"""filters.py - Common filters for postings"""

# 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/>.

from . import data

from typing import (

    Iterable,

)

from .beancount_types import (

    MetaKey,

    MetaValue,

)

Postings = Iterable[data.Posting]

def filter_meta_equal(postings: Postings, key: MetaKey, value: MetaValue) -> Postings:

    for post in postings:

        try:

            if post.meta[key] == value:

                yield post

        except KeyError:

            pass

"""test_filters - Unit tests for filter functions"""

# 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 itertools

import pytest

from . import testutil

from conservancy_beancount import data

from conservancy_beancount import filters

MISSING_POSTING = testutil.Posting('<Missing Posting>', 0)

@pytest.fixture

def cc_txn_pair():

    dates = testutil.date_seq()

    txn_meta = {

        'payee': 'Smith-Dakota',

        'rt-id': 'rt:550',

    }

    return [

        testutil.Transaction(

            **txn_meta,

            date=next(dates),

            receipt='CCReceipt.pdf',

            postings=[

                ('Liabilities:CreditCard', -36),

                ('Expenses:Other', 35),

                ('Expenses:Tax:Sales', 1),

            ],

        ),

        testutil.Transaction(

            **txn_meta,

            date=next(dates),

            receipt='CCPayment.pdf',

            postings=[

                ('Liabilities:CreditCard', 36),

                ('Assets:Checking', -36, {'statement': 'CheckingStatement.pdf'}),

            ],

        ),

    ]

def check_filter(actual, entries, expected_indexes):

    postings = [post for txn in entries for post in txn.postings]

    expected = (postings[ii] for ii in expected_indexes)

    for actual_post, expected_post in itertools.zip_longest(

            actual, expected, fillvalue=MISSING_POSTING,

    ):

        assert actual_post[:-1] == expected_post[:-1]

@pytest.mark.parametrize('key,value,expected_indexes', [

    ('entity', 'Smith-Dakota', range(5)),

    ('receipt', 'CCReceipt.pdf', range(3)),

    ('receipt', 'CCPayment.pdf', range(3, 5)),

    ('receipt', 'CC', ()),

    ('statement', 'CheckingStatement.pdf', [4]),

    ('BadKey', '', ()),

    ('emptykey', '', ()),

])

def test_filter_meta_equal(cc_txn_pair, key, value, expected_indexes):

    postings = data.Posting.from_entries(cc_txn_pair)

    actual = filters.filter_meta_equal(postings, key, value)

    check_filter(actual, cc_txn_pair, expected_indexes)