from datetime import date, timedelta
from sqlalchemy import select

from app.database import async_session_factory
from app.models.batch import Batch
from app.models.medicine import Medicine
from app.config import settings


async def check_expiring_medicines():
    async with async_session_factory() as db:
        today = date.today()

        for days in settings.EXPIRY_WARNING_DAYS:
            target_date = today + timedelta(days=days)

            query = select(Batch, Medicine).join(
                Medicine, Batch.medicine_id == Medicine.id
            ).where(
                Batch.expiry_date <= target_date,
                Batch.is_expired == False,
                Batch.quantity > 0
            )

            result = await db.execute(query)
            batches = result.all()

            if batches:
                from app.notifications.manager import notification_manager
                title = f"药品过期提醒 ({days}天内)"
                content = "以下药品即将过期，请及时处理：\n\n"

                for batch, medicine in batches:
                    content += f"- {medicine.name}: {batch.batch_no or '默认批次'} "
                    content += f"(过期日期: {batch.expiry_date})\n"

                await notification_manager.send_notification(title, content)