feat: 优化 Agent 运行时与聊天设置体验

backend/src/v1/agent/service.py

@@ -19,7 +19,8 @@ from core.config.settings import config
 from core.logging import get_logger
 from schemas.messages.chat_message import (
     AgentChatMessageMetadata,
-    UserMessageAttachments,
+    UserMessageAttachment,
+    extract_user_message_attachments,
 )
 from v1.agent.schemas import HistorySnapshotResponse
 
@@ -27,6 +28,7 @@ logger = get_logger(__name__)
 _ALLOWED_ATTACHMENT_MIME_TYPES = {"image/png", "image/jpeg", "image/webp"}
 _MAX_ATTACHMENT_BYTES = 5 * 1024 * 1024
 _MAX_TOTAL_ATTACHMENT_BYTES = 12 * 1024 * 1024
+_MAX_ATTACHMENTS_PER_MESSAGE = 3
 
 
 @dataclass(frozen=True)
@@ -230,7 +232,7 @@ class AgentService:
     ) -> tuple[str, AgentChatMessageMetadata | None]:
         text, content_blocks = extract_latest_user_payload(run_input)
 
-        user_attachments: UserMessageAttachments | None = None
+        user_attachments: list[UserMessageAttachment] = []
         for block in content_blocks:
             if not isinstance(block, dict):
                 continue
@@ -257,12 +259,15 @@ class AgentService:
                     thread_id=run_input.thread_id,
                     current_user=current_user,
                 )
-                user_attachments = UserMessageAttachments(
-                    bucket=bucket,
-                    path=path,
-                    mime_type=mime_type,
+                user_attachments.append(
+                    UserMessageAttachment(
+                        bucket=bucket,
+                        path=path,
+                        mime_type=mime_type,
+                    )
                 )
-                break
+                if len(user_attachments) > _MAX_ATTACHMENTS_PER_MESSAGE:
+                    raise HTTPException(status_code=422, detail="Too many attachments")
             except HTTPException:
                 raise
             except Exception as exc:  # noqa: BLE001
@@ -270,7 +275,7 @@ class AgentService:
                 raise HTTPException(status_code=422, detail="Invalid signed image url")
 
         metadata: AgentChatMessageMetadata | None = None
-        if user_attachments is not None:
+        if user_attachments:
             metadata = AgentChatMessageMetadata(
                 run_id=run_input.run_id,
                 user_message_attachments=user_attachments,
@@ -438,23 +443,38 @@ class AgentService:
 
         messages: list[HistoryMessage] = []
         if day_payload:
-            raw_messages = day_payload.get("messages") or []
+            raw_messages_obj = day_payload.get("messages")
+            raw_messages = (
+                raw_messages_obj if isinstance(raw_messages_obj, list) else []
+            )
             for msg_dict in raw_messages:
                 msg = AgentChatMessage.model_validate(msg_dict)
 
-                signed_url: str | None = None
-                if self._attachment_storage and msg.metadata:
-                    att = msg.metadata.user_message_attachments
-                    if att:
+                signed_urls: dict[str, str] = {}
+                attachments = extract_user_message_attachments(msg.metadata)
+                if self._attachment_storage and attachments:
+                    expected_prefix = (
+                        f"agent-inputs/{current_user.id}/{thread_id}/uploads/"
+                    )
+                    for attachment in attachments:
+                        if not _is_safe_attachment_path(
+                            attachment.path,
+                            expected_prefix=expected_prefix,
+                        ):
+                            continue
                         signed_url = await self._attachment_storage.create_signed_url(
-                            bucket=att.bucket,
-                            path=att.path,
+                            bucket=attachment.bucket,
+                            path=attachment.path,
                             expires_in_seconds=self._SIGNED_URL_EXPIRES_IN_SECONDS,
                         )
+                        key = f"{attachment.bucket}/{attachment.path}"
+                        signed_urls[key] = signed_url
 
-                converted = convert_message_to_history(msg, None)
-                if signed_url:
-                    converted["url"] = signed_url
+                def _get_signed_url(payload: dict[str, str]) -> str:
+                    key = f"{payload['bucket']}/{payload['path']}"
+                    return signed_urls[key]
+
+                converted = convert_message_to_history(msg, _get_signed_url)
                 messages.append(HistoryMessage.model_validate(converted))
 
         return HistorySnapshotResponse(