import pytest


async def test_update_product_returns_200(auth_client, product):
    response = await auth_client.patch(f"/api/product/{product.id}", json={"name": "Updated Name"})
    assert response.status_code == 200
    assert response.json()["name"] == "Updated Name"


async def test_update_product_recalculates_calories_when_macros_change(auth_client, product):
    response = await auth_client.patch(f"/api/product/{product.id}", json={"protein": 10.0})
    # protein=10, carb=0, fat=3.6, fiber=0 → 10*4 + 3.6*9 = 40 + 32.4 = 72.4
    assert response.json()["calories"] == pytest.approx(72.4)


async def test_update_product_uses_explicit_calories(auth_client, product):
    response = await auth_client.patch(
        f"/api/product/{product.id}", json={"protein": 10.0, "calories": 99.0}
    )
    assert response.json()["calories"] == 99.0


async def test_update_product_not_found_returns_404(auth_client):
    response = await auth_client.patch("/api/product/99999", json={"name": "Ghost"})
    assert response.status_code == 404


async def test_update_product_duplicate_barcode_returns_409(auth_client, product, product_payload):
    await auth_client.post("/api/product", json={**product_payload, "name": "Other", "barcode": "AAA"})
    response = await auth_client.patch(f"/api/product/{product.id}", json={"barcode": "AAA"})
    assert response.status_code == 409


async def test_update_product_without_auth_returns_401(client, product):
    response = await client.patch(f"/api/product/{product.id}", json={"name": "x"})
    assert response.status_code == 401


async def test_create_product_returns_201(auth_client, product_payload):
    response = await auth_client.post("/api/product", json=product_payload)
    assert response.status_code == 201


async def test_create_product_returns_correct_fields(auth_client, product_payload):
    response = await auth_client.post("/api/product", json=product_payload)
    body = response.json()
    assert body["name"] == product_payload["name"]
    assert body["protein"] == product_payload["protein"]
    assert body["carb"] == product_payload["carb"]
    assert body["fat"] == product_payload["fat"]
    assert body["fiber"] == product_payload["fiber"]
    assert "id" in body


async def test_create_product_calculates_calories(auth_client, product_payload):
    response = await auth_client.post("/api/product", json=product_payload)
    # 31*4 + 0*4 + 3.6*9 + 0*2 = 124 + 32.4 = 156.4
    assert response.json()["calories"] == pytest.approx(156.4)


async def test_create_product_uses_explicit_calories(auth_client, product_payload):
    response = await auth_client.post("/api/product", json={**product_payload, "calories": 50.0})
    assert response.json()["calories"] == 50.0


async def test_create_product_duplicate_barcode_returns_409(auth_client, product_payload):
    await auth_client.post("/api/product", json={**product_payload, "barcode": "123456"})
    response = await auth_client.post("/api/product", json={**product_payload, "barcode": "123456"})
    assert response.status_code == 409


async def test_create_product_invalid_protein_returns_422(auth_client, product_payload):
    response = await auth_client.post("/api/product", json={**product_payload, "protein": -1.0})
    assert response.status_code == 422


async def test_create_product_protein_over_100_returns_422(auth_client, product_payload):
    response = await auth_client.post("/api/product", json={**product_payload, "protein": 101.0})
    assert response.status_code == 422


async def test_create_product_without_auth_returns_401(client, product_payload):
    response = await client.post("/api/product", json=product_payload)
    assert response.status_code == 401


async def test_list_products_returns_200(auth_client, product):
    response = await auth_client.get("/api/product")
    assert response.status_code == 200
    assert isinstance(response.json(), list)


async def test_list_products_contains_created(auth_client, product):
    response = await auth_client.get("/api/product")
    ids = [p["id"] for p in response.json()]
    assert product.id in ids


async def test_list_products_filters_by_name(auth_client, product):
    response = await auth_client.get("/api/product", params={"q": product.name})
    assert all(product.name.lower() in p["name"].lower() for p in response.json())


async def test_list_products_without_auth_returns_401(client):
    response = await client.get("/api/product")
    assert response.status_code == 401