'use strict';
// ---- Free audiobooks (LibriVox): search public-domain books read by volunteers, keep a shelf, and listen in the same player as Music. Where you got to in each
// book is kept on the server (per person), so it follows you between devices.
const lvApi = (p, opts) => jfetch('/api/ab/free' + p, opts);
const lvOpt = (m, o) => ({ method: m, headers: { 'content-type': 'application/json' }, body: o ? JSON.stringify(o) : undefined });
const lvDur = s => { s = Math.round(+s || 0); if (!s) return ''; const h = Math.floor(s / 3600), m = Math.floor(s % 3600 / 60); return h ? h + ' h ' + m + ' min' : Math.max(1, m) + ' min'; };
const lvImg = (b, sq) => `<span class="vimg" style="aspect-ratio:1/1;background:linear-gradient(135deg,hsl(${abHue(b.title)} 55% 40%),hsl(${abHue(b.title) + 40} 55% 28%))"><img loading="lazy" alt="" referrerpolicy="no-referrer" src="${esc(b.cover || '')}" onerror="this.remove()"></span>`;
let lvProg = {}, lvQueued = {}, lvLast = 0, lvBook = null, lvLoading = '';
const lvPlaying = () => { const t = cur(), m = t && /^lv:(\d+):(\d+)$/.exec(String(t.key)); return m ? { id: m[1], n: +m[2] } : null; };
const lvOffsets = b => { let t = 0; return b.chapters.map(c => { const o = t; t += c.secs; return o; }); };
const lvTotal = b => b.chapters.reduce((a, c) => a + c.secs, 0) || b.secs;
const lvLoadProg = async () => { try { for (const [id, p] of Object.entries(await lvApi('/progress') || {})) if (!lvProg[id] || p.t > lvProg[id].t) lvProg[id] = p; } catch {} };
const lvPush = keepalive => {
  if (!Object.keys(lvQueued).length) return;
  const body = JSON.stringify(lvQueued); lvQueued = {};
  fetch('/api/ab/free/progress', { method: 'POST', headers: { 'content-type': 'application/json' }, body, keepalive: !!keepalive }).then(r => { if (!r.ok) throw 0; }).catch(() => { lvQueued = { ...JSON.parse(body), ...lvQueued }; });
};
const lvSave = keepalive => {
  const now = lvPlaying(), d = pl.a.duration; if (!now || !isFinite(d) || d <= 0) return;
  if (!lvBook || lvBook.id !== now.id) { // the page was reloaded while a book was playing: fetch its chapter list once, then carry on saving
    if (lvLoading !== now.id) { lvLoading = now.id; lvApi('/book/' + now.id).then(b => { lvBook = { id: b.id, offsets: lvOffsets(b), total: lvTotal(b) }; }).catch(() => {}).finally(() => { lvLoading = ''; }); }
    return;
  }
  const key = 'lv:' + now.id; lvProg[key] = lvQueued[key] = { pos: (lvBook.offsets[now.n] || 0) + pl.a.currentTime, dur: lvBook.total, t: Date.now() }; lvPush(keepalive);
};
pl.a.addEventListener('timeupdate', () => { if (Date.now() - lvLast > 8000) { lvLast = Date.now(); lvSave(); } });
pl.a.addEventListener('pause', () => lvSave());
pl.a.addEventListener('ended', () => lvSave());
addEventListener('pagehide', () => lvSave(true));
let lvShelf = [];
/** Load the saved free books and where you got to in each (for this page and for the main Audiobooks list). Never throws. */
const lvPrime = async () => { try { [lvShelf] = await Promise.all([lvApi('/shelf'), lvLoadProg()]); } catch { lvShelf = []; } return lvShelf; };
const lvCard = (b, wide) => { const p = lvLeft(b.id), pct = p ? Math.min(100, p.pos / p.dur * 100) : 0; return `<a class="vcard${wide ? ' wide' : ''}" href="#" data-lv="${esc(b.id)}" ${wide ? 'style="width:140px;flex:none"' : ''}>${lvImg(b).replace('</span>', pct > 1 ? `<i class="vprog"><b style="width:${pct}%"></b></i></span>` : '</span>')}<b>${esc(b.title)}</b><small>${esc(b.author || '')}${b.secs ? (b.author ? ' · ' : '') + esc(lvDur(b.secs)) : ''}</small></a>`; };
