// Free study data from HelloAO: public-domain commentaries and the Theographic
// people/places/events dataset. Both are keyed by book + chapter, so results are
// cached per chapter for the rest of the visit.
import { useEffect, useState } from 'react';
import { renderVerseContent } from '../utils/bibleUtils.jsx';

const API = 'https://bible.helloao.org/api';

export const COMMENTARIES = [
  { id: 'matthew-henry', name: 'Matthew Henry', credit: 'Matthew Henry Bible Commentary (public domain).' },
  { id: 'john-gill', name: 'John Gill', credit: 'John Gill Bible Commentary (public domain).' },
  { id: 'jamieson-fausset-brown', name: 'Jamieson-Fausset-Brown', credit: 'Jamieson-Fausset-Brown Bible Commentary (public domain).' },
  { id: 'tyndale', name: 'Tyndale Study Notes', credit: 'Tyndale Open Study Notes © Tyndale House Foundation, licensed CC BY-SA 4.0.' },
  { id: 'adam-clarke', name: 'Adam Clarke', credit: 'Adam Clarke Bible Commentary (public domain).' },
  { id: 'john-calvin', name: 'John Calvin', credit: "John Calvin's Commentaries (public domain)." },
  { id: 'keil-delitzsch', name: 'Keil & Delitzsch (OT)', credit: 'Keil & Delitzsch Old Testament Commentary (public domain).' },
];

const commentaryCache = new Map(); // "id/BOOK/ch" -> Promise<entries | null>
const theographicCache = new Map(); // "BOOK/ch" -> Promise<{people, places, events} | null>
const personCache = new Map(); // id -> Promise<person | null>

const getJson = (url) => fetch(url).then((r) => (r.ok ? r.json() : null)).catch(() => null);

// Resolves to [{ number, text }] sorted by verse, or null when the commentary
// doesn't cover that book/chapter.
export function loadCommentary(id, book, chapter) {
  const key = `${id}/${book}/${chapter}`;
  if (!commentaryCache.has(key)) {
    commentaryCache.set(key, getJson(`${API}/c/${id}/${book}/${chapter}.json`).then((data) => {
      const items = data?.chapter?.content;
      if (!Array.isArray(items)) return null;
      return items
        .filter((it) => it?.type === 'verse')
        .map((it) => ({ number: it.number, text: renderVerseContent(it.content).replace(/[ \t]+\n/g, '\n').trim() }))
        .filter((it) => it.text)
        .sort((a, b) => a.number - b.number);
    }));
  }
  return commentaryCache.get(key);
}

export function loadTheographic(book, chapter) {
  const key = `${book}/${chapter}`;
  if (!theographicCache.has(key)) {
    theographicCache.set(key, getJson(`${API}/d/theographic/${book}/${chapter}.json`).then((data) => (
      data?.chapter ? { people: data.chapter.people ?? [], places: data.chapter.places ?? [], events: data.chapter.events ?? [] } : null
    )));
  }
  return theographicCache.get(key);
}

export function loadPerson(id) {
  if (!personCache.has(id)) {
    personCache.set(id, getJson(`${API}/d/theographic/people/${id}.json`).then((d) => d?.person ?? null));
  }
  return personCache.get(id);
}

// For verse N, the commentary entry that starts at N, or otherwise the closest
// earlier one (several commentaries write on whole passages, not each verse).
export function pickCommentaryEntry(entries, verse) {
  if (!entries?.length) return null;
  let best = null;
  for (const e of entries) {
    if (e.number <= verse) best = e;
    else break;
  }
  return best;
}

// Small state wrapper: { status: 'loading' | 'ready' | 'empty', data }.
export function useAsync(loader, deps) {
  const [state, setState] = useState({ status: 'loading', data: null });
  useEffect(() => {
    let active = true;
    setState({ status: 'loading', data: null });
    loader().then((data) => {
      if (active) setState({ status: data ? 'ready' : 'empty', data });
    });
    return () => { active = false; };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, deps);
  return state;
}