"""超期预警每日扫描 job（批3）：树多年未决策 / 花粉批次过期 / 种子批超期。

作为系统级定时任务注册于 app/core/ap_scheduler.py（init_scheduler），
每日执行一次。生成 bre_alert 行时直接 db.add（不经 CRUDBase，防自审计递归）；
同实体已有 open 预警时跳过（去重），待处理人 resolve 后下一轮可再次告警。
"""

import logging
from datetime import date, datetime, timedelta

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import async_db_session

from .model import AlertModel
from app.api.v1.module_bre.tree.model import TreeModel
from app.api.v1.module_bre.selection_result.model import SelectionResultModel
from app.api.v1.module_bre.pollen.model import PollenModel
from app.api.v1.module_bre.seed_lot.model import SeedLotModel

logger = logging.getLogger(__name__)

# 桃育种：杂种实生苗童期通常 3 年进入初选，定植后 3 年仍无选育决策即预警
TREE_UNDECIDED_YEARS = 3
# 种子批库存超过 harvest_year 的年限视为超期，需复检活力/更新
SEED_LOT_MAX_YEARS = 3


def _cutoff_iso(years: int, today: date) -> str:
    """距今 years 年整天的下一日（含当日时间戳单株也命中）。"""
    boundary = datetime(today.year - years, today.month, today.day) + timedelta(days=1)
    return boundary.date().isoformat()


async def _add_open_alert(
    db: AsyncSession,
    alert_type: str,
    entity_type: str,
    entity_id: int,
    message: str,
) -> None:
    """落一条 open 预警（调用方已确认无同实体 open 记录）。"""
    db.add(
        AlertModel(
            alert_type=alert_type,
            entity_type=entity_type,
            entity_id=entity_id,
            message=message,
            status="open",
        )
    )


async def run_overdue_scan() -> bool:
    """每日超期预警扫描：写 bre_alert（open 去重）。返回本轮新增条数。"""
    today = date.today()
    written = 0
    async with async_db_session() as db:
        # ① 树 N 年未决策：定植距今超 N 年且无任何 selection_result 记录
        open_tree = (
            select(AlertModel.id)
            .where(
                AlertModel.alert_type == "tree_undecided",
                AlertModel.entity_type == "bre_tree",
                AlertModel.entity_id == TreeModel.id,
                AlertModel.status == "open",
            )
            .exists()
        )
        trees = (await db.execute(
            select(TreeModel).where(
                TreeModel.planted_date.isnot(None),
                TreeModel.planted_date < _cutoff_iso(TREE_UNDECIDED_YEARS, today),
                ~select(SelectionResultModel.id)
                .where(SelectionResultModel.tree_id == TreeModel.id)
                .exists(),
                ~open_tree,
            )
        )).scalars().all()
        for t in trees:
            await _add_open_alert(
                db,
                "tree_undecided",
                "bre_tree",
                t.id,
                f"单株 {t.tree_no} 定植于 {t.planted_date}，已超 {TREE_UNDECIDED_YEARS} 年无选育决策（selection_result 无记录），请及时评定",
            )
            written += 1

        # ② 花粉批次过期：expiry_date 早于今天
        open_pollen = (
            select(AlertModel.id)
            .where(
                AlertModel.alert_type == "pollen_expiry",
                AlertModel.entity_type == "bre_pollen",
                AlertModel.entity_id == PollenModel.id,
                AlertModel.status == "open",
            )
            .exists()
        )
        pollens = (await db.execute(
            select(PollenModel).where(
                PollenModel.expiry_date.isnot(None),
                PollenModel.expiry_date < today,
                ~open_pollen,
            )
        )).scalars().all()
        for p in pollens:
            await _add_open_alert(
                db,
                "pollen_expiry",
                "bre_pollen",
                p.id,
                f"花粉批次 {p.lot_code} 已于 {p.expiry_date} 失效（贮藏 {p.storage_method}），请复测活力或重新采集",
            )
            written += 1

        # ③ 种子批超期：harvest_year 距今超 N 年（按收获年份）
        open_lot = (
            select(AlertModel.id)
            .where(
                AlertModel.alert_type == "seed_lot_expiry",
                AlertModel.entity_type == "bre_seed_lot",
                AlertModel.entity_id == SeedLotModel.id,
                AlertModel.status == "open",
            )
            .exists()
        )
        lots = (await db.execute(
            select(SeedLotModel).where(
                SeedLotModel.harvest_year.isnot(None),
                SeedLotModel.harvest_year <= today.year - SEED_LOT_MAX_YEARS,
                ~open_lot,
            )
        )).scalars().all()
        for lot in lots:
            age = today.year - (lot.harvest_year or today.year)
            await _add_open_alert(
                db,
                "seed_lot_expiry",
                "bre_seed_lot",
                lot.id,
                f"种子批 {lot.lot_code} 为 {lot.harvest_year} 年收获，已存放 {age} 年，建议复检发芽率/更新库存",
            )
            written += 1

        await db.commit()
    logger.info(f"超期预警扫描完成：新增 {written} 条预警")
    return written