from __future__ import annotations

from datetime import date
from decimal import Decimal
from difflib import SequenceMatcher

from .fingerprints import normalize_counterparty


def _date_distance(a: date, b: date) -> int:
    return abs((a - b).days)


def score_event_match(
    *,
    amount_a: Decimal,
    amount_b: Decimal,
    currency_a: str,
    currency_b: str,
    date_a: date,
    date_b: date,
    party_a: str | None,
    party_b: str | None,
) -> float:
    if currency_a.upper() != currency_b.upper():
        return 0.0

    amount_score = (
        1.0
        if amount_a == amount_b
        else max(0.0, 1.0 - (abs(amount_a - amount_b) / max(abs(amount_a), Decimal("1"))))
    )
    days = _date_distance(date_a, date_b)
    date_score = 1.0 if days == 0 else max(0.0, 1.0 - (days / 14))
    party_score = SequenceMatcher(
        None,
        normalize_counterparty(party_a),
        normalize_counterparty(party_b),
    ).ratio()
    return round((amount_score * 0.45) + (date_score * 0.30) + (party_score * 0.25), 4)