import assert from "node:assert/strict";
import { test } from "node:test";
import { fetchLemfiRate, parseLemfiQuote } from "../utils/lemfi.js";

// Captured from LemFi's Netherlands EUR → NGN calculator endpoint.
const quote = {
    exchange_from: "EUR",
    exchange_to: "NGN",
    rate: "9.8057976951626334827662874e+25",
    ID: "64eeb42d-7f05-4b50-a172-5e581358517a",
};

test("decodes the live quote to the rate displayed by LemFi", () => {
    assert.equal(parseLemfiQuote({ data: quote }), 1522);
});

test("keeps promotional rewards out of the base rate comparison", () => {
    assert.equal(parseLemfiQuote({ data: { ...quote, promotion_rate: { rate: "1e30" } } }), 1522);
});

test("rejects malformed rates and currency pairs", () => {
    for (const change of [
        { exchange_from: "GBP" }, { exchange_to: "USD" },
        { rate: undefined }, { rate: "invalid" }, { rate: true },
        { rate: "Infinity" }, { rate: "0" }, { rate: "-1" },
        { ID: undefined }, { ID: "abc" }, { ID: "000" },
    ]) {
        assert.throws(() => parseLemfiQuote({ data: { ...quote, ...change } }));
    }
    assert.throws(() => parseLemfiQuote({}));
});

test("requests the EUR to NGN Netherlands quote with a timeout", async (t) => {
    t.mock.method(globalThis, "fetch", async (url, options) => {
        assert.equal(url.origin + url.pathname, "https://lemfi.com/api/exchange-quote");
        assert.deepEqual(Object.fromEntries(url.searchParams), {
            from: "EUR", to: "NGN", country: "Netherlands", lang: "en",
        });
        assert.ok(options.signal instanceof AbortSignal);
        return { ok: true, json: async () => ({ data: quote }) };
    });
    assert.equal(await fetchLemfiRate(), 1522);
});

test("rejects upstream HTTP and network errors", async (t) => {
    const fetchMock = t.mock.method(globalThis, "fetch", async () => ({ ok: false, status: 503 }));
    await assert.rejects(fetchLemfiRate(), /503/);
    fetchMock.mock.mockImplementation(async () => { throw new Error("Network unavailable"); });
    await assert.rejects(fetchLemfiRate(), /Network unavailable/);
});