Method budgetedHistory

app/src/AI/Conversation.cpp:2557–2590

* @brief Returns the longest recent suffix of history that fits the provider context window, * cut only at fresh user-turn boundaries so tool_use/tool_result pairs stay intact. */

 *        cut only at fresh user-turn boundaries so tool_use/tool_result pairs stay intact.
 */
QJsonArray AI::Conversation::budgetedHistory(const QJsonArray& tools) const
{
  Q_ASSERT(m_provider);
  if (!m_provider)
    return m_history;

  const auto caps = m_provider->capabilities();
  const int budget =
    caps.contextWindowTokens - caps.maxOutputTokens - kSystemReserveTokens - estimateTokens(tools);
  if (budget <= 0 || estimateTokens(m_history) <= budget)
    return m_history;

  auto suffixFrom = [this](int from) {
    QJsonArray out;
    for (int i = from; i < m_history.size(); ++i)
      out.append(m_history.at(i));

    return out;
  };

  QList<int> boundaries;
  for (int at = firstFreshUserTurnAt(0); at >= 0; at = firstFreshUserTurnAt(at + 1))
    boundaries.append(at);

  int chosen = boundaries.isEmpty() ? 0 : boundaries.constLast();
  for (const int b : boundaries)
    if (estimateTokens(suffixFrom(b)) <= budget) {
      chosen = b;
      break;
    }

  Q_ASSERT(chosen >= 0 && chosen <= m_history.size());
  return suffixFrom(chosen);
}