// ---------- Сравнение текстов (Левенштейн) и doCompare ----------

function normalize(text) {
  return text.toLowerCase().replace(/[.,!?;:«»"'’]/g, '').trim();
}

function levenshtein(a, b) {
  const m = a.length, n = b.length;
  const dp = Array.from({length: m+1}, (_,i) => [i]);
  for (let j=0; j<=n; j++) dp[0][j] = j;
  for (let i=1; i<=m; i++)
    for (let j=1; j<=n; j++)
      dp[i][j] = a[i-1] === b[j-1] ? dp[i-1][j-1] : 1 + Math.min(dp[i-1][j], dp[i][j-1], dp[i-1][j-1]);
  return dp[m][n];
}

function wordSimilarity(a, b) {
  const maxLen = Math.max(a.length, b.length);
  if (maxLen === 0) return 1;
  return 1 - levenshtein(a, b) / maxLen;
}

function compareTexts(original, transcribed) {
  const a = normalize(original).split(/\s+/);
  const b = normalize(transcribed).split(/\s+/);
  let totalScore = 0;
  const result = a.map(word => {
    let best = 0, bestMatch = '';
    for (const t of b) {
      const sim = wordSimilarity(word, t);
      if (sim > best) { best = sim; bestMatch = t; }
    }
    totalScore += best;
    const quality = best >= 0.8 ? 'ok' : best >= 0.5 ? 'near' : 'bad';
    return { word, quality, bestMatch, score: Math.round(best*100) };
  });
  const score = Math.round((totalScore / a.length) * 100);
  return { score, words: result };
}

function renderDiff(words) {
  return words.map(({ word, quality, bestMatch, score }) => {
    const color = quality === 'ok' ? 'green' : quality === 'near' ? '#e6a800' : 'red';
    const tip = quality !== 'ok' ? ` → ${bestMatch} (${score}%)` : '';
    return `<span style="color:${color}; font-weight:bold">${word}</span><span style="color:#888; font-size:0.85em">${tip}</span>`;
  }).join(' ');
}

async function doCompare(blob, originalText, duration) {
  if (isAnalyzing) return '';
  isAnalyzing = true;
  const startTime = Date.now();
  const timerId = setInterval(() => {
    const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
    setStatus('Анализ... ' + elapsed + 'с');
  }, 150);
  let whisperResult;
  try {
    whisperResult = await transcribe(blob);
  } catch(e) {
    clearInterval(timerId);
    isAnalyzing = false;
    setStatus('Ошибка анализа.');
    return '';
  }
  clearInterval(timerId);

  let recHTML = '', diffHTML = '';

  if (whisperResult.text) {
    const _transcribed = whisperResult.text;
    const { score, words } = compareTexts(originalText, whisperResult.text);
    const recEmoji = score >= 90 ? '🟢' : score >= 70 ? '🟡' : '🔴';
    recHTML = recEmoji + ' Распознание: <b>' + score + '%</b> &nbsp;|  🗣 <i>' + whisperResult.text + '</i>';
    diffHTML =
      '<div style="margin:6px 0;font-size:0.8em;color:#999">' +
      '📋 Текст: зелёный ≥80%, жёлтый ≥50%, красный &lt;50%' +
      '</div>' +
      renderDiff(words);
  } else {
    recHTML = '⚠️ Не распознано';
    diffHTML = '';
  }

  document.getElementById('score').innerHTML = recHTML;

  document.getElementById('diff').innerHTML = diffHTML;

  // Слоги — в отдельный div, не в diff (diff перезаписывается)
  _currentBlob = blob;
  _currentSylBuf = null;
  const sylDiv = document.getElementById('syllables');
  sylDiv.innerHTML = '';
  const sy = syllabifyIT(originalText);
  if (sy && sy.includes('-')) {
    const syls = sy.split('-');
    const div = document.createElement('div');
    div.style.cssText = 'margin-top:8px;font-size:1.2em;letter-spacing:2px;user-select:none';
    syls.forEach((s, i) => {
      if (i > 0) {
        const sep = document.createElement('span');
        sep.style.cssText = 'color:#ccc;margin:0 1px';
        sep.textContent = '-';
        div.appendChild(sep);
      }
      const chip = document.createElement('span');
      chip.textContent = s;
      chip.style.cssText = 'cursor:pointer;padding:2px 6px;border-radius:4px;transition:background 0.1s';
      chip.onmouseover = () => { chip.style.background = '#d0d0ff'; };
      chip.onmouseout = () => { chip.style.background = ''; };
      chip.onclick = () => { chip.style.background = '#a0a0ff'; setTimeout(() => { chip.style.background = '#d0d0ff'; }, 200); playSyllable(i, syls.length); };
      div.appendChild(chip);
    });
    sylDiv.appendChild(div);
  }

  setStatus('Готово.');
  isAnalyzing = false;
  return whisperResult.text || '';
}