// Magazine reader — contents tree, article review, dual reading views,
// sentence-highlighted playback and podcast mode.
//
// The canonical object is the ARTICLE, not the page (see
// architecture/magazine-ingestion.md). Nothing is narrated until a human has
// approved the detected boundaries, so the review screen is on the critical
// path rather than an optional extra.
//
// Two views stay linked: the reflowed article (comfortable reading, sentence
// highlighting) and the original PDF page (the visual source of truth). Every
// block carries page + bbox, so either view can jump to the other.
(function (root) {
'use strict';

const MAG = root.TTVC = root.TTVC || {};
const state = {
  docs: [],
  doc: null,            // { id, title, issue, ingest, ... }
  articles: [],
  layout: null,         // { page_count, pages[], blocks[] }
  article: null,        // the article being read or reviewed
  sentences: [],        // [{ text, blockId, page, bbox }]
  images: [],            // current article's figures, in reading order
  view: 'library',      // library | contents | review | read
  pane: 'reflow',       // reflow | pdf
  playing: false,
  cancel: false,
  idx: 0,               // current sentence
  audio: null,
  voices: [],
  podcast: null,
  queue: [],             // article ids for "play all" (empty = not queued)
  queueIndex: -1,
  driving: false,        // large-control, minimal-interaction view
  karaoke: true,         // word-level highlighting (approximate, see estimateWordTimings)
};
MAG.magazine = state;

const $ = (id) => document.getElementById(id);
const esc = (s) => String(s == null ? '' : s).replace(/[&<>"']/g,
  (c) => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c]));

function say(msg, kind) { if (typeof toast === 'function') toast(msg, kind || ''); }

async function api(path, opts) {
  const r = await fetch(path, opts);
  if (!r.ok) {
    let detail = r.statusText;
    try { detail = (await r.json()).detail || detail; } catch (_) {}
    throw new Error(detail);
  }
  const type = r.headers.get('content-type') || '';
  return type.includes('json') ? r.json() : r;
}

function fmtDuration(seconds) {
  const s = Math.max(0, Math.round(seconds || 0));
  if (s < 60) return s + ' sec';
  const m = Math.round(s / 60);
  return m < 60 ? m + ' min' : Math.floor(m / 60) + ' h ' + (m % 60) + ' min';
}

function fmtPages(pages) {
  if (!pages || !pages.length) return '—';
  if (pages.length === 1) return 'p. ' + pages[0];
  // Non-contiguous page lists are the norm once a feature jumps, and showing
  // "18–88" for pages [18, 88] would misdescribe it as a 70-page article.
  const runs = [];
  let start = pages[0], prev = pages[0];
  for (let i = 1; i <= pages.length; i++) {
    if (pages[i] === prev + 1) { prev = pages[i]; continue; }
    runs.push(start === prev ? String(start) : start + '–' + prev);
    start = prev = pages[i];
  }
  return 'pp. ' + runs.join(', ');
}

// ── Library ──────────────────────────────────────────────────────────────────

async function magLoadLibrary() {
  const data = await api('/api/reader/docs');
  state.docs = (data.docs || []).filter((d) => d.kind === 'magazine');
  renderLibrary();
}

function renderLibrary() {
  const host = $('mag-library-list');
  if (!host) return;
  if (!state.docs.length) {
    host.innerHTML =
      '<p class="muted" style="padding:18px 0">No magazines yet. Add one to get started — ' +
      'upload a PDF and the articles are detected for you.</p>';
    return;
  }
  host.innerHTML = state.docs.map((d) => {
    const ing = d.ingest || {};
    const badge = ing.status === 'done'
      ? '<span class="mag-pill ok">' + (ing.articles || 0) + ' articles</span>'
      : ing.status === 'running' ? '<span class="mag-pill warn">ingesting…</span>'
      : ing.status === 'failed' ? '<span class="mag-pill bad">failed</span>'
      : '<span class="mag-pill">not ingested</span>';
    return '<button type="button" class="mag-card" onclick="magOpen(\'' + d.id + '\')">' +
      '<span class="mag-card-title">' + esc(d.title || 'Untitled') + '</span>' +
      '<span class="mag-card-sub">' + esc(d.issue || '') + '</span>' +
      badge + '</button>';
  }).join('');
}

// ── Add-magazine dropzone (mirrors reader.js's setupReaderDropzone) ─────────
const MAG_DROPZONE_DEFAULT_NOTE = 'Scanned issues work too — pages without selectable text are read with OCR.';

function magShowDroppedFile(file) {
  const noteEl = $('mag-dropzone-note');
  if (noteEl) noteEl.textContent = file ? file.name : MAG_DROPZONE_DEFAULT_NOTE;
}

let _magDropGuardInstalled = false;

function setupMagDropzone() {
  const zone = $('mag-dropzone');
  const input = $('mag-new-file');
  if (!zone || !input) return;

  // A page-wide safety net: if a drop ever lands outside the zone (or the
  // zone's own handler below fails to intercept it for any reason), the
  // browser's native behaviour is to navigate to/open the dropped file --
  // confirmed live as exactly what happened before this existed. Installed
  // once regardless of which section is active, since a stray drop can land
  // anywhere on the page.
  if (!_magDropGuardInstalled) {
    _magDropGuardInstalled = true;
    window.addEventListener('dragover', (e) => { e.preventDefault(); });
    window.addEventListener('drop', (e) => { e.preventDefault(); });
  }

  if (zone.dataset.magDropzoneWired) return;
  zone.dataset.magDropzoneWired = '1';

