export const resolveCorrespondents = (doc) => {
  if (!doc || !Array.isArray(doc.correspondents)) {
    return [];
  }

  const seen = new Set();
  const results = [];

  doc.correspondents.forEach((entry = {}, index) => {
    const { id, name } = entry;
    if (typeof name !== 'string') {
      return;
    }

    const trimmedName = name.trim();
    if (!trimmedName) {
      return;
    }

    if (id && seen.has(id)) {
      return;
    }

    if (id) {
      seen.add(id);
    }

    results.push({
      id,
      name: trimmedName,
      key: id ?? `${trimmedName}-${index}`,
    });
  });

  return results;
};

export default resolveCorrespondents;