require('dom-serializer'));
var path = _interopDefault(require('path'));
var postcss = require('postcss');
var mediaParser = _interopDefault(require('postcss-media-query-parser'));
var chalk = _interopDefault(require('chalk'));

var SelectorType;
(function (SelectorType) {
  SelectorType["Attribute"] = "attribute";
  SelectorType["Pseudo"] = "pseudo";
  SelectorType["PseudoElement"] = "pseudo-element";
  SelectorType["Tag"] = "tag";
  SelectorType["Universal"] = "universal";
  // Traversals
  SelectorType["Adjacent"] = "adjacent";
  SelectorType["Child"] = "child";
  SelectorType["Descendant"] = "descendant";
  SelectorType["Parent"] = "parent";
  SelectorType["Sibling"] = "sibling";
  SelectorType["ColumnCombinator"] = "column-combinator";
})(SelectorType || (SelectorType = {}));
var AttributeAction;
(function (AttributeAction) {
  AttributeAction["Any"] = "any";
  AttributeAction["Element"] = "element";
  AttributeAction["End"] = "end";
  AttributeAction["Equals"] = "equals";
  AttributeAction["Exists"] = "exists";
  AttributeAction["Hyphen"] = "hyphen";
  AttributeAction["Not"] = "not";
  AttributeAction["Start"] = "start";
})(AttributeAction || (AttributeAction = {}));

