feat: 初始提交

backend/app/services/update_log_service.py

@@ -0,0 +1,60 @@
+from typing import List, Optional
+
+from fastapi import HTTPException, status
+from sqlalchemy import update
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from ..models import UpdateLog
+from ..repositories.update_log_repository import UpdateLogRepository
+
+
+class UpdateLogService:
+    """更新日志服务，提供增删改查能力，并保证置顶唯一。"""
+
+    def __init__(self, session: AsyncSession):
+        self.session = session
+        self.repo = UpdateLogRepository(session)
+
+    async def list_logs(self, limit: Optional[int] = None) -> List[UpdateLog]:
+        if limit is None:
+            return list(await self.repo.list())
+        return list(await self.repo.list_latest(limit))
+
+    async def create_log(self, content: str, creator: str | None = None, *, is_pinned: bool = False) -> UpdateLog:
+        if is_pinned:
+            await self._clear_pinned()
+        log = UpdateLog(content=content, created_by=creator, is_pinned=is_pinned)
+        await self.repo.add(log)
+        await self.session.commit()
+        await self.session.refresh(log)
+        return log
+
+    async def update_log(self, log_id: int, *, content: Optional[str] = None, is_pinned: Optional[bool] = None) -> UpdateLog:
+        log = await self.repo.get(id=log_id)
+        if not log:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="更新记录不存在")
+
+        updates = {}
+        if content is not None:
+            updates["content"] = content
+        if is_pinned is not None:
+            if is_pinned:
+                await self._clear_pinned()
+            updates["is_pinned"] = is_pinned
+
+        if updates:
+            await self.repo.update_fields(log, **updates)
+            await self.session.commit()
+            await self.session.refresh(log)
+
+        return log
+
+    async def delete_log(self, log_id: int) -> None:
+        log = await self.repo.get(id=log_id)
+        if not log:
+            raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="更新记录不存在")
+        await self.repo.delete(log)
+        await self.session.commit()
+
+    async def _clear_pinned(self) -> None:
+        await self.session.execute(update(UpdateLog).values(is_pinned=False))