"""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,
        }