"""Transaction deduplication rules.

Determines whether two transaction records likely represent the same
underlying financial event captured from different screenshots / pages.
"""
from datetime import timedelta

from app.models.transaction import TransactionRecord

TIME_WINDOW = timedelta(minutes=5)


def is_duplicate_pair(a: TransactionRecord, b: TransactionRecord) -> bool:
    # Rule 1: exact order_no match
    if a.order_no and b.order_no and a.order_no == b.order_no:
        return True

    # Rule 2: same amount + close time + same account tail
    if (
        float(a.amount) == float(b.amount)
        and a.trade_time
        and b.trade_time
        and abs(a.trade_time - b.trade_time) <= TIME_WINDOW
    ):
        if a.self_account_tail_no and b.self_account_tail_no:
            if a.self_account_tail_no == b.self_account_tail_no:
                return True
        # same counterparty and close time is also strong signal
        if a.counterparty_name and a.counterparty_name == b.counterparty_name:
            return True

    return False