'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var CleanCSS = require('clean-css');
var entities = require('entities');
var RelateURL = require('relateurl');
var terser = require('terser');

async function replaceAsync(str, regex, asyncFn) {
  const promises = [];

  str.replace(regex, (match, ...args) => {
    const promise = asyncFn(match, ...args);
    promises.push(promise);
  });

  const data = await Promise.all(promises);
  return str.replace(regex, () => data.shift());
}

/*!
 * HTML Parser By John Resig (ejohn.org)
 * Modified by Juriy “kangax” Zaytsev
 * Original code by Erik Arvidsson, Mozilla Public License
 * http://erik.eae.net/simplehtmlparser/simplehtmlparser.js
 */


class CaseInsensitiveSet extends Set {
  has(str) {
    return super.has(str.toLowerCase());
  }
}

// Regular expressions for parsing tags and attributes
const singleAttrIdentifier = /([^\s"'<>/=]+)/;
const singleAttrAssigns = [/=/];
const singleAttrValues = [
  // attr value double quotes
  /"([^"]*)"+/.source,
  // attr value, single quotes
  /'([^']*)'+/.source,
  // attr value, no quotes
  /([^ \t\n\f\r"'`=<>]+)/.source
];
// https://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-QName
const qnameCapture = (function () {
  // based on https://www.npmjs.com/package/ncname
  const combiningChar = '\\u0300-\\u0345\\u0360\\u0361\\u0483-\\u0486\\u0591-\\u05A1\\u05A3-\\u05B9\\u05BB-\\u05BD\\u05BF\\u05C1\\u05C2\\u05C4\\u064B-\\u0652\\u0670\\u06D6-\\u06E4\\u06E7\\u06E8\\u06EA-\\u06ED\\u0901-\\u0903\\u093C\\u093E-\\u094D\\u0951-\\u0954\\u0962\\u0963\\u0981-\\u0983\\u09BC\\u09BE-\\u09C4\\u09C7\\u09C8\\u09CB-\\u09CD\\u09D7\\u09E2\\u09E3\\u0A02\\u0A3C\\u0A3E-\\u0A42\\u0A47\\u0A48\\u0A4B-\\u0A4D\\u0A70\\u0A71\\u0A81-\\u0A83\\u0ABC\\u0ABE-\\u0AC5\\u0AC7-\\u0AC9\\u0ACB-\\u0ACD\\u0B01-\\u0B03\\u0B3C\\u0B3E-\\u0B43\\u0B47\\u0B48\\u0B4B-\\u0B4D\\u0B56\\u0B57\\u0B82\\u0B83\\u0BBE-\\u0BC2\\u0BC6-\\u0BC8\\u0BCA-\\u0BCD\\u0BD7\\u0C01-\\u0C03\\u0C3E-\\u0C44\\u0C46-\\u0C48\\u0C4A-\\u0C4D\\u0C55\\u0C56\\u0C82\\u0C83\\u0CBE-\\u0CC4\\u0CC6-\\u0CC8\\u0CCA-\\u0CCD\\u0CD5\\u0CD6\\u0D02\\u0D03\\u0D3E-\\u0D43\\u0D46-\\u0D48\\u0D4A-\\u0D4D\\u0D57\\u0E31\\u0E34-\\u0E3A\\u0E47-\\u0E4E\\u0EB1\\u0EB4-\\u0EB9\\u0EBB\\u0EBC\\u0EC8-\\u0ECD\\u0F18\\u0F19\\u0F35\\u0F37\\u0F39\\u0F3E\\u0F3F\\u0F71-\\u0F84\\u0F86-\\u0F8B\\u0F90-\\u0F95\\u0F97\\u0F99-\\u0FAD\\u0FB1-\\u0FB7\\u0FB9\\u20D0-\\u20DC\\u20E1\\u302A-\\u302F\\u3099\\u309A';
  const digit = '0-9\\u0660-\\u0669\\u06F0-\\u06F9\\u0966-\\u096F\\u09E6-\\u09EF\\u0A66-\\u0A6F\\u0AE6-\\u0AEF\\u0B66-\\u0B6F\\u0BE7-\\u0BEF\\u0C66-\\u0C6F\\u0CE6-\\u0CEF\\u0D66-\\u0D6F\\u0E50-\\u0E59\\u0ED0-\\u0ED9\\u0F20-\\u0F29';
  const extender = '\\xB7\\u02D0\\u02D1\\u0387\\u0640\\u0E46\\u0EC6\\u3005\\u3031-\\u3035\\u309D\\u309E\\u30FC-\\u30FE';
  const letter = 'A-Za-z\\xC0-\\xD6\\xD8-\\xF6\\xF8-\\u0131\\u0134-\\u013E\\u0141-\\u0148\\u014A-\\u017E\\u0180-\\u01C3\\u01CD-\\u01F0\\u01F4\\u01F5\\u01FA-\\u0217\\u0250-\\u02A8\\u02BB-\\u02C1\\u0386\\u0388-\\u038A\\u038C\\u038E-\\u03A1\\u03A3-\\u03CE\\u03D0-\\u03D6\\u03DA\\u03DC\\u03DE\\u03E0\\u03E2-\\u03F3\\u0401-\\u040C\\u040E-\\u044F\\u0451-\\u045C\\u045E-\\u0481\\u0490-\\u04C4\\u04C7\\u04C8\\u04CB\\u04CC\\u04D0-\\u04EB\\u04EE-\\u04F5\\u04F8\\u04F9\\u0531-\\u0556\\u0559\\u0561-\\u0586\\u05D0-\\u05EA\\u05F0-\\u05F2\\u0621-\\u063A\\u0641-\\u064A\\u0671-\\u06B7\\u06BA-\\u06BE\\u06C0-\\u06CE\\u06D0-\\u06D3\\u06D5\\u06E5\\u06E6\\u0905-\\u0939\\u093D\\u0958-\\u0961\\u0985-\\u098C\\u098F\\u0990\\u0993-\\u09A8\\u09AA-\\u09B0\\u09B2\\u09B6-\\u09B9\\u09DC\\u09DD\\u09DF-\\u09E1\\u09F0\\u09F1\\u0A05-\\u0A0A\\u0A0F\\u0A10\\u0A13-\\u0A28\\u0A2A-\\u0A30\\u0A32\\u0A33\\u0A35\\u0A36\\u0A38\\u0A39\\u0A59-\\u0A5C\\u0A5E\\u0A72-\\u0A74\\u0A85-\\u0A8B\\u0A8D\\u0A8F-\\u0A91\\u0A93-\\u0AA8\\u0AAA-\\u0AB0\\u0AB2\\u0AB3\\u0AB5-\\u0AB9\\u0ABD\\u0AE0\\u0B05-\\u0B0C\\u0B0F\\u0B10\\u0B13-\\u0B28\\u0B2A-\\u0B30\\u0B32\\u0B33\\u0B36-\\u0B39\\u0B3D\\u0B5C\\u0B5D\\u0B5F-\\u0B61\\u0B85-\\u0B8A\\u0B8E-\\u0B90\\u0B92-\\u0B95\\u0B99\\u0B9A\\u0B9C\\u0B9E\\u0B9F\\u0BA3\\u0BA4\\u0BA8-\\u0BAA\\u0BAE-\\u0BB5\\u0BB7-\\u0BB9\\u0C05-\\u0C0C\\u0C0E-\\u0C10\\u0C12-\\u0C28\\u0C2A-\\u0C33\\u0C35-\\u0C39\\u0C60\\u0C61\\u0C85-\\u0C8C\\u0C8E-\\u0C90\\u0C92-\\u0CA8\\u0CAA-\\u0CB3\\u0CB5-\\u0CB9\\u0CDE\\u0CE0\\u0CE1\\u0D05-\\u0D0C\\u0D0E-\\u0D10\\u0D12-\\u0D28\\u0D2A-\\u0D39\\u0D60\\u0D61\\u0E01-\\u0E2E\\u0E30\\u0E32\\u0E33\\u0E40-\\u0E45\\u0E81\\u0E82\\u0E84\\u0E87\\u0E88\\u0E8A\\u0E8D\\u0E94-\\u0E97\\u0E99-\\u0E9F\\u0EA1-\\u0EA3\\u0EA5\\u0EA7\\u0EAA\\u0EAB\\u0EAD\\u0EAE\\u0EB0\\u0EB2\\u0EB3\\u0EBD\\u0EC0-\\u0EC4\\u0F40-\\u0F47\\u0F49-\\u0F69\\u10A0-\\u10C5\\u10D0-\\u10F6\\u1100\\u1102\\u1103\\u1105-\\u1107\\u1109\\u110B\\u110C\\u110E-\\u1112\\u113C\\u113E\\u1140\\u114C\\u114E\\u1150\\u1154\\u1155\\u1159\\u115F-\\u1161\\u1163\\u1165\\u1167\\u1169\\u116D\\u116E\\u1172\\u1173\\u1175\\u119E\\u11A8\\u11AB\\u11AE\\u11AF\\u11B7\\u11B8\\u11BA\\u11BC-\\u11C2\\u11EB\\u11F0\\u11F9\\u1E00-\\u1E9B\\u1EA0-\\u1EF9\\u1F00-\\u1F15\\u1F18-\\u1F1D\\u1F20-\\u1F45\\u1F48-\\u1F4D\\u1F50-\\u1F57\\u1F59\\u1F5B\\u1F5D\\u1F5F-\\u1F7D\\u1F80-\\u1FB4\\u1FB6-\\u1FBC\\u1FBE\\u1FC2-\\u1FC4\\u1FC6-\\u1FCC\\u1FD0-\\u1FD3\\u1FD6-\\u1FDB\\u1FE0-\\u1FEC\\u1FF2-\\u1FF4\\u1FF6-\\u1FFC\\u2126\\u212A\\u212B\\u212E\\u2180-\\u2182\\u3007\\u3021-\\u3029\\u3041-\\u3094\\u30A1-\\u30FA\\u3105-\\u312C\\u4E00-\\u9FA5\\uAC00-\\uD7A3';
  const ncname = '[' + letter + '_][' + letter + digit + '\\.\\-_' + combiningChar + extender + ']*';
  return '((?:' + ncname + '\\:)?' + ncname + ')';
})();
const startTagOpen = new RegExp('^<' + qnameCapture);
const startTagClose = /^\s*(\/?)>/;
const endTag = new RegExp('^<\\/' + qnameCapture + '[^>]*>');
const doctype = /^<!DOCTYPE\s?[^>]+>/i;

let IS_REGEX_CAPTURING_BROKEN = false;
'x'.replace(/x(.)?/g, function (m, g) {
  IS_REGEX_CAPTURING_BROKEN = g === '';
});

