import { act, renderHook } from "@testing-library/react";
import { afterEach, expect, it, vi } from "vitest";
import { useAgentConnection } from "./use-agent-connection";

afterEach(() => vi.useRealTimers());

it("rechecks an offline service, probes on focus and clears work on unmount", async () => {
  vi.useFakeTimers();
  const getHealth = vi.fn().mockRejectedValueOnce(new Error("offline")).mockResolvedValue(undefined);
  const client = { getHealth };
  const { result, unmount } = renderHook(() => useAgentConnection(client, "project-a"));
  await act(async () => {});
  expect(result.current.connectionStatus).toBe("offline");
  await act(async () => vi.advanceTimersByTimeAsync(1_000));
  expect(result.current.connectionStatus).toBe("online");
  expect(result.current.recoveryVersion).toBe(1);
  await act(async () => window.dispatchEvent(new Event("focus")));
  expect(getHealth).toHaveBeenCalledTimes(3);
  unmount();
  expect(vi.getTimerCount()).toBe(0);
});

it("discards a late result from a previous client and scope", async () => {
  vi.useFakeTimers();
  let finish!: () => void;
  let oldSignal!: AbortSignal;
  const oldClient = { getHealth: vi.fn((signal: AbortSignal) => { oldSignal = signal; return new Promise<void>((resolve) => { finish = resolve; }); }) };
  const nextClient = { getHealth: vi.fn(async () => { throw new Error("next service offline"); }) };
  const { result, rerender, unmount } = renderHook(({ client, scope }) => useAgentConnection(client, scope), { initialProps: { client: oldClient, scope: "old" } });
  await act(async () => {});
  rerender({ client: nextClient, scope: "next" });
  await act(async () => {});
  expect(oldSignal.aborted).toBe(true);
  await act(async () => finish());
  expect(result.current.connectionStatus).toBe("offline");
  unmount();
});

it("aborts a stalled probe and recovers on the next retry", async () => {
  vi.useFakeTimers();
  const getHealth = vi.fn().mockImplementationOnce((signal: AbortSignal) => new Promise<void>((_resolve, reject) => {
    signal.addEventListener("abort", () => reject(new DOMException("timeout", "AbortError")), { once: true });
  })).mockResolvedValue(undefined);
  const client = { getHealth };
  const { result, unmount } = renderHook(() => useAgentConnection(client, "project"));
  await act(async () => vi.advanceTimersByTimeAsync(5_000));
  expect(result.current.connectionStatus).toBe("offline");
  await act(async () => vi.advanceTimersByTimeAsync(1_000));
  expect(result.current.connectionStatus).toBe("online");
  unmount();
});