"""Enhanced Beancount data structures for Conservancy

The classes in this module are interface-compatible with Beancount's core data

structures, and provide additional business logic that we want to use

throughout Conservancy tools.

"""

# 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 collections

import datetime

import decimal

import functools

import re

from beancount.core import account as bc_account

from beancount.core import amount as bc_amount

from beancount.core import convert as bc_convert

from beancount.core import data as bc_data

from beancount.core import position as bc_position

from beancount.parser import options as bc_options

from typing import (

    cast,

    overload,

    Callable,

    Hashable,

    Iterable,

    Iterator,

    MutableMapping,

    Optional,

    Pattern,

    Sequence,

    TypeVar,

    Union,

)

from .beancount_types import (

    Close,

    Currency,

    Directive,

    Meta,

    MetaKey,

    MetaValue,

    Open,

    OptionsMap,

    Posting as BasePosting,

    Transaction,

)

DecimalCompat = Union[decimal.Decimal, int]

LINK_METADATA = frozenset([

    'approval',

    'bank-statement',

    'check',

    'contract',

    'invoice',

    'purchase-order',

    'receipt',

    'rt-id',

    'statement',

    'tax-statement',

])

class AccountMeta(MutableMapping[MetaKey, MetaValue]):

    """Access account metadata

    This class provides a consistent interface to all the metadata provided by

    Beancount's ``open`` and ``close`` directives: open and close dates,

    used currencies, booking method, and the metadata associated with each.

    For convenience, you can use this class as a Mapping to access the ``open``

    directive's metadata directly.

    """

    __slots__ = ('_opening', '_closing')

    def __init__(self, opening: Open, closing: Optional[Close]=None) -> None:

        self._opening = opening

        self._closing: Optional[Close] = None

        if closing is not None:

            self.add_closing(closing)

    def add_closing(self, closing: Close) -> None:

        if self._closing is not None and self._closing is not closing:

            raise ValueError(f"{self.account} already closed by {self._closing!r}")

        elif closing.account != self.account:

            raise ValueError(f"cannot close {self.account} with {closing.account}")

        elif closing.date < self.open_date:

            raise ValueError(f"close date {closing.date} predates open date {self.open_date}")

        else:

            self._closing = closing

    def __iter__(self) -> Iterator[MetaKey]:

        return iter(self._opening.meta)

    def __len__(self) -> int:

        return len(self._opening.meta)

    def __getitem__(self, key: MetaKey) -> MetaValue:

        return self._opening.meta[key]

    def __setitem__(self, key: MetaKey, value: MetaValue) -> None:

        self._opening.meta[key] = value

    def __delitem__(self, key: MetaKey) -> None:

        del self._opening.meta[key]

    @property

    def account(self) -> 'Account':

        return Account(self._opening.account)

    @property

    def booking(self) -> Optional[bc_data.Booking]:

        return self._opening.booking

    @property

    def close_date(self) -> Optional[datetime.date]:

        return None if self._closing is None else self._closing.date

    @property

    def close_meta(self) -> Optional[Meta]:

        return None if self._closing is None else self._closing.meta

    @property

    def currencies(self) -> Optional[Sequence[Currency]]:

        return self._opening.currencies

    @property

    def open_date(self) -> datetime.date:

        return self._opening.date

    @property

    def open_meta(self) -> Meta:

        return self._opening.meta

class Account(str):

    """Account name string

    This is a string that names an account, like Assets:Bank:Checking

    or Income:Donations. This class provides additional methods for common

    account name parsing and queries.

