1.9

backend/app/services/announcement_service.py

@@ -0,0 +1,58 @@
+"""群公告服务"""
+
+import uuid
+from datetime import datetime
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.group_announcement import GroupAnnouncement
+from app.services.conversation_service import ConversationService
+
+
+class AnnouncementService:
+    def __init__(self, db: AsyncSession):
+        self.db = db
+
+    async def get(self, conversation_id: str) -> dict | None:
+        result = await self.db.execute(
+            select(GroupAnnouncement).where(
+                GroupAnnouncement.conversation_id == conversation_id
+            ).order_by(GroupAnnouncement.updated_at.desc())
+        )
+        ann = result.scalars().first()
+        if not ann:
+            return None
+        return self._to_dict(ann)
+
+    async def upsert(self, conversation_id: str, author_id: str, content: str) -> dict:
+        # 校验管理员
+        conv_service = ConversationService(self.db)
+        await conv_service._get_conv_if_admin(conversation_id, author_id)
+
+        result = await self.db.execute(
+            select(GroupAnnouncement).where(GroupAnnouncement.conversation_id == conversation_id)
+        )
+        ann = result.scalars().first()
+        if ann:
+            ann.content = content
+            ann.author_id = author_id
+            ann.updated_at = datetime.utcnow()
+        else:
+            ann = GroupAnnouncement(
+                id=str(uuid.uuid4()),
+                conversation_id=conversation_id,
+                author_id=author_id, content=content,
+            )
+            self.db.add(ann)
+        await self.db.flush()
+        return self._to_dict(ann)
+
+    def _to_dict(self, ann: GroupAnnouncement) -> dict:
+        return {
+            "id": ann.id,
+            "conversation_id": ann.conversation_id,
+            "author_id": ann.author_id,
+            "content": ann.content,
+            "updated_at": ann.updated_at.isoformat() if ann.updated_at else None,
+        }