优化替换角色添加音频

core/backend/apps/ai/services.py

@@ -2917,6 +2917,42 @@ def _asset_preview_url(asset) -> str:
         return ""
 
 
+def asset_stable_url(asset) -> tuple[str, str]:
+    """资产的「长期可打开」直链 (主文件, 封面图)。历史记录这类隔天还要点开的场景必须用这个:
+    预签名链只活 1 小时,存进 payload 快照的话第二天就播不了 —— 公读直链不过期还能被缓存。
+    顺序:落库 preview_url → TOS 公读直链 → 兜底预签名。"""
+    if asset is None:
+        return "", ""
+    files = list(asset.files.all())
+    if not files:
+        return "", ""
+    primary = next((f for f in files if f.is_primary), None) or files[0]
+    # 封面只对视频/音频有意义:图片资产的第二张文件是它自己的兄弟图,不是封面。
+    poster = None
+    if "image" not in (primary.content_type or ""):
+        poster = next(
+            (f for f in files if f is not primary and "image" in (f.content_type or "")), None
+        )
+
+    def _url(f) -> str:
+        if f is None:
+            return ""
+        if f.preview_url:
+            return f.preview_url
+        if not f.object_key:
+            return ""
+        try:
+            return TosStorage().public_url(object_key=f.object_key, bucket=f.bucket or None)
+        except Exception:  # noqa: BLE001
+            pass
+        try:
+            return TosStorage().presigned_get_url(object_key=f.object_key)
+        except Exception:  # noqa: BLE001
+            return ""
+
+    return _url(primary), _url(poster)
+
+
 def _seedance_ref_url(raw_url: str, review_status: str = "", review_remote_id: str = "") -> str:
     """Seedance 参考图 URL:只要资产已进素材库(有 remote_id)就用 asset:// 素材库引用 —— 火山认的是
     「在不在素材库」,与审核态无关(实测 processing 也能引用);未进库才回落原始直链。