304 lines
11 KiB
Python
304 lines
11 KiB
Python
"""销售业务服务：销售单过账（扣库存 + 生成应收）。
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P0 增强：
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- 自动取价（客户专属价 > 价格等级价 > 最近成交价 > 默认售价）
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- 多单位换算（行可带 source_unit/source_quantity，quantity 恒为基本单位）
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- 最低售价校验（allow_below_min=True 视为审批放行）
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- 抹零（round_to=0.01/0.1/1，向下取整，差额记 round_off）
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- 信用额度校验（confirm 时，超限拒绝或 force 放行并预警）
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"""
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from __future__ import annotations
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from datetime import date
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from decimal import Decimal
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from django.db import transaction
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from apps.inventory import services as inv_services
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from apps.finance import services as fin_services
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from apps.core.services import (
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resolve_line_quantity,
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resolve_line_price,
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check_min_price,
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compute_round_off,
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compute_tax,
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resolve_tax_rate,
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resolve_round_to,
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BelowMinPrice,
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InvalidLinePrice,
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InvalidLineQuantity,
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)
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from .models import SalesOrder, SalesBill, SalesBillLine
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class CreditLimitExceeded(Exception):
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"""客户信用额度不足（force=True 可放行）。"""
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def __init__(self, customer_code: str, outstanding: Decimal, limit: Decimal,
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extra: Decimal):
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self.customer_code = customer_code
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self.outstanding = outstanding
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self.limit = limit
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self.extra = extra
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super().__init__(
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f"credit limit exceeded for {customer_code}: "
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f"outstanding={outstanding} + extra={extra} > limit={limit}"
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)
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def _generate_bill_no(tenant, prefix: str) -> str:
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"""取一个候选单号（真正保证唯一由 create_with_unique_bill_no 的重试负责）。
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保留本函数是为了兼容既有调用（storesfront 的 confirm_order 会用）。
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"""
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Model = SalesOrder if prefix == "SO" else SalesBill
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from apps.core.services import next_bill_no
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return next_bill_no(tenant, prefix, Model)
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def _resolve_line(product, ln, customer=None):
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"""解析销售行：换算 + 取价 + 最低售价校验。
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返回 dict(quantity, source_unit, source_quantity, unit_price, amount)。
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"""
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parsed = resolve_line_quantity(product, ln)
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qty = parsed["quantity"]
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src_unit = parsed["source_unit"]
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src_qty = parsed["source_quantity"]
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rate = None
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if src_unit is not None:
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from apps.catalog.models import UnitConversion
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conv = UnitConversion.objects.filter(product=product, unit=src_unit).first()
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rate = conv.rate if conv else None
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# 取价：显式传入优先；否则按基本单位报价 × 换算率
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if ln.get("unit_price") in (None, ""):
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if customer is None:
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base_price = product.sale_price
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source = "default"
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else:
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from apps.partner.services import quote_price
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q = quote_price(tenant=product.tenant, customer=customer, product=product)
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base_price = q["price"]
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source = q["source"]
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price = resolve_line_price(product, ln, base_price=base_price, rate=rate)
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else:
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price = resolve_line_price(product, ln)
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check_min_price(
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product, unit_price=price, rate=rate,
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allow_below_min=bool(ln.get("allow_below_min")),
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)
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if src_unit is not None:
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amount = src_qty * price
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else:
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amount = qty * price
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# 税率（D4）：价内口径——price/amount 视为含税，税额从行金额中拆分
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tax_rate = resolve_tax_rate(product, ln)
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tax = compute_tax(amount, tax_rate)
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return {
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"quantity": qty,
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"source_unit": src_unit,
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"source_quantity": src_qty,
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"unit_price": price,
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"amount": amount,
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"tax_rate": tax_rate,
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"tax_amount": tax["tax"],
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}
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@transaction.atomic
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def create_sales_bill(
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*, tenant, customer, warehouse, bill_date=None, remark="", lines=None,
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order=None, round_to=None,
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) -> SalesBill:
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"""新建一张销售单（草稿态）。
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lines: list of dict(product, quantity[, unit_price][, source_unit][, allow_below_min])
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round_to: 抹零精度（"1"元 / "0.1"角 / "0.01"分；None=不抹零）
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"""
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bill_date = bill_date or date.today()
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# 抹零精度白名单校验（非法值此前会被当成任意精度参与计算）
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round_to = resolve_round_to(round_to)
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lines_total = Decimal("0")
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resolved = []
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for ln in lines or []:
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product = ln["product"]
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parsed = _resolve_line(product, ln, customer=customer)
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resolved.append((product, parsed, ln))
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lines_total += parsed["amount"]
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# 单据必须有实际金额：防止"0.0001 元单据"这类无效数据落库
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if lines_total <= 0:
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raise ValueError(
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f"销售单金额必须大于 0（行合计 {lines_total}）；请检查数量与单价"
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)
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round_off = compute_round_off(lines_total, round_to) if round_to else Decimal("0")
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if round_off > 0:
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# 抹零额不得超过一个精度单位（防御）
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if round_off > Decimal(str(round_to)):
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raise ValueError("round_off exceeds round_to precision")
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remark = (remark + "\n" if remark else "") + f"抹零 {round_off} 元"
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# 并发安全建单：单号冲突时自动换号重试（count()+1 在并发下会撞车）
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from apps.core.services import create_with_unique_bill_no
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bill = create_with_unique_bill_no(
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SalesBill,
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tenant=tenant,
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prefix="XS",
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defaults=dict(
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customer=customer,
