from decimal import Decimal

import pytest
from django.urls import reverse
from django.utils import timezone
from rest_framework import status

from commerce.models import Cost, Product, Sale, SaleLine, SourceSystem, StockSnapshot

pytestmark = pytest.mark.django_db


def test_commerce_api_requires_authentication(api_client):
    response = api_client.get(reverse("api:v1:commerce:product-list"))
    assert response.status_code == status.HTTP_401_UNAUTHORIZED


def test_employee_can_read_but_cannot_create_product(api_client, user_factory):
    user = user_factory()
    Product.objects.create(sku="FISHKA", name="Фишка")
    api_client.force_authenticate(user=user)

    list_response = api_client.get(reverse("api:v1:commerce:product-list"))
    create_response = api_client.post(
        reverse("api:v1:commerce:product-list"),
        {"sku": "NEW", "name": "Новый товар", "kind": "product"},
        format="json",
    )

    assert list_response.status_code == status.HTTP_200_OK
    assert list_response.data["count"] == 1
    assert create_response.status_code == status.HTTP_403_FORBIDDEN


def test_staff_can_create_product(api_client, user_factory):
    user = user_factory(staff=True)
    api_client.force_authenticate(user=user)

    response = api_client.post(
        reverse("api:v1:commerce:product-list"),
        {"sku": "NEW", "name": "Новый товар", "kind": "product"},
        format="json",
    )

    assert response.status_code == status.HTTP_201_CREATED
    assert Product.objects.filter(sku="NEW").exists()


def test_staff_can_manage_normalized_commerce_facts(api_client, user_factory):
    user = user_factory(staff=True)
    source = SourceSystem.objects.create(code="moysklad", name="МойСклад")
    product = Product.objects.create(sku="FISHKA", name="Фишка")
    api_client.force_authenticate(user=user)

    sale_response = api_client.post(
        reverse("api:v1:commerce:sale-list"),
        {
            "source": source.pk,
            "external_id": "order-1",
            "occurred_at": timezone.now().isoformat(),
        },
        format="json",
    )
    assert sale_response.status_code == status.HTTP_201_CREATED

    line_response = api_client.post(
        reverse("api:v1:commerce:saleline-list"),
        {
            "sale": sale_response.data["id"],
            "product": product.pk,
            "external_id": "line-1",
            "quantity": "2",
            "gross_amount": "500.00",
            "discount_amount": "50.00",
            "cost_amount": "200.00",
        },
        format="json",
    )
    assert line_response.status_code == status.HTTP_201_CREATED

    cost_response = api_client.post(
        reverse("api:v1:commerce:cost-list"),
        {
            "source": source.pk,
            "product": product.pk,
            "cost_type": "commission",
            "amount": "25.00",
            "occurred_at": timezone.now().isoformat(),
        },
        format="json",
    )
    assert cost_response.status_code == status.HTTP_201_CREATED, cost_response.data

    stock_response = api_client.post(
        reverse("api:v1:commerce:stocksnapshot-list"),
        {
            "source": source.pk,
            "product": product.pk,
            "warehouse_external_id": "main",
            "quantity": "10",
            "reserved": "2",
            "captured_at": timezone.now().isoformat(),
        },
        format="json",
    )
    assert stock_response.status_code == status.HTTP_201_CREATED
    assert SaleLine.objects.filter(pk=line_response.data["id"]).exists()
    assert Cost.objects.filter(pk=cost_response.data["id"]).exists()
    assert StockSnapshot.objects.filter(pk=stock_response.data["id"]).exists()


def test_product_analytics_endpoint(api_client, user_factory):
    user = user_factory()
    source = SourceSystem.objects.create(code="insales", name="InSales")
    product = Product.objects.create(sku="FISHKA", name="Фишка")
    sale = Sale.objects.create(
        source=source,
        external_id="order-1",
        occurred_at=timezone.now(),
        channel="site",
    )
    SaleLine.objects.create(
        sale=sale,
        product=product,
        external_id="line-1",
        quantity=Decimal("1"),
        gross_amount=Decimal("500"),
        cost_amount=Decimal("200"),
    )
    api_client.force_authenticate(user=user)

    response = api_client.get(
        reverse("api:v1:commerce:product-analytics", args=[product.pk])
    )

    assert response.status_code == status.HTTP_200_OK
    assert response.data["product_id"] == product.pk
    assert response.data["monetary"][0]["net_revenue"] == Decimal("500")
    assert response.data["monetary"][0]["contribution_margin"] == Decimal("300")