"""test_reports_period_postings - Unit tests for PeriodPostings"""

# Copyright © 2020  Brett Smith

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU Affero General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU Affero General Public License for more details.

#

# You should have received a copy of the GNU Affero General Public License

# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import datetime

import operator

from decimal import Decimal

import pytest

from . import testutil

from conservancy_beancount import data

from conservancy_beancount.reports import core

def check_balance_attrs(balance_postings, start_usd, stop_usd):

    if start_usd:

        expected = {'USD': testutil.Amount(start_usd)}

        assert balance_postings.start_bal == expected

        assert balance_postings.begin_bal == expected

    else:

        assert balance_postings.start_bal.is_zero()

        assert balance_postings.begin_bal.is_zero()

    expected = {'USD': testutil.Amount(stop_usd)}

    assert balance_postings.stop_bal == expected

    assert balance_postings.end_bal == expected

    expected = {'USD': testutil.Amount(stop_usd - start_usd)}

    assert balance_postings.period_bal == expected

@pytest.mark.parametrize('start_date,expect_start_bal', [

    (datetime.date(2019, 2, 1), 0),

    (datetime.date(2019, 4, 1), 30),

    (datetime.date(2019, 6, 1), 120),

])

def test_balance_postings_attrs(start_date, expect_start_bal):

    entries = [testutil.Transaction(date=datetime.date(2019, n, 15), postings=[

        ('Income:Donations', -n * 10),

        ('Assets:Cash', n * 10),

    ]) for n in range(3, 7)]

    cls = core.PeriodPostings.with_start_date(start_date)

    actual = dict(cls.group_by_account(data.Posting.from_entries(entries)))

    assert len(actual) == 2

    check_balance_attrs(actual['Assets:Cash'], expect_start_bal, 180)

    check_balance_attrs(actual['Income:Donations'], -expect_start_bal, -180)

@pytest.mark.parametrize('start_date,expect_count', [

    (datetime.date(2019, 2, 1), 4),

    (datetime.date(2019, 4, 1), 3),

    (datetime.date(2019, 6, 1), 1),

])

def test_balance_postings_filter(start_date, expect_count):

    entries = [testutil.Transaction(date=datetime.date(2019, n, 15), postings=[

        ('Income:Donations', -n * 10),

        ('Assets:Cash', n * 10),

    ]) for n in range(3, 7)]

    cls = core.PeriodPostings.with_start_date(start_date)

    for _, related in cls.group_by_account(data.Posting.from_entries(entries)):

        assert len(related) == expect_count