from datetime import date

from odoo.tests.common import TransactionCase
from odoo.tests import tagged
from odoo.addons.fusion_accounting_assets.services.prorate import prorate_factor


@tagged('post_install', '-at_install')
class TestProrate(TransactionCase):

    def test_full_month_convention_always_one(self):
        f = prorate_factor(
            period_start=date(2026, 1, 1),
            period_end=date(2026, 1, 31),
            asset_start=date(2026, 1, 15),
            convention='full_month',
        )
        self.assertEqual(f, 1.0)

    def test_asset_starts_before_period_full_factor(self):
        f = prorate_factor(
            period_start=date(2026, 1, 1),
            period_end=date(2026, 1, 31),
            asset_start=date(2025, 12, 1),
            convention='days_period',
        )
        self.assertEqual(f, 1.0)

    def test_asset_starts_after_period_zero_factor(self):
        f = prorate_factor(
            period_start=date(2026, 1, 1),
            period_end=date(2026, 1, 31),
            asset_start=date(2026, 2, 5),
            convention='days_period',
        )
        self.assertEqual(f, 0.0)

    def test_days_period_mid_month(self):
        # Jan 16 -> Jan 31 inclusive = 16 days; period = 31 days
        f = prorate_factor(
            period_start=date(2026, 1, 1),
            period_end=date(2026, 1, 31),
            asset_start=date(2026, 1, 16),
            convention='days_period',
        )
        self.assertAlmostEqual(f, 16 / 31, places=5)

    def test_days_365_mid_month(self):
        # 16 days / 365
        f = prorate_factor(
            period_start=date(2026, 1, 1),
            period_end=date(2026, 1, 31),
            asset_start=date(2026, 1, 16),
            convention='days_365',
        )
        self.assertAlmostEqual(f, 16 / 365.0, places=5)

    def test_unknown_convention_raises(self):
        with self.assertRaises(ValueError):
            prorate_factor(
                period_start=date(2026, 1, 1),
                period_end=date(2026, 1, 31),
                asset_start=date(2026, 1, 15),
                convention='bogus',  # type: ignore[arg-type]
            )