补

core/backend/apps/ai/creation.py

@@ -150,7 +150,8 @@ def _sync_segmented_video_message(message: CreationMessage) -> bool:
     """同步全能创作的多段出片。
 
     每段仍是普通 FREE_VIDEO 任务，故可沿用既有计费、轮询和资产落库；这里仅把它们聚合成
-    一张结果卡。所有分段完成后停在结果卡，绝不在此处触发 ffmpeg。
+    一张结果卡。任一片段先完成就先写回 GENERATING 卡供用户预览；所有分段完成后才转成
+    可合并的结果卡，绝不在此处触发 ffmpeg。
     """
     from .free_video import finalize_free_video
     from .models import AITask
@@ -189,16 +190,46 @@ def _sync_segmented_video_message(message: CreationMessage) -> bool:
         number = next((index + 1 for index, task in enumerate(refreshed) if task.id == failed.id), 1)
         fail_generating_message(message, f"第 {number} 段生成失败：{failed.error_message or '请重试'}")
         return True
+    assets: list[dict] = []
+    completed_segments = 0
+    for index, task in enumerate(refreshed, start=1):
+        if task.status != AITask.Status.SUCCEEDED:
+            continue
+        task_assets = _assets_from_task(task)
+        # 上游状态先成功、资产稍后才落库时，保留 GENERATING，下一轮再展示这段。
+        if not task_assets:
+            continue
+        completed_segments += 1
+        for asset in task_assets:
+            assets.append({**asset, "label": f"第 {index} 段", "segment_index": index})
+
+    # 先完成的片段必须立刻回到前端，不能等另一段慢任务一起完成才出现。
+    # 保持同一条 GENERATING 消息，避免把一个 60 秒视频拆成多条对话消息。
     if not all(task.status == AITask.Status.SUCCEEDED for task in refreshed):
+        progress = {
+            **payload,
+            "assets": assets,
+            "completed_segment_count": completed_segments,
+        }
+        if progress != payload:
+            message.payload = progress
+            message.save(update_fields=["payload", "updated_at"])
+            return True
+        return False
+
+    # 任务都成功但有片段的资产还在落库，继续保持生成中，避免最终结果缺片。
+    if completed_segments != len(refreshed):
+        progress = {
+            **payload,
+            "assets": assets,
+            "completed_segment_count": completed_segments,
+        }
+        if progress != payload:
+            message.payload = progress
+            message.save(update_fields=["payload", "updated_at"])
+            return True
         return False
 
-    assets: list[dict] = []
-    for index, task in enumerate(refreshed, start=1):
-        task_assets = _assets_from_task(task)
-        if not task_assets:
-            return False
-        for asset in task_assets:
-            assets.append({**asset, "label": f"第 {index} 段"})
     first = refreshed[0]
     finish_generating_message(
         message,

core/backend/apps/ai/test_creation_conversation.py

@@ -161,6 +161,33 @@ class GenerationBackfillTests(TestCase):
         message.refresh_from_db()
         self.assertEqual(message.kind, CreationMessage.Kind.GENERATING)
 
+    def test_segmented_video_shows_completed_first_segment_before_second_finishes(self):
+        first = self._task(AITask.Status.SUCCEEDED, key="k-segment-first")
+        second = self._task(AITask.Status.POLLING, key="k-segment-second")
+        self._asset(first, url="https://cdn.example/segment-1.mp4")
+        message = append_message(
+            self.conversation,
+            role="assistant",
+            kind=CreationMessage.Kind.GENERATING,
+            task=first,
+            payload={
+                "kind": "video_segments",
+                "task_id": str(first.id),
+                "task_ids": [str(first.id), str(second.id)],
+                "segments": [
+                    {"index": 1, "task_id": str(first.id)},
+                    {"index": 2, "task_id": str(second.id)},
+                ],
+            },
+        )
+
+        self.assertEqual(sync_generating_messages(self.conversation), 1)
+        message.refresh_from_db()
+        self.assertEqual(message.kind, CreationMessage.Kind.GENERATING)
+        self.assertEqual(message.payload["completed_segment_count"], 1)
+        self.assertEqual(message.payload["assets"][0]["label"], "第 1 段")
+        self.assertEqual(message.payload["assets"][0]["url"], "https://cdn.example/segment-1.mp4")
+
     def test_retrieve_backfills_before_returning_messages(self):
         task = self._task(AITask.Status.SUCCEEDED, key="k-api")
         self._asset(task, url="https://cdn.example/api.png")