getCountryCode static method

Implementation

static String? getCountryCode(String input) {
  if (input.isEmpty) return null;

  final cleanInput = input.toLowerCase().trim();

  // Check if it's already a 2-letter ISO code
  if (cleanInput.length == 2) {
    final upperCode = cleanInput.toUpperCase();
    if (countryMapping.containsKey(upperCode)) {
      return upperCode;
    }
  }

  // Check if it's a 3-letter ISO code
  if (cleanInput.length == 3) {
    final upperCode = cleanInput.toUpperCase();
    // Convert 3-letter to 2-letter using reverse mapping
    for (final entry in countryMapping.entries) {
      if (entry.key == upperCode) {
        return entry.key;
      }
    }
  }

  // Check if it's a country name (with or without dashes)
  final nameVariations = [
    cleanInput,
    cleanInput.replaceAll(' ', '-'),
    cleanInput.replaceAll('-', ' '),
    cleanInput.replaceAll('_', '-'),
  ];

  for (final variation in nameVariations) {
    if (countryMappings.containsKey(variation)) {
      return countryMappings[variation];
    }
  }

  // Try partial matching for country names
  for (final entry in countryMappings.entries) {
    if (entry.key.contains(cleanInput) || cleanInput.contains(entry.key)) {
      return entry.value;
    }
  }

  return null;
}