// ── Audiobook casting, span mode ────────────────────────────────────────────
// Structure (narration vs dialogue, and the exact text of each piece) comes
// from the book's own quotation marks, deterministically. The LLM is only asked
// who speaks each dialogue span (POST /api/attribute-spans), so it can never
// drop, duplicate or fuse text, and a whole book takes minutes instead of hours.
// Used by audiobookCast() unless switched off (localStorage 'ab-span-mode' = '0')
// or the book has no recognisable quotation style, in which case the classic
// whole-passage engine runs instead.
(function (root) {
'use strict';

function audiobookSpanModeEnabled() {
  try { return localStorage.getItem('ab-span-mode') !== '0'; } catch (_) { return true; }
}

const RECENT_LINES = 6;
const ROSTER_LIMIT = 40;

// Page (1-based) of a character offset, from the reader's page marks.
function _abPageAt(marks, offset) {
  let page = 1;
  for (const m of marks) { if (m.offset <= offset) page = m.page + 1; else break; }
  return page;
}

function _abWindowRequest(win, next, roster, recent, language, llm) {
  const following = (next ? next.spans.slice(0, 2) : []).map(s => s.llmText.slice(0, 300)).join(' ');
  return {
    spans: win.spans.map(s => ({ id: s.id, kind: s.kind, text: s.llmText })),
    known_characters: roster.slice(-ROSTER_LIMIT),
    recent, following, language,
    llm_url: llm.url, model: llm.model,
    timeout_seconds: llm.timeout,
  };
}

async function audiobookCastSpans(overrideUrl, overrideModel, resume) {
  const text = audiobookScopeText();
  if (!text || !root.TTVC?.audiobook?.spans) return false;
  const S = root.TTVC.audiobook.spans;
  const spans = S.segmentByQuotes(text);
  if (!spans || !spans.some(s => s.kind === 'dialogue')) return false;   // no quote style: classic engine
  const windows = S.buildWindows(spans, text);
  const byId = new Map();
  for (const w of windows) for (const sp of w.spans) byId.set(sp.id, sp);

  _audiobook.running = true;
  _audiobook.castMode = 'spans';
  if (!_abBookId()) await _abEnsureLibraryBook();
  const startIndex = (resume && resume.startIndex > 0 && resume.startIndex < windows.length) ? resume.startIndex : 0;
  if (!startIndex) _abClearDraft();
  if (typeof window.setNavCastingBadge === 'function') window.setNavCastingBadge(true);
  const ac = new AbortController();
  _audiobook.cancel = false;
  _audiobook.abort = () => ac.abort();

  if (overrideUrl && typeof overrideUrl !== 'string') overrideUrl = null;
  const llmUrl = overrideUrl || audiobookLlmUrl();
  const model = audiobookSafeLlmModel(overrideModel || audiobookLlmModel());
  const language = audiobookLang(text);
  const view = audiobookCastView(windows.length, llmUrl, model, false);
  if (startIndex && resume.segments && resume.segments.length) view.rebuild(resume.segments);
  const llm = {
    url: document.getElementById('ab-cv-llm-url')?.value.trim() || llmUrl,
    model: audiobookSafeLlmModel(document.getElementById('ab-cv-llm-select')?.value || model),
    timeout: audiobookTimeoutSeconds(AUDIOBOOK_ATTRIBUTION_TIMEOUT_MS),
  };

  const allSegments = startIndex ? resume.segments.slice() : [];
  _audiobook.liveSegments = allSegments;
  const roster = startIndex ? (resume.roster || []).slice() : [];
  let completed = startIndex, degraded = startIndex ? (resume.degraded || 0) : 0, narrationOnly = startIndex ? (resume.narrationOnly || 0) : 0;
  const marks = (_audiobook.pageMarks || []).slice();
  _abStartDraftAutosave(() => { if (allSegments.length) _abSaveDraft(allSegments, roster, text, completed, windows.length); });

  try {
    for (let i = startIndex; i < windows.length; i++) {
      if (_audiobook.cancel) break;
      const win = windows[i];
      view.update(i);
      const segs = [];
      let answer = { speakers: {} };
      if (win.hasDialogue) {
        const recent = allSegments.filter(s => s.type === 'dialogue' && s.speaker && !/^Unknown|Unbekannt/i.test(s.speaker))
          .slice(-RECENT_LINES).map(s => `${s.speaker}: ${(s.text || '').slice(0, 80)}`).join('\n');
        view.processing(win.spans.map(s => s.text).join(' ').slice(0, 900));
        try {
          const r = await audiobookFetchWithTimeout('/api/attribute-spans', {
            method: 'POST', headers: { 'Content-Type': 'application/json' }, signal: ac.signal,
            body: JSON.stringify(_abWindowRequest(win, windows[i + 1], roster, recent, language, llm)),
          }, AUDIOBOOK_ATTRIBUTION_TIMEOUT_MS + 5000);
          if (!r.ok) throw new Error((await r.json().catch(() => ({}))).detail || ('HTTP ' + r.status));
          answer = await r.json();
        } catch (err) {
          if (err.name === 'AbortError') throw err;
          answer = { failed: true, speakers: {} };
          view.note(`⚠️ Passage ${i + 1}: speaker lookup failed (${err.message}) — falling back to speech tags`);
        }
        if (answer.failed) degraded++;
      } else narrationOnly++;

