"""biz_work_order 工单仓储：查工单 + 流转条件更新（防并发，不 commit）。"""
from __future__ import annotations

from sqlalchemy import func, select, update

from model.biz_work_order import BizWorkOrder
from repositories.base import BaseRepository


class BizWorkOrderRepo(BaseRepository):
    model = BizWorkOrder

    async def get_by_work_order_no(self, work_order_no: str) -> BizWorkOrder | None:
        return await self.db.scalar(
            select(BizWorkOrder).where(BizWorkOrder.work_order_no == work_order_no)
        )

    async def list_with_filter(
        self,
        *,
        handler_id: int | None = None,
        status: str | None = None,
        customer_id: int | None = None,
        limit: int = 10,
        offset: int = 0,
    ) -> list[BizWorkOrder]:
        stmt = select(BizWorkOrder)
        if handler_id is not None:
            stmt = stmt.where(BizWorkOrder.handler_id == handler_id)
        if status is not None:
            stmt = stmt.where(BizWorkOrder.status == status)
        if customer_id is not None:
            stmt = stmt.where(BizWorkOrder.customer_id == customer_id)
        stmt = stmt.order_by(BizWorkOrder.id.desc()).limit(limit).offset(offset)
        return list((await self.db.scalars(stmt)).all())

    async def count_with_filter(
        self,
        *,
        handler_id: int | None = None,
        status: str | None = None,
        customer_id: int | None = None,
    ) -> int:
        """统计工单筛选结果总数，供分页响应使用。"""
        stmt = select(func.count()).select_from(BizWorkOrder)
        if handler_id is not None:
            stmt = stmt.where(BizWorkOrder.handler_id == handler_id)
        if status is not None:
            stmt = stmt.where(BizWorkOrder.status == status)
        if customer_id is not None:
            stmt = stmt.where(BizWorkOrder.customer_id == customer_id)
        return int((await self.db.scalar(stmt)) or 0)

    async def conditional_transition(
        self, work_order_id: int, *, from_status: str, to_status: str, **fields
    ) -> bool:
        """工单流转：条件更新 WHERE id=? AND status=from_status。

        不 commit，由 service 层事务统一提交；rowcount==0 表示状态已变（并发冲突），
        返回 False 供上层提示，避免跳步流转。
        """
        result = await self.db.execute(
            update(BizWorkOrder)
            .where(
                BizWorkOrder.id == work_order_id,
                BizWorkOrder.status == from_status,
            )
            .values(status=to_status, **fields)
        )
        return result.rowcount > 0