import type { ModuleUiHostContext } from "@ekklesia/module-ui-sdk";
import { act, Component, type ReactElement, type ReactNode } from "react";
import { createRoot, type Root } from "react-dom/client";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import { HostApp } from "../src/browser/HostApp.js";
import { DisplayApp } from "../src/display/DisplayApp.js";
import type {
  EkklesiaHostConfig,
  HostEventSourceFactory,
  HostEventSourceOptions,
} from "../src/host-protocol.js";

declare global {
  // eslint-disable-next-line no-var
  var IS_REACT_ACT_ENVIRONMENT: boolean | undefined;
}

const apiBaseUrl = "https://ekklesia.example.test";

let container: HTMLDivElement;
let root: Root;
let consoleError: ReturnType<typeof vi.spyOn>;

beforeEach(() => {
  globalThis.IS_REACT_ACT_ENVIRONMENT = true;
  container = document.createElement("div");
  document.body.append(container);
  root = createRoot(container);
  consoleError = vi.spyOn(console, "error").mockImplementation(() => undefined);
});

afterEach(async () => {
  await act(async () => root.unmount());
  container.remove();
  consoleError.mockRestore();
});

function descriptorPayload(
  id = "announcements",
  version = "1.2.0",
  viewer: unknown = {
    kind: "authenticated",
    userId: "user-1",
  },
) {
  return {
    viewer,
    module: {
      api: { baseUrl: `/api/v1/modules/${id}` },
      display: { url: `/api/v1/module-ui/${id}/${version}/display` },
      id,
      permissions: [`${id}.slideshow.view`],
      realtime: { baseUrl: `/api/v1/module-realtime/${id}` },
      version,
    },
  };
}

function json(body: unknown, status = 200): Response {
  return new Response(JSON.stringify(body), {
    headers: { "content-type": "application/json" },
    status,
  });
}

interface PlatformOptions {
  readonly descriptorStatus?: number;
  readonly principal?: unknown;
}

function platform(options: PlatformOptions = {}) {
  const calls: Array<{ readonly init: RequestInit | undefined; readonly url: string }> = [];
  const fetch = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
    const url = String(input);
    calls.push({ init, url });
    if (url.endsWith("/api/v1/principal")) {
      return json(options.principal ?? { kind: "authenticated", userId: "user-1" });
    }
    if (url.endsWith("/api/v1/module-displays/announcements")) {
      return json(descriptorPayload(), options.descriptorStatus ?? 200);
    }
    if (url.endsWith("/api/v1/device-pairing/requests")) {
      return json(
        { code: "482731", expiresAt: new Date().toISOString(), pollIntervalMs: 60_000 },
        201,
      );
    }
    if (url.endsWith("/api/v1/device-pairing/claims")) {
      return json({ status: "pending" });
    }
    if (url.endsWith("/api/v1/modules/announcements/slides")) {
      return json([{ id: "slide-1" }]);
    }
    return json({ code: "NOT_FOUND" }, 404);
  }) as unknown as typeof globalThis.fetch;
  return { calls, fetch };
}

class FakeEventSource {
  readonly CLOSED = 2 as const;
  readonly CONNECTING = 0 as const;
  readonly OPEN = 1 as const;
  readonly listeners = new Map<string, Set<EventListener>>();
  closeCalls = 0;
  readyState: number = this.CONNECTING;

  addEventListener(type: string, listener: EventListener): void {
    const listeners = this.listeners.get(type) ?? new Set<EventListener>();
    listeners.add(listener);
    this.listeners.set(type, listeners);
  }

  removeEventListener(type: string, listener: EventListener): void {
    this.listeners.get(type)?.delete(listener);
  }

  close(): void {
    this.closeCalls += 1;
    this.readyState = this.CLOSED;
  }

  emit(type: string, data?: string): void {
    if (type === "open") {
      this.readyState = this.OPEN;
    }
    const event = Object.freeze({ data, type }) as unknown as Event;
    for (const listener of this.listeners.get(type) ?? []) {
      listener(event);
    }
  }
}