const reName = /^[^\\#]?(?:\\(?:[\da-f]{1,6}\s?|.)|[\w\-\u00b0-\uFFFF])+/;
const reEscape = /\\([\da-f]{1,6}\s?|(\s)|.)/gi;
const actionTypes = new Map([[126 /* Tilde */, AttributeAction.Element], [94 /* Circumflex */, AttributeAction.Start], [36 /* Dollar */, AttributeAction.End], [42 /* Asterisk */, AttributeAction.Any], [33 /* ExclamationMark */, AttributeAction.Not], [124 /* Pipe */, AttributeAction.Hyphen]]);
// Pseudos, whose data property is parsed as well.
const unpackPseudos = new Set(["has", "not", "matches", "is", "where", "host", "host-context"]);
/**
 * Checks whether a specific selector is a traversal.
 * This is useful eg. in swapping the order of elements that
 * are not traversals.
 *
 * @param selector Selector to check.
 */
function isTraversal(selector) {
  switch (selector.type) {
    case SelectorType.Adjacent:
    case SelectorType.Child:
    case SelectorType.Descendant:
    case SelectorType.Parent:
    case SelectorType.Sibling:
    case SelectorType.ColumnCombinator:
      return true;
    default:
      return false;
  }
}
const stripQuotesFromPseudos = new Set(["contains", "icontains"]);
// Unescape function taken from https://github.com/jquery/sizzle/blob/master/src/sizzle.js#L152
function funescape(_, escaped, escapedWhitespace) {
  const high = parseInt(escaped, 16) - 0x10000;
  // NaN means non-codepoint
  return high !== high || escapedWhitespace ? escaped : high < 0 ?
  // BMP codepoint
  String.fromCharCode(high + 0x10000) :
  // Supplemental Plane codepoint (surrogate pair)
  String.fromCharCode(high >> 10 | 0xd800, high & 0x3ff | 0xdc00);
}
function unescapeCSS(str) {
  return str.replace(reEscape, funescape);
}
function isQuote(c) {
  return c === 39 /* SingleQuote */ || c === 34 /* DoubleQuote */;
}
function isWhitespace(c) {
  return c === 32 /* Space */ || c === 9 /* Tab */ || c === 10 /* NewLine */ || c === 12 /* FormFeed */ || c === 13 /* CarriageReturn */;
}
/**
 * Parses `selector`, optionally with the passed `options`.
 *
 * @param selector Selector to parse.
 * @param options Options for parsing.
 * @returns Returns a two-dimensional array.
 * The first dimension represents selectors separated by commas (eg. `sub1, sub2`),
 * the second contains the relevant tokens for that selector.
 */
function parse(selector) {
  const subselects = [];
  const endIndex = parseSelector(subselects, `${selector}`, 0);
  if (endIndex < selector.length) {
    throw new Error(`Unmatched selector: ${selector.slice(endIndex)}`);
  }
  return subselects;
}
function parseSelector(subselects, selector, selectorIndex) {
  let tokens = [];
  function getName(offset) {
    const match = selector.slice(selectorIndex + offset).match(reName);
    if (!match) {
      throw new Error(`Expected name, found ${selector.slice(selectorIndex)}`);
    }
    const [name] = match;
    selectorIndex += offset + name.length;
    return unescapeCSS(name);
  }
  function stripWhitespace(offset) {
    selectorIndex += offset;
    while (selectorIndex < selector.length && isWhitespace(selector.charCodeAt(selectorIndex))) {
      selectorIndex++;
    }
  }
  function readValueWithParenthesis() {
    selectorIndex += 1;
    const start = selectorIndex;
    let counter = 1;
    for (; counter > 0 && selectorIndex < selector.length; selectorIndex++) {
      if (selector.charCodeAt(selectorIndex) === 40 /* LeftParenthesis */ && !isEscaped(selectorIndex)) {
        counter++;
      } else if (selector.charCodeAt(selectorIndex) === 41 /* RightParenthesis */ && !isEscaped(selectorIndex)) {
        counter--;
      }
    }
    if (counter) {
      throw new Error("Parenthesis not matched");
    }
    return unescapeCSS(selector.slice(start, selectorIndex - 1));
  }
  function isEscaped(pos) {
    let slashCount = 0;
    while (selector.charCodeAt(--pos) === 92 /* BackSlash */) slashCount++;
    return (slashCount & 1) === 1;
  }
  function ensureNotTraversal() {
    if (tokens.length > 0 && isTraversal(tokens[tokens.length - 1])) {
      throw new Error("Did not expect successive traversals.");
    }
  }
  function addTraversal(type) {
    if (tokens.length > 0 && tokens[tokens.length - 1].type === SelectorType.Descendant) {
      tokens[tokens.length - 1].type = type;
      return;
    }
    ensureNotTraversal();
    tokens.push({
      type
    });
  }
  function addSpecialAttribute(name, action) {
    tokens.push({
      type: SelectorType.Attribute,
      name,
      action,
      value: getName(1),
      namespace: null,
      ignoreCase: "quirks"
    });
  }
  /**
   * We have finished parsing the current part of the selector.
   *
   * Remove descendant tokens at the end if they exist,
   * and return the last index, so that parsing can be
   * picked up from here.
   */
  function finalizeSubselector() {
    if (tokens.length && tokens[tokens.length - 1].type === SelectorType.Descendant) {
      tokens.pop();
    }
    if (tokens.length === 0) {
      throw new Error("Empty sub-selector");
    }
    subselects.push(tokens);
  }
  stripWhitespace(0);
  if (selector.length === selectorIndex) {
    return selectorIndex;
  }
  loop: while (selectorIndex < selector.length) {
    const firstChar = selector.charCodeAt(selectorIndex);
    switch (firstChar) {
      // Whitespace
      case 32 /* Space */:
      case 9 /* Tab */:
      case 10 /* NewLine */:
      case 12 /* FormFeed */:
      case 13 /* CarriageReturn */:
        {
          if (tokens.length === 0 || tokens[0].type !== SelectorType.Descendant) {
            ensureNotTraversal();
            tokens.push({
              type: SelectorType.Descendant
            });
          }
          stripWhitespace(1);
          break;
        }
      // Traversals
      case 62 /* GreaterThan */:
        {
          addTraversal(SelectorType.Child);
          stripWhitespace(1);
          break;
        }
      case 60 /* LessThan */:
        {
          addTraversal(SelectorType.Parent);
          stripWhitespace(1);
          break;
        }
      case 126 /* Tilde */:
        {
          addTraversal(SelectorType.Sibling);
          stripWhitespace(1);
          break;
        }
      case 43 /* Plus */:
        {
          addTraversal(SelectorType.Adjacent);
          stripWhitespace(1);
          break;
        }
      // Special attribute selectors: .class, #id
      case 46 /* Period */:
        {
          addSpecialAttribute("class", AttributeAction.Element);
          break;
        }
      case 35 /* Hash */:
        {
          addSpecialAttribute("id", AttributeAction.Equals);
          break;
        }
      case 91 /* LeftSquareBracket */:
        {
          stripWhitespace(1);
          // Determine attribute name and namespace
          let name;
          let namespace = null;
          if (selector.charCodeAt(selectorIndex) === 124 /* Pipe */) {
            // Equivalent to no namespace
            name = getName(1);
          } else if (selector.startsWith("*|", selectorIndex)) {
            namespace = "*";
            name = getName(2);
          } else {
            name = getName(0);
            if (selector.charCodeAt(selectorIndex) === 124 /* Pipe */ && selector.charCodeAt(selectorIndex + 1) !== 61 /* Equal */) {
              namespace = name;
              name = getName(1);
            }
          }
          stripWhitespace(0);
          // Determine comparison operation
          let action = AttributeAction.Exists;
          const possibleAction = actionTypes.get(selector.charCodeAt(selectorIndex));
          if (possibleAction) {
            action = possibleAction;
            if (selector.charCodeAt(selectorIndex + 1) !== 61 /* Equal */) {
              throw new Error("Expected `=`");
            }
            stripWhitespace(2);
          } else if (selector.charCodeAt(selectorIndex) === 61 /* Equal */) {
            action = AttributeAction.Equals;
            stripWhitespace(1);
          }
          // Determine value
          let value = "";
          let ignoreCase = null;
          if (action !== "exists") {
            if (isQuote(selector.charCodeAt(selectorIndex))) {
              const quote = selector.charCodeAt(selectorIndex);
              let sectionEnd = selectorIndex + 1;
              while (sectionEnd < selector.length && (selector.charCodeAt(sectionEnd) !== quote || isEscaped(sectionEnd))) {
                sectionEnd += 1;
              }
              if (selector.charCodeAt(sectionEnd) !== quote) {
                throw new Error("Attribute value didn't end");
              }
              value = unescapeCSS(selector.slice(selectorIndex + 1, sectionEnd));
              selectorIndex = sectionEnd + 1;
            } else {
              const valueStart = selectorIndex;
              while (selectorIndex < selector.length && (!isWhitespace(selector.charCodeAt(selectorIndex)) && selector.charCodeAt(selectorIndex) !== 93 /* RightSquareBracket */ || isEscaped(selectorIndex))) {
                selectorIndex += 1;
              }
              value = unescapeCSS(selector.slice(valueStart, selectorIndex));
            }
            stripWhitespace(0);
            // See if we have a force ignore flag
            const forceIgnore = selector.charCodeAt(selectorIndex) | 0x20;
            // If the forceIgnore flag is set (either `i` or `s`), use that value
            if (forceIgnore === 115 /* LowerS */) {
              ignoreCase = false;
              stripWhitespace(1);
            } else if (forceIgnore === 105 /* LowerI */) {
              ignoreCase = true;
              stripWhitespace(1);
            }
          }
          if (selector.charCodeAt(selectorIndex) !== 93 /* RightSquareBracket */) {
            throw new Error("Attribute selector didn't terminate");
          }
          selectorIndex += 1;
          const attributeSelector = {
            type: SelectorType.Attribute,
            name,
            action,
            value,
            namespace,
            ignoreCase
          };
          tokens.push(attributeSelector);
          break;
        }
      case 58 /* Colon */:
        {
          if (selector.charCodeAt(selectorIndex + 1) === 58 /* Colon */) {
            tokens.push({
              type: SelectorType.PseudoElement,
              name: getName(2).toLowerCase(),
              data: selector.charCodeAt(selectorIndex) === 40 /* LeftParenthesis */ ? readValueWithParenthesis() : null
            });
            continue;
          }
          const name = getName(1).toLowerCase();
          let data = null;
          if (selector.charCodeAt(selectorIndex) === 40 /* LeftParenthesis */) {
            if (unpackPseudos.has(name)) {
              if (isQuote(selector.charCodeAt(selectorIndex + 1))) {
                throw new Error(`Pseudo-selector ${name} cannot be quoted`);
              }
              data = [];
              selectorIndex = parseSelector(data, selector, selectorIndex + 1);
              if (selector.charCodeAt(selectorIndex) !== 41 /* RightParenthesis */) {
                throw new Error(`Missing closing parenthesis in :${name} (${selector})`);
              }
              selectorIndex += 1;
            } else {
              data = readValueWithParenthesis();
              if (stripQuotesFromPseudos.has(name)) {
                const quot = data.charCodeAt(0);
                if (quot === data.charCodeAt(data.length - 1) && isQuote(quot)) {
                  data = data.slice(1, -1);
                }
              }
              data = unescapeCSS(data);
            }
          }
          tokens.push({
            type: SelectorType.Pseudo,
            name,
            data
          });
          break;
        }
      case 44 /* Comma */:
        {
          finalizeSubselector();
          tokens = [];
          stripWhitespace(1);
          break;
        }
      default:
        {
          if (selector.startsWith("/*", selectorIndex)) {
            const endIndex = selector.indexOf("*/", selectorIndex + 2);
            if (endIndex < 0) {
              throw new Error("Comment was not terminated");
            }
            selectorIndex = endIndex + 2;
            // Remove leading whitespace
            if (tokens.length === 0) {
              stripWhitespace(0);
            }
            break;
          }
          let namespace = null;
          let name;
          if (firstChar === 42 /* Asterisk */) {
            selectorIndex += 1;
            name = "*";
          } else if (firstChar === 124 /* Pipe */) {
            name = "";
            if (selector.charCodeAt(selectorIndex + 1) === 124 /* Pipe */) {
              addTraversal(SelectorType.ColumnCombinator);
              stripWhitespace(2);
              break;
            }
          } else if (reName.test(selector.slice(selectorIndex))) {
            name = getName(0);
          } else {
            break loop;
          }
          if (selector.charCodeAt(selectorIndex) === 124 /* Pipe */ && selector.charCodeAt(selectorIndex + 1) !== 124 /* Pipe */) {
            namespace = name;
            if (selector.charCodeAt(selectorIndex + 1) === 42 /* Asterisk */) {
              name = "*";
              selectorIndex += 2;
            } else {
              name = getName(1);
            }
          }
          tokens.push(name === "*" ? {
            type: SelectorType.Universal,
            namespace
          } : {
            type: SelectorType.Tag,
            name,
            namespace
          });
        }
    }
  }
  finalizeSubselector();
  return selectorIndex;
}

/**
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
let classCache = null;
let idCache = null;
function buildCache(container) {
  classCache = new Set();
  idCache = new Set();
  const queue = [container];
  while (queue.length) {
    const node = queue.shift();
    if (node.hasAttribute('class')) {
      const classList = node.getAttribute('class').trim().split(' ');
      classList.forEach(cls => {
        classCache.add(cls);
      });
    }
    if (node.hasAttribute('id')) {
      const id = node.getAttribute('id').trim();
      idCache.add(id);
    }
    queue.push(...node.children.filter(child => child.type === 'tag'));
  }
}

/**
 * Parse HTML into a mutable, serializable DOM Document.
 * The DOM implementation is an htmlparser2 DOM enhanced with basic DOM mutation methods.
 * @param {String} html   HTML to parse into a Document instance
 */
function createDocument(html) {
  const document = /** @type {HTMLDocument} */htmlparser2.parseDocument(html, {
    decodeEntities: false
  });
  defineProperties(document, DocumentExtensions);

  // Extend Element.prototype with DOM manipulation methods.
  defineProperties(domhandler.Element.prototype, ElementExtensions);

  // Critters container is the viewport to evaluate critical CSS
  let crittersContainer = document.querySelector('[data-critters-container]');
  if (!crittersContainer) {
    document.documentElement.setAttribute('data-critters-container', '');
    crittersContainer = document.documentElement;
  }
  document.crittersContainer = crittersContainer;
  buildCache(crittersContainer);
  return document;
}

/**
 * Serialize a Document to an HTML String
 * @param {HTMLDocument} document   A Document, such as one created via `createDocument()`
 */
function serializeDocument(document) {
  return render(document, {
    decodeEntities: false
  });
}

/** @typedef {treeAdapter.Document & typeof ElementExtensions} HTMLDocument */

/**
 * Methods and descriptors to mix into Element.prototype
 * @private
 */
const ElementExtensions = {
  /** @extends treeAdapter.Element.prototype */

  nodeName: {
    get() {
      return this.tagName.toUpperCase();
    }
  },
  id: reflectedProperty('id'),
  className: reflectedProperty('class'),
  insertBefore(child, referenceNode) {
    if (!referenceNode) return this.appendChild(child);
    htmlparser2.DomUtils.prepend(referenceNode, child);
    return child;
  },
  appendChild(child) {
    htmlparser2.DomUtils.appendChild(this, child);
    return child;
  },
  removeChild(child) {
    htmlparser2.DomUtils.removeElement(child);
  },
  remove() {
    htmlparser2.DomUtils.removeElement(this);
  },
  textContent: {
    get() {
      return htmlparser2.DomUtils.getText(this);
    },
    set(text) {
      this.children = [];
      htmlparser2.DomUtils.appendChild(this, new domhandler.Text(text));
    }
  },
  setAttribute(name, value) {
    if (this.attribs == null) this.attribs = {};
    if (value == null) value = '';
    this.attribs[name] = value;
  },
  removeAttribute(name) {
    if (this.attribs != null) {
      delete this.attribs[name];
    }
  },
  getAttribute(name) {
    return this.attribs != null && this.attribs[name];
  },
  hasAttribute(name) {
    return this.attribs != null && this.attribs[name] != null;
  },
  getAttributeNode(name) {
    const value = this.getAttribute(name);
    if (value != null) return {
      specified: true,
      value
    };
  },
  exists(sel) {
    return cachedQuerySelector(sel, this);
  },
  querySelector(sel) {
    return cssSelect.selectOne(sel, this);
  },
  querySelectorAll(sel) {
    return cssSelect.selectAll(sel, this);
  }
};

/**
 * Methods and descriptors to mix into the global document instance
 * @private
 */
const DocumentExtensions = {
  /** @extends treeAdapter.Document.prototype */

  // document is just an Element in htmlparser2, giving it a nodeType of ELEMENT_NODE.
  // TODO: verify if these are needed for css-select
  nodeType: {
    get() {
      return 9;
    }
  },
  contentType: {
    get() {
      return 'text/html';
    }
  },
  nodeName: {
    get() {
      return '#document';
    }
  },
  documentElement: {
    get() {
      // Find the first <html> element within the document
      return this.children.find(child => String(child.tagName).toLowerCase() === 'html');
    }
  },
  head: {
    get() {
      return this.querySelector('head');
    }
  },
  body: {
    get() {
      return this.querySelector('body');
    }
  },
  createElement(name) {
    return new domhandler.Element(name);
  },
  createTextNode(text) {
    // there is no dedicated createTextNode equivalent exposed in htmlparser2's DOM
    return new domhandler.Text(text);
  },
  exists(sel) {
    return cachedQuerySelector(sel, this);
  },
  querySelector(sel) {
    return cssSelect.selectOne(sel, this);
  },
  querySelectorAll(sel) {
    if (sel === ':root') {
      return this;
    }
    return cssSelect.selectAll(sel, this);
  }
};