// Empty elements
const empty = new CaseInsensitiveSet(['area', 'base', 'basefont', 'br', 'col', 'embed', 'frame', 'hr', 'img', 'input', 'isindex', 'keygen', 'link', 'meta', 'param', 'source', 'track', 'wbr']);

// Inline elements
const inline = new CaseInsensitiveSet(['a', 'abbr', 'acronym', 'applet', 'b', 'basefont', 'bdo', 'big', 'br', 'button', 'cite', 'code', 'del', 'dfn', 'em', 'font', 'i', 'iframe', 'img', 'input', 'ins', 'kbd', 'label', 'map', 'noscript', 'object', 'q', 's', 'samp', 'script', 'select', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'svg', 'textarea', 'tt', 'u', 'var']);

// Elements that you can, intentionally, leave open
// (and which close themselves)
const closeSelf = new CaseInsensitiveSet(['colgroup', 'dd', 'dt', 'li', 'option', 'p', 'td', 'tfoot', 'th', 'thead', 'tr', 'source']);

// Attributes that have their values filled in disabled='disabled'
const fillAttrs = new CaseInsensitiveSet(['checked', 'compact', 'declare', 'defer', 'disabled', 'ismap', 'multiple', 'nohref', 'noresize', 'noshade', 'nowrap', 'readonly', 'selected']);

// Special elements (can contain anything)
const special = new CaseInsensitiveSet(['script', 'style']);

// HTML elements https://html.spec.whatwg.org/multipage/indices.html#elements-3
// Phrasing Content https://html.spec.whatwg.org/multipage/dom.html#phrasing-content
const nonPhrasing = new CaseInsensitiveSet(['address', 'article', 'aside', 'base', 'blockquote', 'body', 'caption', 'col', 'colgroup', 'dd', 'details', 'dialog', 'div', 'dl', 'dt', 'fieldset', 'figcaption', 'figure', 'footer', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'head', 'header', 'hgroup', 'hr', 'html', 'legend', 'li', 'menuitem', 'meta', 'ol', 'optgroup', 'option', 'param', 'rp', 'rt', 'source', 'style', 'summary', 'tbody', 'td', 'tfoot', 'th', 'thead', 'title', 'tr', 'track', 'ul']);

const reCache = {};

function attrForHandler(handler) {
  let pattern = singleAttrIdentifier.source +
    '(?:\\s*(' + joinSingleAttrAssigns(handler) + ')' +
    '[ \\t\\n\\f\\r]*(?:' + singleAttrValues.join('|') + '))?';
  if (handler.customAttrSurround) {
    const attrClauses = [];
    for (let i = handler.customAttrSurround.length - 1; i >= 0; i--) {
      attrClauses[i] = '(?:' +
        '(' + handler.customAttrSurround[i][0].source + ')\\s*' +
        pattern +
        '\\s*(' + handler.customAttrSurround[i][1].source + ')' +
        ')';
    }
    attrClauses.push('(?:' + pattern + ')');
    pattern = '(?:' + attrClauses.join('|') + ')';
  }
  return new RegExp('^\\s*' + pattern);
}

function joinSingleAttrAssigns(handler) {
  return singleAttrAssigns.concat(
    handler.customAttrAssign || []
  ).map(function (assign) {
    return '(?:' + assign.source + ')';
  }).join('|');
}

class HTMLParser {
  constructor(html, handler) {
    this.html = html;
    this.handler = handler;
  }

  async parse() {
    let html = this.html;
    const handler = this.handler;

    const stack = []; let lastTag;
    const attribute = attrForHandler(handler);
    let last, prevTag, nextTag;
    while (html) {
      last = html;
      // Make sure we’re not in a `script` or `style` element
      if (!lastTag || !special.has(lastTag)) {
        let textEnd = html.indexOf('<');
        if (textEnd === 0) {
          // Comment
          if (/^<!--/.test(html)) {
            const commentEnd = html.indexOf('-->');

            if (commentEnd >= 0) {
              if (handler.comment) {
                await handler.comment(html.substring(4, commentEnd));
              }
              html = html.substring(commentEnd + 3);
              prevTag = '';
              continue;
            }
          }

          // https://en.wikipedia.org/wiki/Conditional_comment#Downlevel-revealed_conditional_comment
          if (/^<!\[/.test(html)) {
            const conditionalEnd = html.indexOf(']>');

            if (conditionalEnd >= 0) {
              if (handler.comment) {
                await handler.comment(html.substring(2, conditionalEnd + 1), true /* non-standard */);
              }
              html = html.substring(conditionalEnd + 2);
              prevTag = '';
              continue;
            }
          }

          // Doctype
          const doctypeMatch = html.match(doctype);
          if (doctypeMatch) {
            if (handler.doctype) {
              handler.doctype(doctypeMatch[0]);
            }
            html = html.substring(doctypeMatch[0].length);
            prevTag = '';
            continue;
          }

          // End tag
          const endTagMatch = html.match(endTag);
          if (endTagMatch) {
            html = html.substring(endTagMatch[0].length);
            await replaceAsync(endTagMatch[0], endTag, parseEndTag);
            prevTag = '/' + endTagMatch[1].toLowerCase();
            continue;
          }

          // Start tag
          const startTagMatch = parseStartTag(html);
          if (startTagMatch) {
            html = startTagMatch.rest;
            await handleStartTag(startTagMatch);
            prevTag = startTagMatch.tagName.toLowerCase();
            continue;
          }

          // Treat `<` as text
          if (handler.continueOnParseError) {
            textEnd = html.indexOf('<', 1);
          }
        }

        let text;
        if (textEnd >= 0) {
          text = html.substring(0, textEnd);
          html = html.substring(textEnd);
        } else {
          text = html;
          html = '';
        }

        // Next tag
        let nextTagMatch = parseStartTag(html);
        if (nextTagMatch) {
          nextTag = nextTagMatch.tagName;
        } else {
          nextTagMatch = html.match(endTag);
          if (nextTagMatch) {
            nextTag = '/' + nextTagMatch[1];
          } else {
            nextTag = '';
          }
        }

        if (handler.chars) {
          await handler.chars(text, prevTag, nextTag);
        }
        prevTag = '';
      } else {
        const stackedTag = lastTag.toLowerCase();
        const reStackedTag = reCache[stackedTag] || (reCache[stackedTag] = new RegExp('([\\s\\S]*?)</' + stackedTag + '[^>]*>', 'i'));

        html = await replaceAsync(html, reStackedTag, async (_, text) => {
          if (stackedTag !== 'script' && stackedTag !== 'style' && stackedTag !== 'noscript') {
            text = text
              .replace(/<!--([\s\S]*?)-->/g, '$1')
              .replace(/<!\[CDATA\[([\s\S]*?)]]>/g, '$1');
          }

          if (handler.chars) {
            await handler.chars(text);
          }

          return '';
        });

        await parseEndTag('</' + stackedTag + '>', stackedTag);
      }

      if (html === last) {
        throw new Error('Parse Error: ' + html);
      }
    }

    if (!handler.partialMarkup) {
      // Clean up any remaining tags
      await parseEndTag();
    }

    function parseStartTag(input) {
      const start = input.match(startTagOpen);
      if (start) {
        const match = {
          tagName: start[1],
          attrs: []
        };
        input = input.slice(start[0].length);
        let end, attr;
        while (!(end = input.match(startTagClose)) && (attr = input.match(attribute))) {
          input = input.slice(attr[0].length);
          match.attrs.push(attr);
        }
        if (end) {
          match.unarySlash = end[1];
          match.rest = input.slice(end[0].length);
          return match;
        }
      }
    }

    function findTagInCurrentTable(tagName) {
      let pos;
      const needle = tagName.toLowerCase();
      for (pos = stack.length - 1; pos >= 0; pos--) {
        const currentTag = stack[pos].tag.toLowerCase();
        if (currentTag === needle) {
          return pos;
        }
        // Stop searching if we hit a table boundary
        if (currentTag === 'table') {
          break;
        }
      }
      return -1;
    }

    async function parseEndTagAt(pos) {
      // Close all open elements up to pos (mirrors parseEndTag’s core branch)
      for (let i = stack.length - 1; i >= pos; i--) {
        if (handler.end) {
          await handler.end(stack[i].tag, stack[i].attrs, true);
        }
      }
      stack.length = pos;
      lastTag = pos && stack[pos - 1].tag;
    }

    async function closeIfFoundInCurrentTable(tagName) {
      const pos = findTagInCurrentTable(tagName);
      if (pos >= 0) {
        // Close at the specific index to avoid re-searching
        await parseEndTagAt(pos);
        return true;
      }
      return false;
    }

    async function handleStartTag(match) {
      const tagName = match.tagName;
      let unarySlash = match.unarySlash;

      if (handler.html5) {
        if (lastTag === 'p' && nonPhrasing.has(tagName)) {
          await parseEndTag('', lastTag);
        } else if (tagName === 'tbody') {
          await closeIfFoundInCurrentTable('thead');
        } else if (tagName === 'tfoot') {
          if (!await closeIfFoundInCurrentTable('tbody')) {
            await closeIfFoundInCurrentTable('thead');
          }
        } else if (tagName === 'thead') {
          // If a `tbody` or `tfoot` is open in the current table, close it
          if (!await closeIfFoundInCurrentTable('tbody')) {
            await closeIfFoundInCurrentTable('tfoot');
          }
        }
        if (tagName === 'col' && findTag('colgroup') < 0) {
          lastTag = 'colgroup';
          stack.push({ tag: lastTag, attrs: [] });
          if (handler.start) {
            await handler.start(lastTag, [], false, '');
          }
        }
      }

      if (!handler.html5 && !inline.has(tagName)) {
        while (lastTag && inline.has(lastTag)) {
          await parseEndTag('', lastTag);
        }
      }

      if (closeSelf.has(tagName) && lastTag === tagName) {
        await parseEndTag('', tagName);
      }