    """

    __slots__ = ()

    ACCOUNT_RE: Pattern

    SEP = bc_account.sep

    _meta_map: MutableMapping[str, AccountMeta] = {}

    _options_map: OptionsMap

    @classmethod

    def load_options_map(cls, options_map: OptionsMap) -> None:

        cls._options_map = options_map

        roots: Sequence[str] = bc_options.get_account_types(options_map)

        cls.ACCOUNT_RE = re.compile(

            r'^(?:{})(?:{}[A-Z0-9][-A-Za-z0-9]*)+$'.format(

                '|'.join(roots), cls.SEP,

            ))

    @classmethod

    def load_opening(cls, opening: Open) -> None:

        cls._meta_map[opening.account] = AccountMeta(opening)

    @classmethod

    def load_closing(cls, closing: Close) -> None:

        try:

            cls._meta_map[closing.account].add_closing(closing)

        except KeyError:

            raise ValueError(

                f"tried to load {closing.account} close directive before open",

            ) from None

    @classmethod

    def load_openings_and_closings(cls, entries: Iterable[Directive]) -> None:

        for entry in entries:

            # type ignores because Beancount's directives aren't type-checkable.

            if isinstance(entry, bc_data.Open):

                cls.load_opening(entry)  # type:ignore[arg-type]

            elif isinstance(entry, bc_data.Close):

                cls.load_closing(entry)  # type:ignore[arg-type]

    @classmethod

    def is_account(cls, s: str) -> bool:

        return cls.ACCOUNT_RE.fullmatch(s) is not None

    @property

    def meta(self) -> AccountMeta:

        return self._meta_map[self]

    def is_cash_equivalent(self) -> bool:

        return (

            self.is_under('Assets:') is not None

            and self.is_under('Assets:Prepaid', 'Assets:Receivable') is None

        )

    def is_checking(self) -> bool:

        return self.is_cash_equivalent() and ':Check' in self

    def is_credit_card(self) -> bool:

        return self.is_under('Liabilities:CreditCard') is not None

    def is_opening_equity(self) -> bool:

        return self.is_under('Equity:Funds', 'Equity:OpeningBalance') is not None

    def is_under(self, *acct_seq: str) -> Optional[str]:

        """Return a match if this account is "under" a part of the hierarchy

        Pass in any number of account name strings as arguments. If this

        account is under one of those strings in the account hierarchy, the

        first matching string will be returned. Otherwise, None is returned.

        You can use the return value of this method as a boolean if you don't

        care which account string is matched.

        An account is considered to be under itself:

          Account('Expenses:Tax').is_under('Expenses:Tax') # returns 'Expenses:Tax'

        To do a "strictly under" search, end your search strings with colons:

          Account('Expenses:Tax').is_under('Expenses:Tax:') # returns None

          Account('Expenses:Tax').is_under('Expenses:') # returns 'Expenses:'

        This method does check that all the account boundaries match:

          Account('Expenses:Tax').is_under('Exp') # returns None

        """

        for prefix in acct_seq:

            if self.startswith(prefix) and (

                prefix.endswith(self.SEP)

                or self == prefix

                or self[len(prefix)] == self.SEP

            ):

                return prefix

        return None

    def _find_part_slice(self, index: int) -> slice:

        if index < 0:

            raise ValueError(f"bad part index {index!r}")

        start = 0

        for _ in range(index):

            try:

                start = self.index(self.SEP, start) + 1

            except ValueError:

                raise IndexError("part index {index!r} out of range") from None

        try:

            stop = self.index(self.SEP, start + 1)

        except ValueError:

            stop = len(self)

        return slice(start, stop)

    def count_parts(self) -> int:

        return self.count(self.SEP) + 1

    @overload

    def slice_parts(self, start: None=None, stop: None=None) -> Sequence[str]: ...

    @overload

    def slice_parts(self, start: slice, stop: None=None) -> Sequence[str]: ...

    @overload

    def slice_parts(self, start: int, stop: int) -> Sequence[str]: ...

    @overload

    def slice_parts(self, start: int, stop: None=None) -> str: ...

    def slice_parts(self,

                    start: Optional[Union[int, slice]]=None,

                    stop: Optional[int]=None,

    ) -> Sequence[str]:

        """Slice the account parts like they were a list

        Given a single index, return that part of the account name as a string.

