// ── Audiobook cast serialization ────────────────────────────────────────────
// Live casting remains in audiobook.js; these deterministic export/migration
// helpers have no casting-state side effects and can be loaded independently.

function _abCastMarkdown(data) {
  const payload = data || {};
  const segments = Array.isArray(payload.segments) ? payload.segments : [];
  const speakers = [...new Set(segments.filter(s => s?.type === 'dialogue' && s.speaker).map(s => String(s.speaker)))].sort();
  const lines = [`# ${payload.title || 'Cast Script'}`, ''];
  const metaBits = [];
  if (payload.savedAt) metaBits.push('exported ' + new Date(payload.savedAt).toISOString().slice(0, 16).replace('T', ' '));
  metaBits.push(`${speakers.length} character${speakers.length !== 1 ? 's' : ''}`);
  metaBits.push(`${segments.length} segment${segments.length !== 1 ? 's' : ''}`);
  lines.push(`*${metaBits.join(' · ')}*`, '');
  if (speakers.length) lines.push(`**Characters:** ${speakers.join(', ')}`, '');
  let lastPage = null;
  for (const seg of segments) {
    const text = String(seg?.text || '').trim();
    if (!text) continue;
    if (seg.page != null && seg.page !== lastPage) {
      lines.push('---', '', `## Page ${seg.page}`, '');
      lastPage = seg.page;
    }
    if (seg.type === 'dialogue') {
      const speaker = String(seg.speaker || 'Narrator');
      const tag = seg.emotion ? ` *(${seg.emotion})*` : '';
      lines.push(`**${speaker.toUpperCase()}**${tag}: "${text}"`);
    } else lines.push(text);
    lines.push('');
  }
  return lines.join('\n');
}

function _abStampSegmentPages(segs, pageMarks, text) {
  if (!Array.isArray(segs) || !segs.length || segs.some(s => s && s.page != null)) return;
  const marks = (pageMarks || []).slice().sort((a, b) => (a.offset || 0) - (b.offset || 0));
  const src = text || '';
  if (!marks.length || !src) return;
  let markIdx = 0, searchPos = 0, cur = null;
  if (marks[0].offset <= 2) { cur = marks[0].page + 1; markIdx = 1; }
  for (const s of segs) {
    const probe = String(s.text || '').trim().slice(0, 24);
    const at = probe ? src.indexOf(probe, searchPos) : -1;
    const pos = at >= 0 ? at : searchPos;
    if (at >= 0) searchPos = at + probe.length;
    while (markIdx < marks.length && pos >= marks[markIdx].offset) {
      cur = marks[markIdx].page + 1;
      markIdx++;
    }
    if (cur != null) s.page = cur;
  }
}

// Merge adjacent segments assigned to the same speaker without crossing a
// page boundary. Kept separate from the live casting orchestration because it
// is a deterministic post-cast normalization pass.
function _audiobookMergeAdjacentSameSpeaker(segments) {
  const out = [];
  for (const s of segments) {
    const last = out[out.length - 1];
    if (last && last.type === s.type && last.page === s.page) {
      const lastSpeaker = (last.speaker || 'Narrator').trim().toLowerCase();
      const curSpeaker = (s.speaker || 'Narrator').trim().toLowerCase();
      // Dialogue keeps its emotion tag distinct so one mood is not silently
      // discarded when two adjacent rows are combined.
      const sameEmotion = s.type !== 'dialogue' || (last.emotion || '').toLowerCase() === (s.emotion || '').toLowerCase();
      const unknownSpeaker = !lastSpeaker || lastSpeaker === 'unknown' || lastSpeaker === 'unbekannt';
      if (lastSpeaker === curSpeaker && sameEmotion && !(s.type === 'dialogue' && unknownSpeaker)) {
        const lastText = last.text.trimEnd(), curText = s.text.trimStart();
        last.text = /[.!?…»«”"’']$/.test(lastText) ? lastText + '\n\n' + curText : lastText + ' ' + curText;
        continue;
      }
    }
    out.push(Object.assign({}, s));
  }
  return out;
}

// Merge consecutive segments spoken by the same named character. This is a
// dialogue-only normalization pass; narration is intentionally left alone.
function _audiobookMergeAdjacentDialogue(segments) {
  const out = [];
  let merged = 0;
  for (const s of segments) {
    if (out.length) {
      const last = out[out.length - 1];
      const spk = String(s.speaker || '').trim().toLowerCase();
      const known = spk && !/^(unknown|unbekannt|narrator)$/i.test(spk);
      if (last.type === 'dialogue' && s.type === 'dialogue' && known
          && String(last.speaker || '').trim().toLowerCase() === spk) {
        const a = String(last.text || '').trimEnd(), b = String(s.text || '').trimStart();
        last.text = a + (/[.!?…»«"']$/.test(a) ? '\n\n' : ' ') + b;
        if (!String(last.emotion || '').trim() && String(s.emotion || '').trim()) last.emotion = s.emotion;
        merged++;
        continue;
      }
    }
    out.push(s);
  }
  return { segments: out, merged };
}

window.TTVC = window.TTVC || {};
window.TTVC.audiobook = window.TTVC.audiobook || {};
window.TTVC.audiobook.cast = {
  toMarkdown: _abCastMarkdown,
  stampPages: _abStampSegmentPages,
  mergeAdjacentSameSpeaker: _audiobookMergeAdjacentSameSpeaker,
  mergeAdjacentDialogue: _audiobookMergeAdjacentDialogue,
};