fix: avoid repeating last 3 rubrics in cover selection (no more similar covers)

src/services/covers.js

@@ -466,13 +466,34 @@ async function generateCoverViaPollinations({ prompt }) {
  * Выбирает наиболее подходящую рубрику для обложки статьи.
  * Дешёвый haiku-вызов: ~50 токенов. При ошибке — случайная рубрика.
  */
-async function selectRubric({ title, tags = [], rubrics }) {
+async function selectRubric({ title, tags = [], rubrics, channelId = null }) {
   if (!rubrics || rubrics.length === 0) return null;
   if (rubrics.length === 1) return rubrics[0];
 
-  const rubricList = rubrics.map((r, i) => `${i}. ${r.id}: ${r.desc}`).join('\n');
-  const userMsg = `Article title: "${title}"\nTags: ${tags.join(', ') || 'none'}\n\nRubrics:\n${rubricList}\n\nRespond with ONLY the index number (0-${rubrics.length - 1}) of the best matching rubric.`;
+  // Получаем последние использованные рубрики из БД (анти-повтор)
+  let recentlyUsed = [];
+  if (channelId) {
+    try {
+      const r = await query(
+        'SELECT last_rubrics_used FROM channel_style WHERE channel_id = $1',
+        [channelId]
+      );
+      recentlyUsed = Array.isArray(r.rows[0]?.last_rubrics_used)
+        ? r.rows[0].last_rubrics_used
+        : [];
+    } catch (_) {}
+  }
 
+  // Доступные рубрики = все минус последние 3 использованные
+  // (если осталось < 2 — берём все, иначе AI выбирает только из свежих)
+  const recent = recentlyUsed.slice(-3);
+  let available = rubrics.filter(r => !recent.includes(r.id));
+  if (available.length < 2) available = rubrics;
+
+  const rubricList = available.map((r, i) => `${i}. ${r.id}: ${r.desc}`).join('\n');
+  const userMsg = `Article title: "${title}"\nTags: ${tags.join(', ') || 'none'}\n\nRubrics:\n${rubricList}\n\nRespond with ONLY the index number (0-${available.length - 1}) of the best matching rubric.`;
+
+  let selected = null;
   try {
     const res = await axios.post(
       `${config.ai.baseUrl}/chat/completions`,
@@ -489,12 +510,25 @@ async function selectRubric({ title, tags = [], rubrics }) {
     );
     const raw = res.data?.choices?.[0]?.message?.content?.trim() || '0';
     const idx = parseInt(raw.replace(/\D/g, '')) || 0;
-    const safeIdx = Math.min(Math.max(idx, 0), rubrics.length - 1);
-    return rubrics[safeIdx];
+    const safeIdx = Math.min(Math.max(idx, 0), available.length - 1);
+    selected = available[safeIdx];
   } catch (err) {
     console.warn('[Cover] selectRubric failed, using random:', err.message.slice(0, 80));
-    return rubrics[Math.floor(Math.random() * rubrics.length)];
+    selected = available[Math.floor(Math.random() * available.length)];
   }
+
+  // Записываем в last_rubrics_used (храним последние 5)
+  if (channelId && selected) {
+    try {
+      const newList = [...recentlyUsed, selected.id].slice(-5);
+      await query(
+        'UPDATE channel_style SET last_rubrics_used = $1 WHERE channel_id = $2',
+        [JSON.stringify(newList), channelId]
+      );
+    } catch (_) {}
+  }
+
+  return selected;
 }
 
 async function generateCover({ articleId, title, tags = [], channelId = null }) {
@@ -514,7 +548,7 @@ async function generateCover({ articleId, title, tags = [], channelId = null })
   let styleName;
   const rubrics = channelStyle?.image_rubrics;
   if (Array.isArray(rubrics) && rubrics.length > 0) {
-    selectedRubric = await selectRubric({ title, tags, rubrics });
+    selectedRubric = await selectRubric({ title, tags, rubrics, channelId });
     styleName = selectedRubric?.id || 'rubric';
     console.log(`[Cover] article=${articleId} channel=${channelId} rubric=${styleName}`);
   } else {