function eventSources() {
  const calls: Array<{
    readonly options: HostEventSourceOptions;
    readonly source: FakeEventSource;
    readonly url: string;
  }> = [];
  const factory = ((url: string, options: HostEventSourceOptions): EventSource => {
    const source = new FakeEventSource();
    calls.push({ options, source, url });
    return source as unknown as EventSource;
  }) as HostEventSourceFactory;
  return { calls, factory };
}

function artifact(
  id = "announcements",
  version = "1.2.0",
  options: {
    readonly cleanup?: () => void;
    readonly mount?: (container: Element, context: ModuleUiHostContext) => undefined | (() => void);
  } = {},
) {
  return {
    default: {
      id,
      mount(element: Element, context: ModuleUiHostContext) {
        if (options.mount) {
          return options.mount(element, context);
        }
        element.textContent = `${context.moduleId}:display`;
        return () => {
          options.cleanup?.();
          element.replaceChildren();
        };
      },
      version,
    },
  };
}

async function render(
  config: EkklesiaHostConfig,
  importModule?: (url: string) => Promise<unknown>,
  moduleId = "announcements",
): Promise<void> {
  await act(async () => {
    root.render(
      <DisplayApp
        config={config}
        {...(importModule ? { importModule } : {})}
        moduleId={moduleId}
      />,
    );
  });
}

function query(testId: string): HTMLElement | null {
  return container.querySelector(`[data-testid="${testId}"]`);
}

function moduleUrl(source: string): string {
  return `data:text/javascript;base64,${Buffer.from(source, "utf8").toString("base64")}`;
}

describe("display host — full-viewport boundary", () => {
  it("mounts only the display artifact with no Dashboard chrome", async () => {
    const server = platform();
    const imported: string[] = [];
    await render({ apiBaseUrl, fetch: server.fetch }, async (url) => {
      imported.push(url);
      return artifact();
    });

    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/announcements/1.2.0/display`]);
    expect(query("display-module-container")?.textContent).toBe("announcements:display");
    expect(container.querySelector("header")).toBeNull();
    expect(container.querySelector("nav")).toBeNull();
    expect(container.querySelector("aside")).toBeNull();
    expect(container.textContent).not.toContain("Ekklesia");
    expect(query("display-host")?.style.height).toBe("100%");
    expect(query("display-host")?.style.minHeight).toBe("100dvh");
  });

  it("constructs the same browser-safe API, principal, permission, and realtime context", async () => {
    const server = platform();
    const live = eventSources();
    let seenContext: ModuleUiHostContext | undefined;
    await render({ apiBaseUrl, eventSourceFactory: live.factory, fetch: server.fetch }, async () =>
      artifact("announcements", "1.2.0", {
        mount(element, context) {
          seenContext = context;
          void context.api.request("slides");
          const subscription = context.realtime.subscribe("state", {});
          element.textContent = context.permissions.has("announcements.slideshow.view")
            ? "permitted"
            : "denied";
          return () => subscription.close();
        },
      }),
    );

    expect(Object.keys(seenContext ?? {}).sort()).toEqual([
      "api",
      "moduleId",
      "permissions",
      "principal",
      "realtime",
    ]);
    expect(seenContext?.principal).toEqual({ kind: "authenticated", userId: "user-1" });
    expect(query("display-module-container")?.textContent).toBe("permitted");
    expect(
      server.calls.some((call) => call.url.endsWith("/api/v1/modules/announcements/slides")),
    ).toBe(true);
    expect(live.calls[0]).toMatchObject({
      options: { withCredentials: true },
      url: `${apiBaseUrl}/api/v1/module-realtime/announcements/state`,
    });
  });

  it("uses a genuine dynamic import and renders an Announcements snapshot with its direct object URL unchanged", async () => {
    const server = platform();
    const live = eventSources();
    const requestedArtifacts: string[] = [];
    const source = `
      export default {
        id: "announcements",
        version: "1.2.0",
        mount(container, context) {
          const image = document.createElement("img");
          image.setAttribute("data-testid", "announcement-slide");
          container.append(image);
          const subscription = context.realtime.subscribe("state", {
            onSnapshot(state) {
              image.src = state.mode === "on" ? state.slides[state.currentSlide].url : "";
            },
            onUpdate(state) {
              image.src = state.mode === "on" ? state.slides[state.currentSlide].url : "";
            },
          });
          return () => { subscription.close(); container.replaceChildren(); };
        },
      };
    `;