      // Handle `dt`/`dd` cross-closing: `dt` followed by `dd`, or `dd` followed by `dt`
      if ((tagName === 'dt' || tagName === 'dd') && (lastTag === 'dt' || lastTag === 'dd')) {
        await parseEndTag('', lastTag);
      }

      const unary = empty.has(tagName) || (tagName === 'html' && lastTag === 'head') || !!unarySlash;

      const attrs = match.attrs.map(function (args) {
        let name, value, customOpen, customClose, customAssign, quote;
        const ncp = 7; // Number of captured parts, scalar

        // Hackish workaround for FF bug https://bugzilla.mozilla.org/show_bug.cgi?id=369778
        if (IS_REGEX_CAPTURING_BROKEN && args[0].indexOf('""') === -1) {
          if (args[3] === '') { delete args[3]; }
          if (args[4] === '') { delete args[4]; }
          if (args[5] === '') { delete args[5]; }
        }

        function populate(index) {
          customAssign = args[index];
          value = args[index + 1];
          if (typeof value !== 'undefined') {
            return '"';
          }
          value = args[index + 2];
          if (typeof value !== 'undefined') {
            return '\'';
          }
          value = args[index + 3];
          if (typeof value === 'undefined' && fillAttrs.has(name)) {
            value = name;
          }
          return '';
        }

        let j = 1;
        if (handler.customAttrSurround) {
          for (let i = 0, l = handler.customAttrSurround.length; i < l; i++, j += ncp) {
            name = args[j + 1];
            if (name) {
              quote = populate(j + 2);
              customOpen = args[j];
              customClose = args[j + 6];
              break;
            }
          }
        }

        if (!name && (name = args[j])) {
          quote = populate(j + 1);
        }

        return {
          name,
          value,
          customAssign: customAssign || '=',
          customOpen: customOpen || '',
          customClose: customClose || '',
          quote: quote || ''
        };
      });

      if (!unary) {
        stack.push({ tag: tagName, attrs });
        lastTag = tagName;
        unarySlash = '';
      }

      if (handler.start) {
        await handler.start(tagName, attrs, unary, unarySlash);
      }
    }

    function findTag(tagName) {
      let pos;
      const needle = tagName.toLowerCase();
      for (pos = stack.length - 1; pos >= 0; pos--) {
        if (stack[pos].tag.toLowerCase() === needle) {
          break;
        }
      }
      return pos;
    }

    async function parseEndTag(tag, tagName) {
      let pos;

      // Find the closest opened tag of the same type
      if (tagName) {
        pos = findTag(tagName);
      } else { // If no tag name is provided, clean shop
        pos = 0;
      }

      if (pos >= 0) {
        // Close all the open elements, up the stack
        for (let i = stack.length - 1; i >= pos; i--) {
          if (handler.end) {
            handler.end(stack[i].tag, stack[i].attrs, i > pos || !tag);
          }
        }

        // Remove the open elements from the stack
        stack.length = pos;
        lastTag = pos && stack[pos - 1].tag;
      } else if (tagName.toLowerCase() === 'br') {
        if (handler.start) {
          await handler.start(tagName, [], true, '');
        }
      } else if (tagName.toLowerCase() === 'p') {
        if (handler.start) {
          await handler.start(tagName, [], false, '', true);
        }
        if (handler.end) {
          handler.end(tagName, []);
        }
      }
    }
  }
}

class Sorter {
  sort(tokens, fromIndex = 0) {
    for (let i = 0, len = this.keys.length; i < len; i++) {
      const key = this.keys[i];
      const token = key.slice(1);

      let index = tokens.indexOf(token, fromIndex);

      if (index !== -1) {
        do {
          if (index !== fromIndex) {
            tokens.splice(index, 1);
            tokens.splice(fromIndex, 0, token);
          }
          fromIndex++;
        } while ((index = tokens.indexOf(token, fromIndex)) !== -1);

        return this[key].sort(tokens, fromIndex);
      }
    }
    return tokens;
  }
}

class TokenChain {
  add(tokens) {
    tokens.forEach((token) => {
      const key = '$' + token;
      if (!this[key]) {
        this[key] = [];
        this[key].processed = 0;
      }
      this[key].push(tokens);
    });
  }

  createSorter() {
    const sorter = new Sorter();

    sorter.keys = Object.keys(this).sort((j, k) => {
      const m = this[j].length;
      const n = this[k].length;
      return m < n ? 1 : m > n ? -1 : j < k ? -1 : j > k ? 1 : 0;
    }).filter((key) => {
      if (this[key].processed < this[key].length) {
        const token = key.slice(1);
        const chain = new TokenChain();

        this[key].forEach((tokens) => {
          let index;
          while ((index = tokens.indexOf(token)) !== -1) {
            tokens.splice(index, 1);
          }
          tokens.forEach((token) => {
            this['$' + token].processed++;
          });
          chain.add(tokens.slice(0));
        });
        sorter[key] = chain.createSorter();
        return true;
      }
      return false;
    });
    return sorter;
  }
}

const trimWhitespace = str => str && str.replace(/^[ \n\r\t\f]+/, '').replace(/[ \n\r\t\f]+$/, '');

function collapseWhitespaceAll(str) {
  // Non-breaking space is specifically handled inside the replacer function here:
  return str && str.replace(/[ \n\r\t\f\xA0]+/g, function (spaces) {
    return spaces === '\t' ? '\t' : spaces.replace(/(^|\xA0+)[^\xA0]+/g, '$1 ');
  });
}

function collapseWhitespace(str, options, trimLeft, trimRight, collapseAll) {
  let lineBreakBefore = ''; let lineBreakAfter = '';

  if (options.preserveLineBreaks) {
    str = str.replace(/^[ \n\r\t\f]*?[\n\r][ \n\r\t\f]*/, function () {
      lineBreakBefore = '\n';
      return '';
    }).replace(/[ \n\r\t\f]*?[\n\r][ \n\r\t\f]*$/, function () {
      lineBreakAfter = '\n';
      return '';
    });
  }

  if (trimLeft) {
    // Non-breaking space is specifically handled inside the replacer function here:
    str = str.replace(/^[ \n\r\t\f\xA0]+/, function (spaces) {
      const conservative = !lineBreakBefore && options.conservativeCollapse;
      if (conservative && spaces === '\t') {
        return '\t';
      }
      return spaces.replace(/^[^\xA0]+/, '').replace(/(\xA0+)[^\xA0]+/g, '$1 ') || (conservative ? ' ' : '');
    });
  }

  if (trimRight) {
    // Non-breaking space is specifically handled inside the replacer function here:
    str = str.replace(/[ \n\r\t\f\xA0]+$/, function (spaces) {
      const conservative = !lineBreakAfter && options.conservativeCollapse;
      if (conservative && spaces === '\t') {
        return '\t';
      }
      return spaces.replace(/[^\xA0]+(\xA0+)/g, ' $1').replace(/[^\xA0]+$/, '') || (conservative ? ' ' : '');
    });
  }

  if (collapseAll) {
    // Strip non-space whitespace then compress spaces to one
    str = collapseWhitespaceAll(str);
  }

  return lineBreakBefore + str + lineBreakAfter;
}

// Non-empty elements that will maintain whitespace around them
const inlineElementsToKeepWhitespaceAround = ['a', 'abbr', 'acronym', 'b', 'bdi', 'bdo', 'big', 'button', 'cite', 'code', 'del', 'dfn', 'em', 'font', 'i', 'img', 'input', 'ins', 'kbd', 'label', 'mark', 'math', 'meter', 'nobr', 'object', 'output', 'progress', 'q', 'rb', 'rp', 'rt', 'rtc', 'ruby', 's', 'samp', 'select', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'svg', 'textarea', 'time', 'tt', 'u', 'var', 'wbr'];
// Non-empty elements that will maintain whitespace within them
const inlineElementsToKeepWhitespaceWithin = new Set(['a', 'abbr', 'acronym', 'b', 'big', 'del', 'em', 'font', 'i', 'ins', 'kbd', 'mark', 'nobr', 's', 'samp', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'time', 'tt', 'u', 'var']);
// Elements that will always maintain whitespace around them
const inlineElementsToKeepWhitespace = new Set(['comment', 'img', 'input', 'wbr']);

function collapseWhitespaceSmart(str, prevTag, nextTag, options, inlineElements, inlineTextSet) {
  let trimLeft = prevTag && !inlineElementsToKeepWhitespace.has(prevTag);
  if (trimLeft && !options.collapseInlineTagWhitespace) {
    trimLeft = prevTag.charAt(0) === '/' ? !inlineElements.has(prevTag.slice(1)) : !inlineTextSet.has(prevTag);
  }
  let trimRight = nextTag && !inlineElementsToKeepWhitespace.has(nextTag);
  if (trimRight && !options.collapseInlineTagWhitespace) {
    trimRight = nextTag.charAt(0) === '/' ? !inlineTextSet.has(nextTag.slice(1)) : !inlineElements.has(nextTag);
  }
  return collapseWhitespace(str, options, trimLeft, trimRight, prevTag && nextTag);
}

function isConditionalComment(text) {
  return /^\[if\s[^\]]+]|\[endif]$/.test(text);
}

function isIgnoredComment(text, options) {
  for (let i = 0, len = options.ignoreCustomComments.length; i < len; i++) {
    if (options.ignoreCustomComments[i].test(text)) {
      return true;
    }
  }
  return false;
}

function isEventAttribute(attrName, options) {
  const patterns = options.customEventAttributes;
  if (patterns) {
    for (let i = patterns.length; i--;) {
      if (patterns[i].test(attrName)) {
        return true;
      }
    }
    return false;
  }
  return /^on[a-z]{3,}$/.test(attrName);
}

function canRemoveAttributeQuotes(value) {
  // https://mathiasbynens.be/notes/unquoted-attribute-values
  return /^[^ \t\n\f\r"'`=<>]+$/.test(value);
}

function attributesInclude(attributes, attribute) {
  for (let i = attributes.length; i--;) {
    if (attributes[i].name.toLowerCase() === attribute) {
      return true;
    }
  }
  return false;
}

