Function resolveSlackUserDisplayName

server/src/slack/client.ts:261–310

(
  slackUserId: string
)

 * Persists to database for future lookups.
 */
export async function resolveSlackUserDisplayName(
  slackUserId: string
): Promise<ResolvedSlackUser | null> {
  const db = getSlackDb();

  // Check database first
  const existing = await db.getBySlackUserId(slackUserId);
  if (existing) {
    return {
      slack_user_id: existing.slack_user_id,
      display_name: existing.slack_display_name || existing.slack_real_name,
      email: existing.slack_email,
    };
  }

  // Fetch from Slack API and persist
  try {
    const slackUser = await getSlackUser(slackUserId);
    if (!slackUser) {
      return null;
    }

    const displayName = slackUser.profile?.display_name ||
                       slackUser.profile?.real_name ||
                       slackUser.real_name ||
                       null;
    const email = slackUser.profile?.email || null;

    // Persist for future requests
    await db.upsertSlackUser({
      slack_user_id: slackUserId,
      slack_email: email,
      slack_display_name: slackUser.profile?.display_name || null,
      slack_real_name: slackUser.profile?.real_name || slackUser.real_name || null,
      slack_is_bot: slackUser.is_bot,
      slack_is_deleted: slackUser.deleted,
    });

    logger.debug({ slackUserId, displayName }, 'Resolved and persisted Slack user from API');

    return {
      slack_user_id: slackUserId,
      display_name: displayName,
      email: email,
    };
  } catch (error) {
    logger.debug({ slackUserId, error }, 'Failed to resolve Slack user');
    return null;
  }
}

/**
 * Resolve multiple Slack user IDs to display names with concurrency limiting.