import json
from decimal import Decimal
from pathlib import Path

import pytest

from opengoods.etl.transform import (
    is_valid_gtin,
    map_category,
    parse_quantity,
    transform,
    transform_nutriments,
)

FIXTURE = json.loads((Path(__file__).parent / "fixtures" / "off_product.json").read_text())


def test_is_valid_gtin():
    assert is_valid_gtin("3017624010701")  # real EAN-13
    assert is_valid_gtin("5449000000996")  # Coca-Cola
    assert not is_valid_gtin("3017624010700")  # bad check digit
    assert not is_valid_gtin("123")
    assert not is_valid_gtin("notanumber")


def test_parse_quantity():
    assert parse_quantity("400 g") == (Decimal("400"), "g")
    assert parse_quantity("1,5 L") == (Decimal("1.5"), "L")
    assert parse_quantity("") is None
    assert parse_quantity("family size") is None


def test_map_category():
    assert map_category({"product_name": "Spring Water"}) == "food.beverages.water"
    assert map_category({"categories": "Dark chocolate"}) == "food.snacks.chocolate"
    assert map_category({"product_name": "Mystery"}) is None


def test_transform_nutriments_dual_energy():
    out = transform_nutriments(FIXTURE["nutriments"])
    assert out["energy_kj"] == 2252.0
    assert out["energy_kcal"] == 539.0
    assert out["fat"] == 30.9
    assert out["salt"] == 0.107


def test_transform_nutriments_fills_missing_energy():
    out = transform_nutriments({"energy-kcal_100g": 100})
    assert out["energy_kj"] == pytest.approx(418.4)


def test_transform_full_record():
    rec = transform(FIXTURE)
    assert rec is not None
    assert rec["gtin"] == "3017624010701"
    assert rec["name"] == "Nutella"
    assert rec["brand"] == "Ferrero"
    assert rec["net_content_unit"] == "g"
    assert rec["net_content_canonical"] == Decimal("400")
    assert rec["country_of_origin"] == "France"
    assert rec["food"]["nutri_score"] == "E"
    assert "milk" in rec["food"]["allergens"]
    assert rec["image_url"].endswith(".jpg")


def test_transform_drops_unnamed():
    assert transform({"code": "0000000000000"}) is None