"use client";

// Client fetch for a site's shipped /tags.json — the curated per-video tag
// vocabulary (lib/curatedTags.ts) with the per-site counts compose-site wrote.
// Mirrors aliasesCache / summariesCache exactly, including its answer to
// absence, because the two documents have the same shape of optionality: a
// site publishes one only when it has something to publish.
//
// A 404 is the NORMAL state here in two different ways, and neither is an
// error: compose-site writes no file at all for a site with no visible,
// non-zero-count tag, and a site built before corpus spec 4 has never heard of
// tags. Both resolve to an empty list, which the chip row reads as "offer no
// chips" — the operator's rule that a site's row is built only from what that
// site actually publishes, with no static list anywhere.

import { useQuery } from "@tanstack/react-query";
import { ArchiveHttpError } from "../lib/archive/reader";
import { readerFor } from "../lib/archive/readers";
import { coercePublishedTags } from "../lib/publishedTags";
import type { PublishedTag } from "../lib/curatedTags";

const EMPTY: PublishedTag[] = [];

// ANY status the archive itself returned resolves empty — a 404 because the
// site ships no tags, but a 500 or a 403 the same way. A TRANSPORT failure is
// different and is rethrown: it is not an answer at all, and with
// staleTime: Infinity below a swallowed blip would mean "this site has no
// tags" for the rest of the session. Same reasoning as fetchAliases.
export async function fetchTags(origin = ""): Promise<PublishedTag[]> {
  try {
    return coercePublishedTags(await readerFor(origin).readTags());
  } catch (err) {
    if (err instanceof ArchiveHttpError) return [];
    throw err;
  }
}

export function useCuratedTags(origin = ""): PublishedTag[] {
  const { data } = useQuery<PublishedTag[]>({
    queryKey: ["curated-tags", origin],
    queryFn: () => fetchTags(origin),
    staleTime: Infinity, // static per export build
  });
  return data ?? EMPTY;
}