        Otherwise, return a list of part names sliced according to the arguments.

        """

        if start is None:

            part_slice = slice(None)

        elif isinstance(start, slice):

            part_slice = start

        elif stop is None:

            return self[self._find_part_slice(start)]

        else:

            part_slice = slice(start, stop)

        return self.split(self.SEP)[part_slice]

    def root_part(self, count: int=1) -> str:

        """Return the first part(s) of the account name as a string"""

        try:

            stop = self._find_part_slice(count - 1).stop

        except IndexError:

            return self

        else:

            return self[:stop]

Account.load_options_map(bc_options.OPTIONS_DEFAULTS)

class Amount(bc_amount.Amount):

    """Beancount amount after processing

    Beancount's native Amount class declares number to be Optional[Decimal],

    because the number is None when Beancount first parses a posting that does

    not have an amount, because the user wants it to be automatically balanced.

    As part of the loading process, Beancount replaces those None numbers

    with the calculated amount, so it will always be a Decimal. This class

    overrides the type declaration accordingly, so the type checker knows

    that our code doesn't have to consider the possibility that number is

    None.

    """

    number: decimal.Decimal

    # beancount.core._Amount is the plain namedtuple.

    # beancore.core.Amount adds instance methods to it.

    # b.c.Amount.__New__ calls `b.c._Amount.__new__`, which confuses type

    # checking. See <https://github.com/python/mypy/issues/1279>.

    # It works fine if you use super(), which is better practice anyway.

    # So we override __new__ just to call _Amount.__new__ this way.

    def __new__(cls, number: decimal.Decimal, currency: str) -> 'Amount':

        return super(bc_amount.Amount, Amount).__new__(cls, number, currency)

class Metadata(MutableMapping[MetaKey, MetaValue]):

    """Transaction or posting metadata

    This class wraps a Beancount metadata dictionary with additional methods

    for common parsing and query tasks.

    """

    __slots__ = ('meta',)

    _HUMAN_NAMES: MutableMapping[MetaKey, str] = {

        # Initialize this dict with special cases.

        # We use it as a cache for other metadata names as they're queried.

        'check-id': 'Check Number',

        'paypal-id': 'PayPal ID',

        'rt-id': 'Ticket',

    }

    def __init__(self, source: MutableMapping[MetaKey, MetaValue]) -> None:

        self.meta = source

    def __iter__(self) -> Iterator[MetaKey]:

        return iter(self.meta)

    def __len__(self) -> int:

        return len(self.meta)

    def __getitem__(self, key: MetaKey) -> MetaValue:

        return self.meta[key]

    def __setitem__(self, key: MetaKey, value: MetaValue) -> None:

        self.meta[key] = value

    def __delitem__(self, key: MetaKey) -> None:

        del self.meta[key]

    def get_links(self, key: MetaKey) -> Sequence[str]:

        try:

            value = self.meta[key]

        except KeyError:

            return ()

        if isinstance(value, str):

            return value.split()

        else:

            raise TypeError("{} metadata is a {}, not str".format(

                key, type(value).__name__,

            ))

    def report_links(self, key: MetaKey) -> Sequence[str]:

        """Return a sequence of link strings under the named metadata key

        get_links raises a TypeError if the metadata is not a string.

        This method simply returns the empty sequence.

        Validation code (like in the plugin) usually uses get_links()

        while reporting code uses report_links().

        """

        try:

            return self.get_links(key)

        except TypeError:

            return ()

    @overload

    def first_link(self, key: MetaKey, default: None=None) -> Optional[str]: ...

    @overload

    def first_link(self, key: MetaKey, default: str) -> str: ...

    def first_link(self, key: MetaKey, default: Optional[str]=None) -> Optional[str]:

        try:

            return self.get_links(key)[0]

        except (IndexError, TypeError):

            return default

    @classmethod

    def human_name(cls, key: MetaKey) -> str:

        """Return the "human" version of a metadata name

        This is usually the metadata key with punctuation replaced with spaces,

        and then titlecased, with a few special cases. The return value is

        suitable for using in reports.

