from decimal import Decimal
import unittest

from trytond.exceptions import UserError
from trytond.modules.account_debit_note.invoice import Invoice
from trytond.tests.test_tryton import ModuleTestCase


class MockInvoice:
    untaxed_amount = Decimal('100.00')
    total_amount = Decimal('118.00')


class MockLine:
    type = 'line'

    def __init__(self, quantity, unit_price):
        self.quantity = Decimal(quantity)
        self.unit_price = Decimal(unit_price)


class MockTax:

    def __init__(self, base, amount):
        self.base = Decimal(base)
        self.amount = Decimal(amount)


class MockDebitNote:

    def __init__(self, lines=(), taxes=()):
        self.lines = list(lines)
        self.taxes = list(taxes)


class AccountDebitNoteTestCase(ModuleTestCase):
    'Test Account Debit Note module'
    module = 'account_debit_note'


class AccountDebitNoteLogicTestCase(unittest.TestCase):

    def test_full_factor(self):
        self.assertEqual(
            Invoice._debit_compute_factor(
                MockInvoice(), 'full', None, None, 'total'),
            Decimal('1'))

    def test_percent_factor_supports_user_and_internal_values(self):
        self.assertEqual(
            Invoice._debit_compute_factor(
                MockInvoice(), 'percent', Decimal('20'), None, 'total'),
            Decimal('0.2'))
        self.assertEqual(
            Invoice._debit_compute_factor(
                MockInvoice(), 'percent', Decimal('0.20'), None, 'total'),
            Decimal('0.20'))

    def test_amount_factor_uses_selected_basis(self):
        self.assertEqual(
            Invoice._debit_compute_factor(
                MockInvoice(), 'amount', None, Decimal('59'), 'total'),
            Decimal('0.5'))
        self.assertEqual(
            Invoice._debit_compute_factor(
                MockInvoice(), 'amount', None, Decimal('25'), 'untaxed'),
            Decimal('0.25'))

    def test_invalid_percent_is_rejected(self):
        with self.assertRaises(UserError):
            Invoice._debit_compute_factor(
                MockInvoice(), 'percent', Decimal('101'), None, 'total')

    def test_fixed_amount_rejects_multiple_invoices(self):
        with self.assertRaises(UserError):
            Invoice.debit(
                [MockInvoice(), MockInvoice()],
                debit_mode='amount', debit_amount=Decimal('10'))

    def test_debit_restores_negative_adjustment_line_sign(self):
        # Core _credit() changed the original quantity 2 to -2 while keeping
        # the original negative adjustment price.
        line = MockLine('-2', '-15')
        debit = MockDebitNote([line])

        Invoice._debit_force_positive_sign(debit)

        self.assertEqual(line.quantity, Decimal('2'))
        self.assertEqual(line.unit_price, Decimal('-15'))

    def test_debit_restores_manual_tax_sign_without_abs(self):
        # Core _credit() negated the original base 100 and amount -18.
        tax = MockTax('-100', '18')
        debit = MockDebitNote(taxes=[tax])

        Invoice._debit_force_positive_sign(debit)

        self.assertEqual(tax.base, Decimal('100'))
        self.assertEqual(tax.amount, Decimal('-18'))

    def test_partial_debit_preserves_relative_line_signs(self):
        positive = MockLine('2', '50')
        adjustment = MockLine('1', '-20')
        debit = MockDebitNote([positive, adjustment])
        origin = MockInvoice()
        origin.untaxed_amount = Decimal('80')

        Invoice._debit_apply_factor(origin, debit, Decimal('0.5'))

        self.assertEqual(positive.quantity, Decimal('2'))
        self.assertEqual(positive.unit_price, Decimal('25.00000'))
        self.assertEqual(adjustment.quantity, Decimal('1'))
        self.assertEqual(adjustment.unit_price, Decimal('-10.00000'))


del ModuleTestCase


def suite():
    from trytond.tests.test_tryton import suite
    return suite()