import logging
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, update, insert
from app.models.notification import Notification
from app.models.project import ProjectMember
from typing import List, Optional

logger = logging.getLogger(__name__)

class NotificationService:
    async def create_notification(
        self,
        db: AsyncSession,
        user_id: int,
        title: str,
        content: str = None,
        type: str = "info",
        category: str = "system",
        link: str = None
    ) -> Notification:
        """创建单条通知"""
        db_notification = Notification(
            user_id=user_id,
            title=title,
            content=content,
            type=type,
            category=category,
            link=link
        )
        db.add(db_notification)
        await db.flush()
        return db_notification

    async def broadcast_system_notification(
        self,
        db: AsyncSession,
        title: str,
        content: str,
        user_ids: List[int],
        link: str = None
    ):
        """向指定多个用户发送系统通知"""
        for uid in user_ids:
            db_notification = Notification(
                user_id=uid,
                title=title,
                content=content,
                type="info",
                category="system",
                link=link
            )
            db.add(db_notification)
        await db.flush()

    async def notify_project_members(
        self,
        db: AsyncSession,
        project_id: int,
        exclude_user_id: int,
        title: str,
        content: str,
        link: str = None,
        category: str = "project"
    ):
        """通知项目中除指定用户外的所有成员"""
        result = await db.execute(
            select(ProjectMember.user_id).where(
                ProjectMember.project_id == project_id,
                ProjectMember.user_id != exclude_user_id
            )
        )
        member_ids = result.scalars().all()
        
        logger.info(f"Notifying members of project {project_id}. Found {len(member_ids)} members to notify (excluding user {exclude_user_id}).")
        
        if member_ids:
            for uid in member_ids:
                db_notification = Notification(
                    user_id=uid,
                    title=title,
                    content=content,
                    type="info",
                    category=category,
                    link=link
                )
                db.add(db_notification)
            await db.flush()


notification_service = NotificationService()