// Default attribute values (could apply to any element)
const generalDefaults = {
  autocorrect: 'on',
  fetchpriority: 'auto',
  loading: 'eager',
  popovertargetaction: 'toggle'
};

// Tag-specific default attribute values
const tagDefaults = {
  area: { shape: 'rect' },
  button: { type: 'submit' },
  form: {
    enctype: 'application/x-www-form-urlencoded',
    method: 'get'
  },
  html: { dir: 'ltr' },
  img: { decoding: 'auto' },
  input: {
    colorspace: 'limited-srgb',
    type: 'text'
  },
  marquee: {
    behavior: 'scroll',
    direction: 'left'
  },
  style: { media: 'all' },
  textarea: { wrap: 'soft' },
  track: { kind: 'subtitles' }
};

function isAttributeRedundant(tag, attrName, attrValue, attrs) {
  attrValue = attrValue ? trimWhitespace(attrValue.toLowerCase()) : '';

  // Legacy attributes
  if (tag === 'script' && attrName === 'language' && attrValue === 'javascript') {
    return true;
  }
  if (tag === 'script' && attrName === 'charset' && !attributesInclude(attrs, 'src')) {
    return true;
  }
  if (tag === 'a' && attrName === 'name' && attributesInclude(attrs, 'id')) {
    return true;
  }

  // Check general defaults
  if (generalDefaults[attrName] === attrValue) {
    return true;
  }

  // Check tag-specific defaults
  return tagDefaults[tag]?.[attrName] === attrValue;
}

// https://mathiasbynens.be/demo/javascript-mime-type
// https://developer.mozilla.org/en/docs/Web/HTML/Element/script#attr-type
const executableScriptsMimetypes = new Set([
  'text/javascript',
  'text/ecmascript',
  'text/jscript',
  'application/javascript',
  'application/x-javascript',
  'application/ecmascript',
  'module'
]);

const keepScriptsMimetypes = new Set([
  'module'
]);

function isScriptTypeAttribute(attrValue = '') {
  attrValue = trimWhitespace(attrValue.split(/;/, 2)[0]).toLowerCase();
  return attrValue === '' || executableScriptsMimetypes.has(attrValue);
}

function keepScriptTypeAttribute(attrValue = '') {
  attrValue = trimWhitespace(attrValue.split(/;/, 2)[0]).toLowerCase();
  return keepScriptsMimetypes.has(attrValue);
}

function isExecutableScript(tag, attrs) {
  if (tag !== 'script') {
    return false;
  }
  for (let i = 0, len = attrs.length; i < len; i++) {
    const attrName = attrs[i].name.toLowerCase();
    if (attrName === 'type') {
      return isScriptTypeAttribute(attrs[i].value);
    }
  }
  return true;
}

function isStyleLinkTypeAttribute(attrValue = '') {
  attrValue = trimWhitespace(attrValue).toLowerCase();
  return attrValue === '' || attrValue === 'text/css';
}

function isStyleSheet(tag, attrs) {
  if (tag !== 'style') {
    return false;
  }
  for (let i = 0, len = attrs.length; i < len; i++) {
    const attrName = attrs[i].name.toLowerCase();
    if (attrName === 'type') {
      return isStyleLinkTypeAttribute(attrs[i].value);
    }
  }
  return true;
}

const isSimpleBoolean = new Set(['allowfullscreen', 'async', 'autofocus', 'autoplay', 'checked', 'compact', 'controls', 'declare', 'default', 'defaultchecked', 'defaultmuted', 'defaultselected', 'defer', 'disabled', 'enabled', 'formnovalidate', 'hidden', 'indeterminate', 'inert', 'ismap', 'itemscope', 'loop', 'multiple', 'muted', 'nohref', 'noresize', 'noshade', 'novalidate', 'nowrap', 'open', 'pauseonexit', 'readonly', 'required', 'reversed', 'scoped', 'seamless', 'selected', 'sortable', 'truespeed', 'typemustmatch', 'visible']);
const isBooleanValue = new Set(['true', 'false']);

function isBooleanAttribute(attrName, attrValue) {
  return isSimpleBoolean.has(attrName) || (attrName === 'draggable' && !isBooleanValue.has(attrValue));
}

function isUriTypeAttribute(attrName, tag) {
  return (
    (/^(?:a|area|link|base)$/.test(tag) && attrName === 'href') ||
    (tag === 'img' && /^(?:src|longdesc|usemap)$/.test(attrName)) ||
    (tag === 'object' && /^(?:classid|codebase|data|usemap)$/.test(attrName)) ||
    (tag === 'q' && attrName === 'cite') ||
    (tag === 'blockquote' && attrName === 'cite') ||
    ((tag === 'ins' || tag === 'del') && attrName === 'cite') ||
    (tag === 'form' && attrName === 'action') ||
    (tag === 'input' && (attrName === 'src' || attrName === 'usemap')) ||
    (tag === 'head' && attrName === 'profile') ||
    (tag === 'script' && (attrName === 'src' || attrName === 'for'))
  );
}

function isNumberTypeAttribute(attrName, tag) {
  return (
    (/^(?:a|area|object|button)$/.test(tag) && attrName === 'tabindex') ||
    (tag === 'input' && (attrName === 'maxlength' || attrName === 'tabindex')) ||
    (tag === 'select' && (attrName === 'size' || attrName === 'tabindex')) ||
    (tag === 'textarea' && /^(?:rows|cols|tabindex)$/.test(attrName)) ||
    (tag === 'colgroup' && attrName === 'span') ||
    (tag === 'col' && attrName === 'span') ||
    ((tag === 'th' || tag === 'td') && (attrName === 'rowspan' || attrName === 'colspan'))
  );
}

function isLinkType(tag, attrs, value) {
  if (tag !== 'link') return false;
  const needle = String(value).toLowerCase();
  for (let i = 0; i < attrs.length; i++) {
    if (attrs[i].name.toLowerCase() === 'rel') {
      const tokens = String(attrs[i].value).toLowerCase().split(/\s+/);
      if (tokens.includes(needle)) return true;
    }
  }
  return false;
}

function isMediaQuery(tag, attrs, attrName) {
  return attrName === 'media' && (isLinkType(tag, attrs, 'stylesheet') || isStyleSheet(tag, attrs));
}

const srcsetTags = new Set(['img', 'source']);

function isSrcset(attrName, tag) {
  return attrName === 'srcset' && srcsetTags.has(tag);
}

async function cleanAttributeValue(tag, attrName, attrValue, options, attrs, minifyHTMLSelf) {
  if (isEventAttribute(attrName, options)) {
    attrValue = trimWhitespace(attrValue).replace(/^javascript:\s*/i, '');
    return options.minifyJS(attrValue, true);
  } else if (attrName === 'class') {
    attrValue = trimWhitespace(attrValue);
    if (options.sortClassName) {
      attrValue = options.sortClassName(attrValue);
    } else {
      attrValue = collapseWhitespaceAll(attrValue);
    }
    return attrValue;
  } else if (isUriTypeAttribute(attrName, tag)) {
    attrValue = trimWhitespace(attrValue);
    if (isLinkType(tag, attrs, 'canonical')) {
      return attrValue;
    }
    try {
      const out = await options.minifyURLs(attrValue);
      return typeof out === 'string' ? out : attrValue;
    } catch (err) {
      options.log && options.log(err);
      return attrValue;
    }
  } else if (isNumberTypeAttribute(attrName, tag)) {
    return trimWhitespace(attrValue);
  } else if (attrName === 'style') {
    attrValue = trimWhitespace(attrValue);
    if (attrValue) {
      if (/;$/.test(attrValue) && !/&#?[0-9a-zA-Z]+;$/.test(attrValue)) {
        attrValue = attrValue.replace(/\s*;$/, ';');
      }
      attrValue = await options.minifyCSS(attrValue, 'inline');
    }
    return attrValue;
  } else if (isSrcset(attrName, tag)) {
    // https://html.spec.whatwg.org/multipage/embedded-content.html#attr-img-srcset
    attrValue = (await Promise.all(trimWhitespace(attrValue).split(/\s+,\s*|\s*,\s+/).map(async function (candidate) {
      let url = candidate;
      let descriptor = '';
      const match = candidate.match(/\s+([1-9][0-9]*w|[0-9]+(?:\.[0-9]+)?x)$/);
      if (match) {
        url = url.slice(0, -match[0].length);
        const num = +match[1].slice(0, -1);
        const suffix = match[1].slice(-1);
        if (num !== 1 || suffix !== 'x') {
          descriptor = ' ' + num + suffix;
        }
      }
      try {
        const out = await options.minifyURLs(url);
        return (typeof out === 'string' ? out : url) + descriptor;
      } catch (err) {
        options.log && options.log(err);
        return url + descriptor;
      }
    }))).join(', ');
  } else if (isMetaViewport(tag, attrs) && attrName === 'content') {
    attrValue = attrValue.replace(/\s+/g, '').replace(/[0-9]+\.[0-9]+/g, function (numString) {
      // "0.90000" -> "0.9"
      // "1.0" -> "1"
      // "1.0001" -> "1.0001" (unchanged)
      return (+numString).toString();
    });
  } else if (isContentSecurityPolicy(tag, attrs) && attrName.toLowerCase() === 'content') {
    return collapseWhitespaceAll(attrValue);
  } else if (options.customAttrCollapse && options.customAttrCollapse.test(attrName)) {
    attrValue = trimWhitespace(attrValue.replace(/ ?[\n\r]+ ?/g, '').replace(/\s{2,}/g, options.conservativeCollapse ? ' ' : ''));
  } else if (tag === 'script' && attrName === 'type') {
    attrValue = trimWhitespace(attrValue.replace(/\s*;\s*/g, ';'));
  } else if (isMediaQuery(tag, attrs, attrName)) {
    attrValue = trimWhitespace(attrValue);
    return options.minifyCSS(attrValue, 'media');
  } else if (tag === 'iframe' && attrName === 'srcdoc') {
    // Recursively minify HTML content within srcdoc attribute
    // Fast-path: skip if nothing would change
    if (!shouldMinifyInnerHTML(options)) {
      return attrValue;
    }
    return minifyHTMLSelf(attrValue, options, true);
  }
  return attrValue;
}

function isMetaViewport(tag, attrs) {
  if (tag !== 'meta') {
    return false;
  }
  for (let i = 0, len = attrs.length; i < len; i++) {
    if (attrs[i].name === 'name' && attrs[i].value === 'viewport') {
      return true;
    }
  }
}

function isContentSecurityPolicy(tag, attrs) {
  if (tag !== 'meta') {
    return false;
  }
  for (let i = 0, len = attrs.length; i < len; i++) {
    if (attrs[i].name.toLowerCase() === 'http-equiv' && attrs[i].value.toLowerCase() === 'content-security-policy') {
      return true;
    }
  }
}

function ignoreCSS(id) {
  return '/* clean-css ignore:start */' + id + '/* clean-css ignore:end */';
}

