import { describe, expect, it, vi } from "vitest";

import { BackendReadinessAbortedError } from "./backendReadiness.ts";
import { waitForBackendStartupReady } from "./backendStartupReadiness.ts";

describe("waitForBackendStartupReady", () => {
  it("falls back to the HTTP probe when no listening signal exists", async () => {
    const waitForHttpReady = vi.fn<() => Promise<void>>().mockResolvedValue(undefined);
    const cancelHttpWait = vi.fn();

    await expect(
      waitForBackendStartupReady({
        waitForHttpReady,
        cancelHttpWait,
      }),
    ).resolves.toBe("http");

    expect(waitForHttpReady).toHaveBeenCalledTimes(1);
    expect(cancelHttpWait).not.toHaveBeenCalled();
  });

  it("uses the listening signal and cancels the HTTP probe", async () => {
    let rejectHttpWait: ((error: unknown) => void) | null = null;
    const waitForHttpReady = vi.fn(
      () =>
        new Promise<void>((_resolve, reject) => {
          rejectHttpWait = reject;
        }),
    );
    const cancelHttpWait = vi.fn(() => {
      rejectHttpWait?.(new BackendReadinessAbortedError());
    });

    await expect(
      waitForBackendStartupReady({
        listeningPromise: Promise.resolve(),
        waitForHttpReady,
        cancelHttpWait,
      }),
    ).resolves.toBe("listening");

    expect(waitForHttpReady).toHaveBeenCalledTimes(1);
    expect(cancelHttpWait).toHaveBeenCalledTimes(1);
  });

  it("rejects when the listening signal fails before HTTP readiness", async () => {
    const error = new Error("backend exited");
    const waitForHttpReady = vi.fn(() => new Promise<void>(() => {}));

    await expect(
      waitForBackendStartupReady({
        listeningPromise: Promise.reject(error),
        waitForHttpReady,
        cancelHttpWait: vi.fn(),
      }),
    ).rejects.toBe(error);
  });
});