"""purchase 集成测试：进货单过账 → 写库存 + 生成应付。"""

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.models import Stock, StockMovement
from apps.finance.models import Payable
from apps.purchase import services
from apps.purchase.models import PurchaseBill


@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 supplier(tenant):
    from apps.partner.models import Supplier
    return baker.make(Supplier, tenant=tenant, code="S001", name="供应商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_purchase_bill_calculates_total(tenant, supplier, warehouse, product):
    bill = services.create_purchase_bill(
        tenant=tenant, supplier=supplier, warehouse=warehouse,
        lines=[
            {"product": product, "quantity": Decimal("10"), "unit_price": Decimal("5")},
            {"product": product, "quantity": Decimal("3"), "unit_price": Decimal("5")},
        ],
    )
    assert bill.total_amount == Decimal("65")
    assert bill.state == "draft"
    assert bill.lines.count() == 2


@pytest.mark.django_db
def test_confirm_purchase_bill_writes_stock_and_payable(tenant, supplier, warehouse, product):
    bill = services.create_purchase_bill(
        tenant=tenant, supplier=supplier, warehouse=warehouse,
        lines=[
            {"product": product, "quantity": Decimal("20"), "unit_price": Decimal("8")},
        ],
    )
    services.confirm_purchase_bill(bill)

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

    # 流水
    movements = StockMovement.objects.filter(tenant=tenant)
    assert movements.count() == 1
    assert movements.first().source_type == "purchase"

    # 应付
    payable = Payable.objects.get(tenant=tenant, source_ref=bill.bill_no)
    assert payable.total_amount == Decimal("160")
    assert payable.status == "open"

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


@pytest.mark.django_db
def test_confirm_twice_raises(tenant, supplier, warehouse, product):
    bill = services.create_purchase_bill(
        tenant=tenant, supplier=supplier, warehouse=warehouse,
        lines=[{"product": product, "quantity": Decimal("5"), "unit_price": Decimal("10")}],
    )
    services.confirm_purchase_bill(bill)
    with pytest.raises(ValueError):
        services.confirm_purchase_bill(bill)


# --- API 集成测试 ---


@pytest.mark.django_db
def test_api_list_purchase_bills(auth_client, tenant, supplier, warehouse, product):
    baker.make(
        PurchaseBill, tenant=tenant, supplier=supplier, warehouse=warehouse,
        bill_no="PB0001", total_amount=Decimal("100"),
    )
    resp = auth_client.get("/api/v1/purchase/bills/")
    assert resp.status_code == 200
    assert resp.json()["count"] == 1


@pytest.mark.django_db
def test_api_list_purchase_orders(auth_client, tenant, supplier, warehouse):
    from apps.purchase.models import PurchaseOrder
    baker.make(
        PurchaseOrder, tenant=tenant, supplier=supplier, warehouse=warehouse,
        bill_no="PO0001", total_amount=Decimal("0"),
    )
    resp = auth_client.get("/api/v1/purchase/orders/")
    assert resp.status_code == 200
    assert resp.json()["count"] == 1