import { render, screen } from "@testing-library/react";
import { beforeEach, describe, expect, it, vi } from "vitest";

// Mock the Unleash React SDK: capture provider props, control flag state.
const sdk = vi.hoisted(() => ({
  on: new Set<string>(),
  providerProps: [] as Record<string, unknown>[],
}));
vi.mock("@unleash/proxy-client-react", () => ({
  FlagProvider: (props: { children: React.ReactNode }) => {
    sdk.providerProps.push(props);
    return props.children;
  },
  useFlag: (name: string) => sdk.on.has(name),
  useVariant: () => ({ name: "disabled", enabled: false }),
}));

import { FlagsProvider, unleashConfig, useFlag } from "./flags";

function Probe() {
  return <p>{useFlag("hello-banner") ? "on" : "off"}</p>;
}

beforeEach(() => {
  sdk.on.clear();
  sdk.providerProps.length = 0;
});

describe("unleashConfig", () => {
  const base = { API_BASE_URL: "/api", APP_NAME: "web" };
  it("is null when UNLEASH_URL or token is unset", () => {
    expect(
      unleashConfig({ ...base, UNLEASH_URL: "", UNLEASH_FRONTEND_TOKEN: "" }),
    ).toBeNull();
    expect(
      unleashConfig({
        ...base,
        UNLEASH_URL: "http://u",
        UNLEASH_FRONTEND_TOKEN: "",
      }),
    ).toBeNull();
  });
  it("points at the Frontend API", () => {
    expect(
      unleashConfig({
        ...base,
        UNLEASH_URL: "http://unleash.test/",
        UNLEASH_FRONTEND_TOKEN: "*:development.x",
      }),
    ).toMatchObject({
      url: "http://unleash.test/api/frontend",
      clientKey: "*:development.x",
      appName: "web",
    });
  });
});

describe("FlagsProvider", () => {
  it("starts the client when configured", () => {
    window.__APP_CONFIG__ = {
      APP_NAME: "web",
      UNLEASH_URL: "http://unleash.test",
      UNLEASH_FRONTEND_TOKEN: "tok",
    };
    sdk.on.add("hello-banner");
    render(
      <FlagsProvider>
        <Probe />
      </FlagsProvider>,
    );
    expect(screen.getByText("on")).toBeInTheDocument();
    expect(sdk.providerProps[0]).toMatchObject({
      startClient: true,
      config: { url: "http://unleash.test/api/frontend", clientKey: "tok" },
    });
  });

  it("stays offline when UNLEASH_URL is unset", () => {
    window.__APP_CONFIG__ = { APP_NAME: "web" };
    const info = vi.spyOn(console, "info").mockImplementation(() => {});
    render(
      <FlagsProvider>
        <Probe />
      </FlagsProvider>,
    );
    expect(screen.getByText("off")).toBeInTheDocument();
    expect(sdk.providerProps[0]).toMatchObject({
      startClient: false,
      config: { disableRefresh: true, disableMetrics: true },
    });
    expect(info).toHaveBeenCalledTimes(1);
  });
});