// Inline study panel shown under a verse in the Reader: commentary from several
// public-domain / open sources, plus the people, places and events tied to the verse.
import { useState } from 'react';
import { useApp } from '../context/AppContext.js';
import {
  COMMENTARIES, loadCommentary, loadTheographic, loadPerson, pickCommentaryEntry, useAsync,
} from '../hooks/useVerseStudy.js';

export function CommentaryTab({ book, chapter, verse }) {
  // The chosen commentary is a synced preference, shared with the Study stage
  const { readerCommentary: sourceId, setReaderCommentary: changeSource } = useApp();
  const source = COMMENTARIES.find((c) => c.id === sourceId) ?? COMMENTARIES[0];
  const { status, data } = useAsync(() => loadCommentary(source.id, book, chapter), [source.id, book, chapter]);
  const entry = pickCommentaryEntry(data, verse);

  return (
    <div>
      <label className="text-xs text-[var(--r-sub,#64748b)]">
        Commentary{' '}
        <select value={source.id} onChange={(e) => changeSource(e.target.value)}
          className="rounded-lg border border-[var(--r-line,#cbd5e1)] bg-[var(--r-bg,#ffffff)] px-2 py-1 text-xs">
          {COMMENTARIES.map((c) => <option key={c.id} value={c.id}>{c.name}</option>)}
        </select>
      </label>
      <div className="mt-2">
        {status === 'loading' && <p className="text-xs text-[var(--r-sub,#64748b)]">Loading…</p>}
        {status === 'empty' && <p className="text-xs text-[var(--r-sub,#64748b)]">{source.name} has no notes for this chapter.</p>}
        {status === 'ready' && !entry && <p className="text-xs text-[var(--r-sub,#64748b)]">No notes at or before this verse in {source.name}.</p>}
        {status === 'ready' && entry && (
          <>
            {entry.number !== verse && (
              <p className="mb-1 text-[11px] text-[var(--r-sub,#64748b)]">Notes on the passage starting at verse {entry.number}.</p>
            )}
            <div className="max-h-96 overflow-y-auto whitespace-pre-line rounded-xl bg-[var(--r-bg,#ffffff)] p-3 text-[13px] leading-relaxed text-[var(--r-text,#334155)]">
              {entry.text}
            </div>
          </>
        )}
      </div>
      <p className="mt-2 text-[10px] text-[var(--r-sub,#64748b)]">{source.credit}</p>
    </div>
  );
}

function PersonDetails({ id }) {
  const { status, data } = useAsync(() => loadPerson(id), [id]);
  if (status === 'loading') return <p className="mt-1 text-xs text-[var(--r-sub,#64748b)]">Loading…</p>;
  if (status === 'empty') return <p className="mt-1 text-xs text-[var(--r-sub,#64748b)]">No details available.</p>;
  const era = (y) => `${Math.abs(y)}${y < 0 ? ' BC' : ' AD'}`;
  return (
    <div className="mt-1 space-y-1 text-xs leading-relaxed text-[var(--r-sub,#64748b)]">
      {(data.description ?? []).map((d, i) => <p key={i}>{d}</p>)}
      {!data.description?.length && <p>No description available.</p>}
      {data.minYear != null && (
        <p className="text-[var(--r-sub,#64748b)]">
          Lived approx. {era(data.minYear)}{data.maxYear != null && data.maxYear !== data.minYear ? ` – ${era(data.maxYear)}` : ''}
        </p>
      )}
    </div>
  );
}

export function PersonCard({ person }) {
  const [open, setOpen] = useState(false);
  return (
    <li className="rounded-xl bg-[var(--r-bg,#ffffff)] px-3 py-2">
      <button type="button" onClick={() => setOpen((o) => !o)} className="w-full text-left text-sm font-semibold text-[var(--r-text,#334155)]">
        {person.name} <span className="text-xs font-normal text-[var(--r-sub,#64748b)]">{open ? '▾' : '▸'}</span>
      </button>
      {open && <PersonDetails id={person.id} />}
    </li>
  );
}