    await render(
      { apiBaseUrl, eventSourceFactory: live.factory, fetch: server.fetch },
      async (url) => {
        requestedArtifacts.push(url);
        return import(moduleUrl(source));
      },
    );

    const deliveryUrl =
      "https://objects.example.test/ekklesia-announcements-assets/slides%2Fwelcome.jpg?X-Amz-Signature=opaque";
    await act(async () => {
      live.calls[0]?.source.emit("open");
      live.calls[0]?.source.emit(
        "snapshot",
        JSON.stringify({
          payload: {
            currentSlide: 0,
            mode: "on",
            slideSeconds: 7,
            slides: [{ url: deliveryUrl }],
          },
          sequence: 1,
        }),
      );
    });

    expect(requestedArtifacts).toEqual([
      `${apiBaseUrl}/api/v1/module-ui/announcements/1.2.0/display`,
    ]);
    expect(container.querySelector('[data-testid="announcement-slide"]')?.getAttribute("src")).toBe(
      deliveryUrl,
    );
    expect(container.innerHTML).not.toContain("socket.io");
    expect(container.innerHTML).not.toContain("mqtt");
  });

  it("keeps one Announcements-shaped module's management and slideshow roots distinct", async () => {
    const live = eventSources();
    const requestedArtifacts: string[] = [];
    const fetch = vi.fn(async (input: RequestInfo | URL) => {
      const url = String(input);
      if (url.endsWith("/api/v1/principal")) {
        return json({ kind: "authenticated", userId: "user-1" });
      }
      if (url.endsWith("/api/v1/dashboard/navigation")) {
        return json({
          groups: [],
          ungrouped: [
            {
              module: {
                api: { baseUrl: "/api/v1/modules/announcements" },
                id: "announcements",
                permissions: ["announcements.slideshow.view"],
                realtime: { baseUrl: "/api/v1/module-realtime/announcements" },
                ui: { url: "/api/v1/module-ui/announcements/1.2.0" },
                version: "1.2.0",
              },
              name: "Announcements",
            },
          ],
        });
      }
      if (url.endsWith("/api/v1/module-displays/announcements")) {
        return json(descriptorPayload());
      }
      return json({ code: "NOT_FOUND" }, 404);
    }) as unknown as typeof globalThis.fetch;
    const config = { apiBaseUrl, eventSourceFactory: live.factory, fetch };
    const importer = async (url: string): Promise<unknown> => {
      requestedArtifacts.push(url);
      if (!url.endsWith("/display")) {
        return artifact("announcements", "1.2.0", {
          mount(element) {
            element.textContent = "announcement management";
            return () => element.replaceChildren();
          },
        });
      }
      return artifact("announcements", "1.2.0", {
        mount(element, context) {
          const image = document.createElement("img");
          image.dataset.testid = "both-role-slide";
          element.append(image);
          const subscription = context.realtime.subscribe<{
            readonly currentSlide: number;
            readonly mode: "off" | "on";
            readonly slides: readonly { readonly url: string }[];
          }>("state", {
            onSnapshot(state) {
              image.src = state.mode === "on" ? (state.slides[state.currentSlide]?.url ?? "") : "";
            },
          });
          return () => {
            subscription.close();
            element.replaceChildren();
          };
        },
      });
    };

    await act(async () => root.render(<HostApp config={config} importModule={importer} />));
    expect(container.textContent).toContain("announcement management");
    expect(container.querySelector("nav")).not.toBeNull();
    expect(requestedArtifacts).toEqual([`${apiBaseUrl}/api/v1/module-ui/announcements/1.2.0`]);

    await act(async () => root.unmount());
    root = createRoot(container);
    await act(async () =>
      root.render(<DisplayApp config={config} importModule={importer} moduleId="announcements" />),
    );
    const deliveryUrl =
      "https://objects.example.test/module-assets/slide.jpg?X-Amz-Signature=opaque";
    await act(async () => {
      live.calls[0]?.source.emit("open");
      live.calls[0]?.source.emit(
        "snapshot",
        JSON.stringify({
          payload: { currentSlide: 0, mode: "on", slides: [{ url: deliveryUrl }] },
          sequence: 1,
        }),
      );
    });

