"""sales 集成测试：销售单过账 → 扣库存 + 生成应收。"""

import pytest
from decimal import Decimal
from model_bakery import baker
from rest_framework.test import APIClient
from rest_framework_simplejwt.tokens import RefreshToken

from apps.inventory import services as inv_services
from apps.inventory.models import Stock
from apps.finance.models import Receivable
from apps.sales import services
from apps.sales.models import SalesBill


@pytest.fixture
def auth_client(db, user, tenant):
    c = APIClient()
    refresh = RefreshToken.for_user(user)
    c.credentials(
        HTTP_AUTHORIZATION=f"Bearer {refresh.access_token}",
        HTTP_X_TENANT_ID=tenant.code,
    )
    return c


@pytest.fixture
def customer(tenant):
    from apps.partner.models import Customer
    return baker.make(Customer, tenant=tenant, code="C001", name="客户A")


@pytest.fixture
def warehouse(tenant):
    from apps.inventory.models import Warehouse
    return baker.make(Warehouse, tenant=tenant, code="WH01", name="主仓")


@pytest.fixture
def product(tenant):
    from apps.catalog.models import Product
    return baker.make(Product, tenant=tenant, code="P001", name="商品A")


# --- services 单元测试 ---


@pytest.mark.django_db
def test_create_sales_bill_calculates_total(tenant, customer, warehouse, product):
    bill = services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[
            {"product": product, "quantity": Decimal("5"), "unit_price": Decimal("12")},
            {"product": product, "quantity": Decimal("3"), "unit_price": Decimal("12")},
        ],
    )
    assert bill.total_amount == Decimal("96")
    assert bill.state == "draft"
    assert bill.lines.count() == 2


@pytest.mark.django_db
def test_confirm_sales_bill_deducts_stock_and_creates_receivable(
    tenant, customer, warehouse, product
):
    # 准备库存 20
    inv_services.inbound(
        tenant=tenant, warehouse=warehouse, product=product,
        quantity=Decimal("20"), unit_cost=Decimal("8"),
    )
    # 销售 7
    bill = services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("7"), "unit_price": Decimal("12")}],
    )
    services.confirm_sales_bill(bill)

    # 库存
    stock = Stock.objects.get(tenant=tenant, warehouse=warehouse, product=product)
    assert stock.on_hand == Decimal("13")

    # 应收
    recv = Receivable.objects.get(tenant=tenant, source_ref=bill.bill_no)
    assert recv.total_amount == Decimal("84")
    assert recv.status == "open"

    # 单据状态
    bill.refresh_from_db()
    assert bill.state == "confirmed"


@pytest.mark.django_db
def test_confirm_insufficient_stock_rolls_back(tenant, customer, warehouse, product):
    inv_services.inbound(
        tenant=tenant, warehouse=warehouse, product=product,
        quantity=Decimal("5"),
    )
    bill = services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("10"), "unit_price": Decimal("12")}],
    )
    with pytest.raises(inv_services.InsufficientStock):
        services.confirm_sales_bill(bill)

    # 库存不变（事务回滚）
    stock = Stock.objects.get(tenant=tenant, warehouse=warehouse, product=product)
    assert stock.on_hand == Decimal("5")

    # 应收不生成
    assert Receivable.objects.filter(tenant=tenant, source_ref=bill.bill_no).count() == 0

    # 单据仍是 draft
    bill.refresh_from_db()
    assert bill.state == "draft"


@pytest.mark.django_db
def test_confirm_twice_raises(tenant, customer, warehouse, product):
    inv_services.inbound(
        tenant=tenant, warehouse=warehouse, product=product,
        quantity=Decimal("10"),
    )
    bill = services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("3"), "unit_price": Decimal("10")}],
    )
    services.confirm_sales_bill(bill)
    with pytest.raises(ValueError):
        services.confirm_sales_bill(bill)


# --- API 集成测试 ---


@pytest.mark.django_db
def test_api_list_sales_bills(auth_client, tenant, customer, warehouse):
    baker.make(
        SalesBill, tenant=tenant, customer=customer, warehouse=warehouse,
        bill_no="XS0001", total_amount=Decimal("100"),
    )
    resp = auth_client.get("/api/v1/sales/bills/")
    assert resp.status_code == 200
    assert resp.json()["count"] == 1


@pytest.mark.django_db
def test_api_list_sales_orders(auth_client, tenant, customer, warehouse):
    from apps.sales.models import SalesOrder
    baker.make(
        SalesOrder, tenant=tenant, customer=customer, warehouse=warehouse,
        bill_no="SO0001", total_amount=Decimal("0"),
    )
    resp = auth_client.get("/api/v1/sales/orders/")
    assert resp.status_code == 200
    assert resp.json()["count"] == 1