"""Источник: synthetic-group/gen/ledger.py (#35). Книга проводок компании: двойная запись, сальдо и обороты как свёртка списка."""

import csv
from dataclasses import dataclass
from datetime import date
from decimal import Decimal
from pathlib import Path

CENT = Decimal("0.01")


@dataclass(frozen=True)
class An:
    cp: str | None
    contract: str | None = None
    item: str | None = None
    name_override: str | None = None
    inn_override: str | None = None


@dataclass(frozen=True)
class Posting:
    day: date
    dt: str
    dt_an: An | None
    ct: str
    ct_an: An | None
    amount: Decimal
    memo: str


Key = tuple[str, An | None]


class Ledger:
    def __init__(self, company: str):
        self.company = company
        self.postings: list[Posting] = []
        self._cache: dict = {}

    def post(self, day, dt, dt_an, ct, ct_an, amount, memo) -> None:
        if amount <= 0 or amount != amount.quantize(CENT):
            raise ValueError(f"сумма должна быть > 0 с двумя знаками: {amount}")
        self.postings.append(Posting(day, dt, dt_an, ct, ct_an, amount, memo))
        self._cache.clear()

    @staticmethod
    def _match(code: str, prefix: str | None) -> bool:
        return prefix is None or code == prefix or code.startswith(prefix + ".")

    def balance(self, at: date, account_prefix: str | None = None) -> dict[Key, Decimal]:
        ck = ("b", at, account_prefix)
        if ck not in self._cache:
            res: dict[Key, Decimal] = {}
            for p in self.postings:
                if p.day > at:
                    continue
                if self._match(p.dt, account_prefix):
                    res[(p.dt, p.dt_an)] = res.get((p.dt, p.dt_an), Decimal(0)) + p.amount
                if self._match(p.ct, account_prefix):
                    res[(p.ct, p.ct_an)] = res.get((p.ct, p.ct_an), Decimal(0)) - p.amount
            self._cache[ck] = {k: v for k, v in res.items() if v != 0}
        return dict(self._cache[ck])

    def turnover(self, start: date, end: date, account_prefix: str | None = None) -> dict[Key, tuple[Decimal, Decimal]]:
        ck = ("t", start, end, account_prefix)
        if ck not in self._cache:
            res: dict[Key, list[Decimal]] = {}
            for p in self.postings:
                if not (start <= p.day <= end):
                    continue
                if self._match(p.dt, account_prefix):
                    res.setdefault((p.dt, p.dt_an), [Decimal(0), Decimal(0)])[0] += p.amount
                if self._match(p.ct, account_prefix):
                    res.setdefault((p.ct, p.ct_an), [Decimal(0), Decimal(0)])[1] += p.amount
            self._cache[ck] = {k: (v[0], v[1]) for k, v in res.items()}
        return dict(self._cache[ck])

    def to_csv(self, path: Path) -> None:
        with Path(path).open("w", encoding="utf-8", newline="") as f:
            w = csv.writer(f, delimiter=";", lineterminator="\n")
            w.writerow("day;dt;dt_cp;dt_contract;dt_item;ct;ct_cp;ct_contract;ct_item;amount;memo".split(";"))
            for p in self.postings:
                da, ca = p.dt_an, p.ct_an
                w.writerow([
                    p.day.isoformat(), p.dt, (da.cp or "") if da else "", (da.contract or "") if da else "",
                    (da.item or "") if da else "", p.ct, (ca.cp or "") if ca else "", (ca.contract or "") if ca else "",
                    (ca.item or "") if ca else "", f"{p.amount:.2f}", p.memo,
                ])


def opening(ledger: Ledger, day: date, account: str, an: An | None, amount: Decimal) -> None:
    """Входящий остаток проводкой против вспомогательного счёта 000; amount со знаком (Дт > 0)."""
    if amount > 0:
        ledger.post(day, account, an, "000", None, amount, "входящий остаток")
    elif amount < 0:
        ledger.post(day, "000", None, account, an, -amount, "входящий остаток")