function selectTop(scored, topN, config) {
  const eligible = scored.filter((item) => !item.excludedFromTop10);
  const excluded = scored.filter((item) => item.excludedFromTop10);

  const sorted = [...eligible].sort((a, b) => b.score - a.score);

  const groupCap = Math.max(1, Math.ceil(topN * 0.5));
  const groupCounts = {};
  const firstPass = [];
  const deferred = [];

  for (const item of sorted) {
    const count = groupCounts[item.group] || 0;
    if (count < groupCap && firstPass.length < topN) {
      firstPass.push(item);
      groupCounts[item.group] = count + 1;
    } else {
      deferred.push(item);
    }
  }

  let selected = firstPass;
  if (selected.length < topN) {
    selected = selected.concat(deferred.slice(0, topN - selected.length));
  }
  selected = selected.slice(0, topN);

  const selectedIds = new Set(selected.map((item) => item.ticket.id));
  const notSelected = sorted.filter((item) => !selectedIds.has(item.ticket.id));

  return { selected, excluded: excluded.concat(notSelected) };
}

module.exports = { selectTop };