"""Base classes for plugin checks"""

# 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 errors as errormod

class PostingChecker:

    VALUES_ENUM = {}

    def _meta_get(self, txn, post, key, default=None):

        try:

            return post.meta[key]

        except (KeyError, TypeError):

            return txn.meta.get(key, default)

    def _meta_set(self, post, key, value):

        if post.meta is None:

            post.meta = {}

        post.meta[key] = value

    def _default_value(self, txn, post):

        raise errormod.InvalidMetadataError(txn, post, self.METADATA_KEY)

    def check(self, txn, post):

        errors = []

        source_value = self._meta_get(txn, post, self.METADATA_KEY)

        set_value = source_value

        if source_value is None:

            try:

                set_value = self._default_value(txn, post)

            except errormod._BaseError as error:

                errors.append(error)

        else:

            try:

                set_value = self.VALUES_ENUM[source_value].value

            except KeyError:

                errors.append(errormod.InvalidMetadataError(

                    txn, post, self.METADATA_KEY, source_value,

                ))

        if not errors:

            self._meta_set(post, self.METADATA_KEY, set_value)

        return errors

"""Error classes for plugins to report problems in the books"""

# 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/>.

class _BaseError(Exception):

    def __init__(self, message, entry, source=None):

        self.message = message

        self.entry = entry

        self.source = entry.meta if source is None else source

class InvalidMetadataError(_BaseError):

    def __init__(self, txn, post, key, value=None, source=None):

        if value is None:

            msg_fmt = "{post.account} missing {key}"

        else:

            msg_fmt = "{post.account} has invalid {key}: {value}"

        super().__init__(

            msg_fmt.format(post=post, key=key, value=value),

            txn,

            source,

        )

"""meta_expense_allocation - Validate expenseAllocation metadata"""

# 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 enum

from . import core

class ExpenseAllocations(enum.Enum):

    administration = 'administration'

    fundraising = 'fundraising'

    program = 'program'

class MetaExpenseAllocation(core.PostingChecker):

    METADATA_KEY = 'expenseAllocation'

    VALUES_ENUM = ExpenseAllocations

"""Test handling of expenseAllocation metadata"""

# 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 pytest

from . import testutil

from conservancy_beancount.plugin import meta_expense_allocation

@pytest.mark.parametrize('value,value_ok', [

    ('program', True),

    ('administration', True),

    ('fundraising', True),

    ('invalid', False),

    ('', False),

])

def test_validity_on_postings(value, value_ok):

    txn = testutil.Transaction(postings=[

        ('Assets:Cash', -25),

        ('Expenses:General', 25, {'expenseAllocation': value}),

    ])

    checker = meta_expense_allocation.MetaExpenseAllocation()

    errors = checker.check(txn, txn.postings[-1])

    if value_ok:

        assert not errors

    else:

        assert errors

"""Mock Beancount objects for testing"""

# 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 beancount.core.amount as bc_amount

import beancount.core.data as bc_data

from decimal import Decimal

FY_START_DATE = datetime.date(2020, 3, 1)

FY_MID_DATE = datetime.date(2020, 9, 1)

def parse_date(s, fmt='%Y-%m-%d'):

    return datetime.datetime.strptime(s, fmt).date()

def Posting(account, number,

            currency='USD', cost=None, price=None, flag=None,

            **meta):

    return bc_data.Posting(

        account,

        bc_amount.Amount(Decimal(number), currency),

        cost,

        price,

        flag,

        meta,

    )

class Transaction:

    def __init__(self,

                 date=FY_MID_DATE, flag='*', payee=None,

                 narration='', tags=None, links=None, postings=None,

                 **meta):

        if isinstance(date, str):

            date = parse_date(date)

        self.date = date

        self.flag = flag

        self.payee = payee

        self.narration = narration

        self.tags = set(tags or '')

        self.links = set(links or '')

        self.postings = []

        self.meta = {

            'filename': '<test>',

            'lineno': 0,

        }

        self.meta.update(meta)

        for posting in postings:

            self.add_posting(*posting)

    def add_posting(self, arg, *args, **kwargs):

        """Add a posting to this transaction. Use any of these forms:

           txn.add_posting(account, number, …, kwarg=value, …)

           txn.add_posting(account, number, …, posting_kwargs_dict)

           txn.add_posting(posting_object)

        """

        if kwargs:

            posting = Posting(arg, *args, **kwargs)

        elif args:

            if isinstance(args[-1], dict):

                kwargs = args[-1]

                args = args[:-1]

            posting = Posting(arg, *args, **kwargs)

        else:

            posting = arg

        self.postings.append(posting)