llink/js/src/hooks/use-particle-children.ts

import { useState, useEffect, useMemo } from "react";
import { subscribeToParticleChildren } from "@/lib/firestore-particles";
import { firestorePath } from "@/lib/firestore-paths";
import type { Particle } from "@/api/types";

interface UseParticleChildrenResult {
  children: Particle[];
  isLoading: boolean;
  error: Error | null;
}

export function useParticleChildren(
  networkId: string,
  parentSegments: string[],
): UseParticleChildrenResult {
  const [children, setChildren] = useState<Particle[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<Error | null>(null);

  const collectionPath = useMemo(() => {
    if (parentSegments.length === 0) return firestorePath(networkId, []);
    return `${firestorePath(networkId, parentSegments)}/children`;
  }, [networkId, parentSegments.join("/")]);

  useEffect(() => {
    setIsLoading(true);
    setError(null);
    setChildren([]);

    const unsubscribe = subscribeToParticleChildren(
      collectionPath,
      (data) => {
        setChildren(data);
        setIsLoading(false);
      },
      (err) => {
        setError(err);
        setIsLoading(false);
      },
    );

    return unsubscribe;
  }, [collectionPath]);

  return { children, isLoading, error };
}