text: /**
   * @license
   * Copyright The Closure Library Authors.
   * SPDX-License-Identifier: Apache-2.0
   */
  
  /**
   * @fileoverview Utility function for linkifying text.
   */
  
  goog.provide('goog.string.linkify');
  
  goog.require('goog.html.SafeHtml');
  goog.require('goog.html.uncheckedconversions');
  goog.require('goog.string');
  goog.require('goog.string.Const');
  
  
  /**
   * Takes a string of plain text and linkifies URLs and email addresses. For a
   * URL (unless opt_attributes is specified), the target of the link will be
   * _blank and it will have a rel=nofollow attribute applied to it so that links
   * created by linkify will not be of interest to search engines.
   * @param {string} text Plain text.
   * @param {!Object<string, ?goog.html.SafeHtml.AttributeValue>=} opt_attributes
   *     Attributes to add to all links created. Default are rel=nofollow and
   *     target=_blank. To clear those default attributes set rel='' and
   *     target=''.
   * @param {boolean=} opt_preserveNewlines Whether to preserve newlines with
   *     &lt;br&gt;.
   * @param {boolean=} opt_preserveSpacesAndTabs Whether to preserve spaces with
   *     non-breaking spaces and tabs with <span style="white-space:pre">
   * @return {!goog.html.SafeHtml} Linkified HTML. Any text that is not part of a
   *      link will be HTML-escaped.
   */
  goog.string.linkify.linkifyPlainTextAsHtml = function(
      text, opt_attributes, opt_preserveNewlines, opt_preserveSpacesAndTabs) {
    'use strict';
  
    /**
     * @param {string} plainText
     * @return {!goog.html.SafeHtml} html
     */
    const htmlEscape = function(plainText) {
      if (opt_preserveSpacesAndTabs) {
        const html = goog.html.SafeHtml.htmlEscape(plainText);
        let modifiedHtml =
            goog.html.SafeHtml
                .unwrap(html)
                // Leading space is converted into a non-breaking space, and
                // spaces following whitespace are converted into non-breaking
                // spaces. This must happen first, to ensure we preserve spaces
                // after newlines.
                .replace(/(^|[\n\r\t\ ])\ /g, '$1&#160;')
                // Preserve tabs by using style="white-space:pre"
                .replace(/(\t+)/g, '<span style="white-space:pre">$1</span>');
        if (opt_preserveNewlines) {
          modifiedHtml = goog.string.newLineToBr(modifiedHtml);
        }
        return goog.html.uncheckedconversions
            .safeHtmlFromStringKnownToSatisfyTypeContract(
                goog.string.Const.from('Escaped plain text'), modifiedHtml,
                html.getDirection());
      } else if (opt_preserveNewlines) {
        return goog.html.SafeHtml.htmlEscapePreservingNewlines(plainText);
      } else {
        return goog.html.SafeHtml.htmlEscape(plainText);
      }
    };
  
    // This shortcut makes linkifyPlainText ~10x faster if text doesn't contain
    // URLs or email addresses and adds insignificant performance penalty if it
    // does.
    if (text.indexOf('@') == -1 && text.indexOf('://') == -1 &&
        text.indexOf('www.') == -1 && text.indexOf('Www.') == -1 &&
        text.indexOf('WWW.') == -1) {
      return htmlEscape(text);
    }
  
    const attributesMap = {};
    for (let key in opt_attributes) {
      if (!opt_attributes[key]) {
        // Our API allows '' to omit the attribute, SafeHtml requires null.
        attributesMap[key] = null;
      } else {
        attributesMap[key] = opt_attributes[key];
      }
    }
    // Set default options if they haven't been explicitly set.
    if (!('rel' in attributesMap)) {
      attributesMap['rel'] = 'nofollow';
    }
    if (!('target' in attributesMap)) {
      attributesMap['target'] = '_blank';
    }
  
    const output = [];
    // Return value is ignored.
    text.replace(
        goog.string.linkify.FIND_LINKS_RE_,
        function(part, before, original, email, protocol) {
          'use strict';
          output.push(htmlEscape(before));
          if (!original) {
            return '';
          }
          let href = '';
          /** @type {string} */
          let linkText;
          /** @type {string} */
          let afterLink;
          if (email) {
            href = 'mailto:';
            linkText = email;
            afterLink = '';
          } else {
            // This is a full url link.
            if (!protocol) {
              href = 'http://';
            }
            const splitEndingPunctuation =
                original.match(goog.string.linkify.ENDS_WITH_PUNCTUATION_RE_);
            // An open paren in the link will often be matched with a close paren
            // at the end, so skip cutting off ending punctuation if
            // opening/closing parens are matched in the link. Same for curly
            // brackets. For example:
            // End symbol is linkified:
            // * http://en.wikipedia.org/wiki/Titanic_(1997_film)
            // * http://google.com/abc{arg=1}
            // e.g. needEndingPunctuationForBalance for split
            // 'http://google.com/abc{arg=', and '} is true.
            // End symbol is not linkified because there is no open parens to
            // close in the link itself, as the open parens occurs before the URL:
            // * (http://google.com/)
            // e.g. needEndingPunctuationForBalance for split 'http://google.com/
            // and ')' is false.
            function needEndingPunctuationForBalance(
                split, openSymbol, closeSymbol) {
              return goog.string.contains(split[2], closeSymbol) &&
                  goog.string.countOf(split[1], openSymbol) >
                  goog.string.countOf(split[1], closeSymbol);
            }
            if (splitEndingPunctuation &&
                !needEndingPunctuationForBalance(
                    splitEndingPunctuation, '(', ')') &&
                !needEndingPunctuationForBalance(
                    splitEndingPunctuation, '{', '}')) {
              linkText = splitEndingPunctuation[1];
              afterLink = splitEndingPunctuation[2];
            } else {
              linkText = original;
              afterLink = '';
            }
          }
          attributesMap['href'] = href + linkText;
          output.push(goog.html.SafeHtml.create('a', attributesMap, linkText));
          output.push(htmlEscape(afterLink));
          return '';
        });
    return goog.html.SafeHtml.concat(output);
  };
  
