import { describe, expect, it } from "@suaveplan/testing/runner";
import { distanceKm, distanceMetresRaw, distanceNm } from "./distance.js";

const SINGAPORE = { latitude: 1.2644, longitude: 103.8198 };
const ROTTERDAM = { latitude: 51.9, longitude: 4.49 };

describe("distance helpers", () => {
    it("distanceNm zero between identical coords", { timeout: 5000 }, () => {
        expect(distanceNm(SINGAPORE, SINGAPORE)).toBe(0);
    });

    it("distanceKm zero between identical coords", { timeout: 5000 }, () => {
        expect(distanceKm(SINGAPORE, SINGAPORE)).toBe(0);
    });

    it("distanceMetresRaw produces unrounded metres", { timeout: 5000 }, () => {
        const raw = distanceMetresRaw(SINGAPORE, ROTTERDAM);
        expect(raw).toBeGreaterThan(10_000_000);
        expect(raw).toBeLessThan(12_000_000);
    });

    it("Singapore to Rotterdam great-circle is ~5800 nm", {
        timeout: 5000,
    }, () => {
        const nm = distanceNm(SINGAPORE, ROTTERDAM);
        expect(nm).toBeGreaterThan(5600);
        expect(nm).toBeLessThan(6000);
    });

    it("Singapore to Rotterdam great-circle is ~10800 km", {
        timeout: 5000,
    }, () => {
        const km = distanceKm(SINGAPORE, ROTTERDAM);
        expect(km).toBeGreaterThan(10500);
        expect(km).toBeLessThan(11200);
    });

    it("nm * 1.852 ≈ km within 1% tolerance", { timeout: 5000 }, () => {
        const nm = distanceNm(SINGAPORE, ROTTERDAM);
        const km = distanceKm(SINGAPORE, ROTTERDAM);
        const expected = nm * 1.852;
        expect(Math.abs(km - expected) / km).toBeLessThan(0.01);
    });
});