"""Compare snapshots without writing or discarding candidate movements."""
from decimal import Decimal
import unicodedata


def signature(*, account_id, currency, posting_date, amount, description, kind,
              installment_number=None, installment_total=None):
    return (str(account_id), currency, str(posting_date), Decimal(amount),
            " ".join(unicodedata.normalize("NFC", description).casefold().split()),
            kind, installment_number, installment_total)


def candidate_signature(candidate, account, decision):
    return signature(account_id=account.pk, currency=account.currency,
                     posting_date=candidate["posting_date"], amount=candidate["amount"],
                     description=candidate["description"], kind=decision.get("kind", candidate["kind"]),
                     installment_number=candidate.get("installment_number"),
                     installment_total=candidate.get("installment_total"))


def transaction_signature(row):
    return signature(account_id=row.account_id, currency=row.account.currency,
                     posting_date=row.posting_date, amount=row.amount, description=row.description,
                     kind=row.kind, installment_number=row.installment_number,
                     installment_total=row.installment_plan.total_installments if row.installment_plan_id else None)