/**
 * Essentially `Object.defineProperties()`, except function values are assigned as value descriptors for convenience.
 * @private
 */
function defineProperties(obj, properties) {
  for (const i in properties) {
    const value = properties[i];
    Object.defineProperty(obj, i, typeof value === 'function' ? {
      value
    } : value);
  }
}

/**
 * Create a property descriptor defining a getter/setter pair alias for a named attribute.
 * @private
 */
function reflectedProperty(attributeName) {
  return {
    get() {
      return this.getAttribute(attributeName);
    },
    set(value) {
      this.setAttribute(attributeName, value);
    }
  };
}
function cachedQuerySelector(sel, node) {
  const selectorTokens = parse(sel);
  for (const tokens of selectorTokens) {
    // Check if the selector is a class selector
    if (tokens.length === 1) {
      const token = tokens[0];
      if (token.type === 'attribute' && token.name === 'class') {
        return classCache.has(token.value);
      }
      if (token.type === 'attribute' && token.name === 'id') {
        return idCache.has(token.value);
      }
    }
  }
  return !!cssSelect.selectOne(sel, node);
}

/**
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * Parse a textual CSS Stylesheet into a Stylesheet instance.
 * Stylesheet is a mutable postcss AST with format similar to CSSOM.
 * @see https://github.com/postcss/postcss/
 * @private
 * @param {String} stylesheet
 * @returns {css.Stylesheet} ast
 */
function parseStylesheet(stylesheet) {
  return postcss.parse(stylesheet);
}

/**
 * Serialize a postcss Stylesheet to a String of CSS.
 * @private
 * @param {css.Stylesheet} ast          A Stylesheet to serialize, such as one returned from `parseStylesheet()`
 * @param {Object} options              Options used by the stringify logic
 * @param {Boolean} [options.compress]  Compress CSS output (removes comments, whitespace, etc)
 */
function serializeStylesheet(ast, options) {
  let cssStr = '';
  postcss.stringify(ast, (result, node, type) => {
    var _node$raws;
    if ((node == null ? void 0 : node.type) === 'decl' && node.value.includes('</style>')) {
      return;
    }
    if (!options.compress) {
      cssStr += result;
      return;
    }

    // Simple minification logic
    if ((node == null ? void 0 : node.type) === 'comment') return;
    if ((node == null ? void 0 : node.type) === 'decl') {
      const prefix = node.prop + node.raws.between;
      cssStr += result.replace(prefix, prefix.trim());
      return;
    }
    if (type === 'start') {
      if (node.type === 'rule' && node.selectors) {
        cssStr += node.selectors.join(',') + '{';
      } else {
        cssStr += result.replace(/\s\{$/, '{');
      }
      return;
    }
    if (type === 'end' && result === '}' && node != null && (_node$raws = node.raws) != null && _node$raws.semicolon) {
      cssStr = cssStr.slice(0, -1);
    }
    cssStr += result.trim();
  });
  return cssStr;
}

/**
 * Converts a walkStyleRules() iterator to mark nodes with `.$$remove=true` instead of actually removing them.
 * This means they can be removed in a second pass, allowing the first pass to be nondestructive (eg: to preserve mirrored sheets).
 * @private
 * @param {Function} iterator   Invoked on each node in the tree. Return `false` to remove that node.
 * @returns {(rule) => void} nonDestructiveIterator
 */
function markOnly(predicate) {
  return rule => {
    const sel = rule.selectors;
    if (predicate(rule) === false) {
      rule.$$remove = true;
    }
    rule.$$markedSelectors = rule.selectors;
    if (rule._other) {
      rule._other.$$markedSelectors = rule._other.selectors;
    }
    rule.selectors = sel;
  };
}

/**
 * Apply filtered selectors to a rule from a previous markOnly run.
 * @private
 * @param {css.Rule} rule The Rule to apply marked selectors to (if they exist).
 */
function applyMarkedSelectors(rule) {
  if (rule.$$markedSelectors) {
    rule.selectors = rule.$$markedSelectors;
  }
  if (rule._other) {
    applyMarkedSelectors(rule._other);
  }
}

/**
 * Recursively walk all rules in a stylesheet.
 * @private
 * @param {css.Rule} node       A Stylesheet or Rule to descend into.
 * @param {Function} iterator   Invoked on each node in the tree. Return `false` to remove that node.
 */
function walkStyleRules(node, iterator) {
  node.nodes = node.nodes.filter(rule => {
    if (hasNestedRules(rule)) {
      walkStyleRules(rule, iterator);
    }
    rule._other = undefined;
    rule.filterSelectors = filterSelectors;
    return iterator(rule) !== false;
  });
}

/**
 * Recursively walk all rules in two identical stylesheets, filtering nodes into one or the other based on a predicate.
 * @private
 * @param {css.Rule} node       A Stylesheet or Rule to descend into.
 * @param {css.Rule} node2      A second tree identical to `node`
 * @param {Function} iterator   Invoked on each node in the tree. Return `false` to remove that node from the first tree, true to remove it from the second.
 */
function walkStyleRulesWithReverseMirror(node, node2, iterator) {
  if (node2 === null) return walkStyleRules(node, iterator);
  [node.nodes, node2.nodes] = splitFilter(node.nodes, node2.nodes, (rule, index, rules, rules2) => {
    const rule2 = rules2[index];
    if (hasNestedRules(rule)) {
      walkStyleRulesWithReverseMirror(rule, rule2, iterator);
    }
    rule._other = rule2;
    rule.filterSelectors = filterSelectors;
    return iterator(rule) !== false;
  });
}

// Checks if a node has nested rules, like @media
// @keyframes are an exception since they are evaluated as a whole
function hasNestedRules(rule) {
  var _rule$nodes;
  return ((_rule$nodes = rule.nodes) == null ? void 0 : _rule$nodes.length) && rule.name !== 'keyframes' && rule.name !== '-webkit-keyframes' && rule.nodes.some(n => n.type === 'rule' || n.type === 'atrule');
}

// Like [].filter(), but applies the opposite filtering result to a second copy of the Array without a second pass.
// This is just a quicker version of generating the compliment of the set returned from a filter operation.
function splitFilter(a, b, predicate) {
  const aOut = [];
  const bOut = [];
  for (let index = 0; index < a.length; index++) {
    if (predicate(a[index], index, a, b)) {
      aOut.push(a[index]);
    } else {
      bOut.push(a[index]);
    }
  }
  return [aOut, bOut];
}

