"""Example unit tests for the nutrition service (spec §8.4: test the math)."""

from models import Food
from services import nutrition


def make_food(**overrides) -> Food:
    """In-memory Food (no DB needed for pure math tests)."""
    defaults = dict(
        id=1,
        name="Test Food",
        brand=None,
        barcode=None,
        source="manual",
        is_meal=False,
        unit_type="weight",
        calories_per_unit=250.0,
        protein_per_unit=None,
        carbs_per_unit=None,
        fat_per_unit=None,
        fiber_per_unit=None,
        saturated_fat_per_unit=None,
        sugars_per_unit=None,
        sodium_per_unit=None,
        serving_size_g=None,
        serving_name=None,
        off_data=None,
        deleted_at=None,
    )
    defaults.update(overrides)
    return Food(**defaults)


def test_weight_type_scales_per_100g():
    food = make_food(unit_type="weight", calories_per_unit=250.0)
    assert nutrition.entry_calories(food, 200.0) == 500.0


def test_count_type_scales_per_item():
    food = make_food(unit_type="count", calories_per_unit=80.0)
    assert nutrition.entry_calories(food, 3.0) == 240.0


def test_missing_nutrition_counts_as_zero():
    food = make_food(calories_per_unit=None)
    assert nutrition.entry_calories(food, 100.0) == 0.0