import { act, fireEvent, render, screen } from "@testing-library/react";
import { beforeEach } from "vitest";
import { useSessionStore } from "../store/sessionStore";
import { CentralStatus } from "./CentralStatus";

beforeEach(() => useSessionStore.getState().resetSession());

function setScrollGeometry(
  element: HTMLElement,
  values: { scrollHeight: number; clientHeight: number; scrollTop: number },
) {
  Object.defineProperties(element, {
    scrollHeight: { configurable: true, value: values.scrollHeight },
    clientHeight: { configurable: true, value: values.clientHeight },
    scrollTop: { configurable: true, writable: true, value: values.scrollTop },
  });
}

test("renders only the chronological assistant transcript log while working", () => {
  useSessionStore.setState({
    lastUserEntry: { kind: "input", text: "how many patients?" },
    stepMessages: [{ level: "warning", text: "Searching the schema…" }],
    transcript: [
      { role: "assistant", text: "First line\n\nSecond line" },
      { role: "assistant", text: "Third line" },
    ],
  });

  render(<CentralStatus working />);

  const log = screen.getByRole("log", { name: "Live model activity" });
  expect(log).toHaveTextContent("First line");
  expect(log).toHaveTextContent("Second line");
  expect(log).toHaveTextContent("Third line");
  expect(log).toHaveClass("max-h-28", "overflow-y-auto");
  expect(screen.queryByText("how many patients?")).not.toBeInTheDocument();
  expect(screen.queryByText("Searching the schema…")).not.toBeInTheDocument();
  expect(screen.queryByRole("status")).not.toBeInTheDocument();
  expect(screen.queryByText(/\d+s/)).not.toBeInTheDocument();
});

test("wraps live log lines instead of truncating them", () => {
  useSessionStore.setState({
    transcript: [{ role: "assistant", text: "a_very_long_model_activity_line" }],
  });
  render(<CentralStatus working />);
  expect(screen.getByText("a_very_long_model_activity_line")).toHaveClass(
    "whitespace-pre-wrap",
    "break-words",
  );
  expect(screen.getByText("a_very_long_model_activity_line")).not.toHaveClass("truncate");
});

test.each([
  { working: false, transcript: [{ role: "assistant" as const, text: "hidden" }] },
  { working: true, transcript: [] },
  { working: true, transcript: [{ role: "assistant" as const, text: " \n " }] },
])("renders nothing without active non-blank transcript content", ({ working, transcript }) => {
  useSessionStore.setState({ transcript });
  const { container } = render(<CentralStatus working={working} />);
  expect(container).toBeEmptyDOMElement();
});

test("bottom-follows appended transcript text only while near the bottom", () => {
  useSessionStore.setState({ transcript: [{ role: "assistant", text: "First" }] });
  render(<CentralStatus working />);
  const log = screen.getByRole("log", { name: "Live model activity" });
  setScrollGeometry(log, { scrollHeight: 400, clientHeight: 100, scrollTop: 300 });

  act(() => useSessionStore.getState().applyEvent({ type: "text_delta", text: " second" }));

  expect(log.scrollTop).toBe(400);
});

test("preserves manual live-log scroll position away from the bottom", () => {
  useSessionStore.setState({ transcript: [{ role: "assistant", text: "First" }] });
  render(<CentralStatus working />);
  const log = screen.getByRole("log", { name: "Live model activity" });
  setScrollGeometry(log, { scrollHeight: 400, clientHeight: 100, scrollTop: 100 });
  fireEvent.scroll(log);

  act(() => useSessionStore.getState().applyEvent({ type: "text_delta", text: " second" }));

  expect(log.scrollTop).toBe(100);
});