  // dragenter AND dragover both need preventDefault() -- some browsers only
  // arm the element as a valid drop target once dragenter itself has been
  // cancelled, not just the dragover events that follow it. Not gated on
  // dataTransfer.types: during a real OS file drag, Chromium does not
  // always populate that list synchronously on every one of these events,
  // and gating on it here (confirmed live) silently skipped preventDefault
  // often enough that neither the hover highlight nor the drop interception
  // ever fired -- the browser fell through to opening the file itself.
  const armDropTarget = (e) => { e.preventDefault(); zone.classList.add('dragover'); };
  zone.addEventListener('dragenter', armDropTarget);
  zone.addEventListener('dragover', armDropTarget);
  zone.addEventListener('dragleave', () => zone.classList.remove('dragover'));
  zone.addEventListener('drop', (e) => {
    e.preventDefault();
    zone.classList.remove('dragover');
    const file = e.dataTransfer?.files?.[0];
    if (!file) return;
    if (file.type !== 'application/pdf' && !/\.pdf$/i.test(file.name)) {
      return say('Only PDF files are supported', 'err');
    }
    // Route the dropped file through the same hidden <input> magCreate()
    // already reads, so drag-and-drop and "Choose file" share one code path.
    const dt = new DataTransfer();
    dt.items.add(file);
    input.files = dt.files;
    magShowDroppedFile(file);
  });
  input.addEventListener('change', () => magShowDroppedFile(input.files?.[0]));
}

async function magCreate() {
  const title = ($('mag-new-title')?.value || '').trim();
  const issue = ($('mag-new-issue')?.value || '').trim();
  const file = $('mag-new-file')?.files?.[0];
  if (!title) return say('Give the magazine a title', 'err');
  if (!file) return say('Choose or drop the PDF', 'err');
  try {
    const { id } = await api('/api/magazine/docs', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ title, issue }),
    });
    await api('/api/reader/docs/' + id + '/source?ext=pdf', { method: 'PUT', body: file });
    say('Magazine added — starting ingestion', 'ok');
    if ($('mag-new-title')) $('mag-new-title').value = '';
    if ($('mag-new-issue')) $('mag-new-issue').value = '';
    if ($('mag-new-file')) $('mag-new-file').value = '';
    magShowDroppedFile(null);
    await magOpen(id);
    await magIngest();
  } catch (e) {
    say('Could not add magazine: ' + e.message, 'err');
  }
}

// ── Ingestion ────────────────────────────────────────────────────────────────

// Remembers which magazine was open so a full page reload or the browser's
// own Back button (which, unlike in-app navigation, tears down all JS state)
// lands back on it instead of the empty library — confirmed live as the
// cause of a user re-uploading the same PDF, creating a duplicate under a
// completely different kind ("book", via Studio/Reader's own import) because
// the magazine they had been working on appeared to have vanished.
const MAG_LAST_DOC_KEY = 'ttsvc_mag_last_doc';

async function magOpen(docId) {
  try {
    state.doc = await api('/api/reader/docs/' + docId);
    state.doc.id = docId;
    await magRefreshArticles();
    magShow('contents');
    try { localStorage.setItem(MAG_LAST_DOC_KEY, docId); } catch (_) {}
    if ((state.doc.ingest || {}).status === 'running') pollIngest();
  } catch (e) {
    say('Could not open magazine: ' + e.message, 'err');
    try { localStorage.removeItem(MAG_LAST_DOC_KEY); } catch (_) {}
  }
}

function magForgetLastDoc() {
  try { localStorage.removeItem(MAG_LAST_DOC_KEY); } catch (_) {}
}

async function magIngest() {
  if (!state.doc) return;
  try {
    await api('/api/magazine/' + state.doc.id + '/ingest', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({}),
    });
    pollIngest();
  } catch (e) {
    say('Ingestion could not start: ' + e.message, 'err');
  }
}

// "OCR again" for the whole issue: forces every page through the vision
// engine regardless of its current quality, then re-detects articles --
// which is why this asks for confirmation. A single page's "OCR again" in
// review does not touch article grouping; re-reading the whole document
// does, since detection runs again over the freshly re-read text.
async function magReocrMagazine() {
  if (!state.doc) return;
  const hasReviewed = state.articles.some((a) => a.status !== 'detected');
  if (hasReviewed && !confirm(
    'Re-reading the whole magazine runs article detection again. ' +
    'Any articles you already approved or rejected will need reviewing again. Continue?'
  )) return;
  try {
    await api('/api/magazine/' + state.doc.id + '/ingest', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ force_vision_ocr: true }),
    });
    pollIngest();
  } catch (e) {
    say('Could not start OCR: ' + e.message, 'err');
  }
}

// "Analysing page 28 of 204" -> a real percentage, not just spinner text.
function magParsePageProgress(detail) {
  const m = /page (\d+) of (\d+)/i.exec(detail || '');
  if (!m) return null;
  const page = parseInt(m[1], 10), total = parseInt(m[2], 10);
  if (!total) return null;
  return { page, total, pct: Math.min(100, Math.round((page / total) * 100)) };
}

async function pollIngest() {
  const bar = $('mag-ingest-status');
  if (bar) { bar.hidden = false; bar.className = 'mag-status is-running'; }
  for (;;) {
    let data;
    try {
      data = await api('/api/magazine/' + state.doc.id + '/ingest/status');
    } catch (_) { break; }
    const ing = data.ingest || {};
    const detail = (data.job || {}).detail || '';
    if (bar) {
      if (ing.status === 'running') {
        bar.className = 'mag-status is-running';
        const p = magParsePageProgress(detail);
        bar.innerHTML =
          '<div class="mag-ingest-row">' +
            '<span class="mdi mdi-progress-clock mag-ingest-icon"></span>' +
            '<div class="mag-ingest-text">' +
              '<strong>' + esc(detail || 'Analysing…') + '</strong>' +
              (p ? '<div class="mag-ingest-track"><div class="mag-ingest-fill" style="width:' + p.pct + '%"></div></div>' : '') +
            '</div>' +
            (p ? '<span class="mag-ingest-pct">' + p.pct + '%</span>' : '') +
          '</div>';
      } else if (ing.status === 'failed') {
        bar.className = 'mag-status is-failed';
        bar.innerHTML = '<div class="mag-ingest-row"><span class="mdi mdi-alert mag-ingest-icon"></span>' +
          '<span>Ingestion failed: ' + esc(ing.error || '') + '</span></div>';
      } else {
        bar.className = 'mag-status is-done';
        bar.innerHTML = '<div class="mag-ingest-row"><span class="mdi mdi-check-circle mag-ingest-icon"></span>' +
          '<span>' + (ing.articles || 0) + ' article' + (ing.articles === 1 ? '' : 's') + ' detected</span></div>';
      }
    }
    if (ing.status !== 'running') {
      if (ing.status === 'done') await magRefreshArticles();
      break;
    }
    await new Promise((r) => setTimeout(r, 2000));
  }
}

async function magRefreshArticles() {
  if (!state.doc) return;
  try {
    const data = await api('/api/magazine/' + state.doc.id + '/articles');
    state.articles = data.articles || [];
    state.doc.progress = data.progress || {};
    state.doc.podcast = data.podcast || { hosts: [] };
    state.doc.default_voice = data.default_voice || '';
  } catch (_) {
    state.articles = [];
  }
  renderContents();
}

