Transaction,

)

DecimalCompat = Union[decimal.Decimal, int]

LINK_METADATA = frozenset([

    'approval',

    'check',

    'contract',

    'invoice',

    'purchase-order',

    'receipt',

    'statement',

])

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__ = ()

    SEP = bc_account.sep

    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

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':

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',)

    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__,

            ))

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: