// ── Seed Finder — find the best RNG seed for a voice ─────────────────────────
//
// Appended to the voice inspector body by voice-inspector.js.
// Generates audio samples for a voice across a range of seeds so the user
// can listen and pick the most natural-sounding one, then save it to the
// TTS server's voices.json with one click.

const SEED_FINDER_TEXT_DE = (
  'Die 3.500 neuen High-End Geräte für das Server-Update benötigen eine ' +
  'außergewöhnlich starke Kühlung und regelmäßige Maßnahmen, um die Performance ' +
  'bei großer Last zu gewährleisten.'
);
const SEED_FINDER_TEXT_EN = (
  'The system administrator successfully configured the customized Docker stacks ' +
  'and benchmarked the inference engines at exactly 8:45 AM.'
);
const SEED_FINDER_TEXT_MIXED = SEED_FINDER_TEXT_DE + ' - ' + SEED_FINDER_TEXT_EN;

function _seedFinderDefaultText(voiceId) {
  const lc = (voiceId || '').toLowerCase();
  if (lc.startsWith('de_')) return SEED_FINDER_TEXT_MIXED;
  if (lc.startsWith('en_') || lc.startsWith('gb_')) return SEED_FINDER_TEXT_EN;
  return SEED_FINDER_TEXT_MIXED;
}

// Called from voice-inspector.js after the persona panel is appended.
function attachSeedFinder(voiceId, body) {
  const panel = document.createElement('div');
  panel.className = 'opt-group seed-finder-group';
  panel.innerHTML = `
    <div class="opt-group-title">
      <span class="opt-chevron"></span>
      <span class="opt-title-text">🎲 Seed Finder</span>
      <span class="opt-group-meta">Find the most natural-sounding voice</span>
    </div>
    <div class="opt-group-subtitle">
      Generates audio for each seed so you can listen and pick the best one.
      Click "Use this seed" to save it to the TTS server.
    </div>
    <div class="opt-group-body seed-finder-body">
      <div class="seed-finder-config">
        <div class="seed-finder-row">
          <label class="seed-finder-label">Test sentence</label>
          <textarea class="seed-finder-text" rows="3" spellcheck="false"></textarea>
        </div>
        <div class="seed-finder-row seed-finder-params">
          <div class="seed-finder-field">
            <label>Seeds: from</label>
            <input class="seed-finder-from" type="number" min="0" max="9999" value="1" step="1">
            <label>to</label>
            <input class="seed-finder-to" type="number" min="1" max="9999" value="15" step="1">
          </div>
          <div class="seed-finder-field">
            <label>Backend</label>
            <select class="seed-finder-backend">
              <option value="voice_clone" selected>Voice Clone</option>
              <option value="streaming">Streaming</option>
            </select>
          </div>
        </div>
        <div class="seed-finder-actions">
          <button class="btn-primary seed-finder-run-btn">▶ Run Seed Finder</button>
          <button class="btn-secondary seed-finder-cancel-btn" style="display:none">✕ Cancel</button>
          <span class="seed-finder-status"></span>
        </div>
      </div>

      <div class="seed-finder-progress" style="display:none">
        <div class="seed-finder-progress-head">
          <span class="seed-finder-progress-label">Generating…</span>
          <span class="seed-finder-progress-count">0 / 0</span>
        </div>
        <div class="benchmark-progress-track">
          <div class="seed-finder-bar" style="width:0%"></div>
        </div>
      </div>

      <div class="seed-finder-results"></div>
    </div>
  `;

  body.appendChild(panel);

  // Toggle open/closed
  panel.querySelector('.opt-group-title').addEventListener('click', () => {
    panel.classList.toggle('open');
  });

  const textEl      = panel.querySelector('.seed-finder-text');
  const fromEl      = panel.querySelector('.seed-finder-from');
  const toEl        = panel.querySelector('.seed-finder-to');
  const backendEl   = panel.querySelector('.seed-finder-backend');
  const runBtn      = panel.querySelector('.seed-finder-run-btn');
  const cancelBtn   = panel.querySelector('.seed-finder-cancel-btn');
  const statusEl    = panel.querySelector('.seed-finder-status');
  const progressEl  = panel.querySelector('.seed-finder-progress');
  const progLabel   = panel.querySelector('.seed-finder-progress-label');
  const progCount   = panel.querySelector('.seed-finder-progress-count');
  const progBar     = panel.querySelector('.seed-finder-bar');
  const resultsEl   = panel.querySelector('.seed-finder-results');

  textEl.value = _seedFinderDefaultText(voiceId);