// ── Contents tree ────────────────────────────────────────────────────────────

function confidenceLabel(c) {
  if (c >= 0.85) return { cls: 'ok', text: Math.round(c * 100) + '% · listed in contents' };
  if (c >= 0.5) return { cls: 'warn', text: Math.round(c * 100) + '% · from headline — check boundaries' };
  return { cls: 'bad', text: Math.round(c * 100) + '% · little body copy — likely not an article' };
}

function renderContents() {
  const host = $('mag-contents');
  if (!host) return;
  const title = $('mag-doc-title');
  if (title && state.doc) {
    title.textContent = (state.doc.title || 'Magazine') +
      (state.doc.issue ? ' — ' + state.doc.issue : '');
  }
  if (!state.articles.length) {
    host.innerHTML = '<p class="muted">No articles yet. Run ingestion to detect them.</p>';
    return;
  }
  const bySection = new Map();
  state.articles.forEach((a) => {
    const key = a.section || 'Articles';
    if (!bySection.has(key)) bySection.set(key, []);
    bySection.get(key).push(a);
  });

  let html = '';
  bySection.forEach((arts, section) => {
    html += '<div class="mag-section"><h4>' + esc(section) + '</h4><ul class="mag-toc">';
    arts.forEach((a) => {
      const conf = confidenceLabel(a.confidence);
      const done = a.status === 'approved';
      const progress = (state.doc.progress || {})[a.id];
      html += '<li class="mag-toc-row' + (done ? ' is-approved' : '') + '">' +
        '<div class="mag-toc-main">' +
          '<span class="mag-toc-title">' + esc(a.title || 'Untitled') + '</span>' +
          (a.author ? '<span class="mag-toc-by">by ' + esc(a.author) + '</span>' : '') +
        '</div>' +
        '<div class="mag-toc-meta">' +
          '<span>' + fmtPages(a.pages) + '</span>' +
          '<span>' + fmtDuration(a.estimated_seconds) + '</span>' +
          '<span class="mag-pill ' + conf.cls + '" title="' + esc(conf.text) + '">' +
            Math.round(a.confidence * 100) + '%</span>' +
          '<span class="mag-pill ' + (done ? 'ok' : '') + '">' +
            (done ? 'approved' : a.status === 'rejected' ? 'rejected' : 'needs review') + '</span>' +
        '</div>' +
        '<div class="mag-toc-actions">' +
          '<button type="button" class="btn-sm" onclick="magReview(\'' + a.id + '\')">Review</button>' +
          (done
            ? '<button type="button" class="btn-sm primary" onclick="magRead(\'' + a.id + '\')">' +
              (progress ? 'Continue' : 'Listen') + '</button>'
            : '') +
        '</div></li>';
    });
    html += '</ul></div>';
  });
  host.innerHTML = html;
}

// ── Review (Stage D) ─────────────────────────────────────────────────────────

async function magReview(articleId) {
  const article = state.articles.find((a) => a.id === articleId);
  if (!article) return;
  state.article = article;
  await ensureLayout();
  // The whole review is one page at a time -- showing every page of a
  // 10-page feature stacked at once was unreadable and made the boxes tiny.
  state.reviewSpan = magReviewSpan(article);
  state.reviewPage = state.reviewSpan[0] || null;
  _magReviewChecked = null;
  magShow('review');
  renderReview();
}

async function ensureLayout() {
  if (state.layout) return;
  try {
    state.layout = await api('/api/magazine/' + state.doc.id + '/layout');
  } catch (e) {
    say('Could not load layout: ' + e.message, 'err');
    state.layout = { blocks: [], pages: [], page_count: 0 };
  }
}

function blocksForPages(pages) {
  const want = new Set(pages || []);
  return (state.layout.blocks || [])
    .filter((b) => want.has(b.page))
    .sort((a, b) => a.page - b.page || a.reading_order - b.reading_order);
}

// Offer neighbouring pages too, so a boundary that started a page late (or a
// jump tail that should have been included) can be corrected without
// leaving the screen.
function magReviewSpan(article) {
  if (!article.pages.length) return [];
  return Array.from(new Set(article.pages.concat(
    [article.pages[0] - 1, article.pages[article.pages.length - 1] + 1])))
    .filter((p) => p >= 1 && p <= (state.layout.page_count || 0)).sort((x, y) => x - y);
}

function magReviewGoPage(page) {
  if (!state.reviewSpan.includes(page)) return;
  state.reviewPage = page;
  renderReview();
}

function renderReview() {
  const host = $('mag-review');
  const a = state.article;
  if (!host || !a) return;
  const included = new Set(a.blocks || []);
  const conf = confidenceLabel(a.confidence);
  const page = state.reviewPage;
  const pageMeta = (state.layout.pages || []).find((p) => p.page === page);
  const pageBlocks = page == null ? [] : blocksForPages([page]);

  const spanIdx = state.reviewSpan.indexOf(page);
  const prevPage = spanIdx > 0 ? state.reviewSpan[spanIdx - 1] : null;
  const nextPage = spanIdx >= 0 && spanIdx < state.reviewSpan.length - 1 ? state.reviewSpan[spanIdx + 1] : null;

