getLocalizedContent function

String getLocalizedContent(String content, AppLanguage language)

Parses multiline text with language delimiters (e.g. ### en ###) and extracts the block matching the current language.

Fallback Strategy:

1. Finds direct language match (e.g., es).
2. If missing, falls back to English (en).
3. If English is also missing, falls back to the first language defined in the text.
4. If no delimiters are detected at all, returns the entire string (ensures backward compatibility).

Implementation

String getLocalizedContent(String content, AppLanguage language) {
  // Regex matches "### en ###", "### en-US ###", "### nb ###", case-insensitively.
  // Using multiLine: true lets ^ match at the beginning of any line.
  final pattern = RegExp(r'^###\s*([a-zA-Z-]+)\s*###', multiLine: true);
  final matches = pattern.allMatches(content).toList();

  // Backward compatibility: if no markup is found, return the whole text.
  if (matches.isEmpty) {
    return content;
  }

  final sections = <String, String>{};

  for (int i = 0; i < matches.length; i++) {
    final match = matches[i];
    final langCode = match.group(1)!.trim().toLowerCase();

    final start = match.end;
    final end = (i + 1 < matches.length) ? matches[i + 1].start : content.length;

    sections[langCode] = content.substring(start, end).trim();
  }

  // 1. Direct Match
  final targetLang = language.name.toLowerCase();
  if (sections.containsKey(targetLang)) {
    return sections[targetLang]!;
  }

  // 2. English Fallback
  if (sections.containsKey('en')) {
    return sections['en']!;
  }

  // 3. First available language block
  if (sections.isNotEmpty) {
    return sections.values.first;
  }

  return content;
}