brackt/app/lib/owner-map.ts

import { findUserByClerkId } from "~/models/user";

/**
 * Builds a map of teamId -> manager username (or displayName fallback).
 * Accepts any array of objects that have a `team` with `id` and `ownerId`.
 */
export async function buildOwnerMap(
  slots: Array<{ team: { id: string; ownerId: string | null } }>
): Promise<Record<string, string>> {
  const ownerIds = slots
    .map((s) => s.team.ownerId)
    .filter((id): id is string => id !== null);
  const uniqueOwnerIds = [...new Set(ownerIds)];

  const ownerEntries = await Promise.all(
    uniqueOwnerIds.map(async (ownerId) => {
      const user = await findUserByClerkId(ownerId);
      const name = user?.username || user?.displayName || null;
      return name ? { ownerId, name } : null;
    })
  );

  const ownerByClerkId = new Map(
    ownerEntries
      .filter((e): e is NonNullable<typeof e> => e !== null)
      .map((e) => [e.ownerId, e.name])
  );

  const ownerMap: Record<string, string> = {};
  for (const slot of slots) {
    const name = slot.team.ownerId
      ? ownerByClerkId.get(slot.team.ownerId)
      : undefined;
    if (name) {
      ownerMap[slot.team.id] = name;
    }
  }
  return ownerMap;
}