  let html =
    '<div class="mag-review-head">' +
      '<label>Title<input id="mag-rev-title" type="text" value="' + esc(a.title) + '"></label>' +
      '<label>Author<input id="mag-rev-author" type="text" value="' + esc(a.author) + '"></label>' +
      '<div class="mag-pill ' + conf.cls + '">' + esc(conf.text) + '</div>' +
    '</div>' +
    '<p class="muted">Untick anything that is not part of this article — a sidebar, an advert, ' +
    'or a neighbouring piece. Only ticked text is read aloud. Click a numbered region on the page, ' +
    'or its matching entry on the right, to line the two up.</p>';

  html += '<div class="mag-review-pagenav">' +
    '<button type="button" class="btn-sm" ' + (prevPage ? '' : 'disabled') +
      ' onclick="magReviewGoPage(' + prevPage + ')"><span class="mdi mdi-chevron-left"></span></button>' +
    '<span>Page ' + (page ?? '—') + '</span>' +
    '<button type="button" class="btn-sm" ' + (nextPage ? '' : 'disabled') +
      ' onclick="magReviewGoPage(' + nextPage + ')"><span class="mdi mdi-chevron-right"></span></button>' +
    '<span class="mag-review-pagenav-spacer"></span>' +
    '<button type="button" class="btn-sm" id="mag-reocr-btn" onclick="magReocrPage()">' +
      '<span class="mdi mdi-text-recognition"></span> OCR again (this page)</button>' +
    '<span id="mag-reocr-status" class="muted"></span>' +
  '</div>';

  html += '<div class="mag-review-split">';

  // Left: the rendered page with a numbered box per block.
  html += '<div class="mag-review-page">';
  if (page != null) {
    html += '<div class="mag-review-page-wrap">' +
      '<img src="/api/magazine/' + state.doc.id + '/pages/' + page + '" alt="Page ' + page + '">';
    pageBlocks.forEach((b, i) => {
      if (!pageMeta) return;
      const on = included.has(b.id);
      const left = (b.bbox[0] / pageMeta.width * 100).toFixed(2);
      const top = (b.bbox[1] / pageMeta.height * 100).toFixed(2);
      const w = (b.bbox[2] / pageMeta.width * 100).toFixed(2);
      const h = (b.bbox[3] / pageMeta.height * 100).toFixed(2);
      html += '<div class="mag-review-box' + (on ? '' : ' is-excluded') + '" data-block="' + esc(b.id) +
        '" style="left:' + left + '%;top:' + top + '%;width:' + w + '%;height:' + h + '%" ' +
        'onclick="magReviewFocusBlock(\'' + esc(b.id) + '\')" title="' + esc(b.type) + '">' +
        '<span class="mag-review-box-num">' + (i + 1) + '</span></div>';
    });
    html += '</div>';
  } else {
    html += '<p class="muted">No page to show.</p>';
  }
  html += '</div>';

  // Right: the same blocks as text, numbered to match.
  html += '<div class="mag-blocks">';
  pageBlocks.forEach((b, i) => {
    const narratable = ['title', 'deck', 'byline', 'body'].includes(b.type);
    const on = included.has(b.id);
    html += '<label class="mag-block' + (narratable ? '' : ' is-aux') + '" data-block-row="' + esc(b.id) + '" ' +
      'onmouseenter="magReviewHighlightBox(\'' + esc(b.id) + '\')" onmouseleave="magReviewHighlightBox(null)">' +
      '<span class="mag-block-num">' + (i + 1) + '</span>' +
      '<input type="checkbox" ' + (on ? 'checked' : '') + ' data-block="' + esc(b.id) + '" onchange="magReviewToggleBox(this)">' +
      '<span class="mag-block-type">' + esc(b.type) + '</span>' +
      '<span class="mag-block-text">' + esc(b.text.slice(0, 220)) +
        (b.text.length > 220 ? '…' : '') + '</span></label>';
  });
  if (!pageBlocks.length) html += '<p class="muted">Nothing detected on this page.</p>';
  html += '</div>';

  html += '</div>'; // /mag-review-split

  html += '<div class="mag-review-foot">' +
      '<button type="button" class="btn" onclick="magShow(\'contents\')">Back to contents</button>' +
      '<button type="button" class="btn" onclick="magSetStatus(\'rejected\')">Not an article</button>' +
      '<button type="button" class="btn primary" onclick="magApprove()">Approve</button>' +
    '</div>';
  host.innerHTML = html;
}

// Tracks every ticked block across ALL reviewed pages of this article, not
// just the one currently on screen -- switching pages must not forget a
// change made on a previous one.
let _magReviewChecked = null;

function magReviewToggleBox(input) {
  if (!_magReviewChecked) _magReviewChecked = new Set(state.article.blocks || []);
  if (input.checked) _magReviewChecked.add(input.dataset.block);
  else _magReviewChecked.delete(input.dataset.block);
  const box = document.querySelector('.mag-review-box[data-block="' + CSS.escape(input.dataset.block) + '"]');
  if (box) box.classList.toggle('is-excluded', !input.checked);
}

function magReviewFocusBlock(blockId) {
  const cb = document.querySelector('#mag-review input[data-block="' + CSS.escape(blockId) + '"]');
  if (cb) { cb.checked = !cb.checked; magReviewToggleBox(cb); }
  const row = document.querySelector('#mag-review [data-block-row="' + CSS.escape(blockId) + '"]');
  if (row) row.scrollIntoView({ block: 'nearest', behavior: prefersReducedMotion() ? 'auto' : 'smooth' });
}

function magReviewHighlightBox(blockId) {
  document.querySelectorAll('.mag-review-box.is-linked').forEach((el) => el.classList.remove('is-linked'));
  if (!blockId) return;
  const box = document.querySelector('.mag-review-box[data-block="' + CSS.escape(blockId) + '"]');
  if (box) box.classList.add('is-linked');
}

function selectedBlockIds() {
  if (_magReviewChecked) return Array.from(_magReviewChecked);
  return Array.from(document.querySelectorAll('#mag-review input[data-block]:checked'))
    .map((el) => el.dataset.block);
}