// Wrap CSS declarations for CleanCSS > 3.x
// See https://github.com/jakubpawlowicz/clean-css/issues/418
function wrapCSS(text, type) {
  switch (type) {
    case 'inline':
      return '*{' + text + '}';
    case 'media':
      return '@media ' + text + '{a{top:0}}';
    default:
      return text;
  }
}

function unwrapCSS(text, type) {
  let matches;
  switch (type) {
    case 'inline':
      matches = text.match(/^\*\{([\s\S]*)\}$/);
      break;
    case 'media':
      matches = text.match(/^@media ([\s\S]*?)\s*{[\s\S]*}$/);
      break;
  }
  return matches ? matches[1] : text;
}

async function cleanConditionalComment(comment, options) {
  return options.processConditionalComments
    ? await replaceAsync(comment, /^(\[if\s[^\]]+]>)([\s\S]*?)(<!\[endif])$/, async function (match, prefix, text, suffix) {
      return prefix + await minifyHTML(text, options, true) + suffix;
    })
    : comment;
}

async function processScript(text, options, currentAttrs) {
  for (let i = 0, len = currentAttrs.length; i < len; i++) {
    if (currentAttrs[i].name.toLowerCase() === 'type' &&
      options.processScripts.indexOf(currentAttrs[i].value) > -1) {
      return await minifyHTML(text, options);
    }
  }
  return text;
}

// Tag omission rules from https://html.spec.whatwg.org/multipage/syntax.html#optional-tags with the following extensions:
// - retain <body> if followed by <noscript>
// - <rb>, <rt>, <rtc>, <rp> follow HTML Ruby Markup Extensions draft (https://www.w3.org/TR/html-ruby-extensions/)
// - retain all tags which are adjacent to non-standard HTML tags
const optionalStartTags = new Set(['html', 'head', 'body', 'colgroup', 'tbody']);
const optionalEndTags = new Set(['html', 'head', 'body', 'li', 'dt', 'dd', 'p', 'rb', 'rt', 'rtc', 'rp', 'optgroup', 'option', 'colgroup', 'caption', 'thead', 'tbody', 'tfoot', 'tr', 'td', 'th']);
const headerTags = new Set(['meta', 'link', 'script', 'style', 'template', 'noscript']);
const descriptionTags = new Set(['dt', 'dd']);
const pBlockTags = new Set(['address', 'article', 'aside', 'blockquote', 'details', 'dialog', 'div', 'dl', 'fieldset', 'figcaption', 'figure', 'footer', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'header', 'hgroup', 'hr', 'main', 'menu', 'nav', 'ol', 'p', 'pre', 'search', 'section', 'table', 'ul']);
const pInlineTags = new Set(['a', 'audio', 'del', 'ins', 'map', 'noscript', 'video']);
const rubyEndTagOmission = new Set(['rb', 'rt', 'rtc', 'rp']); // </rb>, </rt>, </rp> can be omitted if followed by <rb>, <rt>, <rtc>, or <rp>
const rubyRtcEndTagOmission = new Set(['rb', 'rtc']); // </rtc> can be omitted if followed by <rb> or <rtc> (not <rt> or <rp>)
const optionTag = new Set(['option', 'optgroup']);
const tableContentTags = new Set(['tbody', 'tfoot']);
const tableSectionTags = new Set(['thead', 'tbody', 'tfoot']);
const cellTags = new Set(['td', 'th']);
const topLevelTags = new Set(['html', 'head', 'body']);
const compactTags = new Set(['html', 'body']);
const looseTags = new Set(['head', 'colgroup', 'caption']);
const trailingTags = new Set(['dt', 'thead']);
const htmlTags = new Set(['a', 'abbr', 'acronym', 'address', 'applet', 'area', 'article', 'aside', 'audio', 'b', 'base', 'basefont', 'bdi', 'bdo', 'bgsound', 'big', 'blink', 'blockquote', 'body', 'br', 'button', 'canvas', 'caption', 'center', 'cite', 'code', 'col', 'colgroup', 'command', 'content', 'data', 'datalist', 'dd', 'del', 'details', 'dfn', 'dialog', 'dir', 'div', 'dl', 'dt', 'element', 'em', 'embed', 'fieldset', 'figcaption', 'figure', 'font', 'footer', 'form', 'frame', 'frameset', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'head', 'header', 'hgroup', 'hr', 'html', 'i', 'iframe', 'image', 'img', 'input', 'ins', 'isindex', 'kbd', 'keygen', 'label', 'legend', 'li', 'link', 'listing', 'main', 'map', 'mark', 'marquee', 'menu', 'menuitem', 'meta', 'meter', 'multicol', 'nav', 'nobr', 'noembed', 'noframes', 'noscript', 'object', 'ol', 'optgroup', 'option', 'output', 'p', 'param', 'picture', 'plaintext', 'pre', 'progress', 'q', 'rb', 'rp', 'rt', 'rtc', 'ruby', 's', 'samp', 'script', 'section', 'select', 'shadow', 'small', 'source', 'spacer', 'span', 'strike', 'strong', 'style', 'sub', 'summary', 'sup', 'table', 'tbody', 'td', 'template', 'textarea', 'tfoot', 'th', 'thead', 'time', 'title', 'tr', 'track', 'tt', 'u', 'ul', 'var', 'video', 'wbr', 'xmp']);

function canRemoveParentTag(optionalStartTag, tag) {
  switch (optionalStartTag) {
    case 'html':
    case 'head':
      return true;
    case 'body':
      return !headerTags.has(tag);
    case 'colgroup':
      return tag === 'col';
    case 'tbody':
      return tag === 'tr';
  }
  return false;
}

function isStartTagMandatory(optionalEndTag, tag) {
  switch (tag) {
    case 'colgroup':
      return optionalEndTag === 'colgroup';
    case 'tbody':
      return tableSectionTags.has(optionalEndTag);
  }
  return false;
}

function canRemovePrecedingTag(optionalEndTag, tag) {
  switch (optionalEndTag) {
    case 'html':
    case 'head':
    case 'body':
    case 'colgroup':
    case 'caption':
      return true;
    case 'li':
    case 'optgroup':
    case 'tr':
      return tag === optionalEndTag;
    case 'dt':
    case 'dd':
      return descriptionTags.has(tag);
    case 'p':
      return pBlockTags.has(tag);
    case 'rb':
    case 'rt':
    case 'rp':
      return rubyEndTagOmission.has(tag);
    case 'rtc':
      return rubyRtcEndTagOmission.has(tag);
    case 'option':
      return optionTag.has(tag);
    case 'thead':
    case 'tbody':
      return tableContentTags.has(tag);
    case 'tfoot':
      return tag === 'tbody';
    case 'td':
    case 'th':
      return cellTags.has(tag);
  }
  return false;
}

const reEmptyAttribute = new RegExp(
  '^(?:class|id|style|title|lang|dir|on(?:focus|blur|change|click|dblclick|mouse(' +
  '?:down|up|over|move|out)|key(?:press|down|up)))$');

function canDeleteEmptyAttribute(tag, attrName, attrValue, options) {
  const isValueEmpty = !attrValue || /^\s*$/.test(attrValue);
  if (!isValueEmpty) {
    return false;
  }
  if (typeof options.removeEmptyAttributes === 'function') {
    return options.removeEmptyAttributes(attrName, tag);
  }
  return (tag === 'input' && attrName === 'value') || reEmptyAttribute.test(attrName);
}

function hasAttrName(name, attrs) {
  for (let i = attrs.length - 1; i >= 0; i--) {
    if (attrs[i].name === name) {
      return true;
    }
  }
  return false;
}

function canRemoveElement(tag, attrs) {
  switch (tag) {
    case 'textarea':
      return false;
    case 'audio':
    case 'script':
    case 'video':
      if (hasAttrName('src', attrs)) {
        return false;
      }
      break;
    case 'iframe':
      if (hasAttrName('src', attrs) || hasAttrName('srcdoc', attrs)) {
        return false;
      }
      break;
    case 'object':
      if (hasAttrName('data', attrs)) {
        return false;
      }
      break;
    case 'applet':
      if (hasAttrName('code', attrs)) {
        return false;
      }
      break;
  }
  return true;
}

function canCollapseWhitespace(tag) {
  return !/^(?:script|style|pre|textarea)$/.test(tag);
}

function canTrimWhitespace(tag) {
  return !/^(?:pre|textarea)$/.test(tag);
}

async function normalizeAttr(attr, attrs, tag, options) {
  const attrName = options.name(attr.name);
  let attrValue = attr.value;

  if (options.decodeEntities && attrValue) {
    attrValue = entities.decodeHTMLStrict(attrValue);
  }

  if ((options.removeRedundantAttributes &&
    isAttributeRedundant(tag, attrName, attrValue, attrs)) ||
    (options.removeScriptTypeAttributes && tag === 'script' &&
      attrName === 'type' && isScriptTypeAttribute(attrValue) && !keepScriptTypeAttribute(attrValue)) ||
    (options.removeStyleLinkTypeAttributes && (tag === 'style' || tag === 'link') &&
      attrName === 'type' && isStyleLinkTypeAttribute(attrValue))) {
    return;
  }

  if (attrValue) {
    attrValue = await cleanAttributeValue(tag, attrName, attrValue, options, attrs, minifyHTML);
  }

  if (options.removeEmptyAttributes &&
    canDeleteEmptyAttribute(tag, attrName, attrValue, options)) {
    return;
  }

