"""Tests for the 18+ age gate on user registration."""

from datetime import date, timedelta

import pytest

from app.routers.auth import calculate_age


class TestCalculateAge:
    """Unit tests for the calculate_age helper."""

    def test_exactly_18(self):
        """A person born exactly 18 years ago today is 18."""
        today = date(2025, 6, 15)
        dob = today.replace(year=today.year - 18)
        assert calculate_age(dob, today=today) == 18

    def test_just_turned_18(self):
        """A person who turned 18 yesterday is 18."""
        today = date(2025, 6, 15)
        dob = today.replace(year=today.year - 18) - timedelta(days=1)
        assert calculate_age(dob, today=today) == 18

    def test_one_day_short_of_18(self):
        """A person born one day after their 18th birthday is 17."""
        today = date(2025, 6, 15)
        dob = today.replace(year=today.year - 18) + timedelta(days=1)
        assert calculate_age(dob, today=today) == 17

    def test_17_years_old(self):
        """A person who is 17 years old today is 17."""
        today = date(2025, 6, 15)
        dob = date(2008, 6, 15)
        assert calculate_age(dob, today=today) == 17

    def test_65_years_old(self):
        """A person who is 65 is correctly calculated."""
        today = date(2025, 6, 15)
        dob = today.replace(year=today.year - 65)
        assert calculate_age(dob, today=today) == 65

    def test_newborn(self):
        """A newborn is 0."""
        today = date(2025, 6, 15)
        dob = today
        assert calculate_age(dob, today=today) == 0

    def test_birthday_not_yet_this_year(self):
        """Person born Dec 31, 2000 — on Jan 1, 2025 they are still 24."""
        dob = date(2000, 12, 31)
        assert calculate_age(dob, today=date(2025, 1, 1)) == 24

    def test_birthday_today(self):
        """Person born Dec 31, 2000 — on Dec 31, 2024 they turn 24."""
        dob = date(2000, 12, 31)
        assert calculate_age(dob, today=date(2024, 12, 31)) == 24


class TestRegisterRequestOver18Field:
    """Tests for RegisterRequest's over_18 field.

    Replaces TestRegisterRequestDateValidation -- date_of_birth and its
    field_validator were removed from RegisterRequest 2026-08-20 (interim
    simplification: a plain client-side over_18 confirmation instead of
    collecting/validating an actual date of birth; see calculate_age's
    own docstring in app/routers/auth.py for why that function is still
    here even though this endpoint no longer calls it). There's no date
    format left to validate, so the equivalent coverage is just: the
    field exists, is a real bool, and is required."""

    def test_over_18_true_accepted(self):
        from app.routers.auth import RegisterRequest

        req = RegisterRequest(username="u", email="u@example.com", password="p", over_18=True)
        assert req.over_18 is True

    def test_over_18_false_accepted(self):
        """False is a valid value at the schema level -- the endpoint,
        not the schema, is what rejects it (see
        TestRegister::test_register_rejects_not_over_18 in
        test_auth_endpoints.py)."""
        from app.routers.auth import RegisterRequest

        req = RegisterRequest(username="u", email="u@example.com", password="p", over_18=False)
        assert req.over_18 is False

    def test_over_18_missing_rejected(self):
        """over_18 has no default -- omitting it entirely is a validation error."""
        from app.routers.auth import RegisterRequest
        from pydantic import ValidationError

        with pytest.raises(ValidationError):
            RegisterRequest(username="u", email="u@example.com", password="p")