import { content } from "@deadhead/content";
import { describe, expect, it } from "vitest";
import { fuelCost, routeDistance } from "../src/index";

const courier = content.shipModel("courier")!;
const earth = content.location("earth")!;
const moon = content.location("moon")!;

describe("fuel cost", () => {
  it("costs more Earth→Moon than Moon→Earth for the same ship", () => {
    const t = Date.parse("2100-01-01T00:00:00Z");
    const distance = routeDistance(earth, moon, t);
    expect(fuelCost(courier, earth, distance)).toBeGreaterThan(fuelCost(courier, moon, distance));
  });

  it("scales linearly with distance", () => {
    expect(fuelCost(courier, earth, 2)).toBe(2 * fuelCost(courier, earth, 1));
    expect(fuelCost(courier, earth, 10)).toBe(10 * fuelCost(courier, earth, 1));
  });

  it("matches a hand calculation", () => {
    // 0.5M km × 200 credits/M km × Earth multiplier 2.1.
    expect(fuelCost(courier, earth, 0.5)).toBeCloseTo(210);
  });
});