import { act } from "react";
import { createRoot } from "react-dom/client";
import { expect, it, vi } from "vitest";
import type { Spec } from "@json-render/core";
import type { AnswerViewStateRecord, AnswerViewStateWrite } from "../api/answer-view-state";
import { AnswerViewStateScope } from "./answer-view-state-scope";
import { useAnswerViewState } from "./use-answer-view-state";

it("keeps rerenders debounced, flushes a switched session and retains drafts across component remounts", async () => {
  vi.useFakeTimers();
  const root = createRoot(document.createElement("div"));
  const spec: Spec = { root: "form", elements: { form: { type: "FollowUpForm", children: [], props: { fields: [{ name: "note", kind: "text" }] } } } };
  const remote = (session: string): AnswerViewStateRecord => ({ version: "answer-view-state@1", message_id: "message", block_id: "block", revision: 0,
    schema_digest: "digest", updated_at: null, nodes: { form: { type: "FollowUpForm", values: { note: session } } }, block: { evidenceFilter: "all" } });
  const client = { getAnswerViewState: vi.fn(async (session: string) => remote(session)),
    putAnswerViewState: vi.fn(async (session: string, state: AnswerViewStateWrite) => ({ ...remote(session), revision: state.expected_revision + 1, nodes: state.nodes })) };
  const scope = new AnswerViewStateScope("actor:project", client);
  let current!: ReturnType<typeof useAnswerViewState>;
  function Probe({ session }: { session: string }) { current = useAnswerViewState(scope, session, "message", "block", spec); return null; }
  try {
    await act(async () => root.render(<Probe session="first" />));
    await act(async () => current.update({ ...current.state, nodes: { form: { type: "FollowUpForm", values: { note: "draft" } } } }, ["/nodes/form/values/note"]));
    await act(async () => root.render(<Probe session="first" />));
    expect(client.putAnswerViewState).not.toHaveBeenCalled();
    await act(async () => root.render(<Probe session="second" />));
    expect(client.putAnswerViewState.mock.calls[0][0]).toBe("first");
    expect(current.state.nodes.form).toMatchObject({ values: { note: "second" } });
    await act(async () => root.render(<Probe session="first" />));
    expect(current.state.nodes.form).toMatchObject({ values: { note: "draft" } });
    expect(client.getAnswerViewState).toHaveBeenCalledTimes(2);
  } finally { await act(async () => root.unmount()); scope.dispose(); vi.useRealTimers(); }
});