from decimal import Decimal

import pytest
from django.core.exceptions import ImproperlyConfigured

from finance.payroll.access import has_payroll_permission, has_simple_admin_access
from finance.payroll.config import build_rules, simple_admin_access_enabled
from payroll_core import PointPolicy, RoundingPolicy


@pytest.mark.parametrize(
    ("configured_value", "expected"),
    [
        ("half_up", RoundingPolicy.HALF_UP),
        ("ROUND_HALF_UP", RoundingPolicy.HALF_UP),
        ("half_even", RoundingPolicy.HALF_EVEN),
        ("down", RoundingPolicy.DOWN),
    ],
)
def test_rounding_accepts_environment_and_canonical_names(
    settings,
    configured_value,
    expected,
):
    settings.FINANCE_PAYROLL = {
        "ROUNDING": configured_value,
        "POINT_POLICY": PointPolicy.DISABLED.value,
    }

    assert build_rules().rounding is expected


def test_payroll_adapter_is_safe_by_default(settings):
    settings.FINANCE_PAYROLL = {}

    rules = build_rules()

    assert rules.point_policy is PointPolicy.PROPORTIONAL_WITH_EXCESS
    assert rules.money_quantum == Decimal("0.01")
    assert rules.allow_negative_payable is True


def test_simple_admin_access_defaults_to_enabled_and_accepts_boolean_strings(settings):
    settings.FINANCE_PAYROLL = {}
    assert simple_admin_access_enabled() is True

    settings.FINANCE_PAYROLL = {"SIMPLE_ADMIN_ACCESS": "false"}
    assert simple_admin_access_enabled() is False


@pytest.mark.django_db
def test_simple_admin_access_grants_staff_operational_permissions(
    settings,
    user_factory,
):
    settings.FINANCE_PAYROLL = {"SIMPLE_ADMIN_ACCESS": True}
    administrator = user_factory(email="payroll.admin.access@example.test", staff=True)
    regular_user = user_factory(email="payroll.regular.access@example.test")

    assert has_simple_admin_access(administrator) is True
    assert (
        has_payroll_permission(
            administrator,
            "finance.publish_payroll",
        )
        is True
    )
    assert has_simple_admin_access(regular_user) is False
    assert (
        has_payroll_permission(
            regular_user,
            "finance.publish_payroll",
        )
        is False
    )

    settings.FINANCE_PAYROLL = {"SIMPLE_ADMIN_ACCESS": False}
    assert has_simple_admin_access(administrator) is False
    assert (
        has_payroll_permission(
            administrator,
            "finance.publish_payroll",
        )
        is False
    )


def test_config_accepts_enum_values(settings):
    settings.FINANCE_PAYROLL = {
        "POINT_POLICY": PointPolicy.DISABLED,
        "ROUNDING": RoundingPolicy.HALF_UP,
    }

    rules = build_rules()

    assert rules.point_policy is PointPolicy.DISABLED
    assert rules.rounding is RoundingPolicy.HALF_UP


@pytest.mark.parametrize(
    "override",
    [
        {"MONEY_QUANTUM": "0.001"},
        {"ROUNDING": "bankers-ish"},
        {"POINT_POLICY": "invented"},
    ],
)
def test_adapter_rejects_rules_that_cannot_be_persisted(settings, override):
    settings.FINANCE_PAYROLL = override

    with pytest.raises(ImproperlyConfigured):
        build_rules()