import 'package:html/parser.dart' as html_parser; // To parse the HTML
import 'package:html/dom.dart'; // For working with the DOM structure

void main() {
  // Example HTML content with some nested tags
  String htmlContent = '''
    <div>
      Line 1<br>
      <div>Line 2<br>Line 3<br><span>Nested Line 4</span></div>
      Line 5
    </div>
  ''';

  // Parse the HTML content
  Document document = html_parser.parse(htmlContent);

  // Find the desired element
  Element? divElement = document.querySelector('div');

  if (divElement != null) {
    // Extract and preserve newlines recursively
    String preservedText = preserveTextWithNewlines(divElement);
    print(preservedText);
  }
}

String preserveTextWithNewlines(Element element) {
  final buffer = StringBuffer();

  for (var node in element.nodes) {
    if (node is Text) {
      // Append text content
      buffer.write(node.text);
    } else if (node is Element) {
      if (node.localName == 'br') {
        // Add newline for <br> tags
        buffer.write('\n');
      } else {
        // Recursively process child elements
        buffer.write(preserveTextWithNewlines(node));
      }
    }
  }

  return buffer.toString();
}