  if (options.decodeEntities && attrValue) {
    attrValue = attrValue.replace(/&(#?[0-9a-zA-Z]+;)/g, '&amp;$1');
  }

  return {
    attr,
    name: attrName,
    value: attrValue
  };
}

function buildAttr(normalized, hasUnarySlash, options, isLast, uidAttr) {
  const attrName = normalized.name;
  let attrValue = normalized.value;
  const attr = normalized.attr;
  let attrQuote = attr.quote;
  let attrFragment;
  let emittedAttrValue;

  if (typeof attrValue !== 'undefined' && (!options.removeAttributeQuotes ||
    ~attrValue.indexOf(uidAttr) || !canRemoveAttributeQuotes(attrValue))) {
    if (!options.preventAttributesEscaping) {
      if (typeof options.quoteCharacter === 'undefined') {
        const apos = (attrValue.match(/'/g) || []).length;
        const quot = (attrValue.match(/"/g) || []).length;
        attrQuote = apos < quot ? '\'' : '"';
      } else {
        attrQuote = options.quoteCharacter === '\'' ? '\'' : '"';
      }
      if (attrQuote === '"') {
        attrValue = attrValue.replace(/"/g, '&#34;');
      } else {
        attrValue = attrValue.replace(/'/g, '&#39;');
      }
    }
    emittedAttrValue = attrQuote + attrValue + attrQuote;
    if (!isLast && !options.removeTagWhitespace) {
      emittedAttrValue += ' ';
    }
  } else if (isLast && !hasUnarySlash && !/\/$/.test(attrValue)) {
    // Make sure trailing slash is not interpreted as HTML self-closing tag
    emittedAttrValue = attrValue;
  } else {
    emittedAttrValue = attrValue + ' ';
  }

  if (typeof attrValue === 'undefined' || (options.collapseBooleanAttributes &&
    isBooleanAttribute(attrName.toLowerCase(), attrValue.toLowerCase()))) {
    attrFragment = attrName;
    if (!isLast) {
      attrFragment += ' ';
    }
  } else {
    attrFragment = attrName + attr.customAssign + emittedAttrValue;
  }

  return attr.customOpen + attrFragment + attr.customClose;
}

function identity(value) {
  return value;
}

function identityAsync(value) {
  return Promise.resolve(value);
}

function shouldMinifyInnerHTML(options) {
  return Boolean(
    options.collapseWhitespace ||
    options.removeComments ||
    options.removeOptionalTags ||
    options.minifyJS !== identity ||
    options.minifyCSS !== identityAsync ||
    options.minifyURLs !== identity
  );
}

const processOptions = (inputOptions) => {
  const options = {
    name: function (name) {
      return name.toLowerCase();
    },
    canCollapseWhitespace,
    canTrimWhitespace,
    html5: true,
    ignoreCustomComments: [
      /^!/,
      /^\s*#/
    ],
    ignoreCustomFragments: [
      /<%[\s\S]*?%>/,
      /<\?[\s\S]*?\?>/
    ],
    includeAutoGeneratedTags: true,
    log: identity,
    minifyCSS: identityAsync,
    minifyJS: identity,
    minifyURLs: identity
  };

  Object.keys(inputOptions).forEach(function (key) {
    const option = inputOptions[key];

    if (key === 'caseSensitive') {
      if (option) {
        options.name = identity;
      }
    } else if (key === 'log') {
      if (typeof option === 'function') {
        options.log = option;
      }
    } else if (key === 'minifyCSS' && typeof option !== 'function') {
      if (!option) {
        return;
      }

      const cleanCssOptions = typeof option === 'object' ? option : {};

      options.minifyCSS = async function (text, type) {
        text = await replaceAsync(
          text,
          /(url\s*\(\s*)(?:"([^"]*)"|'([^']*)'|([^\s)]+))(\s*\))/ig,
          async function (match, prefix, dq, sq, unq, suffix) {
            const quote = dq != null ? '"' : (sq != null ? "'" : '');
            const url = dq ?? sq ?? unq ?? '';
            try {
              const out = await options.minifyURLs(url);
              return prefix + quote + (typeof out === 'string' ? out : url) + quote + suffix;
            } catch (err) {
              options.log && options.log(err);
              return match;
            }
          }
        );

        const inputCSS = wrapCSS(text, type);

        return new Promise((resolve) => {
          new CleanCSS(cleanCssOptions).minify(inputCSS, (_err, output) => {
            if (output.errors.length > 0) {
              output.errors.forEach(options.log);
              resolve(text);
            }

            const outputCSS = unwrapCSS(output.styles, type);
            resolve(outputCSS);
          });
        });
      };
    } else if (key === 'minifyJS' && typeof option !== 'function') {
      if (!option) {
        return;
      }

      const terserOptions = typeof option === 'object' ? option : {};

      terserOptions.parse = {
        ...terserOptions.parse,
        bare_returns: false
      };

      options.minifyJS = async function (text, inline) {
        const start = text.match(/^\s*<!--.*/);
        const code = start ? text.slice(start[0].length).replace(/\n\s*-->\s*$/, '') : text;

        terserOptions.parse.bare_returns = inline;

        try {
          const result = await terser.minify(code, terserOptions);
          return result.code.replace(/;$/, '');
        } catch (error) {
          options.log(error);
          return text;
        }
      };
    } else if (key === 'minifyURLs' && typeof option !== 'function') {
      if (!option) {
        return;
      }

      let relateUrlOptions = option;

      if (typeof option === 'string') {
        relateUrlOptions = { site: option };
      } else if (typeof option !== 'object') {
        relateUrlOptions = {};
      }

      options.minifyURLs = function (text) {
        try {
          return RelateURL.relate(text, relateUrlOptions);
        } catch (err) {
          options.log(err);
          return text;
        }
      };
    } else {
      options[key] = option;
    }
  });
  return options;
};

function uniqueId(value) {
  let id;
  do {
    id = Math.random().toString(36).replace(/^0\.[0-9]*/, '');
  } while (~value.indexOf(id));
  return id;
}

const specialContentTags = new Set(['script', 'style']);

async function createSortFns(value, options, uidIgnore, uidAttr) {
  const attrChains = options.sortAttributes && Object.create(null);
  const classChain = options.sortClassName && new TokenChain();

  function attrNames(attrs) {
    return attrs.map(function (attr) {
      return options.name(attr.name);
    });
  }

  function shouldSkipUID(token, uid) {
    return !uid || token.indexOf(uid) === -1;
  }

  function shouldSkipUIDs(token) {
    return shouldSkipUID(token, uidIgnore) && shouldSkipUID(token, uidAttr);
  }

  async function scan(input) {
    let currentTag, currentType;
    const parser = new HTMLParser(input, {
      start: function (tag, attrs) {
        if (attrChains) {
          if (!attrChains[tag]) {
            attrChains[tag] = new TokenChain();
          }
          attrChains[tag].add(attrNames(attrs).filter(shouldSkipUIDs));
        }
        for (let i = 0, len = attrs.length; i < len; i++) {
          const attr = attrs[i];
          if (classChain && attr.value && options.name(attr.name) === 'class') {
            classChain.add(trimWhitespace(attr.value).split(/[ \t\n\f\r]+/).filter(shouldSkipUIDs));
          } else if (options.processScripts && attr.name.toLowerCase() === 'type') {
            currentTag = tag;
            currentType = attr.value;
          }
        }
      },
      end: function () {
        currentTag = '';
      },
      chars: async function (text) {
        if (options.processScripts && specialContentTags.has(currentTag) &&
          options.processScripts.indexOf(currentType) > -1) {
          await scan(text);
        }
      }
    });

    await parser.parse();
  }

  const log = options.log;
  options.log = identity;
  options.sortAttributes = false;
  options.sortClassName = false;
  await scan(await minifyHTML(value, options));
  options.log = log;
  if (attrChains) {
    const attrSorters = Object.create(null);
    for (const tag in attrChains) {
      attrSorters[tag] = attrChains[tag].createSorter();
    }
    options.sortAttributes = function (tag, attrs) {
      const sorter = attrSorters[tag];
      if (sorter) {
        const attrMap = Object.create(null);
        const names = attrNames(attrs);
        names.forEach(function (name, index) {
          (attrMap[name] || (attrMap[name] = [])).push(attrs[index]);
        });
        sorter.sort(names).forEach(function (name, index) {
          attrs[index] = attrMap[name].shift();
        });
      }
    };
  }
  if (classChain) {
    const sorter = classChain.createSorter();
    options.sortClassName = function (value) {
      return sorter.sort(value.split(/[ \n\f\r]+/)).join(' ');
    };
  }
}

async function minifyHTML(value, options, partialMarkup) {
  // Check input length limitation to prevent ReDoS attacks
  if (options.maxInputLength && value.length > options.maxInputLength) {
    throw new Error(`Input length (${value.length}) exceeds maximum allowed length (${options.maxInputLength})`);
  }

  if (options.collapseWhitespace) {
    value = collapseWhitespace(value, options, true, true);
  }

  const buffer = [];
  let charsPrevTag;
  let currentChars = '';
  let hasChars;
  let currentTag = '';
  let currentAttrs = [];
  const stackNoTrimWhitespace = [];
  const stackNoCollapseWhitespace = [];
  let optionalStartTag = '';
  let optionalEndTag = '';
  const ignoredMarkupChunks = [];
  const ignoredCustomMarkupChunks = [];
  let uidIgnore;
  let uidAttr;
  let uidPattern;
  // Create inline tags/text sets with custom elements
  const customElementsInput = options.inlineCustomElements ?? [];
  const customElementsArr = Array.isArray(customElementsInput) ? customElementsInput : Array.from(customElementsInput);
  const normalizedCustomElements = customElementsArr.map(name => options.name(name));
  const inlineTextSet = new Set([...inlineElementsToKeepWhitespaceWithin, ...normalizedCustomElements]);
  const inlineElements = new Set([...inlineElementsToKeepWhitespaceAround, ...normalizedCustomElements]);