async function magReocrPage() {
  const page = state.reviewPage;
  if (page == null) return;
  const btn = $('mag-reocr-btn');
  const statusEl = $('mag-reocr-status');
  if (btn) btn.disabled = true;
  if (statusEl) statusEl.textContent = 'Reading page ' + page + '…';
  let jobId;
  try {
    const r = await api('/api/magazine/' + state.doc.id + '/pages/' + page + '/reocr', {
      method: 'POST', headers: { 'Content-Type': 'application/json' }, body: '{}',
    });
    jobId = r.job_id;
  } catch (e) {
    if (statusEl) statusEl.textContent = '';
    if (btn) btn.disabled = false;
    return say('Could not start OCR: ' + e.message, 'err');
  }
  for (;;) {
    let job;
    try { job = await api('/api/jobs/' + jobId); } catch (_) { break; }
    if (job.done) {
      if (job.error) say('OCR failed: ' + job.error, 'err');
      else say('Page ' + page + ' re-read', 'ok');
      break;
    }
    await new Promise((r) => setTimeout(r, 2000));
  }
  if (btn) btn.disabled = false;
  if (statusEl) statusEl.textContent = '';
  state.layout = null;
  await ensureLayout();
  renderReview();
}

async function magApprove() {
  const a = state.article;
  if (!a) return;
  const blocks = selectedBlockIds();
  if (!blocks.length) return say('Tick at least one block before approving', 'err');
  try {
    const updated = await api('/api/magazine/' + state.doc.id + '/articles/' + a.id, {
      method: 'PATCH',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        blocks,
        status: 'approved',
        title: ($('mag-rev-title')?.value || a.title).trim(),
        author: ($('mag-rev-author')?.value || a.author).trim(),
      }),
    });
    Object.assign(a, updated);
    say('Approved — ready to listen', 'ok');
    await magRefreshArticles();
    magShow('contents');
  } catch (e) {
    say('Could not approve: ' + e.message, 'err');
  }
}

async function magSetStatus(status) {
  const a = state.article;
  if (!a) return;
  try {
    const updated = await api('/api/magazine/' + state.doc.id + '/articles/' + a.id, {
      method: 'PATCH',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ status }),
    });
    Object.assign(a, updated);
    await magRefreshArticles();
    magShow('contents');
  } catch (e) {
    say('Could not update: ' + e.message, 'err');
  }
}

// ── Reading: sentences, both views ───────────────────────────────────────────

// Sentence splitting keeps each piece tied to its source block, so highlighting
// in the reflowed view can drive the page shown in the PDF view.
function splitSentences(blocks) {
  const out = [];
  blocks.forEach((b) => {
    const parts = String(b.text || '')
      .split(/(?<=[.!?…])\s+(?=[A-ZÀ-Ü»„"'‘])/)
      .map((s) => s.trim()).filter(Boolean);
    (parts.length ? parts : [b.text]).forEach((text) => {
      if (text && text.trim()) {
        out.push({
          text: text.trim(), blockId: b.id, page: b.page, bbox: b.bbox, type: b.type,
          // Used to pick "the image reached so far" during playback (see
          // currentImageIndex) -- the backend already computes this per
          // block relative to the whole page, not just this article.
          readingOrder: b.reading_order || 0,
          words: text.trim().split(/\s+/).filter(Boolean),
        });
      }
    });
  });
  return out;
}

// The current article's figures, in reading order, resolved from the full
// layout (fetched once) filtered to this article's own image ids. Kept
// separate from state.sentences because an image has no sentence of its
// own -- it is matched to "the most recent sentence at or before it".
function articleImages(article) {
  const ids = new Set(article.images || []);
  return (state.layout.images || [])
    .filter((img) => ids.has(img.id))
    .sort((a, b) => (a.reading_order || 0) - (b.reading_order || 0));
}

// The image to show once sentence `i` has been reached: the last image
// whose position in the page's reading order is at or before that
// sentence's own block. Falls back to the first image before any text has
// caught up to it, so a lead photo is not left blank at the very start.
function currentImageIndex(i) {
  if (!state.images.length) return -1;
  const order = (state.sentences[i] || {}).readingOrder || 0;
  let found = -1;
  for (let k = 0; k < state.images.length; k++) {
    if ((state.images[k].reading_order || 0) <= order) found = k;
    else break;
  }
  return found === -1 ? 0 : found;
}

function renderCurrentImage(i) {
  const host = $('mag-read-image');
  if (!host) return;
  const idx = currentImageIndex(i);
  if (idx < 0) { host.hidden = true; return; }
  const img = state.images[idx];
  if (state._shownImageId === img.id) { host.hidden = false; return; }
  state._shownImageId = img.id;
  host.hidden = false;
  host.innerHTML = '<img src="/api/magazine/' + state.doc.id + '/images/' + encodeURIComponent(img.filename) +
    '" alt="Figure from page ' + img.page + '" loading="lazy">';
}

async function magRead(articleId, opts) {
  const a = state.articles.find((x) => x.id === articleId);
  if (!a) return;
  state.article = a;
  await ensureLayout();
  try {
    const data = await api('/api/magazine/' + state.doc.id + '/articles/' + a.id + '/text?captions=' +
      ($('mag-read-captions')?.checked ? 1 : 0));
    state.sentences = splitSentences(data.blocks || []);
  } catch (e) {
    return say('Could not load article text: ' + e.message, 'err');
  }
  state.images = articleImages(a);
  state._shownImageId = null;
  const forceStart = opts && opts.fromStart;
  const saved = !forceStart && (state.doc.progress || {})[a.id];
  state.idx = saved && saved.sentence < state.sentences.length ? saved.sentence : 0;
  magShow('read');
  renderArticle();
  loadPodcastIfAny();
}

function renderArticle() {
  const host = $('mag-article');
  const a = state.article;
  if (!host || !a) return;
  $('mag-read-title').textContent = a.title || 'Untitled';
  $('mag-read-by').textContent = a.author ? 'By ' + a.author : '';
  $('mag-read-pages').textContent = fmtPages(a.pages);

