"""催缴纳入规则（纯函数）"""

from __future__ import annotations

from datetime import date, timedelta
from decimal import Decimal
from typing import Any, Dict, Iterable, Mapping, Optional, Tuple

from app.services.sample_payment_period_summary import summarize_period


def _dec(v: Any) -> Decimal:
    if v is None or v == "":
        return Decimal("0")
    return Decimal(str(v))


def chase_period_money(
    *,
    due_amount: Any,
    transfers: Iterable[Mapping[str, Any]],
) -> Tuple[Decimal, Decimal]:
    """已缴 = 仅 yjf；欠缴 = max(应缴 − 已缴, 0)。"""
    summary: Dict[str, Any] = summarize_period(
        due_amount=due_amount, transfers=transfers
    )
    return summary["displayPaidAmount"], summary["arrearsAmount"]


def is_chase_candidate(*, due_date: date, today: date, arrears: Any) -> bool:
    """欠缴>0，且应缴日已逾期或落在 [today, today+30]。"""
    if _dec(arrears) <= 0:
        return False
    if due_date < today:
        return True
    return today <= due_date <= today + timedelta(days=30)


def parse_due_date_ymd(raw: Any) -> Optional[date]:
    value = str(raw or "")
    if len(value) == 8 and value.isdigit():
        normalized = value
    elif (
        len(value) == 10
        and value[4] == "-"
        and value[7] == "-"
        and value[:4].isdigit()
        and value[5:7].isdigit()
        and value[8:].isdigit()
    ):
        normalized = value.replace("-", "")
    else:
        return None
    try:
        return date(
            int(normalized[:4]),
            int(normalized[4:6]),
            int(normalized[6:8]),
        )
    except ValueError:
        return None