  // Temporarily replace ignored chunks with comments,
  // so that we don’t have to worry what’s there.
  // For all we care there might be
  // completely-horribly-broken-alien-non-html-emoj-cthulhu-filled content
  value = value.replace(/<!-- htmlmin:ignore -->([\s\S]*?)<!-- htmlmin:ignore -->/g, function (match, group1) {
    if (!uidIgnore) {
      uidIgnore = uniqueId(value);
      const pattern = new RegExp('^' + uidIgnore + '([0-9]+)$');
      if (options.ignoreCustomComments) {
        options.ignoreCustomComments = options.ignoreCustomComments.slice();
      } else {
        options.ignoreCustomComments = [];
      }
      options.ignoreCustomComments.push(pattern);
    }
    const token = '<!--' + uidIgnore + ignoredMarkupChunks.length + '-->';
    ignoredMarkupChunks.push(group1);
    return token;
  });

  const customFragments = options.ignoreCustomFragments.map(function (re) {
    return re.source;
  });
  if (customFragments.length) {
    // Warn about potential ReDoS if custom fragments use unlimited quantifiers
    for (let i = 0; i < customFragments.length; i++) {
      if (/[*+]/.test(customFragments[i])) {
        options.log('Warning: Custom fragment contains unlimited quantifiers (* or +) which may cause ReDoS vulnerability');
        break;
      }
    }

    // Safe approach: Use bounded quantifiers instead of unlimited ones to prevent ReDoS
    const maxQuantifier = options.customFragmentQuantifierLimit || 200;
    const whitespacePattern = `\\s{0,${maxQuantifier}}`;

    // Use bounded quantifiers to prevent ReDoS - this approach prevents exponential backtracking
    const reCustomIgnore = new RegExp(
      whitespacePattern + '(?:' + customFragments.join('|') + '){1,' + maxQuantifier + '}' + whitespacePattern,
      'g'
    );
    // Temporarily replace custom ignored fragments with unique attributes
    value = value.replace(reCustomIgnore, function (match) {
      if (!uidAttr) {
        uidAttr = uniqueId(value);
        uidPattern = new RegExp('(\\s*)' + uidAttr + '([0-9]+)' + uidAttr + '(\\s*)', 'g');

        if (options.minifyCSS) {
          options.minifyCSS = (function (fn) {
            return function (text, type) {
              text = text.replace(uidPattern, function (match, prefix, index) {
                const chunks = ignoredCustomMarkupChunks[+index];
                return chunks[1] + uidAttr + index + uidAttr + chunks[2];
              });

              const ids = [];
              new CleanCSS().minify(wrapCSS(text, type)).warnings.forEach(function (warning) {
                const match = uidPattern.exec(warning);
                if (match) {
                  const id = uidAttr + match[2] + uidAttr;
                  text = text.replace(id, ignoreCSS(id));
                  ids.push(id);
                }
              });

              return fn(text, type).then(chunk => {
                ids.forEach(function (id) {
                  chunk = chunk.replace(ignoreCSS(id), id);
                });

                return chunk;
              });
            };
          })(options.minifyCSS);
        }

        if (options.minifyJS) {
          options.minifyJS = (function (fn) {
            return function (text, type) {
              return fn(text.replace(uidPattern, function (match, prefix, index) {
                const chunks = ignoredCustomMarkupChunks[+index];
                return chunks[1] + uidAttr + index + uidAttr + chunks[2];
              }), type);
            };
          })(options.minifyJS);
        }
      }

      const token = uidAttr + ignoredCustomMarkupChunks.length + uidAttr;
      ignoredCustomMarkupChunks.push(/^(\s*)[\s\S]*?(\s*)$/.exec(match));
      return '\t' + token + '\t';
    });
  }

  if ((options.sortAttributes && typeof options.sortAttributes !== 'function') ||
    (options.sortClassName && typeof options.sortClassName !== 'function')) {
    await createSortFns(value, options, uidIgnore, uidAttr);
  }

  function _canCollapseWhitespace(tag, attrs) {
    return options.canCollapseWhitespace(tag, attrs, canCollapseWhitespace);
  }

  function _canTrimWhitespace(tag, attrs) {
    return options.canTrimWhitespace(tag, attrs, canTrimWhitespace);
  }

  function removeStartTag() {
    let index = buffer.length - 1;
    while (index > 0 && !/^<[^/!]/.test(buffer[index])) {
      index--;
    }
    buffer.length = Math.max(0, index);
  }

  function removeEndTag() {
    let index = buffer.length - 1;
    while (index > 0 && !/^<\//.test(buffer[index])) {
      index--;
    }
    buffer.length = Math.max(0, index);
  }

  // Look for trailing whitespaces, bypass any inline tags
  function trimTrailingWhitespace(index, nextTag) {
    for (let endTag = null; index >= 0 && _canTrimWhitespace(endTag); index--) {
      const str = buffer[index];
      const match = str.match(/^<\/([\w:-]+)>$/);
      if (match) {
        endTag = match[1];
      } else if (/>$/.test(str) || (buffer[index] = collapseWhitespaceSmart(str, null, nextTag, options, inlineElements, inlineTextSet))) {
        break;
      }
    }
  }

  // Look for trailing whitespaces from previously processed text
  // which may not be trimmed due to a following comment or an empty
  // element which has now been removed
  function squashTrailingWhitespace(nextTag) {
    let charsIndex = buffer.length - 1;
    if (buffer.length > 1) {
      const item = buffer[buffer.length - 1];
      if (/^(?:<!|$)/.test(item) && item.indexOf(uidIgnore) === -1) {
        charsIndex--;
      }
    }
    trimTrailingWhitespace(charsIndex, nextTag);
  }

  const parser = new HTMLParser(value, {
    partialMarkup,
    continueOnParseError: options.continueOnParseError,
    customAttrAssign: options.customAttrAssign,
    customAttrSurround: options.customAttrSurround,
    html5: options.html5,

    start: async function (tag, attrs, unary, unarySlash, autoGenerated) {
      if (tag.toLowerCase() === 'svg') {
        options = Object.create(options);
        options.caseSensitive = true;
        options.keepClosingSlash = true;
        options.name = identity;
      }
      tag = options.name(tag);
      currentTag = tag;
      charsPrevTag = tag;
      if (!inlineTextSet.has(tag)) {
        currentChars = '';
      }
      hasChars = false;
      currentAttrs = attrs;

      let optional = options.removeOptionalTags;
      if (optional) {
        const htmlTag = htmlTags.has(tag);
        // <html> may be omitted if first thing inside is not a comment
        // <head> may be omitted if first thing inside is an element
        // <body> may be omitted if first thing inside is not space, comment, <meta>, <link>, <script>, <style> or <template>
        // <colgroup> may be omitted if first thing inside is <col>
        // <tbody> may be omitted if first thing inside is <tr>
        if (htmlTag && canRemoveParentTag(optionalStartTag, tag)) {
          removeStartTag();
        }
        optionalStartTag = '';
        // End-tag-followed-by-start-tag omission rules
        if (htmlTag && canRemovePrecedingTag(optionalEndTag, tag)) {
          removeEndTag();
          // <colgroup> cannot be omitted if preceding </colgroup> is omitted
          // <tbody> cannot be omitted if preceding </tbody>, </thead> or </tfoot> is omitted
          optional = !isStartTagMandatory(optionalEndTag, tag);
        }
        optionalEndTag = '';
      }

      // Set whitespace flags for nested tags (e.g., <code> within a <pre>)
      if (options.collapseWhitespace) {
        if (!stackNoTrimWhitespace.length) {
          squashTrailingWhitespace(tag);
        }
        if (!unary) {
          if (!_canTrimWhitespace(tag, attrs) || stackNoTrimWhitespace.length) {
            stackNoTrimWhitespace.push(tag);
          }
          if (!_canCollapseWhitespace(tag, attrs) || stackNoCollapseWhitespace.length) {
            stackNoCollapseWhitespace.push(tag);
          }
        }
      }

      const openTag = '<' + tag;
      const hasUnarySlash = unarySlash && options.keepClosingSlash;

      buffer.push(openTag);

      if (options.sortAttributes) {
        options.sortAttributes(tag, attrs);
      }

      const parts = [];
      for (let i = attrs.length, isLast = true; --i >= 0;) {
        const normalized = await normalizeAttr(attrs[i], attrs, tag, options);
        if (normalized) {
          parts.unshift(buildAttr(normalized, hasUnarySlash, options, isLast, uidAttr));
          isLast = false;
        }
      }
      if (parts.length > 0) {
        buffer.push(' ');
        buffer.push.apply(buffer, parts);
      } else if (optional && optionalStartTags.has(tag)) {
        // Start tag must never be omitted if it has any attributes
        optionalStartTag = tag;
      }

      buffer.push(buffer.pop() + (hasUnarySlash ? '/' : '') + '>');

      if (autoGenerated && !options.includeAutoGeneratedTags) {
        removeStartTag();
        optionalStartTag = '';
      }
    },
    end: function (tag, attrs, autoGenerated) {
      if (tag.toLowerCase() === 'svg') {
        options = Object.getPrototypeOf(options);
      }
      tag = options.name(tag);

