import { renderHook } from "@testing-library/react";
import { act } from "react";
import { FakeEventSource } from "../test/fakeEventSource";
import { useSessionStream } from "./useSessionStream";
import { useSessionStore } from "../store/sessionStore";

beforeEach(() => {
  FakeEventSource.instances = [];
  (globalThis as any).EventSource = FakeEventSource;
  useSessionStore.getState().resetSession();
});

test("opens an EventSource and feeds NAMED events to the store", () => {
  renderHook(() => useSessionStream("s1"));
  const es = FakeEventSource.instances[0];
  expect(es.url).toBe("http://localhost:8787/sessions/s1/events");
  // Backend sends `event: ui_request` (named) — drive the addEventListener path
  // that production relies on, not the unnamed onmessage fallback.
  act(() =>
    es.emitNamed("ui_request", { type: "ui_request", ui_request: { id: "u1", widget: "select" } })
  );
  expect(useSessionStore.getState().pendingWidget?.id).toBe("u1");
});

test("feeds named activity_delta events to the model activity store", () => {
  renderHook(() => useSessionStream("s1"));
  const es = FakeEventSource.instances[0];

  act(() =>
    es.emitNamed("activity_delta", { type: "activity_delta", text: "Analizzo le ambiguità" })
  );

  expect(useSessionStore.getState().activity.at(-1)?.text).toBe("Analizzo le ambiguità");
});

test("also feeds UNNAMED (default message) events to the store", () => {
  renderHook(() => useSessionStream("s1"));
  const es = FakeEventSource.instances[0];
  act(() => es.emit({ type: "text_delta", text: "hello" }));
  expect(useSessionStore.getState().transcript.at(-1)?.text).toBe("hello");
});

test("closes the stream on unmount", () => {
  const { unmount } = renderHook(() => useSessionStream("s1"));
  const es = FakeEventSource.instances[0];
  unmount();
  expect(es.closed).toBe(true);
});

test("reconnects the same session when the generation changes", () => {
  const { rerender } = renderHook(
    ({ generation }) => useSessionStream("s1", generation),
    { initialProps: { generation: 0 } },
  );
  const first = FakeEventSource.instances[0];

  rerender({ generation: 1 });

  expect(first.closed).toBe(true);
  expect(FakeEventSource.instances).toHaveLength(2);
  expect(FakeEventSource.instances[1].url).toBe(first.url);
});