完善写作类题型的处理逻辑

ef_course_autopilot.py

@@ -311,23 +311,33 @@ def build_response_categorisation(task: TaskInfo) -> dict:
 
 
 def build_response_writing_challenge(task: TaskInfo) -> dict:
-    """writing-challenge: 写作挑战 — 优先使用expectedResponse，否则提交占位文本"""
+    """writing-challenge: 写作挑战 — 优先使用expectedResponse，否则生成足够字数的占位文本"""
     expected = task.expected_response.get("contents", {}).get("writingChallenge", {})
-    if expected:
+    if expected and expected.get("userInput", "").strip():
         return {"writingChallenge": expected}
 
-    # 回退：提交一段较长占位文本（确保满足最低字数要求）
+    # 从task_detail获取字数要求
+    min_words = task.task_detail.get("writingChallenge", {}).get("minWordCount", 20)
+
+    # 生成满足最低字数要求的占位文本
+    paragraph = (
+        "I think this is a very interesting topic. There are many things "
+        "to consider when writing about this subject. First of all, it is "
+        "important to understand the main ideas and think carefully about "
+        "the best way to express your thoughts. In my opinion, practice "
+        "is the key to success and everyone should try their best to "
+        "improve their skills every day. This is why I believe that "
+        "learning English is very useful for communication with people "
+        "from different countries and cultures around the world."
+    )
+    word_count = len(paragraph.split())
+    if word_count < min_words:
+        repeat = (min_words // word_count) + 1
+        paragraph = " ".join([paragraph] * repeat)
+
     return {
         "writingChallenge": {
-            "userInput": (
+            "userInput": paragraph,
-                "I think this is a good topic. There are many things to consider "
-                "when writing about this subject. First of all, it is important to "
-                "understand the main ideas and think carefully about the best way to "
-                "express your thoughts. In my opinion, practice is the key to success "
-                "and everyone should try their best to improve their skills every day. "
-                "This is why I believe that learning English is very useful for "
-                "communication with people from different countries and cultures."
-            ),
         }
     }