public inherited sharing class MetadataXml {
  public static String escape(String value) {
    if (value == null) {
      return '';
    }
    return value
      .replace('&', '&')
      .replace('<', '&lt;')
      .replace('>', '&gt;')
      .replace('"', '&quot;')
      .replace('\'', '&apos;');
  }

  public static Dom.XmlNode child(Dom.XmlNode parent, String localName) {
    if (parent == null) {
      return null;
    }
    for (Dom.XmlNode candidate : parent.getChildElements()) {
      if (candidate.getName() == localName) {
        return candidate;
      }
    }
    return null;
  }

  public static List<Dom.XmlNode> children(
    Dom.XmlNode parent,
    String localName
  ) {
    List<Dom.XmlNode> matches = new List<Dom.XmlNode>();
    if (parent == null) {
      return matches;
    }
    for (Dom.XmlNode candidate : parent.getChildElements()) {
      if (candidate.getName() == localName) {
        matches.add(candidate);
      }
    }
    return matches;
  }

  public static Dom.XmlNode findDescendant(
    Dom.XmlNode parent,
    String localName
  ) {
    if (parent == null) {
      return null;
    }
    if (parent.getName() == localName) {
      return parent;
    }
    for (Dom.XmlNode candidate : parent.getChildElements()) {
      Dom.XmlNode match = findDescendant(candidate, localName);
      if (match != null) {
        return match;
      }
    }
    return null;
  }

  public static String text(Dom.XmlNode parent, String localName) {
    Dom.XmlNode valueNode = child(parent, localName);
    return valueNode == null ? null : valueNode.getText();
  }

  public static Boolean booleanValue(Dom.XmlNode parent, String localName) {
    return 'true'.equalsIgnoreCase(text(parent, localName));
  }

  public static String serialize(Dom.XmlNode node) {
    String name = node.getName();
    List<Dom.XmlNode> childNodes = node.getChildElements();
    if (childNodes.isEmpty()) {
      return '<' + name + '>' + escape(node.getText()) + '</' + name + '>';
    }

    String result = '<' + name + '>';
    for (Dom.XmlNode childNode : childNodes) {
      result += serialize(childNode);
    }
    return result + '</' + name + '>';
  }

  public static String serializeChildren(Dom.XmlNode parent) {
    String result = '';
    for (Dom.XmlNode childNode : parent.getChildElements()) {
      result += serialize(childNode);
    }
    return result;
  }

  public static String replaceOrInsertChild(
    Dom.XmlNode parent,
    String childName,
    String replacementXml
  ) {
    String result = '';
    Boolean replaced = false;
    for (Dom.XmlNode childNode : parent.getChildElements()) {
      if (childNode.getName() == childName) {
        if (!replaced) {
          result += replacementXml;
          replaced = true;
        }
      } else if (!replaced && childNode.getName().compareTo(childName) > 0) {
        result += replacementXml;
        result += serialize(childNode);
        replaced = true;
      } else {
        result += serialize(childNode);
      }
    }
    if (!replaced) {
      result += replacementXml;
    }
    return result;
  }

  public static String developerName(String label) {
    String value = String.isBlank(label)
      ? ''
      : label.trim().replaceAll('[^A-Za-z0-9_]+', '_');
    value = value.replaceAll('_+', '_').replaceAll('^_+|_+$', '');
    if (String.isBlank(value)) {
      throw new IllegalArgumentException(
        'A developer name could not be generated from the label.'
      );
    }
    if (Pattern.matches('^[0-9].*', value)) {
      value = 'X_' + value;
    }
    return value.length() > 80 ? value.substring(0, 80) : value;
  }

  public static void require(Boolean condition, String message) {
    if (!condition) {
      throw new IllegalArgumentException(message);
    }
  }
}