  host.innerHTML = state.sentences.map((s, i) => {
    const tag = s.type === 'title' ? 'h2' : s.type === 'deck' ? 'p class="mag-deck"'
      : s.type === 'byline' ? 'p class="mag-byline"' : s.type === 'caption'
      ? 'p class="mag-caption"' : 'span';
    const open = tag.split(' ')[0];
    // Each word gets its own span so playback can highlight it individually
    // (see estimateWordTimings) -- sentence-level highlighting alone doesn't
    // need this, but word-level does and this markup serves both.
    const wordsHtml = s.words.map((w, j) =>
      '<span class="mag-w" data-w="' + j + '">' + esc(w) + '</span>').join(' ');
    return '<' + tag + ' class="mag-s' + (open === 'span' ? '' : '') + '" data-i="' + i + '" ' +
      'onclick="magSeek(' + i + ')">' + wordsHtml + '</' + open + '> ';
  }).join('');
  highlight(state.idx);
}

function highlight(i) {
  document.querySelectorAll('#mag-article [data-i]').forEach((el) => {
    el.classList.toggle('is-current', Number(el.dataset.i) === i);
  });
  clearWordHighlight();
  const el = document.querySelector('#mag-article [data-i="' + i + '"]');
  if (el && !prefersReducedMotion()) el.scrollIntoView({ block: 'center', behavior: 'smooth' });
  else if (el) el.scrollIntoView({ block: 'center' });
  const s = state.sentences[i];
  if (s && state.pane === 'pdf') showPage(s.page, s.bbox);
  renderCurrentImage(i);
  const counter = $('mag-read-progress');
  if (counter) counter.textContent = (i + 1) + ' / ' + state.sentences.length;
  const qText = state.queue.length ? 'Article ' + (state.queueIndex + 1) + ' / ' + state.queue.length : '';
  ['mag-queue-progress', 'mag-queue-progress-2'].forEach((id) => {
    const el = $(id);
    if (el) el.textContent = qText;
  });
}

function clearWordHighlight() {
  document.querySelectorAll('#mag-article .mag-w.is-current').forEach((el) => el.classList.remove('is-current'));
}

// ── Word-level highlighting (approximate) ────────────────────────────────
// No forced-alignment or TTS timestamp source exists in this pipeline, so
// per-word timing is ESTIMATED, not measured: each word's share of the
// sentence's real (measured) audio duration is proportional to its own
// character length, with a small fixed share added per word so short words
// are not given an unrealistically instant duration. This is a common
// karaoke approximation, not true alignment -- it can drift on sentences
// with heavy punctuation-driven pauses.
function estimateWordTimings(words, totalSeconds) {
  if (!words.length || !totalSeconds) return [];
  const FIXED = 0.6;   // arbitrary units, shifts weight toward evening out short words
  const weights = words.map((w) => Math.max(1, w.replace(/[.,!?;:"'()«»„"]/g, '').length) + FIXED);
  const total = weights.reduce((a, b) => a + b, 0);
  let t = 0;
  return weights.map((w) => {
    const dur = totalSeconds * (w / total);
    const start = t;
    t += dur;
    return { start, end: t };
  });
}

function highlightWord(sentenceIdx, wordIdx) {
  const sentenceEl = document.querySelector('#mag-article [data-i="' + sentenceIdx + '"]');
  if (!sentenceEl) return;
  sentenceEl.querySelectorAll('.mag-w').forEach((el) => {
    el.classList.toggle('is-current', Number(el.dataset.w) === wordIdx);
  });
}

function prefersReducedMotion() {
  try { return window.matchMedia('(prefers-reduced-motion: reduce)').matches; }
  catch (_) { return false; }
}

function magSeek(i) {
  state.idx = Math.max(0, Math.min(state.sentences.length - 1, i));
  highlight(state.idx);
  saveProgress();
}

function magSetPane(pane) {
  state.pane = pane;
  const reflow = $('mag-pane-reflow'), pdf = $('mag-pane-pdf');
  if (reflow) reflow.hidden = pane !== 'reflow';
  if (pdf) pdf.hidden = pane !== 'pdf';
  document.querySelectorAll('[data-mag-pane]').forEach((b) => {
    const on = b.dataset.magPane === pane;
    b.classList.toggle('active', on);
    b.setAttribute('aria-pressed', on ? 'true' : 'false');
  });
  if (pane === 'pdf') {
    const s = state.sentences[state.idx];
    if (s) showPage(s.page, s.bbox);
  }
}

function showPage(page, bbox) {
  const img = $('mag-page-img');
  const box = $('mag-page-box');
  if (!img) return;
  const src = '/api/magazine/' + state.doc.id + '/pages/' + page;
  if (img.getAttribute('src') !== src) img.setAttribute('src', src);
  img.setAttribute('alt', 'Page ' + page + ' of ' + (state.doc.title || 'the magazine'));
  const label = $('mag-page-label');
  if (label) label.textContent = 'Page ' + page;
  if (!box || !bbox) return;
  // The layout stores PDF user-space units; the rendered PNG is a different
  // size, so scale by the page dimensions rather than assuming they match.
  const meta = (state.layout.pages || []).find((p) => p.page === page);
  if (!meta) { box.hidden = true; return; }
  box.hidden = false;
  box.style.left = (bbox[0] / meta.width * 100) + '%';
  box.style.top = (bbox[1] / meta.height * 100) + '%';
  box.style.width = (bbox[2] / meta.width * 100) + '%';
  box.style.height = (bbox[3] / meta.height * 100) + '%';
}

function magPeekPage(page) {
  magShow('read');
  magSetPane('pdf');
  showPage(page, null);
}