// can be invoked on a style rule to subset its selectors (with reverse mirroring)
function filterSelectors(predicate) {
  if (this._other) {
    const [a, b] = splitFilter(this.selectors, this._other.selectors, predicate);
    this.selectors = a;
    this._other.selectors = b;
  } else {
    this.selectors = this.selectors.filter(predicate);
  }
}
const MEDIA_TYPES = new Set(['all', 'print', 'screen', 'speech']);
const MEDIA_KEYWORDS = new Set(['and', 'not', ',']);
const MEDIA_FEATURES = new Set(['width', 'aspect-ratio', 'color', 'color-index', 'grid', 'height', 'monochrome', 'orientation', 'resolution', 'scan'].flatMap(feature => [feature, `min-${feature}`, `max-${feature}`]));
function validateMediaType(node) {
  const {
    type: nodeType,
    value: nodeValue
  } = node;
  if (nodeType === 'media-type') {
    return MEDIA_TYPES.has(nodeValue);
  } else if (nodeType === 'keyword') {
    return MEDIA_KEYWORDS.has(nodeValue);
  } else if (nodeType === 'media-feature') {
    return MEDIA_FEATURES.has(nodeValue);
  }
}

/**
 *
 * @param {string} Media query to validate
 * @returns {boolean}
 *
 * This function performs a basic media query validation
 * to ensure the values passed as part of the 'media' config
 * is HTML safe and does not cause any injection issue
 */
function validateMediaQuery(query) {
  // The below is needed for consumption with webpack.
  const mediaParserFn = 'default' in mediaParser ? mediaParser.default : mediaParser;
  const mediaTree = mediaParserFn(query);
  const nodeTypes = new Set(['media-type', 'keyword', 'media-feature']);
  const stack = [mediaTree];
  while (stack.length > 0) {
    const node = stack.pop();
    if (nodeTypes.has(node.type) && !validateMediaType(node)) {
      return false;
    }
    if (node.nodes) {
      stack.push(...node.nodes);
    }
  }
  return true;
}

const LOG_LEVELS = ['trace', 'debug', 'info', 'warn', 'error', 'silent'];
const defaultLogger = {
  trace(msg) {
    console.trace(msg);
  },
  debug(msg) {
    console.debug(msg);
  },
  warn(msg) {
    console.warn(chalk.yellow(msg));
  },
  error(msg) {
    console.error(chalk.bold.red(msg));
  },
  info(msg) {
    console.info(chalk.bold.blue(msg));
  },
  silent() {}
};
function createLogger(logLevel) {
  const logLevelIdx = LOG_LEVELS.indexOf(logLevel);
  return LOG_LEVELS.reduce((logger, type, index) => {
    if (index >= logLevelIdx) {
      logger[type] = defaultLogger[type];
    } else {
      logger[type] = defaultLogger.silent;
    }
    return logger;
  }, {});
}
function isSubpath(basePath, currentPath) {
  return !path.relative(basePath, currentPath).startsWith('..');
}

/**
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

/**
 * The mechanism to use for lazy-loading stylesheets.
 *
 * Note: <kbd>JS</kbd> indicates a strategy requiring JavaScript (falls back to `<noscript>` unless disabled).
 *
 * - **default:** Move stylesheet links to the end of the document and insert preload meta tags in their place.
 * - **"body":** Move all external stylesheet links to the end of the document.
 * - **"media":** Load stylesheets asynchronously by adding `media="not x"` and removing once loaded. <kbd>JS</kbd>
 * - **"swap":** Convert stylesheet links to preloads that swap to `rel="stylesheet"` once loaded ([details](https://www.filamentgroup.com/lab/load-css-simpler/#the-code)). <kbd>JS</kbd>
 * - **"swap-high":** Use `<link rel="alternate stylesheet preload">` and swap to `rel="stylesheet"` once loaded ([details](http://filamentgroup.github.io/loadCSS/test/new-high.html)). <kbd>JS</kbd>
 * - **"js":** Inject an asynchronous CSS loader similar to [LoadCSS](https://github.com/filamentgroup/loadCSS) and use it to load stylesheets. <kbd>JS</kbd>
 * - **"js-lazy":** Like `"js"`, but the stylesheet is disabled until fully loaded.
 * - **false:** Disables adding preload tags.
 * @typedef {(default|'body'|'media'|'swap'|'swap-high'|'js'|'js-lazy')} PreloadStrategy
 * @public
 */

/**
 * Controls which keyframes rules are inlined.
 *
 * - **"critical":** _(default)_ inline keyframes rules that are used by the critical CSS.
 * - **"all":** Inline all keyframes rules.
 * - **"none":** Remove all keyframes rules.
 * @typedef {('critical'|'all'|'none')} KeyframeStrategy
 * @private
 * @property {String} keyframes     Which {@link KeyframeStrategy keyframe strategy} to use (default: `critical`)_
 */

/**
 * Controls log level of the plugin. Specifies the level the logger should use. A logger will
 * not produce output for any log level beneath the specified level. Available levels and order
 * are:
 *
 * - **"info"** _(default)_
 * - **"warn"**
 * - **"error"**
 * - **"trace"**
 * - **"debug"**
 * - **"silent"**
 * @typedef {('info'|'warn'|'error'|'trace'|'debug'|'silent')} LogLevel
 * @public
 */

/**
 * Custom logger interface:
 * @typedef {object} Logger
 * @public
 * @property {function(String)} trace - Prints a trace message
 * @property {function(String)} debug - Prints a debug message
 * @property {function(String)} info - Prints an information message
 * @property {function(String)} warn - Prints a warning message
 * @property {function(String)} error - Prints an error message
 */

