"""Thin shim around `job_hunter.fx` (Frankfurter-backed) so callers
inside fire-planner have a single import. Re-exports the public API.

The job-hunter package isn't a hard dependency — when it isn't on
the Python path (e.g. running `fire-planner` outside the monorepo),
fall back to a tiny inline implementation that hits Frankfurter
directly with no DB caching.
"""
from __future__ import annotations

from datetime import date
from decimal import Decimal
from typing import Any

import httpx

FRANKFURTER_URL = "https://api.frankfurter.dev/v1/{date}"


async def fetch_rates(as_of: date, client: httpx.AsyncClient | None = None) -> dict[str, Decimal]:
    """Return GBP-base rates for `as_of` — `{currency: rate_to_gbp}`.

    rate_to_gbp[X] = "how much GBP one unit of X is worth", so
    `gbp_amount = foreign_amount * rate_to_gbp[foreign]`.
    """
    owns = client is None
    if client is None:
        client = httpx.AsyncClient(timeout=httpx.Timeout(20.0))
    try:
        resp = await client.get(
            FRANKFURTER_URL.format(date=as_of.isoformat()),
            params={"base": "GBP"},
            follow_redirects=True,
        )
        resp.raise_for_status()
        payload: dict[str, Any] = resp.json()
    finally:
        if owns:
            await client.aclose()
    rates = payload.get("rates") or {}
    out: dict[str, Decimal] = {"GBP": Decimal("1")}
    for currency, rate in rates.items():
        if not rate:
            continue
        try:
            out[currency] = Decimal("1") / Decimal(str(rate))
        except (ArithmeticError, ValueError):
            continue
    return out