SkateSpots/src/hooks/useCrewmates.ts

import { useMemo } from 'react';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useCrews } from '@/hooks/useCrews';

export interface Crewmate {
  pubkey: string;
  /** Crews (names) the person shares with the viewer. */
  sharedCrews: string[];
}

/**
 * The people in the viewer's crews — founder + members of every crew the
 * logged-in user belongs to (as founder or listed member), minus themselves.
 *
 * Powers the "Crew-mates" tab in Contacts: the human network the user has
 * already opted into by being in shared crews.
 */
export function useCrewmates() {
  const { user } = useCurrentUser();
  const { data: crews, isLoading } = useCrews(200);

  const crewmates = useMemo<Crewmate[]>(() => {
    if (!user || !crews) return [];

    const myCrews = crews.filter(
      (c) => c.pubkey === user.pubkey || c.members.includes(user.pubkey),
    );

    const map = new Map<string, Set<string>>();
    for (const crew of myCrews) {
      const people = [crew.pubkey, ...crew.members];
      for (const pk of people) {
        if (pk === user.pubkey) continue;
        if (!map.has(pk)) map.set(pk, new Set());
        map.get(pk)!.add(crew.name);
      }
    }

    return Array.from(map.entries())
      .map(([pubkey, names]) => ({ pubkey, sharedCrews: Array.from(names) }))
      .sort((a, b) => b.sharedCrews.length - a.sharedCrews.length);
  }, [user, crews]);

  return { crewmates, isLoading };
}