// ── Playback ─────────────────────────────────────────────────────────────────

async function magPlay() {
  if (state.playing) return magPause();
  const voice = ($('mag-voice')?.value || state.doc.default_voice || '').trim();
  if (!voice) return say('Pick a narrator voice first', 'err');
  state.playing = true;
  state.cancel = false;
  syncPlayButton();
  let finishedArticle = false;
  try {
    while (state.idx < state.sentences.length && !state.cancel) {
      highlight(state.idx);
      const sentence = state.sentences[state.idx];
      let blob;
      try {
        blob = await fetchTtsPreviewBlob(voice, sentence.text, 'mp3');
      } catch (e) {
        say('Synthesis failed: ' + e.message, 'err');
        break;
      }
      if (state.cancel) break;
      await playBlob(blob, sentence);
      if (state.cancel) break;
      state.idx += 1;
      saveProgress();
    }
    finishedArticle = state.idx >= state.sentences.length && !state.cancel;
  } finally {
    state.playing = false;
    state.cancel = false;
    syncPlayButton();
  }
  if (finishedArticle) {
    state.idx = state.sentences.length - 1;
    if (state.queue.length && state.queueIndex < state.queue.length - 1) {
      // Play-all: move straight to the next approved article rather than
      // stopping -- the whole point of a queue is not touching the screen
      // between articles.
      state.queueIndex += 1;
      await magRead(state.queue[state.queueIndex], { fromStart: true });
      magPlay();
    } else {
      state.queue = [];
      state.queueIndex = -1;
      say('Article finished', 'ok');
    }
  }
}

function playBlob(blob, sentence) {
  return new Promise((resolve) => {
    const url = URL.createObjectURL(blob);
    const audio = new Audio(url);
    state.audio = audio;
    let timings = null;
    const onTimeUpdate = () => {
      if (!state.karaoke || !sentence || !sentence.words.length) return;
      if (!timings) {
        if (!audio.duration || !isFinite(audio.duration)) return;
        timings = estimateWordTimings(sentence.words, audio.duration);
      }
      const t = audio.currentTime;
      const wi = timings.findIndex((w) => t >= w.start && t < w.end);
      if (wi !== -1) highlightWord(state.idx, wi);
    };
    if (state.karaoke) audio.addEventListener('timeupdate', onTimeUpdate);
    const done = () => {
      audio.removeEventListener('timeupdate', onTimeUpdate);
      URL.revokeObjectURL(url);
      state.audio = null;
      resolve();
    };
    audio.onended = done;
    audio.onerror = done;
    audio.play().catch(done);
  });
}

// ── Play all approved articles in sequence ──────────────────────────────
async function magPlayAll() {
  const ids = state.articles.filter((a) => a.status === 'approved').map((a) => a.id);
  if (!ids.length) return say('Approve at least one article first', 'err');
  state.queue = ids;
  state.queueIndex = 0;
  await magRead(ids[0], { fromStart: true });
  magPlay();
}

function magStopQueue() {
  state.queue = [];
  state.queueIndex = -1;
  ['mag-queue-progress', 'mag-queue-progress-2'].forEach((id) => {
    const el = $(id);
    if (el) el.textContent = '';
  });
}

async function magQueueNext() {
  if (!state.queue.length || state.queueIndex >= state.queue.length - 1) return;
  const wasPlaying = state.playing;
  if (wasPlaying) magPause();
  state.queueIndex += 1;
  await magRead(state.queue[state.queueIndex], { fromStart: true });
  if (wasPlaying) magPlay();
}

function magPause() {
  state.cancel = true;
  if (state.audio) { try { state.audio.pause(); } catch (_) {} }
  state.playing = false;
  syncPlayButton();
}

function syncPlayButton() {
  const btn = $('mag-play');
  if (btn) {
    btn.innerHTML = state.playing
      ? '<span class="mdi mdi-pause"></span> Pause'
      : '<span class="mdi mdi-play"></span> Listen';
    btn.setAttribute('aria-label', state.playing ? 'Pause narration' : 'Play narration');
  }
  if (state.driving) syncDrivingPlayButton();
}

let _saveTimer = null;
function saveProgress() {
  if (!state.doc || !state.article) return;
  clearTimeout(_saveTimer);
  _saveTimer = setTimeout(() => {
    fetch('/api/magazine/' + state.doc.id + '/progress', {
      method: 'PATCH',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ article: state.article.id, sentence: state.idx }),
    }).catch(() => {});
  }, 800);
}

// ── Podcast mode ─────────────────────────────────────────────────────────────

async function magLoadVoices() {
  try {
    const data = await api('/api/voices');
    state.voices = data.voices || data || [];
  } catch (_) { state.voices = []; }
  const options = '<option value="">— pick a voice —</option>' +
    state.voices.map((v) => {
      const id = v.id || v.name || v;
      return '<option value="' + esc(id) + '">' + esc(v.name || id) + '</option>';
    }).join('');
  ['mag-voice', 'mag-host-a', 'mag-host-b', 'mag-host-c'].forEach((id) => {
    const el = $(id);
    if (el) {
      const keep = el.value;
      el.innerHTML = options;
      if (keep) el.value = keep;
    }
  });
  const def = state.doc && state.doc.default_voice;
  if (def && $('mag-voice') && !$('mag-voice').value) $('mag-voice').value = def;
}

async function loadPodcastIfAny() {
  state.podcast = null;
  renderPodcast();
  // has_podcast comes from the articles listing so an article that never had
  // a script generated skips the request entirely, rather than a 404 on
  // every open.
  if (!state.article || !state.article.has_podcast) return;
  try {
    state.podcast = await api('/api/magazine/' + state.doc.id + '/articles/' +
      state.article.id + '/podcast');
  } catch (_) { /* generated flag was stale — treat as none */ }
  renderPodcast();
}

async function magGeneratePodcast() {
  const a = state.article;
  if (!a) return;
  if (a.status !== 'approved') {
    return say('Approve the article first — unreviewed boundaries may include an advert', 'err');
  }
  const hosts = ['mag-host-a', 'mag-host-b', 'mag-host-c']
    .map((id) => ($(id)?.value || '').trim())
    .filter(Boolean)
    .map((voice, i) => ({ voice, name: ($('mag-host-name-' + 'abc'[i])?.value || '').trim() }));
  if (hosts.length < 2) return say('Pick at least two host voices', 'err');

  const btn = $('mag-podcast-gen');
  if (btn) { btn.disabled = true; btn.textContent = 'Writing script…'; }
  try {
    state.podcast = await api('/api/magazine/' + state.doc.id + '/articles/' + a.id + '/podcast', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ hosts }),
    });
    a.has_podcast = true;
    say('Podcast script ready', 'ok');
    renderPodcast();
  } catch (e) {
    say('Could not generate: ' + e.message, 'err');
  } finally {
    if (btn) { btn.disabled = false; btn.textContent = 'Generate script'; }
  }
}

