localized property

Implementation

String get localized {
  // If [UserAgent] starts with [Config.userAgentProduct], then it's probably
  // the one generated by us via [WebUtils.userAgent] method.
  if (val.startsWith(Config.userAgentProduct)) {
    // Retrieve `.../... (this part)` from the header.
    final String meta = val.substring(
      max(val.indexOf('(') + 1, 0),
      val.endsWith(')') ? val.length - 1 : val.length,
    );

    // Header values are separated by semicolons.
    final List<String> parts = meta.split(';');

    // First part should have the name of operating system.
    final String system = parts.first.trim();

    // If there's no second part at all, return the first one right away.
    if (parts.length < 2) {
      return system;
    }

    // Android devices have an identifier that should be embedded into the
    // second part of the header, thus should return it.
    if (system.startsWith('Android')) {
      return parts.elementAt(1).trim();
    }

    // The following systems have a device identifier that should be embedded
    // into the second part of the header, thus should parse it with
    // [AppleProductName] and return it.
    if (system.startsWith('macOS') ||
        system.startsWith('iOS') ||
        system.startsWith('iPadOS') ||
        system.startsWith('visionOS') ||
        system.startsWith('watchOS') ||
        system.startsWith('tvOS')) {
      return AppleProductName().lookup(parts.elementAt(1).trim());
    }

    return system;
  }
  // Otherwise it may be a browser's `User-Agent` header.
  else {
    // Header values are separated by spaces.
    final List<String> parts = val.split(' ');

    // Browser's `User-Agent` may contain the `Version` tag.
    final String? versionPart = parts.firstWhereOrNull(
      (e) => e.startsWith('Version/'),
    );

    for (final BrowserRule e in _rules) {
      // Lookup the part that is identifiable by any [BrowserRule] out there.
      final int i = parts.indexWhere((p) => p.startsWith(e.rule));

      if (i != -1) {
        // `User-Agent` tag should be something like `Label/1.0.0`, and we
        // need the number part, so try to retrieve it.
        final List<String> tag = (versionPart ?? parts[i]).split('/');

        if (tag.length > 1) {
          String version = tag[1];

          // If the [BrowserRule] requests the version to contain only
          // specified depth, then trim it.
          if (e.versionDepth != null) {
            version =
                version = version.split('.').take(e.versionDepth!).join('.');
          }

          return '${e.name} $version';
        } else {
          return e.name;
        }
      }
    }
  }

  return val;
}