  let _cancelled = false;
  let _currentAudio = null;

  function _playBlob(blob) {
    if (_currentAudio) { _currentAudio.pause(); _currentAudio = null; }
    const url = URL.createObjectURL(blob);
    const audio = new Audio(url);
    _currentAudio = audio;
    audio.play().catch(() => {});
    audio.addEventListener('ended', () => { URL.revokeObjectURL(url); _currentAudio = null; });
  }

  function _addResultRow(seed, blob, durationSec, err, activeSeedSet) {
    const row = document.createElement('div');
    row.className = 'seed-finder-result-row' + (err ? ' seed-finder-result-error' : '');
    row.dataset.seed = seed;

    if (err) {
      row.innerHTML = `
        <span class="sfr-seed">Seed ${seed}</span>
        <span class="sfr-error">Failed: ${escHtml(String(err))}</span>
      `;
    } else {
      const durStr = durationSec ? `${durationSec.toFixed(1)}s` : '';
      row.innerHTML = `
        <span class="sfr-seed">Seed ${seed}</span>
        <span class="sfr-dur">${durStr}</span>
        <button class="btn-secondary sfr-play-btn"><span class="mdi mdi-play"></span> Play</button>
        <button class="btn-primary sfr-use-btn">★ Use seed ${seed}</button>
        <span class="sfr-saved"></span>
      `;
      row.querySelector('.sfr-play-btn').addEventListener('click', () => _playBlob(blob));
      row.querySelector('.sfr-use-btn').addEventListener('click', async () => {
        // Stop any playback
        if (_currentAudio) { _currentAudio.pause(); _currentAudio = null; }
        try {
          const resp = await fetch('/api/tts-voice-seed', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ voice: voiceId, seed }),
          });
          if (!resp.ok) {
            const e = await resp.json().catch(() => ({}));
            throw new Error(e.detail || resp.statusText);
          }
          // Clear all other "saved" markers
          resultsEl.querySelectorAll('.sfr-saved').forEach(el => el.textContent = '');
          resultsEl.querySelectorAll('.seed-finder-result-row').forEach(r => r.classList.remove('sfr-active'));
          row.classList.add('sfr-active');
          row.querySelector('.sfr-saved').textContent = '✓ Saved';
          if (typeof toast === 'function') toast(`Seed ${seed} saved for ${voiceId}`, 'success');
        } catch (e) {
          if (typeof toast === 'function') toast('Save failed: ' + e.message, 'error');
        }
      });
    }

    resultsEl.appendChild(row);
  }

  async function _runFinder() {
    const text = textEl.value.trim();
    if (!text) { statusEl.textContent = 'Enter a test sentence.'; return; }

    const seedFrom = Math.max(0, parseInt(fromEl.value, 10) || 1);
    const seedTo   = Math.max(seedFrom, parseInt(toEl.value, 10) || 15);
    const backend  = backendEl.value;
    const seeds    = [];
    for (let s = seedFrom; s <= seedTo; s++) seeds.push(s);
    const total = seeds.length;

    _cancelled = false;
    resultsEl.innerHTML = '';
    progressEl.style.display = '';
    runBtn.style.display = 'none';
    cancelBtn.style.display = '';
    statusEl.textContent = '';
    progBar.style.width = '0%';
    progCount.textContent = `0 / ${total}`;
    progLabel.textContent = 'Generating…';

    for (let i = 0; i < seeds.length; i++) {
      if (_cancelled) break;
      const seed = seeds[i];
      progLabel.textContent = `Seed ${seed}…`;
      progCount.textContent = `${i} / ${total}`;
      progBar.style.width = `${Math.round(i / total * 100)}%`;

      try {
        const blob = await fetchTtsPreviewBlob(
          voiceId, text, 'wav', '', backend, false, { seed }
        );
        // Estimate duration from WAV byte length: (bytes - 44 header) / (24000 * 2)
        const durSec = Math.max(0, (blob.size - 44) / (24000 * 2));
        _addResultRow(seed, blob, durSec, null, false);
      } catch (e) {
        _addResultRow(seed, null, 0, e.message || String(e), false);
      }
    }

    progBar.style.width = '100%';
    progCount.textContent = `${seeds.length} / ${total}`;
    progLabel.textContent = _cancelled ? 'Cancelled.' : 'Done — listen and pick your seed.';
    runBtn.style.display = '';
    cancelBtn.style.display = 'none';
  }

  runBtn.addEventListener('click', _runFinder);
  cancelBtn.addEventListener('click', () => { _cancelled = true; });
}