import { act, renderHook, waitFor } from "@testing-library/react";
import type { ReactNode } from "react";
import { beforeEach, describe, expect, it, vi } from "vitest";

import { useSessions } from "@/hooks/useSessions";
import * as api from "@/lib/api";
import { ClientProvider } from "@/providers/ClientProvider";

vi.mock("@/lib/api", async (importOriginal) => {
  const actual = await importOriginal<typeof import("@/lib/api")>();
  return {
    ...actual,
    listSessions: vi.fn(),
    deleteSession: vi.fn(),
    fetchSessionMessages: vi.fn(),
  };
});

function fakeClient() {
  return {
    status: "open" as const,
    defaultChatId: null as string | null,
    onStatus: () => () => {},
    onChat: () => () => {},
    sendMessage: vi.fn(),
    newChat: vi.fn(),
    attach: vi.fn(),
    connect: vi.fn(),
    close: vi.fn(),
    updateUrl: vi.fn(),
  };
}

function wrap(client: ReturnType<typeof fakeClient>) {
  return function Wrapper({ children }: { children: ReactNode }) {
    return (
      <ClientProvider
        client={client as unknown as import("@/lib/nanobot-client").NanobotClient}
        token="tok"
      >
        {children}
      </ClientProvider>
    );
  };
}

describe("useSessions", () => {
  beforeEach(() => {
    vi.mocked(api.listSessions).mockReset();
    vi.mocked(api.deleteSession).mockReset();
    vi.mocked(api.fetchSessionMessages).mockReset();
  });

  it("removes a session from the local list after delete succeeds", async () => {
    vi.mocked(api.listSessions).mockResolvedValue([
      {
        key: "websocket:chat-a",
        channel: "websocket",
        chatId: "chat-a",
        createdAt: "2026-04-16T10:00:00Z",
        updatedAt: "2026-04-16T10:00:00Z",
        preview: "Alpha",
      },
      {
        key: "websocket:chat-b",
        channel: "websocket",
        chatId: "chat-b",
        createdAt: "2026-04-16T11:00:00Z",
        updatedAt: "2026-04-16T11:00:00Z",
        preview: "Beta",
      },
    ]);
    vi.mocked(api.deleteSession).mockResolvedValue(true);

    const { result } = renderHook(() => useSessions(), {
      wrapper: wrap(fakeClient()),
    });

    await waitFor(() => expect(result.current.sessions).toHaveLength(2));

    await act(async () => {
      await result.current.deleteChat("websocket:chat-a");
    });

    expect(api.deleteSession).toHaveBeenCalledWith("tok", "websocket:chat-a");
    expect(result.current.sessions.map((s) => s.key)).toEqual(["websocket:chat-b"]);
  });

  it("keeps the session in the list when delete fails", async () => {
    vi.mocked(api.listSessions).mockResolvedValue([
      {
        key: "websocket:chat-a",
        channel: "websocket",
        chatId: "chat-a",
        createdAt: "2026-04-16T10:00:00Z",
        updatedAt: "2026-04-16T10:00:00Z",
        preview: "Alpha",
      },
    ]);
    vi.mocked(api.deleteSession).mockRejectedValue(new Error("boom"));

    const { result } = renderHook(() => useSessions(), {
      wrapper: wrap(fakeClient()),
    });

    await waitFor(() => expect(result.current.sessions).toHaveLength(1));

    await expect(
      act(async () => {
        await result.current.deleteChat("websocket:chat-a");
      }),
    ).rejects.toThrow("boom");

    expect(result.current.sessions.map((s) => s.key)).toEqual(["websocket:chat-a"]);
  });
});