    expect(requestedArtifacts).toEqual([
      `${apiBaseUrl}/api/v1/module-ui/announcements/1.2.0`,
      `${apiBaseUrl}/api/v1/module-ui/announcements/1.2.0/display`,
    ]);
    expect(container.querySelector('[data-testid="both-role-slide"]')?.getAttribute("src")).toBe(
      deliveryUrl,
    );
    expect(container.querySelector("nav")).toBeNull();
    expect(container.querySelector("header")).toBeNull();
    expect(JSON.stringify(requestedArtifacts)).not.toMatch(/socket\.io|mqtt|10\.|localhost/u);
  });
});

describe("display host — authentication and controlled failures", () => {
  it("shows a pairing code instead of a human login when it has no identity", async () => {
    const server = platform({ descriptorStatus: 403 });
    const importer = vi.fn(async () => artifact());

    await render({ apiBaseUrl, fetch: server.fetch }, importer);

    // An unattended screen must never be sent to an email/password form: nobody is standing at it.
    expect(query("display-host-signed-out")).toBeNull();
    expect(query("display-pairing")).not.toBeNull();
    expect(query("display-pairing-code")?.textContent).toBe("482731");
    // The protected artifact is still not fetched, which is the invariant that matters.
    expect(importer).not.toHaveBeenCalled();
    // And the display never asks the human principal endpoint at all.
    expect(server.calls.some((call) => call.url.endsWith("/api/v1/principal"))).toBe(false);
  });

  it("puts no request id, secret, or permission on a screen anyone can read", async () => {
    const server = platform({ descriptorStatus: 403 });
    await render(
      { apiBaseUrl, fetch: server.fetch },
      vi.fn(async () => artifact()),
    );

    const rendered = container.textContent ?? "";
    expect(rendered).toContain("482731");
    expect(rendered).not.toMatch(/announcements\.slideshow\.view|device-pairing|claim|token/u);
  });

  it("does not import protected display code when the display is unavailable", async () => {
    const server = platform({ descriptorStatus: 404 });
    const importer = vi.fn(async () => artifact());

    await render({ apiBaseUrl, fetch: server.fetch }, importer);

    // 404 is "there is no such display", which pairing cannot fix — so it stays a plain message.
    expect(query("display-host-unavailable")).not.toBeNull();
    expect(query("display-pairing")).toBeNull();
    expect(importer).not.toHaveBeenCalled();
  });

  it("clears partial mount DOM, renders no caught detail, and retries in a fresh container", async () => {
    const server = platform();
    let attempts = 0;
    const containers: Element[] = [];
    const importer = vi.fn(async () => {
      attempts += 1;
      return artifact("announcements", "1.2.0", {
        mount(element) {
          containers.push(element);
          if (attempts === 1) {
            element.textContent = "secret at /srv/modules/announcements";
            throw new Error("mount exploded with token=secret");
          }
          element.textContent = "recovered";
          return () => element.replaceChildren();
        },
      });
    });

    await render({ apiBaseUrl, fetch: server.fetch }, importer);

    expect(query("display-error")).not.toBeNull();
    expect(container.textContent).not.toContain("/srv/");
    expect(container.textContent).not.toContain("secret");
    await act(async () => query("display-retry")?.click());

    expect(query("display-error")).toBeNull();
    expect(query("display-module-container")?.textContent).toBe("recovered");
    expect(containers).toHaveLength(2);
    expect(containers[0]).not.toBe(containers[1]);
    expect(containers[0]?.isConnected).toBe(false);
    expect(consoleError).toHaveBeenCalledWith(
      "[ekklesia] display UI failure module=announcements code=MODULE_UI_MOUNT_FAILED",
    );
  });

