import { describe, expect, test } from "bun:test";
import { createQueryCache } from "./query-cache";

describe("query cache", () => {
  test("returns cached values inside TTL", async () => {
    let now = 1_000;
    const cache = createQueryCache({ ttlMs: 100, maxEntries: 10, now: () => now });
    let calls = 0;

    const first = await cache.cached("key", async () => {
      calls += 1;
      return { value: "first" };
    });
    now += 50;
    const second = await cache.cached("key", async () => {
      calls += 1;
      return { value: "second" };
    });

    expect(first).toEqual({ value: "first" });
    expect(second).toEqual({ value: "first" });
    expect(calls).toBe(1);
  });

  test("refreshes expired values", async () => {
    let now = 1_000;
    const cache = createQueryCache({ ttlMs: 100, maxEntries: 10, now: () => now });

    await cache.cached("key", async () => "first");
    now += 101;
    const second = await cache.cached("key", async () => "second");

    expect(second).toBe("second");
  });

  test("evicts oldest entries beyond max size", async () => {
    const cache = createQueryCache({ ttlMs: 1_000, maxEntries: 2, now: () => 1_000 });
    let calls = 0;

    await cache.cached("a", async () => "a");
    await cache.cached("b", async () => "b");
    await cache.cached("c", async () => "c");
    const value = await cache.cached("a", async () => {
      calls += 1;
      return "new-a";
    });

    expect(value).toBe("new-a");
    expect(calls).toBe(1);
  });
});