const lvBind = (root, after, known) => root.querySelectorAll('[data-lv]').forEach(a => a.onclick = e => { e.preventDefault(); lvSheet(a.dataset.lv, after, known); });
const lvRecent = () => lvShelf.slice().sort((a, b) => ((lvProg['lv:' + b.id] || {}).t || b.added) - ((lvProg['lv:' + a.id] || {}).t || a.added));
const lvLeft = id => { const p = lvProg['lv:' + id]; return p && p.pos > 10 && p.dur && p.pos < p.dur - 30 ? p : null; };

/** Play a book from `at` seconds into it (default: where you left off), as one queue of chapters so the next chapter follows by itself. */
function lvPlay(b, at) {
  const offs = lvOffsets(b), p = lvLeft(b.id), pos = at != null ? at : p ? p.pos : 0;
  let n = 0; for (let i = 0; i < offs.length; i++) if (offs[i] <= pos) n = i;
  const now = lvPlaying(); lvBook = { id: b.id, offsets: offs, total: lvTotal(b) };
  if (now && now.id === b.id && now.n === n && at == null) { if (pl.a.paused) pl.a.play().catch(() => {}); return; }
  playQueue(b.chapters.map(c => ({ key: `lv:${b.id}:${c.n}`, title: c.title, artist: b.author, album: b.title, thumb: b.cover, src: `/api/ab/free/audio/${b.id}/${c.n}`, dur: c.secs * 1000, nocache: true })), n);
  const within = Math.max(0, pos - offs[n]); if (within > 1) pl.a.addEventListener('loadedmetadata', () => { const t = lvPlaying(); if (t && t.id === b.id && t.n === n) pl.a.currentTime = within; }, { once: true });
  lvApi('/shelf', lvOpt('POST', { id: b.id })).catch(() => {}); // a book you start is kept on your shelf
}

async function viewFreeBooks() {
  const v = $('#view'); v.innerHTML = '<div class="wrap"><h1>Free audiobooks</h1><p class="empty">Loading…</p></div>';
  try { lvShelf = await lvApi('/shelf'); await lvLoadProg(); } catch (e) { v.innerHTML = `<div class="wrap"><a class="btn ghost" href="#/audio">${icon('back')}Audiobooks</a><p class="err">${esc(e.message)}</p></div>`; return; }
  if (!location.hash.startsWith('#/audio/free')) return;
  const S = { q: '', page: 1, items: [], more: false, busy: false, seq: 0 };
  const card = b => lvCard(b);
  v.innerHTML = `<div class="wrap"><div class="ptop"><a class="btn ghost" href="#/audio">${icon('back')}Audiobooks</a><h1 style="margin:0">Free audiobooks</h1></div>
    <p class="sub">Public-domain books read aloud by volunteers (LibriVox). Free, with no sign-in. A book you start is kept on your shelf.</p>
    <input type="search" id="lvq" placeholder="Search by title or author" autocomplete="off" autocapitalize="off" style="width:100%"><div id="lvnote"></div><div id="lvbody"></div><div id="lvmore" class="bar" style="justify-content:center"></div></div>`;
  const known = new Map(lvShelf.map(b => [b.id, b]));
  const draw = () => {
    const mine = lvRecent();
    $('#lvbody').innerHTML = (!S.q && mine.length ? `<h2>My free audiobooks</h2><div class="vgrid">${mine.map(card).join('')}</div>` : '') +
      (S.q ? (S.items.length ? `<h2>Results</h2><div class="vgrid">${S.items.map(card).join('')}</div>` : S.busy ? '' : '<p class="empty">Nothing found.</p>') : `<h2>${S.items.length ? 'Browse' : ''}</h2>${S.items.length ? `<div class="vgrid">${S.items.map(card).join('')}</div>` : S.busy ? '' : ''}`);
    lvBind($('#lvbody'), draw, known);
    $('#lvmore').innerHTML = S.busy ? '<span class="sub">Searching…</span>' : S.more ? '<button class="btn ghost" id="lvmb">Show more</button>' : '';
    if ($('#lvmb')) $('#lvmb').onclick = () => run(false);
  };
  const run = async reset => {
    const my = ++S.seq; if (reset) { S.page = 1; S.items = []; } else S.page++; S.busy = true; $('#lvnote').innerHTML = ''; draw();
    try { const r = await lvApi(`/search?q=${encodeURIComponent(S.q)}&page=${S.page}`); if (my !== S.seq) return; S.items = S.items.concat(r.items); S.more = r.more; r.items.forEach(b => known.set(b.id, known.get(b.id) || b)); }
