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

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

// Step 15.2 (decision 0.5.93): positions and distances take no time; they never change.
describe("route distance", () => {
  it("keeps Earth→Moon under 1 million km", () => {
    expect(routeDistance(earth, moon)).toBeLessThan(1);
  });

  it("is symmetric", () => {
    for (const a of content.locations) {
      for (const b of content.locations) {
        expect(routeDistance(a, b)).toBe(routeDistance(b, a));
      }
    }
  });

  it("returns the same value for the same inputs, every time", () => {
    for (const a of content.locations) {
      expect(locationPosition(a)).toEqual(locationPosition(a));
      for (const b of content.locations) {
        expect(routeDistance(a, b)).toBe(routeDistance(a, b));
      }
    }
  });
});