/**
 * All optional. Pass them to `new Critters({ ... })`.
 * @public
 * @typedef Options
 * @property {String} path     Base path location of the CSS files _(default: `''`)_
 * @property {String} publicPath     Public path of the CSS resources. This prefix is removed from the href _(default: `''`)_
 * @property {Boolean} external     Inline styles from external stylesheets _(default: `true`)_
 * @property {Number} inlineThreshold Inline external stylesheets smaller than a given size _(default: `0`)_
 * @property {Number} minimumExternalSize If the non-critical external stylesheet would be below this size, just inline it _(default: `0`)_
 * @property {Boolean} pruneSource  Remove inlined rules from the external stylesheet _(default: `false`)_
 * @property {Boolean} mergeStylesheets Merged inlined stylesheets into a single `<style>` tag _(default: `true`)_
 * @property {String[]} additionalStylesheets Glob for matching other stylesheets to be used while looking for critical CSS.
 * @property {String} preload       Which {@link PreloadStrategy preload strategy} to use
 * @property {Boolean} noscriptFallback Add `<noscript>` fallback to JS-based strategies
 * @property {Boolean} inlineFonts  Inline critical font-face rules _(default: `false`)_
 * @property {Boolean} preloadFonts Preloads critical fonts _(default: `true`)_
 * @property {Boolean} fonts        Shorthand for setting `inlineFonts` + `preloadFonts`
 *  - Values:
 *  - `true` to inline critical font-face rules and preload the fonts
 *  - `false` to don't inline any font-face rules and don't preload fonts
 * @property {String} keyframes     Controls which keyframes rules are inlined.
 *  - Values:
 *  - `"critical"`: _(default)_ inline keyframes rules used by the critical CSS
 *  - `"all"` inline all keyframes rules
 *  - `"none"` remove all keyframes rules
 * @property {Boolean} compress     Compress resulting critical CSS _(default: `true`)_
 * @property {String} logLevel      Controls {@link LogLevel log level} of the plugin _(default: `"info"`)_
 * @property {object} logger        Provide a custom logger interface {@link Logger logger}
 */

class Critters {
  /** @private */
  constructor(options) {
    this.options = Object.assign({
      logLevel: 'info',
      path: '',
      publicPath: '',
      reduceInlineStyles: true,
      pruneSource: false,
      additionalStylesheets: [],
      allowRules: []
    }, options || {});
    this.urlFilter = this.options.filter;
    if (this.urlFilter instanceof RegExp) {
      this.urlFilter = this.urlFilter.test.bind(this.urlFilter);
    }
    this.logger = this.options.logger || createLogger(this.options.logLevel);
  }

  /**
   * Read the contents of a file from the specified filesystem or disk
   */
  readFile(filename) {
    const fs$1 = this.fs;
    return new Promise((resolve, reject) => {
      const callback = (err, data) => {
        if (err) reject(err);else resolve(data);
      };
      if (fs$1 && fs$1.readFile) {
        fs$1.readFile(filename, callback);
      } else {
        fs.readFile(filename, 'utf8', callback);
      }
    });
  }

  /**
   * Apply critical CSS processing to the html
   */
  async process(html) {
    const start = process.hrtime.bigint();

    // Parse the generated HTML in a DOM we can mutate
    const document = createDocument(html);
    if (this.options.additionalStylesheets.length > 0) {
      this.embedAdditionalStylesheet(document);
    }

    // `external:false` skips processing of external sheets
    if (this.options.external !== false) {
      const externalSheets = [].slice.call(document.querySelectorAll('link[rel="stylesheet"]'));
      await Promise.all(externalSheets.map(link => this.embedLinkedStylesheet(link, document)));
    }

    // go through all the style tags in the document and reduce them to only critical CSS
    const styles = this.getAffectedStyleTags(document);
    await Promise.all(styles.map(style => this.processStyle(style, document)));
    if (this.options.mergeStylesheets !== false && styles.length !== 0) {
      await this.mergeStylesheets(document);
    }

    // serialize the document back to HTML and we're done
    const output = serializeDocument(document);
    const end = process.hrtime.bigint();
    this.logger.info('Time ' + parseFloat(end - start) / 1000000.0);
    return output;
  }

  /**
   * Get the style tags that need processing
   */
  getAffectedStyleTags(document) {
    const styles = [].slice.call(document.querySelectorAll('style'));

    // `inline:false` skips processing of inline stylesheets
    if (this.options.reduceInlineStyles === false) {
      return styles.filter(style => style.$$external);
    }
    return styles;
  }
  async mergeStylesheets(document) {
    const styles = this.getAffectedStyleTags(document);
    if (styles.length === 0) {
      this.logger.warn('Merging inline stylesheets into a single <style> tag skipped, no inline stylesheets to merge');
      return;
    }
    const first = styles[0];
    let sheet = first.textContent;
    for (let i = 1; i < styles.length; i++) {
      const node = styles[i];
      sheet += node.textContent;
      node.remove();
    }
    first.textContent = sheet;
  }

  /**
   * Given href, find the corresponding CSS asset
   */
  async getCssAsset(href) {
    const outputPath = this.options.path;
    const publicPath = this.options.publicPath;

    // CHECK - the output path
    // path on disk (with output.publicPath removed)
    let normalizedPath = href.replace(/^\//, '');
    const pathPrefix = (publicPath || '').replace(/(^\/|\/$)/g, '') + '/';
    if (normalizedPath.startsWith(pathPrefix)) {
      normalizedPath = normalizedPath.substring(pathPrefix.length).replace(/^\//, '');
    }

    // Ignore remote stylesheets
    if (/^https?:\/\//.test(normalizedPath) || href.startsWith('//')) {
      return undefined;
    }
    const filename = path.resolve(outputPath, normalizedPath);
    // Check if the resolved path is valid
    if (!isSubpath(outputPath, filename)) {
      return undefined;
    }
    let sheet;
    try {
      sheet = await this.readFile(filename);
    } catch (e) {
      this.logger.warn(`Unable to locate stylesheet: ${filename}`);
    }
    return sheet;
  }
  checkInlineThreshold(link, style, sheet) {
    if (this.options.inlineThreshold && sheet.length < this.options.inlineThreshold) {
      const href = style.$$name;
      style.$$reduce = false;
      this.logger.info(`\u001b[32mInlined all of ${href} (${sheet.length} was below the threshold of ${this.options.inlineThreshold})\u001b[39m`);
      link.remove();
      return true;
    }
    return false;
  }

  /**
   * Inline the stylesheets from options.additionalStylesheets (assuming it passes `options.filter`)
   */
  async embedAdditionalStylesheet(document) {
    const styleSheetsIncluded = [];
    const sources = await Promise.all(this.options.additionalStylesheets.map(cssFile => {
      if (styleSheetsIncluded.includes(cssFile)) {
        return;
      }
      styleSheetsIncluded.push(cssFile);
      const style = document.createElement('style');
      style.$$external = true;
      return this.getCssAsset(cssFile, style).then(sheet => [sheet, style]);
    }));
    sources.forEach(([sheet, style]) => {
      if (!sheet) return;
      style.textContent = sheet;
      document.head.appendChild(style);
    });
  }