    catch (e) { if (my === S.seq) $('#lvnote').innerHTML = `<p class="err">${esc(e.message)}</p>`; }
    if (my === S.seq) { S.busy = false; draw(); }
  };
  let t; $('#lvq').oninput = e => { clearTimeout(t); t = setTimeout(() => { S.q = e.target.value.trim(); run(true); }, 450); };
  $('#lvq').onkeydown = e => { if (e.key === 'Enter') { clearTimeout(t); S.q = e.target.value.trim(); run(true); } };
  draw(); run(true);
}

async function lvSheet(id, after, known = new Map()) {
    const sum = known.get(id) || lvShelf.find(x => x.id === id) || { id, title: 'Audiobook', author: '' };
    const el = openSheet(sum.title, sum.author || '', '<p class="empty">Loading…</p>');
    let b; try { b = await lvApi('/book/' + id); } catch (e) { el.querySelector('.empty').outerHTML = `<p class="err">${esc(e.message)}</p>`; return; }
    if (!document.body.contains(el)) return;
    const p = lvLeft(id), total = lvTotal(b), onShelf = () => lvShelf.some(x => x.id === id);
    el.querySelector('.empty').outerHTML = `<div style="display:flex;gap:14px;align-items:flex-start"><span class="vimg" style="width:96px;flex:none;aspect-ratio:1/1;background:linear-gradient(135deg,hsl(${abHue(b.title)} 55% 40%),hsl(${abHue(b.title) + 40} 55% 28%))"><img alt="" referrerpolicy="no-referrer" src="${esc(b.cover || '')}" onerror="this.remove()"></span>
      <div style="min-width:0"><p class="sub" style="margin:0">${esc([b.language, lvDur(total), b.chapters.length + ' chapters'].filter(Boolean).join(' · '))}</p><p class="sub" style="margin:4px 0 0">${p ? esc(abFmt(p.pos) + ' of ' + abFmt(p.dur) + ' · ' + abFmt(p.dur - p.pos) + ' left') : 'Not started'}</p></div></div>
      ${b.description ? `<p style="margin:10px 0 0;white-space:normal;display:-webkit-box;-webkit-line-clamp:5;-webkit-box-orient:vertical;overflow:hidden">${esc(b.description)}</p>` : ''}
      <div class="bar"><button class="btn" id="lvp">${icon('play')}${p ? 'Resume' : 'Play'}</button>${p ? '<button class="btn ghost" id="lvs">From the start</button>' : ''}<button class="btn ghost" id="lvc">Chapters</button><button class="btn ghost" id="lvk">${onShelf() ? 'Remove from shelf' : 'Save to shelf'}</button></div><div class="list" id="lvch" style="max-height:40vh;overflow:auto"></div>`;
    const go = at => { if (!b.chapters.length) return toast('This book has no audio'); lvPlay(b, at); closeSheet(); if (!onShelf()) lvShelf.push({ id, title: b.title, author: b.author, secs: b.secs, cover: b.cover, added: Date.now() }); if (after) after(); };
    el.querySelector('#lvp').onclick = () => go();
    if (el.querySelector('#lvs')) el.querySelector('#lvs').onclick = () => go(0);
    el.querySelector('#lvc').onclick = () => { const offs = lvOffsets(b); el.querySelector('#lvch').innerHTML = b.chapters.map((c, i) => `<button class="row" data-i="${i}"><span class="grow"><b>${esc(c.title)}</b><small>${esc([abFmt(c.secs), c.reader].filter(Boolean).join(' · '))}</small></span></button>`).join(''); el.querySelectorAll('#lvch [data-i]').forEach(x => x.onclick = () => go(offs[x.dataset.i])); };
    el.querySelector('#lvk').onclick = async e => { const btn = e.currentTarget; try { if (onShelf()) { await lvApi('/shelf/' + id, lvOpt('DELETE')); lvShelf = lvShelf.filter(x => x.id !== id); } else { await lvApi('/shelf', lvOpt('POST', { id })); lvShelf.push({ id, title: b.title, author: b.author, secs: b.secs, cover: b.cover, added: Date.now() }); } btn.textContent = onShelf() ? 'Remove from shelf' : 'Save to shelf'; if (after) after(); } catch (x) { toast(x.message); } };
  }