interface FieldErrorObject {
  message?: string;
  [key: string]: any;
}

interface NestedFieldErrors {
  [key: string]: FieldErrorObject | FieldErrorObject[] | NestedFieldErrors | undefined;
}

export const flattenFieldErrors = (obj: NestedFieldErrors, parentKey = '', results: string[] = []): string[] => {
  for (const key in obj) {
    if (obj.hasOwnProperty(key)) {
      const newKey = parentKey ? `${parentKey}.${key}` : key;
      const value = obj[key];

      if (value instanceof Array) {
        value.forEach((item, index) => {
          flattenFieldErrors(item, `${newKey}[${index}]`, results);
        });
      } else if (value && typeof value === 'object') {
        if (value.message) {
          results.push(value.message as string);
        } else {
          flattenFieldErrors(value, newKey, results);
        }
      }
    }
  }
  return results;
};