function renderPodcast() {
  const host = $('mag-podcast-script');
  if (!host) return;
  if (!state.podcast) {
    host.innerHTML = '<p class="muted">No podcast script yet. Pick two or three voices and ' +
      'generate one — the hosts discuss this article for someone who has not read it.</p>';
    const play = $('mag-podcast-play');
    if (play) play.hidden = true;
    return;
  }
  const names = {};
  (state.podcast.hosts || []).forEach((h) => { names[h.label] = h.name || ('Host ' + h.label); });
  host.innerHTML = '<ol class="mag-turns">' + (state.podcast.turns || []).map((t, i) =>
    '<li data-turn="' + i + '"><b>' + esc(names[t.host] || t.host) + '</b> ' +
    esc(t.text) + '</li>').join('') + '</ol>';
  const play = $('mag-podcast-play');
  if (play) play.hidden = false;
}

async function magPlayPodcast() {
  if (state.playing) return magPause();
  if (!state.podcast) return;
  const voiceOf = {};
  (state.podcast.hosts || []).forEach((h) => { voiceOf[h.label] = h.voice; });
  state.playing = true;
  state.cancel = false;
  const btn = $('mag-podcast-play');
  if (btn) btn.textContent = 'Pause';
  try {
    const turns = state.podcast.turns || [];
    for (let i = 0; i < turns.length && !state.cancel; i++) {
      document.querySelectorAll('#mag-podcast-script [data-turn]').forEach((el) => {
        el.classList.toggle('is-current', Number(el.dataset.turn) === i);
      });
      const voice = voiceOf[turns[i].host];
      if (!voice) continue;
      let blob;
      try { blob = await fetchTtsPreviewBlob(voice, turns[i].text, 'mp3'); }
      catch (e) { say('Synthesis failed: ' + e.message, 'err'); break; }
      if (state.cancel) break;
      await playBlob(blob);
    }
  } finally {
    state.playing = false;
    state.cancel = false;
    if (btn) btn.textContent = 'Play podcast';
  }
}

// ── View switching ───────────────────────────────────────────────────────────

function magShow(view) {
  state.view = view;
  ['library', 'contents', 'review', 'read'].forEach((v) => {
    const el = $('mag-view-' + v);
    if (el) el.hidden = v !== view;
  });
  if (view !== 'read') magPause();
}

function magBackToContents() {
  magPause();
  magStopQueue();
  state.driving = false;
  magShow('contents');
  magRefreshArticles();
}

// ── Driving mode ──────────────────────────────────────────────────────────
// Large, minimal-interaction controls for listening without looking at the
// screen (see Manual.md's planned driving-mode behaviour). Reuses whatever
// is already playing/queued rather than starting its own playback path --
// entering driving mode does not interrupt an article already in progress.
function magToggleDriving() {
  state.driving = !state.driving;
  const overlay = $('mag-driving');
  if (overlay) overlay.hidden = !state.driving;
  if (state.driving) renderDriving();
}

function renderDriving() {
  const a = state.article;
  if (!a) return;
  const titleEl = $('mag-driving-title');
  if (titleEl) titleEl.textContent = a.title || 'Untitled';
  const byEl = $('mag-driving-by');
  if (byEl) byEl.textContent = a.author ? 'By ' + a.author : '';
  syncDrivingPlayButton();
  const qEl = $('mag-driving-queue');
  if (qEl) qEl.hidden = !state.queue.length;
}

function syncDrivingPlayButton() {
  const btn = $('mag-driving-play');
  if (!btn) return;
  btn.innerHTML = state.playing
    ? '<span class="mdi mdi-pause"></span>'
    : '<span class="mdi mdi-play"></span>';
  btn.setAttribute('aria-label', state.playing ? 'Pause' : 'Play');
}

// ── Boot ─────────────────────────────────────────────────────────────────────

async function magInit() {
  if (!$('mag-library-list')) return;      // section not mounted
  magLoadLibrary();
  magLoadVoices();
  setupMagDropzone();
  let lastId = null;
  try { lastId = localStorage.getItem(MAG_LAST_DOC_KEY); } catch (_) {}
  if (lastId) {
    // Confirmed live: without this, a full reload or the browser's own Back
    // button (as opposed to in-app navigation) always dropped back to the
    // empty library, making an in-progress magazine look like it had been
    // lost. If it genuinely no longer exists (deleted elsewhere), fall back
    // to the library rather than getting stuck on a permanent error toast.
    try {
      await api('/api/reader/docs/' + lastId);
      await magOpen(lastId);
      return;
    } catch (_) {
      magForgetLastDoc();
    }
  }
  magShow('library');
}

root.magOpen = magOpen;
root.magCreate = magCreate;
root.magIngest = magIngest;
root.magReview = magReview;
root.magReviewGoPage = magReviewGoPage;
root.magReviewFocusBlock = magReviewFocusBlock;
root.magReviewHighlightBox = magReviewHighlightBox;
root.magReviewToggleBox = magReviewToggleBox;
root.magReocrPage = magReocrPage;
root.magReocrMagazine = magReocrMagazine;
root.magApprove = magApprove;
root.magSetStatus = magSetStatus;
root.magRead = magRead;
root.magSeek = magSeek;
root.magPlay = magPlay;
root.magPause = magPause;
root.magSetPane = magSetPane;
root.magPeekPage = magPeekPage;
root.magShow = magShow;
root.magBackToContents = magBackToContents;
root.magGeneratePodcast = magGeneratePodcast;
root.magPlayPodcast = magPlayPodcast;
root.magPlayAll = magPlayAll;
root.magQueueNext = magQueueNext;
root.magStopQueue = magStopQueue;
root.magToggleDriving = magToggleDriving;
root.magInit = magInit;
MAG.magazineApi = { load: magLoadLibrary, refresh: magRefreshArticles, splitSentences, fmtPages };

if (document.readyState === 'loading') {
  document.addEventListener('DOMContentLoaded', magInit);
} else {
  magInit();
}

})(window);