"""地磅模块 — CRM 产品解析与快照写入。"""
from __future__ import annotations

from dataclasses import dataclass

from fastapi import HTTPException, status
from sqlalchemy.orm import Session

from app.crud.crm.product import get_product


@dataclass(frozen=True)
class ProductSnapshot:
    product_id: str
    product_name: str
    specification: str | None


def resolve_crm_product(
    db: Session,
    tenant_no: str,
    product_id: str,
    *,
    require_on_shelf: bool = True,
) -> ProductSnapshot:
    """校验 CRM 产品并返回名称/规格快照。新建单据 product_id 必填。

    require_on_shelf=False 用于运输计划联动地磅等历史单据场景：
    合同/计划中的产品可能已下架，但仍允许按主数据快照继续业务。
    """
    pid = (product_id or "").strip()
    if not pid:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="请选择 CRM 产品",
        )

    row = get_product(db, pid)
    if row is None or row.tenant_no != tenant_no:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="产品不存在或不可用",
        )
    if require_on_shelf and row.status != "on":
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="产品已下架，请重新选择",
        )

    name = (row.product_name or "").strip()
    if not name:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="产品名称无效",
        )

    model = (row.model or "").strip() or None
    return ProductSnapshot(product_id=row.id, product_name=name, specification=model)


def apply_product_snapshot_to_plan(plan, snapshot: ProductSnapshot) -> None:
    plan.product_id = snapshot.product_id
    plan.product = snapshot.product_name
    plan.specification = snapshot.specification


def apply_product_snapshot_to_inventory(row, snapshot: ProductSnapshot) -> None:
    row.product_id = snapshot.product_id
    row.product = snapshot.product_name
    row.specification = snapshot.specification


def apply_product_snapshot_to_weighing(row, snapshot: ProductSnapshot) -> None:
    row.product_id = snapshot.product_id
    row.cargo_name = snapshot.product_name
    row.specification = snapshot.specification