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warehouse=warehouse,
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order=order,
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bill_date=bill_date,
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total_amount=lines_total - round_off,
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round_off=round_off,
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state="draft",
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remark=remark,
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),
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)
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for product, parsed, ln in resolved:
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SalesBillLine.objects.create(
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tenant=tenant,
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bill=bill,
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product=product,
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quantity=parsed["quantity"],
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unit_price=parsed["unit_price"],
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amount=parsed["amount"],
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source_unit=parsed["source_unit"],
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source_quantity=parsed["source_quantity"],
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tax_rate=parsed["tax_rate"],
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tax_amount=parsed["tax_amount"],
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)
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return bill
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@transaction.atomic
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def confirm_sales_bill(bill: SalesBill, *, user=None, force: bool = False) -> SalesBill:
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"""销售单过账：信用额度校验 + 扣库存（批次 FEFO）+ 生成应收单 + 结转成本凭证。
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库存不足抛 InsufficientStock；信用超限抛 CreditLimitExceeded（force=True 放行）。
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"""
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if bill.state != "draft":
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raise ValueError(f"sales bill {bill.bill_no} not in draft state")
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# 0. 信用额度校验
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_enforce_credit_limit(bill, force=force)
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# 1. 扣库存并累加出库成本
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total_cost = Decimal("0")
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for line in bill.lines.select_related("product").all():
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res = inv_services.outbound(
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tenant=bill.tenant,
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warehouse=bill.warehouse,
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product=line.product,
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quantity=line.quantity,
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source_type="sale",
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source_ref=bill.bill_no,
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)
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total_cost += line.quantity * res.movement.unit_cost
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# 2. 生成应收（若财务已就绪，自动生成收入凭证）
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# 税额合计从行上取（D4）：行税率为 0 时合计为 0，凭证保持原两分录
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from django.db.models import Sum as _Sum
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tax_total = bill.lines.aggregate(t=_Sum("tax_amount"))["t"] or Decimal("0")
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fin_services.create_receivable_from_sale(
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tenant=bill.tenant,
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customer=bill.customer,
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total_amount=bill.total_amount,
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source_ref=bill.bill_no,
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bill_date=bill.bill_date,
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tax_amount=tax_total,
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)
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# 3. 结转销售成本凭证（借：主营业务成本 贷：库存商品）
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if total_cost > 0:
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try:
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fin_services.voucher_for_sale_cogs(
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tenant=bill.tenant,
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sales_bill_no=bill.bill_no,
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bill_date=bill.bill_date,
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cost_amount=total_cost,
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auto_post=True,
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)
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except Exception:
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pass
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# 4. 改状态
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bill.state = "confirmed"
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bill.save(update_fields=["state", "updated_at"])
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# 审计：过账是有后果的关键操作，必须留痕
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from apps.core import audit as audit_log
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audit_log.log_bill_posted(
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tenant=bill.tenant, bill=bill, user=user,
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extra={"lines": bill.lines.count()},
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)
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return bill
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def _enforce_credit_limit(bill: SalesBill, *, force: bool) -> None:
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"""信用额度校验：outstanding + 本单 > limit 时拒绝（force 放行并发预警）。"""
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from apps.partner.services import credit_usage
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from apps.notify.services import send_notification
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usage = credit_usage(tenant=bill.tenant, customer=bill.customer)
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if usage["limit"] <= 0:
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return # 0 = 不启用额度管控
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after = usage["outstanding"] + bill.total_amount
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if after <= usage["limit"]:
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# 接近上限（≥90%）预警
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if usage["limit"] > 0 and after >= usage["limit"] * Decimal("0.9"):
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send_notification(
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tenant=bill.tenant,
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title=f"【信用预警】客户 {bill.customer.name} 信用额度即将用尽",
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content=(
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f"销售单 {bill.bill_no} 过账后额度占用 "
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f"{after}/{usage['limit']}，占用率 "
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f"{(after / usage['limit'] * 100):.1f}%，请关注回款。"
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),
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category="warning",
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link="/finance/receivables/",
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extra_data={"customer_id": bill.customer_id, "bill_no": bill.bill_no},
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)
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return
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if not force:
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raise CreditLimitExceeded(
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bill.customer.code, usage["outstanding"], usage["limit"], bill.total_amount
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)
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# 审计：越过管控是高风险动作，必须留痕（谁批的、超了多少）
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from apps.core import audit as audit_log
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audit_log.log_force_release(
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tenant=bill.tenant,
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kind="credit_limit",
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target=bill.bill_no,
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detail={
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# bill_no 必须出现在 detail 里：轨迹查询要按它把
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# "同一单据的所有动作"（过账 + 放行）串成一条时间线
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"bill_no": bill.bill_no,
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"customer_code": bill.customer.code,
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"outstanding": str(usage["outstanding"]),
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"limit": str(usage["limit"]),
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"bill_amount": str(bill.total_amount),
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},
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)
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send_notification(
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tenant=bill.tenant,
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title=f"【信用超限】客户 {bill.customer.name} 赊销超出信用额度（已放行）",
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content=(
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f"销售单 {bill.bill_no} 金额 {bill.total_amount}，过账后占用 "
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f"{after}/{usage['limit']}，已由审批放行，请尽快跟进回款。"
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),
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category="warning",
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link="/finance/receivables/",
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extra_data={"customer_id": bill.customer_id, "bill_no": bill.bill_no,
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"forced": True},
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)
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