secure avatar to s3 by exception control

app/auth.py

@@ -72,31 +72,45 @@ async def auth_callback(request: Request, code: str, state: str):
         user_info = user_res.json()
 
     db = SessionLocal()
+    
+    try:
+        user = db.query(User).filter(User.email == user_info["email"]).first()
 
-    user = db.query(User).filter(User.email == user_info["email"]).first()
-
-    if not user:
-        user = User(
-            google_id=user_info["id"],
-            email=user_info["email"],
-            name=user_info["name"],
-            avatar=user_info["picture"],
-        )
-        db.add(user)
-        db.commit()
-        db.refresh(user)
-        
-        # 异步/同步将头像转存到 S3
-        from app.utils.s3 import upload_google_avatar_to_s3
-        s3_avatar_url = await upload_google_avatar_to_s3(user_info["picture"], str(user.id))
-        
-        # 将更新后的 S3 URL 写回数据库
-        user.avatar = s3_avatar_url
-        db.commit()
-        # 这里不需要再次 refresh，除非后面还要用到更新后的 user 对象
-        # db.refresh(user)
-
-    db.close()
+        if not user:
+            # 提取邮箱前缀作为 handle 基础
+            # 比如 "john.doe@gmail.com" -> "john_doe"
+            base_handle = user_info["email"].split("@")[0].replace(".", "_").lower()
+            
+            # 拼接一个随机短字符串，确保 handle 的唯一性
+            import secrets
+            random_suffix = secrets.token_hex(3) # 生成 6 位随机字符
+            suggested_handle = f"{base_handle}_{random_suffix}"
+            
+            user = User(
+                google_id=user_info["id"],
+                email=user_info["email"],
+                name=user_info["name"],
+                avatar=user_info["picture"],
+                handle=suggested_handle,
+            )
+            db.add(user)
+            db.commit()
+            db.refresh(user)
+            
+            # 异步/同步将头像转存到 S3
+            from app.utils.s3 import upload_google_avatar_to_s3
+            try:
+                s3_avatar_url = await upload_google_avatar_to_s3(user_info["picture"], str(user.id))
+                # 将更新后的 S3 URL 写回数据库
+                user.avatar = s3_avatar_url
+                db.commit()
+            except Exception as s3_err:
+                print(f"S3 Upload failed: {s3_err}")
+            
+            # 这里不需要再次 refresh，除非后面还要用到更新后的 user 对象
+            # db.refresh(user)
+    finally:
+        db.close()
 
     jwt_token = create_jwt_token({
         "sub": user.id,