  it.each([
    "error",
    "unhandledrejection",
  ] as const)("turns a post-mount page %s into one sanitized failure with manual retry", async (eventType) => {
    const server = platform();
    const cleanups: Element[] = [];
    const mountedInto: Element[] = [];
    const importer = vi.fn(async () =>
      artifact("announcements", "1.2.0", {
        mount(element) {
          mountedInto.push(element);
          element.textContent = "private render at /srv/modules/announcements";
          return () => {
            cleanups.push(element);
            element.replaceChildren();
          };
        },
      }),
    );

    await render({ apiBaseUrl, fetch: server.fetch }, importer);
    expect(query("display-module-container")?.textContent).toContain("/srv/modules");
    consoleError.mockClear();

    await act(async () => {
      const event =
        eventType === "error"
          ? new ErrorEvent("error", {
              error: new Error("token=secret-render-error"),
              message: "token=secret-render-error",
            })
          : new Event("unhandledrejection");
      window.dispatchEvent(event);
      // A second signal from the same failed render must not run cleanup or transition twice.
      window.dispatchEvent(new Event(eventType));
    });

    expect(query("display-error")).not.toBeNull();
    expect(query("display-module-container")?.textContent).toBe("");
    expect(container.textContent).toBe("This display could not be loaded.Retry");
    expect(container.textContent).not.toMatch(/secret|\/srv\//u);
    expect(importer).toHaveBeenCalledTimes(1);
    expect(cleanups).toEqual([mountedInto[0]]);
    expect(consoleError).toHaveBeenCalledTimes(1);
    expect(consoleError).toHaveBeenCalledWith(
      `[ekklesia] display UI failure module=announcements code=${
        eventType === "error" ? "DISPLAY_UI_RUNTIME_ERROR" : "DISPLAY_UI_UNHANDLED_REJECTION"
      }`,
    );

    await act(async () => query("display-retry")?.click());

    expect(importer).toHaveBeenCalledTimes(2);
    expect(query("display-error")).toBeNull();
    expect(query("display-module-container")?.textContent).toContain("/srv/modules");
    expect(mountedInto[0]?.isConnected).toBe(false);
    expect(mountedInto[1]?.isConnected).toBe(true);
  });

  it("catches a React render failure reported after the artifact mount has returned", async () => {
    const server = platform();
    const cleanup = vi.fn();
    await render({ apiBaseUrl, fetch: server.fetch }, async () =>
      artifact("announcements", "1.2.0", {
        mount(element) {
          const moduleRoot = createRoot(element);
          class ReportRenderFailure extends Component<{ readonly children: ReactNode }> {
            override componentDidCatch(error: unknown): void {
              // React's browser default reports an uncaught render through the page's global error
              // facility. This test boundary makes that report deterministic under happy-dom,
              // whose test runner otherwise intercepts the global exception first.
              window.dispatchEvent(
                new ErrorEvent("error", {
                  cancelable: true,
                  error,
                  message: error instanceof Error ? error.message : "display render failure",
                }),
              );
            }

            override render(): ReactNode {
              return this.props.children;
            }
          }
          const BrokenDisplay = (): ReactElement => {
            throw new Error("late component secret at /srv/modules/announcements");
          };
          moduleRoot.render(
            <ReportRenderFailure>
              <BrokenDisplay />
            </ReportRenderFailure>,
          );
          return () => {
            cleanup();
            moduleRoot.unmount();
          };
        },
      }),
    );

    await act(async () => undefined);

    expect(query("display-error")).not.toBeNull();
    expect(container.textContent).toBe("This display could not be loaded.Retry");
    expect(container.textContent).not.toMatch(/secret|\/srv\//u);
    expect(cleanup).toHaveBeenCalledTimes(1);
  });

  it("does not treat a module media/resource error as a crashed display runtime", async () => {
    const server = platform();
    const cleanup = vi.fn();
    await render({ apiBaseUrl, fetch: server.fetch }, async () =>
      artifact("announcements", "1.2.0", {
        mount(element) {
          const image = document.createElement("img");
          image.dataset.testid = "display-media";
          element.append(image);
          return () => cleanup();
        },
      }),
    );