        """

        try:

            retval = cls._HUMAN_NAMES[key]

        except KeyError:

            retval = key.replace('-', ' ').title()

            retval = re.sub(r'\bId$', 'ID', retval)

            cls._HUMAN_NAMES[key] = retval

        return retval

class PostingMeta(Metadata):

    """Combined access to posting metadata with its parent transaction metadata

    This lets you access posting metadata through a single dict-like object.

    If you try to look up metadata that doesn't exist on the posting, it will

    look for the value in the parent transaction metadata instead.

    You can set and delete metadata as well. Changes only affect the metadata

    of the posting, never the transaction. Changes are propagated to the

    underlying Beancount data structures.

    Functionally, you can think of this as identical to:

      collections.ChainMap(post.meta, txn.meta)

    Under the hood, this class does a little extra work to avoid creating

    posting metadata if it doesn't have to.

    """

    __slots__ = ('txn', 'index', 'post')

    def __init__(self,

                 txn: Transaction,

                 index: int,

                 post: Optional[BasePosting]=None,

    ) -> None:

        if post is None:

            post = txn.postings[index]

        self.txn = txn

        self.index = index

        self.post = post

        if post.meta is None:

            self.meta = self.txn.meta

        else:

            self.meta = collections.ChainMap(post.meta, txn.meta)

    def __getitem__(self, key: MetaKey) -> MetaValue:

        try:

            return super().__getitem__(key)

        except KeyError:

            if key == 'entity' and self.txn.payee is not None:

                return self.txn.payee

            else:

                raise

    def __setitem__(self, key: MetaKey, value: MetaValue) -> None:

        if self.post.meta is None:

            self.post = self.post._replace(meta={key: value})

            self.txn.postings[self.index] = self.post

            # mypy complains that self.post.meta could be None, but we know

            # from two lines up that it's not.

            self.meta = collections.ChainMap(self.post.meta, self.txn.meta)  # type:ignore[arg-type]

        else:

            super().__setitem__(key, value)

    def __delitem__(self, key: MetaKey) -> None:

        if self.post.meta is None:

            raise KeyError(key)

        else:

            super().__delitem__(key)

    # This is arguably cheating a litttle bit, but I'd argue the date of

    # the parent transaction still qualifies as posting metadata, and

    # it's something we want to access so often it's good to have it

    # within easy reach.

    @property

    def date(self) -> datetime.date:

        return self.txn.date

class Posting(BasePosting):

    """Enhanced Posting objects

    This class is a subclass of Beancount's native Posting class where

    specific fields are replaced with enhanced versions:

    * The `account` field is an Account object

    * The `units` field is our Amount object (which simply declares that the

      number is always a Decimal—see that docstring for details)

    * The `meta` field is a PostingMeta object

    """

    __slots__ = ()

    account: Account

    units: Amount

    cost: Optional[bc_position.Cost]

    # mypy correctly complains that our MutableMapping is not compatible

    # with Beancount's meta type declaration of Optional[Dict]. IMO

    # Beancount's type declaration is a smidge too specific: I think its type

    # declaration should also use MutableMapping, because it would be very

    # unusual for code to specifically require a Dict over that.

    # If it did, this declaration would pass without issue.

    meta: PostingMeta  # type:ignore[assignment]

    @classmethod

    def from_beancount(cls,

                       txn: Transaction,

                       index: int,

                       post: Optional[BasePosting]=None,

    ) -> 'Posting':

        if post is None:

            post = txn.postings[index]

        return cls(

            Account(post.account),

            *post[1:5],

            # see rationale above about Posting.meta

            PostingMeta(txn, index, post), # type:ignore[arg-type]

        )

    @classmethod

    def from_txn(cls, txn: Transaction) -> Iterator['Posting']:

        """Yield an enhanced Posting object for every posting in the transaction"""

        for index, post in enumerate(txn.postings):

            yield cls.from_beancount(txn, index, post)

    @classmethod

    def from_entries(cls, entries: Iterable[Directive]) -> Iterator['Posting']:

        """Yield an enhanced Posting object for every posting in these entries"""

        for entry in entries:

            # Because Beancount's own Transaction class isn't type-checkable,

            # we can't statically check this. Might as well rely on duck

            # typing while we're at it: just try to yield postings from

            # everything, and ignore entries that lack a postings attribute.

            try:

                yield from cls.from_txn(entry)  # type:ignore[arg-type]

            except AttributeError:

                pass

    def at_cost(self) -> Amount:

        if self.cost is None:

            return self.units

        else:

            return Amount(self.units.number * self.cost.number, self.cost.currency)

_KT = TypeVar('_KT', bound=Hashable)

_VT = TypeVar('_VT')

class _SizedDict(collections.OrderedDict, MutableMapping[_KT, _VT]):

    def __init__(self, maxsize: int=128) -> None:

        self.maxsize = maxsize

        super().__init__()

    def __setitem__(self, key: _KT, value: _VT) -> None:

        super().__setitem__(key, value)

        for _ in range(self.maxsize, len(self)):

            self.popitem(last=False)

def balance_of(txn: Transaction,

               *preds: Callable[[Account], Optional[bool]],

) -> Amount:

    """Return the balance of specified postings in a transaction.

    Given a transaction and a series of account predicates, balance_of

    returns the balance of the amounts of all postings with accounts that

    match any of the predicates.

    balance_of uses the "weight" of each posting, so the return value will

    use the currency of the postings' cost when available.

    """

    match_posts = [post for post in Posting.from_txn(txn)

                   if any(pred(post.account) for pred in preds)]

    number = decimal.Decimal(0)

    if not match_posts:

        currency = ''

    else:

        weights: Sequence[Amount] = [

            bc_convert.get_weight(post) for post in match_posts

        ]

        number = sum((wt.number for wt in weights), number)

        currency = weights[0].currency

    return Amount(number, currency)

_opening_balance_cache: MutableMapping[str, bool] = _SizedDict()

def is_opening_balance_txn(txn: Transaction) -> bool:

    key = '\0'.join(

        f'{post.account}={post.units}' for post in txn.postings

    )

    try:

        return _opening_balance_cache[key]

    except KeyError:

        pass

    opening_equity = balance_of(txn, Account.is_opening_equity)

    if not opening_equity.currency:

        retval = False

    else:

        rest = balance_of(txn, lambda acct: not acct.is_opening_equity())

        if not rest.currency:

            retval = False

        else:

            retval = abs(opening_equity.number + rest.number) < decimal.Decimal('.01')

    _opening_balance_cache[key] = retval

    return retval

"""Test Account class"""

# 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 datetime import date as Date

from beancount.core.data import Open, Close, Booking

from beancount.parser import options as bc_options

from conservancy_beancount import data

clean_account_meta = pytest.fixture()(testutil.clean_account_meta)

def check_account_meta(acct_meta, opening, closing=None):

    if isinstance(acct_meta, str):

        acct_meta = data.Account(acct_meta).meta

    assert acct_meta == opening.meta

    assert acct_meta.account == opening.account

    assert acct_meta.booking == opening.booking

    assert acct_meta.currencies == opening.currencies

    assert acct_meta.open_date == opening.date

    assert acct_meta.open_meta == opening.meta

    if closing is None:

        assert acct_meta.close_date is None

        assert acct_meta.close_meta is None

    else:

        assert acct_meta.close_date == closing.date

        assert acct_meta.close_meta == closing.meta

@pytest.mark.parametrize('acct_name,under_arg,expected', [

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

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

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

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

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

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

    ('Expenses:Tax:Sales', 'Expense', False),

    ('Expenses:Tax:Sales', 'Equity:', False),

    ('Expenses:Tax:Sales', 'Equity', False),

])