export function PeoplePlacesTab({ book, chapter, verse }) {
  const { status, data } = useAsync(() => loadTheographic(book, chapter), [book, chapter]);
  if (status === 'loading') return <p className="text-xs text-[var(--r-sub,#64748b)]">Loading…</p>;
  if (status === 'empty') return <p className="text-xs text-[var(--r-sub,#64748b)]">No people or places data for this chapter.</p>;
  const here = (list) => list.filter((x) => x.verses?.includes(verse));
  // Theographic lists some places twice (variant spellings) — collapse by name.
  const places = [...new Map(here(data.places).map((p) => [p.name, p])).values()];
  const people = here(data.people);
  const events = here(data.events);
  if (!people.length && !places.length && !events.length) {
    return <p className="text-xs text-[var(--r-sub,#64748b)]">Nothing tagged on verse {verse}.</p>;
  }
  return (
    <div className="space-y-3">
      {people.length > 0 && (
        <div>
          <p className="mb-1 text-xs font-semibold uppercase tracking-wide text-[var(--r-sub,#64748b)]">People</p>
          <ul className="space-y-1">{people.map((p) => <PersonCard key={p.id} person={p} />)}</ul>
        </div>
      )}
      {places.length > 0 && (
        <div>
          <p className="mb-1 text-xs font-semibold uppercase tracking-wide text-[var(--r-sub,#64748b)]">Places</p>
          <ul className="space-y-1">
            {places.map((p) => (
              <li key={p.id} className="flex items-center justify-between gap-2 rounded-xl bg-[var(--r-bg,#ffffff)] px-3 py-2 text-sm text-[var(--r-text,#334155)]">
                <span>{p.name}{p.featureType && <span className="ml-1 text-xs text-[var(--r-sub,#64748b)]">{p.featureType}</span>}</span>
                {p.latitude != null && p.longitude != null && (
                  <a href={`https://www.openstreetmap.org/?mlat=${p.latitude}&mlon=${p.longitude}#map=8/${p.latitude}/${p.longitude}`}
                    target="_blank" rel="noopener noreferrer" className="text-xs font-semibold text-sky-600 hover:underline">
                    Map ↗
                  </a>
                )}
              </li>
            ))}
          </ul>
        </div>
      )}
      {events.length > 0 && (
        <div>
          <p className="mb-1 text-xs font-semibold uppercase tracking-wide text-[var(--r-sub,#64748b)]">Events</p>
          <ul className="space-y-1">
            {events.map((e) => (
              <li key={e.id} className="rounded-xl bg-[var(--r-bg,#ffffff)] px-3 py-2 text-sm text-[var(--r-text,#334155)]">
                {e.name}{e.startDate && <span className="ml-1 text-xs text-[var(--r-sub,#64748b)]">approx. AD {e.startDate}</span>}
              </li>
            ))}
          </ul>
        </div>
      )}
      <p className="text-[10px] text-[var(--r-sub,#64748b)]">
        People, places and events: Theographic Bible Metadata, licensed CC BY-SA 4.0.
      </p>
    </div>
  );
}

export default function StudyPanel({ book, chapter, verse, onClose }) {
  const [tab, setTab] = useState('commentary');
  const tabBtn = (id, label) => (
    <button type="button" onClick={() => setTab(id)}
      className={`rounded-lg px-3 py-1 text-xs font-semibold ${tab === id ? 'bg-slate-900 text-white' : 'bg-[var(--r-bg,#ffffff)] text-[var(--r-sub,#64748b)] hover:bg-slate-100'}`}>
      {label}
    </button>
  );
  return (
    <div className="mt-2 mb-1 ml-6 rounded-2xl border border-indigo-100 bg-indigo-50 p-3">
      <div className="mb-2 flex items-center justify-between gap-2">
        <div className="flex gap-1">
          {tabBtn('commentary', 'Commentary')}
          {tabBtn('people', 'People & Places')}
        </div>
        <button type="button" onClick={onClose} className="rounded p-1 text-xs text-[var(--r-sub,#64748b)] hover:bg-[var(--r-bg,#ffffff)]" title="Close">✕</button>
      </div>
      {tab === 'commentary'
        ? <CommentaryTab book={book} chapter={chapter} verse={verse} />
        : <PeoplePlacesTab book={book} chapter={chapter} verse={verse} />}
    </div>
  );
}