    await act(async () => {
      container.querySelector('[data-testid="display-media"]')?.dispatchEvent(
        new ErrorEvent("error", {
          bubbles: true,
          cancelable: true,
          message: "a signed media URL expired",
        }),
      );
    });

    expect(query("display-error")).toBeNull();
    expect(query("display-media")).not.toBeNull();
    expect(cleanup).not.toHaveBeenCalled();
  });

  it("removes the page failure listeners when a display attempt is torn down", async () => {
    const server = platform();
    const cleanup = vi.fn();
    await render({ apiBaseUrl, fetch: server.fetch }, async () =>
      artifact("announcements", "1.2.0", { cleanup }),
    );

    await act(async () => root.render(null));
    expect(cleanup).toHaveBeenCalledTimes(1);
    consoleError.mockClear();

    window.dispatchEvent(new ErrorEvent("error", { message: "after teardown" }));
    window.dispatchEvent(new Event("unhandledrejection"));

    expect(cleanup).toHaveBeenCalledTimes(1);
    expect(consoleError).not.toHaveBeenCalled();
  });
});

describe("display host — independent instances and stale work", () => {
  it("mounts and unmounts two browser instances independently", async () => {
    const server = platform();
    const cleanups: string[] = [];
    const importer = async () =>
      artifact("announcements", "1.2.0", {
        cleanup: () => cleanups.push("cleanup"),
      });
    const config = { apiBaseUrl, fetch: server.fetch };

    await act(async () => {
      root.render(
        <>
          <DisplayApp
            config={config}
            importModule={importer}
            key="first"
            moduleId="announcements"
          />
          <DisplayApp
            config={config}
            importModule={importer}
            key="second"
            moduleId="announcements"
          />
        </>,
      );
    });
    expect(container.querySelectorAll('[data-testid="display-module-container"]')).toHaveLength(2);

    await act(async () => {
      root.render(
        <DisplayApp
          config={config}
          importModule={importer}
          key="second"
          moduleId="announcements"
        />,
      );
    });

    expect(cleanups).toHaveLength(1);
    expect(container.querySelectorAll('[data-testid="display-module-container"]')).toHaveLength(1);
    expect(query("display-module-container")?.textContent).toBe("announcements:display");
  });

  it("discards a late import into its detached container without disturbing the newer route", async () => {
    let releaseAnnouncements: (() => void) | undefined;
    const pendingAnnouncements = new Promise<void>((resolve) => {
      releaseAnnouncements = resolve;
    });
    const mountedInto: Element[] = [];
    const staleUnmounts: Element[] = [];
    const fetch = vi.fn(async (input: RequestInfo | URL) => {
      const url = String(input);
      if (url.endsWith("/api/v1/principal")) {
        return json({ kind: "authenticated", userId: "user-1" });
      }
      if (url.endsWith("/api/v1/module-displays/calendar")) {
        return json(descriptorPayload("calendar", "2.0.0"));
      }
      return json(descriptorPayload());
    }) as unknown as typeof globalThis.fetch;
    const config = { apiBaseUrl, fetch };
    const importer = async (url: string): Promise<unknown> => {
      const isCalendar = url.includes("/calendar/");
      if (!isCalendar) {
        await pendingAnnouncements;
      }
      return artifact(isCalendar ? "calendar" : "announcements", isCalendar ? "2.0.0" : "1.2.0", {
        mount(element) {
          mountedInto.push(element);
          element.textContent = isCalendar ? "calendar-live" : "announcements-stale";
          return () => {
            if (!isCalendar) {
              staleUnmounts.push(element);
            }
            element.replaceChildren();
          };
        },
      });
    };

    await render(config, importer);
    await render(config, importer, "calendar");
    expect(query("display-module-container")?.textContent).toBe("calendar-live");
    const liveContainer = query("display-module-container");

    await act(async () => {
      releaseAnnouncements?.();
      await pendingAnnouncements;
    });

    expect(query("display-module-container")).toBe(liveContainer);
    expect(liveContainer?.textContent).toBe("calendar-live");
    const staleContainer = mountedInto.find((element) => element !== liveContainer);
    expect(staleContainer?.isConnected).toBe(false);
    expect(staleUnmounts).toEqual([staleContainer]);
  });
});