def test_is_under_one_arg(acct_name, under_arg, expected):

    expected = under_arg if expected else None

    assert data.Account(acct_name).is_under(under_arg) == expected

@pytest.mark.parametrize('acct_name,expected', [

    ('Assets:Cash', None),

    ('Assets:Checking', None),

    ('Assets:Prepaid:Expenses', 'Assets:Prepaid'),

    ('Assets:Receivable:Accounts', 'Assets:Receivable'),

])

def test_is_under_multi_arg(acct_name, expected):

    assert expected == data.Account(acct_name).is_under(

        'Assets:Prepaid', 'Assets:Receivable',

    )

    if expected:

        expected += ':'

    assert expected == data.Account(acct_name).is_under(

        'Assets:Prepaid:', 'Assets:Receivable:',

    )

@pytest.mark.parametrize('acct_name,expected', [

    ('Assets:Bank:Checking', True),

    ('Assets:Cash', True),

    ('Assets:Cash:EUR', True),

    ('Assets:Prepaid:Expenses', False),

    ('Assets:Prepaid:Vacation', False),

    ('Assets:Receivable:Accounts', False),

    ('Assets:Receivable:Fraud', False),

    ('Expenses:Other', False),

    ('Equity:OpeningBalance', False),

    ('Income:Other', False),

    ('Liabilities:CreditCard', False),

])

def test_is_cash_equivalent(acct_name, expected):

    assert data.Account(acct_name).is_cash_equivalent() == expected

@pytest.mark.parametrize('acct_name,expected', [

    ('Assets:Bank:Check9999', True),

    ('Assets:Bank:CheckCard', True),

    ('Assets:Bank:Checking', True),

    ('Assets:Bank:Savings', False),

    ('Assets:Cash', False),

    ('Assets:Check9999', True),

    ('Assets:CheckCard', True),

    ('Assets:Checking', True),

    ('Assets:Prepaid:Expenses', False),

    ('Assets:Receivable:Accounts', False),

    ('Expenses:Other', False),

    ('Equity:OpeningBalance', False),

    ('Income:Other', False),

    ('Liabilities:CreditCard', False),

])

def test_is_checking(acct_name, expected):

    assert data.Account(acct_name).is_checking() == expected

@pytest.mark.parametrize('acct_name,expected', [

    ('Assets:Cash', False),

    ('Assets:Prepaid:Expenses', False),

    ('Assets:Receivable:Accounts', False),

    ('Expenses:Other', False),

    ('Equity:OpeningBalance', False),

    ('Income:Other', False),

    ('Liabilities:CreditCard', True),

    ('Liabilities:CreditCard:Visa', True),

    ('Liabilities:Payable:Accounts', False),

    ('Liabilities:UnearnedIncome:Donations', False),

])

def test_is_credit_card(acct_name, expected):

    assert data.Account(acct_name).is_credit_card() == expected

@pytest.mark.parametrize('acct_name,expected', [

    ('Assets:Cash', False),

    ('Assets:Prepaid:Expenses', False),

    ('Assets:Receivable:Accounts', False),

    ('Expenses:Other', False),

    ('Equity:Funds:Restricted', True),

    ('Equity:Funds:Unrestricted', True),

    ('Equity:OpeningBalance', True),

    ('Equity:Retained:Costs', False),

    ('Income:Other', False),

    ('Liabilities:CreditCard', False),

    ('Liabilities:Payable:Accounts', False),

    ('Liabilities:UnearnedIncome:Donations', False),

])

def test_is_opening_equity(acct_name, expected):

    assert data.Account(acct_name).is_opening_equity() == expected

@pytest.mark.parametrize('acct_name', [

    'Assets:Cash',

    'Assets:Receivable:Accounts',

    'Expenses:Other',

    'Equity:Funds:Restricted',

    'Income:Other',

    'Liabilities:CreditCard',

    'Liabilities:Payable:Accounts',

])

def test_slice_parts_no_args(acct_name):

    account = data.Account(acct_name)

    assert account.slice_parts() == acct_name.split(':')

