"""端到端冒烟测试：完整业务链。

链：建商品 → 建仓库 → 建客户/供应商 → 进货单过账（写库存 + 生成应付）
   → 付款单核销 → 销售单过账（扣库存 + 生成应收）→ 收款单核销
   → 最终库存/应付/应收 余额一致
"""

import pytest
from datetime import date
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 import services as fin_services
from apps.finance.models import Receivable, Payable, Receipt, Payment
from apps.purchase import services as purchase_services
from apps.sales import services as sales_services
from apps.purchase.models import PurchaseBill
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 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")


@pytest.fixture
def supplier(tenant):
    from apps.partner.models import Supplier
    return baker.make(Supplier, tenant=tenant, code="S001", name="供应商A")


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


@pytest.mark.django_db
def test_full_business_loop(tenant, warehouse, product, supplier, customer):
    # === 1. 进货：向供应商进 20 件，单价 8 元 ===
    pb = purchase_services.create_purchase_bill(
        tenant=tenant, supplier=supplier, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("20"), "unit_price": Decimal("8")}],
    )
    purchase_services.confirm_purchase_bill(pb)

    # 库存应有 20 件，avg_cost = 8
    stock = Stock.objects.get(tenant=tenant, warehouse=warehouse, product=product)
    assert stock.on_hand == Decimal("20")
    assert stock.avg_cost == Decimal("8")

    # 应付单 20*8 = 160
    payable = Payable.objects.get(tenant=tenant, source_ref=pb.bill_no)
    assert payable.total_amount == Decimal("160")
    assert payable.status == "open"

    # === 2. 付供应商 100 元（部分付款）===
    payment = baker.make(
        Payment, tenant=tenant, supplier=supplier,
        bill_no="PMT-001", bill_date=date.today(),
        amount=Decimal("100"),
    )
    fin_services.allocate_payment(payment, [(payable, Decimal("100"))])

    payable.refresh_from_db()
    payment.refresh_from_db()
    assert payable.paid_amount == Decimal("100")
    assert payable.status == "partial"

    # === 3. 销售：卖给客户 7 件，单价 12 元 ===
    sb = sales_services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("7"), "unit_price": Decimal("12")}],
    )
    sales_services.confirm_sales_bill(sb)

    # 库存减到 13
    stock.refresh_from_db()
    assert stock.on_hand == Decimal("13")

    # 应收 7*12 = 84
    recv = Receivable.objects.get(tenant=tenant, source_ref=sb.bill_no)
    assert recv.total_amount == Decimal("84")
    assert recv.status == "open"

    # === 4. 收客户 84 元（一次结清）===
    receipt = baker.make(
        Receipt, tenant=tenant, customer=customer,
        bill_no="RCT-001", bill_date=date.today(),
        amount=Decimal("84"),
    )
    fin_services.allocate_receipt(receipt, [(recv, Decimal("84"))])

    recv.refresh_from_db()
    receipt.refresh_from_db()
    assert recv.status == "paid"
    assert receipt.status == "posted"

    # === 5. 再付供应商 60 元（结清）===
    payment2 = baker.make(
        Payment, tenant=tenant, supplier=supplier,
        bill_no="PMT-002", bill_date=date.today(),
        amount=Decimal("60"),
    )
    fin_services.allocate_payment(payment2, [(payable, Decimal("60"))])
    payable.refresh_from_db()
    assert payable.status == "paid"

    # === 6. 收尾 ===
    # 最终库存 13
    stock.refresh_from_db()
    assert stock.on_hand == Decimal("13")

    # 应收已结清
    assert Receivable.objects.filter(tenant=tenant, status="open").count() == 0
    # 应付已结清
    assert Payable.objects.filter(tenant=tenant, status="open").count() == 0


@pytest.mark.django_db
def test_two_sales_cannot_overdraw_stock(tenant, warehouse, product, customer):
    inv_services.inbound(
        tenant=tenant, warehouse=warehouse, product=product,
        quantity=Decimal("5"),
    )
    sb1 = sales_services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("4"), "unit_price": Decimal("10")}],
    )
    sales_services.confirm_sales_bill(sb1)

    # 库存剩 1，再卖 2 失败
    sb2 = sales_services.create_sales_bill(
        tenant=tenant, customer=customer, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("2"), "unit_price": Decimal("10")}],
    )
    from apps.inventory.services import InsufficientStock
    with pytest.raises(InsufficientStock):
        sales_services.confirm_sales_bill(sb2)

    # 事务回滚：库存仍 1，sb2 仍 draft
    stock = Stock.objects.get(tenant=tenant, warehouse=warehouse, product=product)
    assert stock.on_hand == Decimal("1")
    sb2.refresh_from_db()
    assert sb2.state == "draft"


@pytest.mark.django_db
def test_api_ping_works_through_asgi():
    from rest_framework.test import APIClient
    c = APIClient()
    r = c.get("/api/v1/ping/")
    assert r.status_code == 200
    assert r.json()["ok"] is True