      win.spans.forEach((sp, k) => {
        const page = _abPageAt(marks, sp.start);
        if (sp.kind === 'narration') { segs.push({ speaker: 'Narrator', type: 'narration', text: sp.text, emotion: '', page }); return; }
        const hit = answer.speakers && answer.speakers[sp.id];
        let speaker = hit && hit.speaker;
        if (!speaker || answer.failed) {
          const before = win.spans[k - 1]?.text || '', after = win.spans[k + 1]?.text || '';
          speaker = audiobookGuessSpeaker(after, before) || 'Unknown';
        }
        if (speaker === 'Narrator') { segs.push({ speaker: 'Narrator', type: 'narration', text: sp.text, emotion: '', page }); return; }
        segs.push({ speaker, type: 'dialogue', text: sp.text, emotion: (hit && hit.emotion) || '', page });
      });

      audiobookResolveUnknowns(segs, allSegments.slice(-2), roster);
      segs.forEach(s => {
        if (s.type === 'dialogue' && s.speaker && !/^Unknown|Unbekannt/i.test(s.speaker) && !roster.includes(s.speaker)) roster.push(s.speaker);
        allSegments.push(s);
      });
      view.addSegments(segs);
      completed = i + 1;
      _abSaveDraft(allSegments, roster, text, completed, windows.length);
    }
    view.update(_audiobook.cancel ? completed : windows.length);
  } catch (err) {
    _audiobook.cancel = true;
    view.note(err.name === 'AbortError' ? 'Casting stopped. Completed passages were preserved.' : `❌ Casting stopped — unexpected error: ${err.message}`);
  } finally {
    _abStopDraftAutosave();
    _audiobook.running = false;
    _audiobook.abort = null;
    _abHideCastingControl();
  }

  if (!allSegments.length) {
    view.done({ stopped: true, message: 'Casting stopped before any passage completed.' });
    return true;
  }
  try {
    { const ph = _audiobookDropPhantomSpeakers(allSegments);
      if (ph.dropped) console.info('[cast] dropped', ph.dropped, 'phantom speaker line(s):', ph.names.join(', ')); }
    { const role = _audiobookResolveRoleAliases(allSegments, text);
      if (role.moved) console.info('[cast] resolved role labels to names:', role.pairs.join(', '), `(${role.moved} lines)`); }
    { const ident = _audiobookConsolidateSpeakerAliases(allSegments);
      if (ident.merged) console.info('[cast] consolidated', ident.merged, 'speaker label variant(s),', ident.moved, 'line(s)'); }
    _abStampConfidence(allSegments);
    _audiobook.segments = allSegments;
    _audiobook.lastText = text;
    _audiobook.roster = roster;
    _audiobook.narratedPassages = narrationOnly;
    _audiobook.degraded = degraded;
    _audiobook.recoveredGaps = 0;
    _audiobook.completedChunks = _audiobook.cancel ? completed : windows.length;
    _audiobook.completedTotal = windows.length;
    _abSaveDraft(allSegments, roster, text, _audiobook.completedChunks, windows.length);
    audiobookSaveAsRehearsal({ silent: true });
    const speakers = new Set(allSegments.filter(s => s.type === 'dialogue' && s.speaker).map(s => s.speaker));
    const stoppedEarly = _audiobook.cancel && completed < windows.length;
    view.complete(`${stoppedEarly ? 'Stopped early · ' : ''}${speakers.size} character${speakers.size !== 1 ? 's' : ''} · ${allSegments.length} segments`,
      audiobookShowPreview, audiobookCast, audiobookRecastUnknown);
    if (!stoppedEarly && !_audiobook.cancel && audiobookAutoRepairEnabled()) {
      const unknown = allSegments.filter(s => s?.type === 'dialogue' && (!s.speaker || /^Unknown|Unbekannt/i.test(s.speaker))).length;
      if (unknown > 10) setTimeout(() => { audiobookAutoRepairCast().catch(e => console.warn('[auto-repair]', e)); }, 800);
    }
  } catch (e) {
    console.error('[audiobookCastSpans] post-processing failed', e);
    view.done({ stopped: true, message: 'Finished casting, but saving/cleanup failed: ' + e.message });
  }
  return true;
}

root.audiobookSpanModeEnabled = audiobookSpanModeEnabled;
root.audiobookCastSpans = audiobookCastSpans;
root.TTVC = root.TTVC || {};
root.TTVC.audiobook = root.TTVC.audiobook || {};
root.TTVC.audiobook.castSpans = audiobookCastSpans;
})(window);