@pytest.mark.parametrize('acct_name', [

    'Assets:Cash',

    'Assets:Receivable:Accounts',

    'Expenses:Other',

    'Equity:Funds:Restricted',

    'Income:Other',

    'Liabilities:CreditCard',

    'Liabilities:Payable:Accounts',

])

def test_slice_parts_index(acct_name):

    account = data.Account(acct_name)

    parts = acct_name.split(':')

    for index, expected in enumerate(parts):

        assert account.slice_parts(index) == expected

    with pytest.raises(IndexError):

        account.slice_parts(index + 1)

@pytest.mark.parametrize('acct_name', [

    'Assets:Cash',

    'Assets:Receivable:Accounts',

    'Expenses:Other',

    'Equity:Funds:Restricted',

    'Income:Other',

    'Liabilities:CreditCard',

    'Liabilities:Payable:Accounts',

])

def test_slice_parts_range(acct_name):

    account = data.Account(acct_name)

    parts = acct_name.split(':')

    for start, stop in zip([0, 0, 1, 1], [2, 3, 2, 3]):

        assert account.slice_parts(start, stop) == parts[start:stop]

@pytest.mark.parametrize('acct_name', [

    'Assets:Cash',

    'Assets:Receivable:Accounts',

    'Expenses:Other',

    'Equity:Funds:Restricted',

    'Income:Other',

    'Liabilities:CreditCard',

    'Liabilities:Payable:Accounts',

])

def test_slice_parts_slice(acct_name):

    account = data.Account(acct_name)

    parts = acct_name.split(':')

    for start, stop in zip([0, 0, 1, 1], [2, 3, 2, 3]):

        sl = slice(start, stop)

        assert account.slice_parts(sl) == parts[start:stop]

@pytest.mark.parametrize('acct_name', [

    'Assets:Cash',

    'Assets:Receivable:Accounts',

    'Expenses:Other',

    'Equity:Funds:Restricted',

    'Income:Other',

    'Liabilities:CreditCard',

    'Liabilities:Payable:Accounts',

])

def test_count_parts(acct_name):

    account = data.Account(acct_name)

    assert account.count_parts() == acct_name.count(':') + 1

@pytest.mark.parametrize('acct_name', [

    'Assets:Cash',

    'Assets:Receivable:Accounts',

    'Expenses:Other',

    'Equity:Funds:Restricted',

    'Income:Other',

    'Liabilities:CreditCard',

    'Liabilities:Payable:Accounts',

])

def test_root_part(acct_name):

    account = data.Account(acct_name)

    parts = acct_name.split(':')

    assert account.root_part() == parts[0]

    assert account.root_part(1) == parts[0]

    assert account.root_part(2) == ':'.join(parts[:2])

def test_load_opening(clean_account_meta):

    opening = Open({'lineno': 210}, Date(2010, 2, 1), 'Assets:Cash', None, None)

    data.Account.load_opening(opening)

    check_account_meta('Assets:Cash', opening)

def test_load_closing(clean_account_meta):

    name = 'Assets:Checking'

    opening = Open({'lineno': 230}, Date(2010, 10, 1), name, None, None)

    closing = Close({'lineno': 235}, Date(2010, 11, 1), name)

    data.Account.load_opening(opening)

    data.Account.load_closing(closing)

    check_account_meta(name, opening, closing)

def test_load_closing_without_opening(clean_account_meta):

    closing = Close({'lineno': 245}, Date(2010, 3, 1), 'Assets:Cash')

    with pytest.raises(ValueError):

        data.Account.load_closing(closing)

def test_load_openings_and_closings(clean_account_meta):

    entries = [

        Open({'lineno': 1, 'income-type': 'Donations'},

             Date(2000, 3, 1), 'Income:Donations', None, None),

        Open({'lineno': 2},