from datetime import date, timedelta
from decimal import Decimal

from sqlalchemy import select

from factories import make_account, make_cbr_rate, make_rule, make_txn, month_back, refresh
from fintracker.analytics import today_local
from fintracker.db import get_sessionmaker
from fintracker.models import MetricCashFlowMonthly, RuleKind, RuleMatchType


async def months() -> dict[date, MetricCashFlowMonthly]:
    async with get_sessionmaker()() as session:
        rows = (
            (
                await session.execute(
                    select(MetricCashFlowMonthly).order_by(MetricCashFlowMonthly.month)
                )
            )
            .scalars()
            .all()
        )
        return {r.month: r for r in rows}


async def test_month_totals_baseline_and_savings_rate(app):
    card = await make_account(balance="0")
    m = month_back(1)
    await make_txn(m + timedelta(days=5), income="100000", income_account_id=card)
    await make_txn(m + timedelta(days=6), outcome="30000", outcome_account_id=card, payee="Лента")
    await make_txn(m + timedelta(days=7), outcome="20000", outcome_account_id=card, payee="Отпуск")
    await make_txn(m + timedelta(days=8), outcome="10000", outcome_account_id=card, payee="Копилка")
    await make_rule(kind=RuleKind.one_off, match_type=RuleMatchType.payee, pattern="Отпуск")
    await make_rule(kind=RuleKind.savings, match_type=RuleMatchType.payee, pattern="Копилка")
    await refresh()

    row = (await months())[m]
    assert row.income_rub == Decimal("100000")
    assert row.expense_rub == Decimal("50000")
    assert row.one_off_rub == Decimal("20000")
    assert row.baseline_rub == Decimal("30000")
    assert row.savings_transfer_rub == Decimal("10000")
    assert row.savings_rate == Decimal("0.5")
    assert row.txn_count == 4


async def test_transfers_and_ignored_flows_do_not_count(app):
    card = await make_account(balance="0")
    other = await make_account(name="Вклад", balance="0")
    m = month_back(1)
    await make_txn(
        m + timedelta(days=2),
        income="50000",
        income_account_id=other,
        outcome="50000",
        outcome_account_id=card,
    )
    await refresh()

    assert await months() == {}


async def test_foreign_expense_uses_the_rate_of_its_own_date(app):
    card = await make_account(balance="0")
    m = month_back(1)
    d = m + timedelta(days=10)
    await make_txn(d, outcome="10", outcome_currency="USD", outcome_account_id=card)
    await make_cbr_rate(d, "USD", "90")
    await make_cbr_rate(today_local(), "USD", "100")
    await refresh()

    assert (await months())[m].expense_rub == Decimal("900")


async def test_income_zero_gives_null_savings_rate(app):
    card = await make_account(balance="0")
    m = month_back(1)
    await make_txn(m + timedelta(days=3), outcome="1000", outcome_account_id=card)
    await refresh()

    assert (await months())[m].savings_rate is None


async def test_unconvertible_expense_leaves_no_phantom_month(app):
    """The month row is created by a successful conversion, not by the attempt: a single
    unquoted expense must not produce an all-zero month."""
    card = await make_account(balance="0")
    m = month_back(1)
    await make_txn(
        m + timedelta(days=4), outcome="1", outcome_currency="XBT", outcome_account_id=card
    )
    await refresh()

    assert await months() == {}