/** The bot marks a steering message with this reaction once it has picked it up. */
const SEEN_REACTION = "👀";

/**
 * User messages sent after the active run started that the bot has not picked
 * up yet. The run's own trigger message predates the run, so it never counts.
 */
export function queuedFollowUps<
  T extends { id: string; role: string; createdAt?: string | undefined },
>(
  messages: readonly T[],
  runCreatedAt: string | undefined,
  reactions: ReadonlyMap<string, ReadonlyMap<string, number>>,
): T[] {
  if (!runCreatedAt) return [];
  const runStart = Date.parse(runCreatedAt);
  if (Number.isNaN(runStart)) return [];
  return messages.filter(
    (message) =>
      message.role === "user" &&
      !message.id.includes(":") &&
      typeof message.createdAt === "string" &&
      Date.parse(message.createdAt) > runStart &&
      !reactions.get(message.id)?.has(SEEN_REACTION),
  );
}