  /**
   * Inline the target stylesheet referred to by a <link rel="stylesheet"> (assuming it passes `options.filter`)
   */
  async embedLinkedStylesheet(link, document) {
    const href = link.getAttribute('href');
    let media = link.getAttribute('media');
    if (media && !validateMediaQuery(media)) {
      media = undefined;
    }
    const preloadMode = this.options.preload;

    // skip filtered resources, or network resources if no filter is provided
    if (this.urlFilter ? this.urlFilter(href) : !(href != null && href.endsWith('.css'))) {
      return Promise.resolve();
    }

    // the reduced critical CSS gets injected into a new <style> tag
    const style = document.createElement('style');
    style.$$external = true;
    const sheet = await this.getCssAsset(href, style);
    if (!sheet) {
      return;
    }
    style.textContent = sheet;
    style.$$name = href;
    style.$$links = [link];
    link.parentNode.insertBefore(style, link);
    if (this.checkInlineThreshold(link, style, sheet)) {
      return;
    }

    // CSS loader is only injected for the first sheet, then this becomes an empty string
    let cssLoaderPreamble = "function $loadcss(u,m,l){(l=document.createElement('link')).rel='stylesheet';l.href=u;document.head.appendChild(l)}";
    const lazy = preloadMode === 'js-lazy';
    if (lazy) {
      cssLoaderPreamble = cssLoaderPreamble.replace('l.href', "l.media='print';l.onload=function(){l.media=m};l.href");
    }

    // Allow disabling any mutation of the stylesheet link:
    if (preloadMode === false) return;
    let noscriptFallback = false;
    if (preloadMode === 'body') {
      document.body.appendChild(link);
    } else {
      link.setAttribute('rel', 'preload');
      link.setAttribute('as', 'style');
      if (preloadMode === 'js' || preloadMode === 'js-lazy') {
        const script = document.createElement('script');
        script.setAttribute('data-href', href);
        script.setAttribute('data-media', media || 'all');
        const js = `${cssLoaderPreamble}$loadcss(document.currentScript.dataset.href,document.currentScript.dataset.media)`;
        // script.appendChild(document.createTextNode(js));
        script.textContent = js;
        link.parentNode.insertBefore(script, link.nextSibling);
        style.$$links.push(script);
        cssLoaderPreamble = '';
        noscriptFallback = true;
      } else if (preloadMode === 'media') {
        // @see https://github.com/filamentgroup/loadCSS/blob/af1106cfe0bf70147e22185afa7ead96c01dec48/src/loadCSS.js#L26
        link.setAttribute('rel', 'stylesheet');
        link.removeAttribute('as');
        link.setAttribute('media', 'print');
        link.setAttribute('onload', `this.media='${media || 'all'}'`);
        noscriptFallback = true;
      } else if (preloadMode === 'swap-high') {
        // @see http://filamentgroup.github.io/loadCSS/test/new-high.html
        link.setAttribute('rel', 'alternate stylesheet preload');
        link.setAttribute('title', 'styles');
        link.setAttribute('onload', `this.title='';this.rel='stylesheet'`);
        noscriptFallback = true;
      } else if (preloadMode === 'swap') {
        link.setAttribute('onload', "this.rel='stylesheet'");
        noscriptFallback = true;
      } else {
        const bodyLink = document.createElement('link');
        bodyLink.setAttribute('rel', 'stylesheet');
        if (media) bodyLink.setAttribute('media', media);
        bodyLink.setAttribute('href', href);
        document.body.appendChild(bodyLink);
        style.$$links.push(bodyLink);
      }
    }
    if (this.options.noscriptFallback !== false && noscriptFallback &&
    // Don't parse the URL if it contains </noscript> as it might cause unexpected behavior
    !href.includes('</noscript>')) {
      const noscript = document.createElement('noscript');
      const noscriptLink = document.createElement('link');
      noscriptLink.setAttribute('rel', 'stylesheet');
      noscriptLink.setAttribute('href', href);
      if (media) noscriptLink.setAttribute('media', media);
      noscript.appendChild(noscriptLink);
      link.parentNode.insertBefore(noscript, link.nextSibling);
      style.$$links.push(noscript);
    }
  }

  /**
   * Prune the source CSS files
   */
  pruneSource(style, before, sheetInverse) {
    // if external stylesheet would be below minimum size, just inline everything
    const minSize = this.options.minimumExternalSize;
    const name = style.$$name;
    if (minSize && sheetInverse.length < minSize) {
      this.logger.info(`\u001b[32mInlined all of ${name} (non-critical external stylesheet would have been ${sheetInverse.length}b, which was below the threshold of ${minSize})\u001b[39m`);
      style.textContent = before;
      // remove any associated external resources/loaders:
      if (style.$$links) {
        for (const link of style.$$links) {
          const parent = link.parentNode;
          if (parent) parent.removeChild(link);
        }
      }
      return true;
    }
    return false;
  }

  /**
   * Parse the stylesheet within a <style> element, then reduce it to contain only rules used by the document.
   */
  async processStyle(style, document) {
    if (style.$$reduce === false) return;
    const name = style.$$name ? style.$$name.replace(/^\//, '') : 'inline CSS';
    const options = this.options;
    const crittersContainer = document.crittersContainer;
    let keyframesMode = options.keyframes || 'critical';
    // we also accept a boolean value for options.keyframes
    if (keyframesMode === true) keyframesMode = 'all';
    if (keyframesMode === false) keyframesMode = 'none';
    let sheet = style.textContent;

    // store a reference to the previous serialized stylesheet for reporting stats
    const before = sheet;

    // Skip empty stylesheets
    if (!sheet) return;
    const ast = parseStylesheet(sheet);
    const astInverse = options.pruneSource ? parseStylesheet(sheet) : null;

    // a string to search for font names (very loose)
    let criticalFonts = '';
    const failedSelectors = [];
    const criticalKeyframeNames = new Set();
    let includeNext = false;
    let includeAll = false;
    let excludeNext = false;
    let excludeAll = false;
    const shouldPreloadFonts = options.fonts === true || options.preloadFonts === true;
    const shouldInlineFonts = options.fonts !== false && options.inlineFonts === true;

