Update app.py

app.py

@@ -81,19 +81,32 @@ excluding the title, author name, source information, chapter number, annotation
 {text}
 """
 
-    with _rewrite_sem:
-        resp = client.chat.completions.create(
-            model=MODEL,
-            messages=[{"role": "user", "content": prompt}],
-            temperature=0.4,
-            max_tokens=5000
-        )
-    return resp.choices[0].message.content.strip()
+    # 安全な max_tokens 候補（大→小）
+    max_tokens_candidates = [3000, 2000, 1500, 1000]
+
+    last_error = None
+    for mt in max_tokens_candidates:
+        try:
+            with _rewrite_sem:
+                resp = client.chat.completions.create(
+                    model=MODEL,
+                    messages=[{"role": "user", "content": prompt}],
+                    temperature=0.4,
+                    max_tokens=mt
+                )
+            return resp.choices[0].message.content.strip()
+
+        except Exception as e:
+            last_error = e
+            # 402（クレジット不足 or トークン過多）の場合は縮めて再試行
+            if "402" in str(e) or "more credits" in str(e):
+                continue
+            else:
+                raise e
+
+    # 全部ダメなら最後のエラーを投げる
+    raise RuntimeError(f"Rewrite failed after retries: {last_error}")
 
-# =========================
-# 指標（FRE + 単語数）
-# =========================
-_word_re = re.compile(r"[A-Za-z]+(?:'[A-Za-z]+)?")
 
 def count_words_english(text: str) -> int:
     return len(_word_re.findall(text))