// Whole-Bible search for translations that can't be downloaded and indexed in the
// browser (ESV, NLT, CSB, NASB): queries go through the server's search proxy.
// Debounced, cancels stale requests, and pages in 25 verses at a time.
import { useCallback, useEffect, useRef, useState } from 'react';

const DEBOUNCE_MS = 450;
const EMPTY = { results: [], total: 0, page: 0, hasMore: false, loading: false, error: '' };

export function useBibleSearch(translation, query, enabled) {
  const [state, setState] = useState(EMPTY);
  const controllerRef = useRef(null);
  const q = query.trim();

  const run = useCallback(async (page) => {
    controllerRef.current?.abort();
    const controller = new AbortController();
    controllerRef.current = controller;
    setState((s) => ({ ...s, loading: true, error: '' }));
    try {
      const res = await fetch(`/api/bible/${translation}/search?q=${encodeURIComponent(q)}&page=${page}`, {
        credentials: 'include', signal: controller.signal,
      });
      const data = await res.json().catch(() => ({}));
      if (!res.ok) throw new Error(data.error || 'Search failed.');
      setState((s) => ({
        results: page === 1 ? data.results : [...s.results, ...data.results],
        total: data.total, page: data.page, hasMore: data.hasMore, loading: false, error: '',
      }));
    } catch (err) {
      if (err.name === 'AbortError') return;
      setState((s) => ({ ...s, loading: false, error: err.message || 'Search failed.' }));
    }
  }, [translation, q]);

  useEffect(() => {
    if (!enabled || q.length < 2) {
      controllerRef.current?.abort();
      setState(EMPTY);
      return undefined;
    }
    const timer = window.setTimeout(() => run(1), DEBOUNCE_MS);
    return () => window.clearTimeout(timer);
  }, [enabled, q, run]);

  useEffect(() => () => controllerRef.current?.abort(), []);

  const loadMore = () => { if (!state.loading && state.hasMore) run(state.page + 1); };
  return { ...state, loadMore, tooShort: q.length < 2 };
}