      // Check if current tag is in a whitespace stack
      if (options.collapseWhitespace) {
        if (stackNoTrimWhitespace.length) {
          if (tag === stackNoTrimWhitespace[stackNoTrimWhitespace.length - 1]) {
            stackNoTrimWhitespace.pop();
          }
        } else {
          squashTrailingWhitespace('/' + tag);
        }
        if (stackNoCollapseWhitespace.length &&
          tag === stackNoCollapseWhitespace[stackNoCollapseWhitespace.length - 1]) {
          stackNoCollapseWhitespace.pop();
        }
      }

      let isElementEmpty = false;
      if (tag === currentTag) {
        currentTag = '';
        isElementEmpty = !hasChars;
      }

      if (options.removeOptionalTags) {
        // <html>, <head> or <body> may be omitted if the element is empty
        if (isElementEmpty && topLevelTags.has(optionalStartTag)) {
          removeStartTag();
        }
        optionalStartTag = '';
        // </html> or </body> may be omitted if not followed by comment
        // </head> may be omitted if not followed by space or comment
        // </p> may be omitted if no more content in non-</a> parent
        // except for </dt> or </thead>, end tags may be omitted if no more content in parent element
        if (htmlTags.has(tag) && optionalEndTag && !trailingTags.has(optionalEndTag) && (optionalEndTag !== 'p' || !pInlineTags.has(tag))) {
          removeEndTag();
        }
        optionalEndTag = optionalEndTags.has(tag) ? tag : '';
      }

      if (options.removeEmptyElements && isElementEmpty && canRemoveElement(tag, attrs)) {
        // Remove last “element” from buffer
        removeStartTag();
        optionalStartTag = '';
        optionalEndTag = '';
      } else {
        if (autoGenerated && !options.includeAutoGeneratedTags) {
          optionalEndTag = '';
        } else {
          buffer.push('</' + tag + '>');
        }
        charsPrevTag = '/' + tag;
        if (!inlineElements.has(tag)) {
          currentChars = '';
        } else if (isElementEmpty) {
          currentChars += '|';
        }
      }
    },
    chars: async function (text, prevTag, nextTag) {
      prevTag = prevTag === '' ? 'comment' : prevTag;
      nextTag = nextTag === '' ? 'comment' : nextTag;
      if (options.decodeEntities && text && !specialContentTags.has(currentTag)) {
        text = entities.decodeHTML(text);
      }
      if (options.collapseWhitespace) {
        if (!stackNoTrimWhitespace.length) {
          if (prevTag === 'comment') {
            const prevComment = buffer[buffer.length - 1];
            if (prevComment.indexOf(uidIgnore) === -1) {
              if (!prevComment) {
                prevTag = charsPrevTag;
              }
              if (buffer.length > 1 && (!prevComment || (!options.conservativeCollapse && / $/.test(currentChars)))) {
                const charsIndex = buffer.length - 2;
                buffer[charsIndex] = buffer[charsIndex].replace(/\s+$/, function (trailingSpaces) {
                  text = trailingSpaces + text;
                  return '';
                });
              }
            }
          }
          if (prevTag) {
            if (prevTag === '/nobr' || prevTag === 'wbr') {
              if (/^\s/.test(text)) {
                let tagIndex = buffer.length - 1;
                while (tagIndex > 0 && buffer[tagIndex].lastIndexOf('<' + prevTag) !== 0) {
                  tagIndex--;
                }
                trimTrailingWhitespace(tagIndex - 1, 'br');
              }
            } else if (inlineTextSet.has(prevTag.charAt(0) === '/' ? prevTag.slice(1) : prevTag)) {
              text = collapseWhitespace(text, options, /(?:^|\s)$/.test(currentChars));
            }
          }
          if (prevTag || nextTag) {
            text = collapseWhitespaceSmart(text, prevTag, nextTag, options, inlineElements, inlineTextSet);
          } else {
            text = collapseWhitespace(text, options, true, true);
          }
          if (!text && /\s$/.test(currentChars) && prevTag && prevTag.charAt(0) === '/') {
            trimTrailingWhitespace(buffer.length - 1, nextTag);
          }
        }
        if (!stackNoCollapseWhitespace.length && nextTag !== 'html' && !(prevTag && nextTag)) {
          text = collapseWhitespace(text, options, false, false, true);
        }
      }
      if (options.processScripts && specialContentTags.has(currentTag)) {
        text = await processScript(text, options, currentAttrs);
      }
      if (isExecutableScript(currentTag, currentAttrs)) {
        text = await options.minifyJS(text);
      }
      if (isStyleSheet(currentTag, currentAttrs)) {
        text = await options.minifyCSS(text);
      }
      if (options.removeOptionalTags && text) {
        // <html> may be omitted if first thing inside is not a comment
        // <body> may be omitted if first thing inside is not space, comment, <meta>, <link>, <script>, <style> or <template>
        if (optionalStartTag === 'html' || (optionalStartTag === 'body' && !/^\s/.test(text))) {
          removeStartTag();
        }
        optionalStartTag = '';
        // </html> or </body> may be omitted if not followed by comment
        // </head>, </colgroup> or </caption> may be omitted if not followed by space or comment
        if (compactTags.has(optionalEndTag) || (looseTags.has(optionalEndTag) && !/^\s/.test(text))) {
          removeEndTag();
        }
        // Don’t reset optionalEndTag if text is only whitespace and will be collapsed (not conservatively)
        if (!/^\s+$/.test(text) || !options.collapseWhitespace || options.conservativeCollapse) {
          optionalEndTag = '';
        }
      }
      charsPrevTag = /^\s*$/.test(text) ? prevTag : 'comment';
      if (options.decodeEntities && text && !specialContentTags.has(currentTag)) {
        // Escape any `&` symbols that start either:
        // 1) a legacy named character reference (i.e. one that doesn't end with `;`)
        // 2) or any other character reference (i.e. one that does end with `;`)
        // Note that `&` can be escaped as `&amp`, without the semi-colon.
        // https://mathiasbynens.be/notes/ambiguous-ampersands
        text = text.replace(/&((?:Iacute|aacute|uacute|plusmn|Otilde|otilde|agrave|Agrave|Yacute|yacute|Oslash|oslash|atilde|Atilde|brvbar|ccedil|Ccedil|Ograve|curren|divide|eacute|Eacute|ograve|Oacute|egrave|Egrave|Ugrave|frac12|frac14|frac34|ugrave|oacute|iacute|Ntilde|ntilde|Uacute|middot|igrave|Igrave|iquest|Aacute|cedil|laquo|micro|iexcl|Icirc|icirc|acirc|Ucirc|Ecirc|ocirc|Ocirc|ecirc|ucirc|Aring|aring|AElig|aelig|acute|pound|raquo|Acirc|times|THORN|szlig|thorn|COPY|auml|ordf|ordm|Uuml|macr|uuml|Auml|ouml|Ouml|para|nbsp|euml|quot|QUOT|Euml|yuml|cent|sect|copy|sup1|sup2|sup3|iuml|Iuml|ETH|shy|reg|not|yen|amp|AMP|REG|uml|eth|deg|gt|GT|LT|lt)(?!;)|(?:#?[0-9a-zA-Z]+;))/g, '&amp$1').replace(/</g, '&lt;');
      }
      if (uidPattern && options.collapseWhitespace && stackNoTrimWhitespace.length) {
        text = text.replace(uidPattern, function (match, prefix, index) {
          return ignoredCustomMarkupChunks[+index][0];
        });
      }
      currentChars += text;
      if (text) {
        hasChars = true;
      }
      buffer.push(text);
    },
    comment: async function (text, nonStandard) {
      const prefix = nonStandard ? '<!' : '<!--';
      const suffix = nonStandard ? '>' : '-->';
      if (isConditionalComment(text)) {
        text = prefix + await cleanConditionalComment(text, options) + suffix;
      } else if (options.removeComments) {
        if (isIgnoredComment(text, options)) {
          text = '<!--' + text + '-->';
        } else {
          text = '';
        }
      } else {
        text = prefix + text + suffix;
      }
      if (options.removeOptionalTags && text) {
        // Preceding comments suppress tag omissions
        optionalStartTag = '';
        optionalEndTag = '';
      }
      buffer.push(text);
    },
    doctype: function (doctype) {
      buffer.push(options.useShortDoctype
        ? '<!doctype' +
        (options.removeTagWhitespace ? '' : ' ') + 'html>'
        : collapseWhitespaceAll(doctype));
    }
  });

  await parser.parse();

  if (options.removeOptionalTags) {
    // <html> may be omitted if first thing inside is not a comment
    // <head> or <body> may be omitted if empty
    if (topLevelTags.has(optionalStartTag)) {
      removeStartTag();
    }
    // except for </dt> or </thead>, end tags may be omitted if no more content in parent element
    if (optionalEndTag && !trailingTags.has(optionalEndTag)) {
      removeEndTag();
    }
  }
  if (options.collapseWhitespace) {
    squashTrailingWhitespace('br');
  }

  return joinResultSegments(buffer, options, uidPattern
    ? function (str) {
      return str.replace(uidPattern, function (match, prefix, index, suffix) {
        let chunk = ignoredCustomMarkupChunks[+index][0];
        if (options.collapseWhitespace) {
          if (prefix !== '\t') {
            chunk = prefix + chunk;
          }
          if (suffix !== '\t') {
            chunk += suffix;
          }
          return collapseWhitespace(chunk, {
            preserveLineBreaks: options.preserveLineBreaks,
            conservativeCollapse: !options.trimCustomFragments
          }, /^[ \n\r\t\f]/.test(chunk), /[ \n\r\t\f]$/.test(chunk));
        }
        return chunk;
      });
    }
    : identity, uidIgnore
    ? function (str) {
      return str.replace(new RegExp('<!--' + uidIgnore + '([0-9]+)-->', 'g'), function (match, index) {
        return ignoredMarkupChunks[+index];
      });
    }
    : identity);
}

function joinResultSegments(results, options, restoreCustom, restoreIgnore) {
  let str;
  const maxLineLength = options.maxLineLength;
  const noNewlinesBeforeTagClose = options.noNewlinesBeforeTagClose;

  if (maxLineLength) {
    let line = ''; const lines = [];
    while (results.length) {
      const len = line.length;
      const end = results[0].indexOf('\n');
      const isClosingTag = Boolean(results[0].match(endTag));
      const shouldKeepSameLine = noNewlinesBeforeTagClose && isClosingTag;

      if (end < 0) {
        line += restoreIgnore(restoreCustom(results.shift()));
      } else {
        line += restoreIgnore(restoreCustom(results[0].slice(0, end)));
        results[0] = results[0].slice(end + 1);
      }
      if (len > 0 && line.length > maxLineLength && !shouldKeepSameLine) {
        lines.push(line.slice(0, len));
        line = line.slice(len);
      } else if (end >= 0) {
        lines.push(line);
        line = '';
      }
    }
    if (line) {
      lines.push(line);
    }
    str = lines.join('\n');
  } else {
    str = restoreIgnore(restoreCustom(results.join('')));
  }
  return options.collapseWhitespace ? collapseWhitespace(str, options, true, true) : str;
}

const minify = async function (value, options) {
  const start = Date.now();
  options = processOptions(options || {});
  const result = await minifyHTML(value, options);
  options.log('minified in: ' + (Date.now() - start) + 'ms');
  return result;
};

var htmlminifier = { minify };

exports.default = htmlminifier;
exports.minify = minify;