    // Walk all CSS rules, marking unused rules with `.$$remove=true` for removal in the second pass.
    // This first pass is also used to collect font and keyframe usage used in the second pass.
    walkStyleRules(ast, markOnly(rule => {
      var _rule$nodes;
      if (rule.type === 'comment') {
        // we might want to remove a leading ! on comment blocks
        // critters can be part of "legal comments" which aren't striped on build
        const crittersComment = rule.text.match(/^(?<!\! )critters:(.*)/);
        const command = crittersComment && crittersComment[1];
        if (command) {
          switch (command) {
            case 'include':
              includeNext = true;
              break;
            case 'exclude':
              excludeNext = true;
              break;
            case 'include start':
              includeAll = true;
              break;
            case 'include end':
              includeAll = false;
              break;
            case 'exclude start':
              excludeAll = true;
              break;
            case 'exclude end':
              excludeAll = false;
              break;
          }
        }
      }
      if (rule.type === 'rule') {
        // Handle comment based markers
        if (includeNext) {
          includeNext = false;
          return true;
        }
        if (excludeNext) {
          excludeNext = false;
          return false;
        }
        if (includeAll) {
          return true;
        }
        if (excludeAll) {
          return false;
        }

        // Filter the selector list down to only those match
        rule.filterSelectors(sel => {
          // Validate rule with 'allowRules' option
          const isAllowedRule = options.allowRules.some(exp => {
            if (exp instanceof RegExp) {
              return exp.test(sel);
            }
            return exp === sel;
          });
          if (isAllowedRule) return true;

          // Strip pseudo-elements and pseudo-classes, since we only care that their associated elements exist.
          // This means any selector for a pseudo-element or having a pseudo-class will be inlined if the rest of the selector matches.
          if (sel === ':root' || sel === 'html' || sel === 'body' || /^::?(before|after)$/.test(sel)) {
            return true;
          }
          sel = sel.replace(/(?<!\\)::?[a-z-]+(?![a-z-(])/gi, '').replace(/::?not\(\s*\)/g, '')
          // Remove tailing or leading commas from cleaned sub selector `is(.active, :hover)` -> `is(.active)`.
          .replace(/\(\s*,/g, '(').replace(/,\s*\)/g, ')').trim();
          if (!sel) return false;
          try {
            return crittersContainer.exists(sel);
          } catch (e) {
            failedSelectors.push(sel + ' -> ' + e.message);
            return false;
          }
        });

        // If there are no matched selectors, remove the rule:
        if (!rule.selector) {
          return false;
        }
        if (rule.nodes) {
          for (const decl of rule.nodes) {
            // detect used fonts
            if (shouldInlineFonts && decl.prop && /\bfont(-family)?\b/i.test(decl.prop)) {
              criticalFonts += ' ' + decl.value;
            }

            // detect used keyframes
            if (decl.prop === 'animation' || decl.prop === 'animation-name') {
              for (const name of decl.value.split(/\s+/)) {
                // @todo: parse animation declarations and extract only the name. for now we'll do a lazy match.
                const nameTrimmed = name.trim();
                if (nameTrimmed) criticalKeyframeNames.add(nameTrimmed);
              }
            }
          }
        }
      }

      // keep font rules, they're handled in the second pass:
      if (rule.type === 'atrule' && rule.name === 'font-face') return;

      // If there are no remaining rules, remove the whole rule:
      const rules = (_rule$nodes = rule.nodes) == null ? void 0 : _rule$nodes.filter(rule => !rule.$$remove);
      return !rules || rules.length !== 0;
    }));
    if (failedSelectors.length !== 0) {
      this.logger.warn(`${failedSelectors.length} rules skipped due to selector errors:\n  ${failedSelectors.join('\n  ')}`);
    }
    const preloadedFonts = new Set();
    // Second pass, using data picked up from the first
    walkStyleRulesWithReverseMirror(ast, astInverse, rule => {
      // remove any rules marked in the first pass
      if (rule.$$remove === true) return false;
      applyMarkedSelectors(rule);

      // prune @keyframes rules
      if (rule.type === 'atrule' && rule.name === 'keyframes') {
        if (keyframesMode === 'none') return false;
        if (keyframesMode === 'all') return true;
        return criticalKeyframeNames.has(rule.params);
      }

      // prune @font-face rules
      if (rule.type === 'atrule' && rule.name === 'font-face') {
        let family, src;
        for (const decl of rule.nodes) {
          if (decl.prop === 'src') {
            // @todo parse this properly and generate multiple preloads with type="font/woff2" etc
            src = (decl.value.match(/url\s*\(\s*(['"]?)(.+?)\1\s*\)/) || [])[2];
          } else if (decl.prop === 'font-family') {
            family = decl.value;
          }
        }
        if (src && shouldPreloadFonts && !preloadedFonts.has(src)) {
          preloadedFonts.add(src);
          const preload = document.createElement('link');
          preload.setAttribute('rel', 'preload');
          preload.setAttribute('as', 'font');
          preload.setAttribute('crossorigin', 'anonymous');
          preload.setAttribute('href', src.trim());
          document.head.appendChild(preload);
        }

        // if we're missing info, if the font is unused, or if critical font inlining is disabled, remove the rule:
        if (!shouldInlineFonts || !family || !src || !criticalFonts.includes(family)) {
          return false;
        }
      }
    });
    sheet = serializeStylesheet(ast, {
      compress: this.options.compress !== false
    });

    // If all rules were removed, get rid of the style element entirely
    if (sheet.trim().length === 0) {
      if (style.parentNode) {
        style.remove();
      }
      return;
    }
    let afterText = '';
    let styleInlinedCompletely = false;
    if (options.pruneSource) {
      const sheetInverse = serializeStylesheet(astInverse, {
        compress: this.options.compress !== false
      });
      styleInlinedCompletely = this.pruneSource(style, before, sheetInverse);
      if (styleInlinedCompletely) {
        const percent = sheetInverse.length / before.length * 100;
        afterText = `, reducing non-inlined size ${percent | 0}% to ${formatSize(sheetInverse.length)}`;
      }
    }

    // replace the inline stylesheet with its critical'd counterpart
    if (!styleInlinedCompletely) {
      style.textContent = sheet;
    }

    // output stats
    const percent = sheet.length / before.length * 100 | 0;
    this.logger.info('\u001b[32mInlined ' + formatSize(sheet.length) + ' (' + percent + '% of original ' + formatSize(before.length) + ') of ' + name + afterText + '.\u001b[39m');
  }
}
function formatSize(size) {
  if (size <= 0) {
    return '0 bytes';
  }
  const abbreviations = ['bytes', 'kB', 'MB', 'GB'];
  const index = Math.floor(Math.log(size) / Math.log(1024));
  const roundedSize = size / Math.pow(1024, index);
  // bytes don't have a fraction
  const fractionDigits = index === 0 ? 0 : 2;
  return `${roundedSize.toFixed(fractionDigits)} ${abbreviations[index]}`;
}

module.exports = Critters;