  
  /**
   * Gets the first URI in text.
   * @param {string} text Plain text.
   * @return {string} The first URL, or an empty string if not found.
   */
  goog.string.linkify.findFirstUrl = function(text) {
    'use strict';
    const link = text.match(goog.string.linkify.URL_RE_);
    return link != null ? link[0] : '';
  };
  
  
  /**
   * Gets the first email address in text.
   * @param {string} text Plain text.
   * @return {string} The first email address, or an empty string if not found.
   */
  goog.string.linkify.findFirstEmail = function(text) {
    'use strict';
    const email = text.match(goog.string.linkify.EMAIL_RE_);
    return email != null ? email[0] : '';
  };
  
  
  /**
   * If a series of these characters is at the end of a url, it will be considered
   * punctuation and not part of the url.
   * @type {string}
   * @const
   * @private
   */
  goog.string.linkify.ENDING_PUNCTUATION_CHARS_ = '\':;,\\.?}\\]\\)!';
  
  
  /**
   * @type {!RegExp}
   * @const
   * @private
   */
  goog.string.linkify.ENDS_WITH_PUNCTUATION_RE_ = new RegExp(
      '^(.*?)([' + goog.string.linkify.ENDING_PUNCTUATION_CHARS_ + ']+)$');
  
  
  /**
   * Set of characters to be put into a regex character set ("[...]"), used to
   * match against a url hostname and everything after it. It includes, in order,
   * \w which represents [a-zA-Z0-9_], "#-;" which represents the characters
   * "#$%&'()*+,-./0123456789:;" and the characters "!=?@[\]`{|}~".
   * @type {string}
   * @const
   * @private
   */
  goog.string.linkify.ACCEPTABLE_URL_CHARS_ = '\\w#-;!=?@\\[\\\\\\]_`{|}~';
  
  
  /**
   * List of all protocols patterns recognized in urls (mailto is handled in email
   * matching).
   * @type {!Array<string>}
   * @const
   * @private
   */
  goog.string.linkify.RECOGNIZED_PROTOCOLS_ = ['https?', 'ftp'];
  
  
  /**
   * Regular expression pattern that matches the beginning of an url.
   * Contains a catching group to capture the scheme.
   * @type {string}
   * @const
   * @private
   */
  goog.string.linkify.PROTOCOL_START_ =
      '(' + goog.string.linkify.RECOGNIZED_PROTOCOLS_.join('|') + ')://';
  
  
  /**
   * Regular expression pattern that matches the beginning of a typical
   * http url without the http:// scheme.
   * @type {string}
   * @const
   * @private
   */
  goog.string.linkify.WWW_START_ = 'www\\.';
  
  
  /**
   * Regular expression pattern that matches an url.
   * @type {string}
   * @const
   * @private
   */
  goog.string.linkify.URL_RE_STRING_ =
      '(?:' + goog.string.linkify.PROTOCOL_START_ + '|' +
      goog.string.linkify.WWW_START_ + ')[' +
      goog.string.linkify.ACCEPTABLE_URL_CHARS_ + ']+';
  
  
  /**
   * Regular expression that matches an url. Case-insensitive.
   * @type {!RegExp}
   * @const
   * @private
   */
  goog.string.linkify.URL_RE_ =
      new RegExp(goog.string.linkify.URL_RE_STRING_, 'i');
  
  
  /**
   * Regular expression pattern that matches a top level domain.
   * @type {string}
   * @const
   * @private
   */
  goog.string.linkify.TOP_LEVEL_DOMAIN_ = '(?:com|org|net|edu|gov' +
      // from http://www.iana.org/gtld/gtld.htm
      '|aero|biz|cat|coop|info|int|jobs|mobi|museum|name|pro|travel' +
      '|arpa|asia|xxx' +
      // a two letter country code
      '|[a-z][a-z])\\b';
  
  
  /**
   * Regular expression pattern that matches an email.
   * Contains a catching group to capture the email without the optional "mailto:"
   * prefix.
   * @type {string}
   * @const
   * @private
   */
  goog.string.linkify.EMAIL_RE_STRING_ =
      '(?:mailto:)?([\\w.!#$%&\'*+-/=?^_`{|}~]+@[A-Za-z0-9.-]+\\.' +
      goog.string.linkify.TOP_LEVEL_DOMAIN_ + ')';
  
  
  /**
   * Regular expression that matches an email. Case-insensitive.
   * @type {!RegExp}
   * @const
   * @private
   */
  goog.string.linkify.EMAIL_RE_ =
      new RegExp(goog.string.linkify.EMAIL_RE_STRING_, 'i');
  
  
  /**
   * Regular expression to match all the links (url or email) in a string.
   * First match is text before first link, might be empty string.
   * Second match is the original text that should be replaced by a link.
   * Third match is the email address in the case of an email.
   * Fourth match is the scheme of the url if specified.
   * @type {!RegExp}
   * @const
   * @private
   */
  goog.string.linkify.FIND_LINKS_RE_ = new RegExp(
      // Match everything including newlines.
      '([\\S\\s]*?)(' +
          // Match email after a word break.
          '\\b' + goog.string.linkify.EMAIL_RE_STRING_ + '|' +
          // Match url after a word break.
          '\\b' + goog.string.linkify.URL_RE_STRING_ + '|$)',
      'gi');
  