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

const earth = content.location("earth")!;
const moon = content.location("moon")!;
const mars = content.location("mars")!;
const ceres = content.location("ceres-station")!;
const jupiter = content.location("jupiter-cloud-platform")!;
const courier = content.shipModel("courier")!;
const freighter = content.shipModel("freighter")!;
const bulkHauler = content.shipModel("bulk-hauler")!;

/** Test-only ship that cannot land on atmospheric worlds. */
const vacuumShip: ShipModel = { ...courier, id: "test-vacuum", landingClass: "vacuum" };

// Every 4 days across 12 years (one Jupiter orbit).
const start = Date.parse("2100-01-01T00:00:00Z");
const samples = Array.from({ length: 1096 }, (_, i) => start + i * 4 * 86_400_000);

/** The sampled time when `to` is closest to (or farthest from) Earth. */
function extremeTime(to: typeof mars, pick: "closest" | "farthest"): number {
  let best = samples[0]!;
  let bestDistance = routeDistance(earth, to, best);
  for (const t of samples) {
    const d = routeDistance(earth, to, t);
    if (pick === "closest" ? d < bestDistance : d > bestDistance) {
      best = t;
      bestDistance = d;
    }
  }
  return best;
}

describe("route eligibility", () => {
  it("lets a Courier fly Earth→Moon and Moon→Earth", () => {
    expect(checkRoute(courier, earth, moon, start)).toEqual({ ok: true });
    expect(checkRoute(courier, moon, earth, start)).toEqual({ ok: true });
  });

  it("keeps a Courier out of range of Mars, Ceres and Jupiter even at their closest", () => {
    for (const to of [mars, ceres, jupiter]) {
      expect(checkRoute(courier, earth, to, extremeTime(to, "closest"))).toEqual({
        ok: false,
        reason: "out-of-range",
      });
    }
  });

  it("rejects a vacuum-only ship at Earth because it cannot land", () => {
    expect(checkRoute(vacuumShip, moon, earth, start)).toEqual({
      ok: false,
      reason: "cannot-land",
    });
    expect(checkRoute(vacuumShip, earth, moon, start)).toEqual({ ok: true });
  });

  it("lets a Freighter reach Mars and Ceres even at their farthest", () => {
    for (const to of [mars, ceres]) {
      expect(checkRoute(freighter, earth, to, extremeTime(to, "farthest"))).toEqual({ ok: true });
    }
  });

  it("lets only the Bulk Hauler reach Jupiter at its farthest", () => {
    const t = extremeTime(jupiter, "farthest");
    expect(checkRoute(bulkHauler, earth, jupiter, t)).toEqual({ ok: true });
    expect(checkRoute(freighter, earth, jupiter, t).ok).toBe(false);
    expect(checkRoute(courier, earth, jupiter, t).ok).toBe(false);
  });

  it("lets a Freighter reach Jupiter at its closest (decision 0.5.25)", () => {
    expect(checkRoute(freighter, earth, jupiter, extremeTime(jupiter, "closest"))).toEqual({
      ok: true,
    });
  });
});