import hashlib
from datetime import date
from decimal import Decimal

from app.parsers.base import ParsedStatement


def balance_difference(p: ParsedStatement) -> Decimal:
    total = sum((t.amount for t in p.transactions), Decimal("0"))
    return (p.opening_balance + total - p.closing_balance).copy_abs()


def dedup_hash(account_id: int, booking_date: date, amount: Decimal, purpose: str) -> str:
    raw = f"{account_id}|{booking_date.isoformat()}|{amount:.2f}|{' '.join(purpose.split())}"
    return hashlib.sha256(raw.encode()).hexdigest()