import { act } from "react";
import { createRoot, type Root } from "react-dom/client";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import { DisplaysSettingsPage } from "../src/browser/DisplaysSettingsPage.js";

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

/**
 * Settings → Displays (ADR 0064, ADR 0065): the active platform displays, setting up a new screen,
 * pairing it, changing what it shows, and revoking it.
 */

const apiBaseUrl = "https://ekklesia.example.test";
const NOW = new Date("2026-10-15T12:00:00.000Z");

/** A screen that asked from Signage's own display page. */
const MODULE_CODE = "123456";
/** A screen that asked from the platform's `/display/setup`, with no module. */
const PLATFORM_CODE = "654321";

let container: HTMLDivElement;
let root: Root;

beforeEach(() => {
  globalThis.IS_REACT_ACT_ENVIRONMENT = true;
  container = document.createElement("div");
  document.body.append(container);
  root = createRoot(container);
});

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

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

interface Device {
  id: string;
  name: string;
  createdAt: string;
  lastSeenAt?: string;
  permissions: string[];
  revoked: boolean;
}

interface ServerOptions {
  readonly devices?: Device[];
  readonly denied?: boolean;
  /** What `GET /api/v1/devices/display-modules` answers. */
  readonly modules?: unknown[] | "fails";
}

const SIGNAGE = { moduleId: "signage", name: "Signage", permissionId: "signage.display" };
const BULLETIN = { moduleId: "bulletin", name: "Bulletin", permissionId: "bulletin.display" };

/**
 * A fake API that behaves like the real one where it matters: an approved display does not exist
 * until its screen collects its credential, which here happens a couple of list requests later.
 */
function server(options: ServerOptions = {}) {
  const devices: Device[] = options.devices ?? [
    {
      createdAt: "2026-10-01T09:00:00.000Z",
      id: "device-1",
      lastSeenAt: "2026-10-15T11:50:00.000Z",
      name: "Foyer TV",
      permissions: [],
      revoked: false,
    },
  ];
  const modules =
    options.modules === "fails" ? [] : ((options.modules ?? [SIGNAGE]) as (typeof SIGNAGE)[]);
  let pending: { device: Device; listsUntilClaimed: number } | undefined;
  const requests: { path: string; method: string; body: unknown }[] = [];
  const fetch = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
    const path = new URL(String(input)).pathname;
    const method = init?.method ?? "GET";
    const body = init?.body === undefined ? undefined : JSON.parse(String(init.body));
    requests.push({ body, method, path });
    if (path === "/api/v1/devices/display-modules") {
      return options.modules === "fails"
        ? json({ code: "DEVICE_LOOKUP_UNAVAILABLE" }, 503)
        : json({ modules });
    }
    if (path === "/api/v1/devices") {
      if (options.denied) {
        return json({ code: "AUTHORIZATION_DENIED" }, 403);
      }
      if (pending !== undefined) {
        pending.listsUntilClaimed -= 1;
        if (pending.listsUntilClaimed <= 0) {
          devices.push(pending.device);
          pending = undefined;
        }
      }
      return json({ devices });
    }
    const display = /^\/api\/v1\/devices\/([^/]+)\/display$/u.exec(path);
    if (display && method === "PUT") {
      const device = devices.find((candidate) => candidate.id === display[1]);
      const moduleId = (body as { moduleId: string | null }).moduleId;
      const module = modules.find((candidate) => candidate.moduleId === moduleId);
      if (!device || device.revoked || (moduleId !== null && !module)) {
        return json({ code: "NOT_FOUND" }, 404);
      }
      device.permissions = module ? [module.permissionId] : [];
      return json({ moduleId });
    }
    const revoke = /^\/api\/v1\/devices\/([^/]+)\/revoke$/u.exec(path);
    if (revoke) {
      for (const device of devices) {
        if (device.id === revoke[1]) {
          device.revoked = true;
          device.permissions = [];
        }
      }
      return new Response(null, { status: 204 });
    }
    if (path === "/api/v1/device-pairing/lookups") {
      const code = (body as { code: string }).code;
      if (code !== MODULE_CODE && code !== PLATFORM_CODE) {
        return json({ code: "DEVICE_PAIRING_NOT_FOUND" }, 404);
      }
      const module = code === MODULE_CODE;
      return json({
        expiresAt: "2026-10-15T12:10:00.000Z",
        moduleId: module ? "signage" : null,
        permissionId: module ? "signage.display" : null,
        requestedAt: "2026-10-15T11:59:00.000Z",
      });
    }
    if (path === "/api/v1/device-pairing/approvals") {
      const approval = body as { code: string; deviceName: string; moduleId?: string };
      const shows = approval.code === MODULE_CODE ? "signage" : approval.moduleId;
      const module = modules.find((candidate) => candidate.moduleId === shows);
      pending = {
        device: {
          createdAt: "2026-10-15T12:00:00.000Z",
          id: `device-${devices.length + 1}`,
          name: approval.deviceName,
          permissions: module ? [module.permissionId] : [],
          revoked: false,
        },
        listsUntilClaimed: 2,
      };
      return json({ moduleId: shows ?? null, permissionId: module?.permissionId ?? null });
    }
    return json({ code: "NOT_FOUND" }, 404);
  }) as unknown as typeof globalThis.fetch;
  return { devices, fetch, requests };
}

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

function required(testId: string): HTMLElement {
  const element = query(testId);
  if (!element) {
    throw new Error(`missing ${testId}`);
  }
  return element;
}

async function settle(): Promise<void> {
  for (let index = 0; index < 6; index += 1) {
    await new Promise((resolve) => setTimeout(resolve, 0));
  }
}

/** Waits, in real time, for something the page does on its own (a revalidation). */
async function eventually(condition: () => boolean, timeoutMs = 2000): Promise<void> {
  const deadline = Date.now() + timeoutMs;
  while (!condition()) {
    if (Date.now() > deadline) {
      throw new Error("timed out");
    }
    await act(async () => {
      await new Promise((resolve) => setTimeout(resolve, 10));
    });
  }
}

async function click(testId: string): Promise<void> {
  await act(async () => {
    required(testId).click();
    await settle();
  });
}

async function type(testId: string, value: string): Promise<void> {
  const input = required(testId) as HTMLInputElement;
  await act(async () => {
    const setter = Object.getOwnPropertyDescriptor(HTMLInputElement.prototype, "value")?.set;
    setter?.call(input, value);
    input.dispatchEvent(new Event("input", { bubbles: true }));
  });
}

async function submit(testId: string): Promise<void> {
  const form = (required(testId) as HTMLButtonElement).form;
  await act(async () => {
    form?.requestSubmit();
    await settle();
  });
}

/** Opens a SelectMenu and chooses an option by its label, as a pointer would. */
async function choose(testId: string, label: string): Promise<void> {
  await click(testId);
  const listId = required(testId).getAttribute("aria-controls") ?? "";
  const option = [...(container.querySelector(`#${CSS.escape(listId)}`)?.children ?? [])].find(
    (candidate) => candidate.textContent === label,
  ) as HTMLElement | undefined;
  if (!option) {
    throw new Error(`no option ${label}`);
  }
  await act(async () => {
    option.click();
    await settle();
  });
}

async function renderPage(options: ServerOptions = {}) {
  const platform = server(options);
  await act(async () => {
    root.render(
      <DisplaysSettingsPage
        back={{ href: "/settings", label: "Back to Settings", onBack: () => undefined }}
        config={{ apiBaseUrl, fetch: platform.fetch }}
        moduleName={(moduleId) => (moduleId === "signage" ? "Signage" : undefined)}
        now={() => NOW}
        pollMs={5}
        refreshMs={0}
      />,
    );
    await settle();
  });
  return platform;
}

describe("Settings → Displays", () => {
  it("lists each active display with its status, what it shows, and its actions", async () => {
    const before = document.activeElement;
    await renderPage();

    const card = required("device-device-1");
    expect(card.textContent).toContain("Foyer TV");
    expect(card.textContent).toContain("Online");
    expect(required("device-device-1-showing").textContent).toBe("Showing: Nothing yet");
    expect(card.textContent).toContain("Last seen within the last hour");
    expect(query("device-change-device-1")?.textContent).toBe("Change");
    expect(query("device-revoke-device-1")?.textContent).toBe("Remove");
    expect(container.querySelector("h1")?.textContent).toBe("Displays");
    // Setting up a new screen comes first, in one place, at the platform's own setup address.
    const setup = required("display-setup");
    expect(required("display-setup-url").textContent).toBe(`${apiBaseUrl}/display/setup`);
    expect(setup.contains(required("add-display"))).toBe(true);
    expect((required("display-setup-steps") as HTMLDetailsElement).open).toBe(false);
    // No pairing form until someone asks for one, and nothing grabbed focus.
    expect(container.querySelector("input")).toBeNull();
    expect(document.activeElement).toBe(before);
  });

  it("shows only active displays: removed ones are history, not the normal list", async () => {
    await renderPage({
      devices: [
        {
          createdAt: "2026-10-01T09:00:00.000Z",
          id: "a",
          name: "Hall",
          permissions: [],
          revoked: false,
        },
        {
          createdAt: "2026-09-01T09:00:00.000Z",
          id: "b",
          name: "Old test screen",
          permissions: [],
          revoked: true,
        },
        {
          createdAt: "2026-09-02T09:00:00.000Z",
          id: "c",
          name: "Another old one",
          permissions: [],
          revoked: true,
        },
      ],
    });
    expect(query("device-a")).not.toBeNull();
    expect(query("device-b")).toBeNull();
    expect(query("device-c")).toBeNull();
    // Removed displays are never described as "revoked" in the normal interface.
    expect(container.textContent).not.toMatch(/revok/iu);
    expect(required("device-a").textContent).toContain("Not connected yet");
  });

  it("says when nothing is paired yet, and when the list is not this person's to see", async () => {
    await renderPage({ devices: [] });
    expect(required("device-list-empty").textContent).toContain("No displays are paired yet");

    await act(async () => root.unmount());
    root = createRoot(container);
    await renderPage({ denied: true });
    expect(container.textContent).toContain("Displays aren't available to you");
    expect(query("add-display")).toBeNull();
  });

  it("shows a newly paired display without a page refresh, once its screen connects", async () => {
    const platform = await renderPage();

    await click("add-display");
    expect(document.activeElement).toBe(required("device-pairing-code-input"));
    await type("device-pairing-code-input", "999999");
    await submit("device-pairing-lookup");
    expect(required("device-pairing-error").textContent).toContain("not waiting for approval");

    await type("device-pairing-code-input", MODULE_CODE);
    await submit("device-pairing-lookup");
    expect(required("device-pairing-found").textContent).toContain("Signage");
    expect(query("device-pairing-shows")).toBeNull();
    expect(document.activeElement).toBe(required("device-pairing-name"));
    await type("device-pairing-name", "Sanctuary left");
    await submit("device-pairing-approve");

    // The dialog closes and the page says so at once; the screen has not connected yet.
    expect(query("add-display-dialog")).toBeNull();
    expect(required("device-pairing-success").textContent).toContain(
      "Sanctuary left is paired and shows Signage.",
    );
    expect(required("device-awaiting").textContent).toContain("Waiting for the screen to connect");

    // The page checks again on its own until the display exists — no reload.
    await eventually(() => query("device-device-2") !== null);
    expect(query("device-awaiting")).toBeNull();
    expect(required("device-device-2-showing").textContent).toBe("Showing: Signage");
    // Never twice, however many times it is fetched again.
    expect(container.querySelectorAll('[data-testid="device-device-2"]')).toHaveLength(1);
    expect(platform.requests.filter((r) => r.path === "/api/v1/devices").length).toBeGreaterThan(2);
    expect(document.activeElement).toBe(required("add-display"));
  });

  it("closes the Add display flow on Cancel without pairing anything", async () => {
    const platform = await renderPage();
    await click("add-display");
    await click("add-display-cancel");

    expect(query("add-display-dialog")).toBeNull();
    expect(platform.requests.map((r) => r.path).sort()).toEqual([
      "/api/v1/devices",
      "/api/v1/devices/display-modules",
    ]);
    expect(document.activeElement).toBe(required("add-display"));
  });
});

describe("setting up a new screen (ADR 0065)", () => {
  it("copies the platform setup address, and says so when the browser cannot", async () => {
    const writeText = vi.fn(async () => undefined);
    Object.defineProperty(window.navigator, "clipboard", {
      configurable: true,
      value: { writeText },
    });
    await renderPage();
    await click("display-setup-copy");
    expect(writeText).toHaveBeenCalledWith(`${apiBaseUrl}/display/setup`);
    expect(required("display-setup").textContent).toContain("Link copied.");

    Object.defineProperty(window.navigator, "clipboard", { configurable: true, value: undefined });
    await click("display-setup-copy");
    expect(required("display-setup").textContent).toContain("couldn't copy it");
  });

  it("pairs a platform display with zero display modules installed", async () => {
    const platform = await renderPage({ modules: [] });
    expect(required("display-setup-url").textContent).toBe(`${apiBaseUrl}/display/setup`);
    expect(required("display-setup").textContent).not.toContain("Signage");

    await click("add-display");
    await type("device-pairing-code-input", PLATFORM_CODE);
    await submit("device-pairing-lookup");
    expect(required("device-pairing-found").textContent).toContain(
      "A new screen is waiting to be paired",
    );
    expect(query("device-pairing-shows")).toBeNull();
    expect(required("device-pairing-no-modules").textContent).toContain(
      "No installed module shows content on screens yet",
    );
    await type("device-pairing-name", "Foyer TV 2");
    await submit("device-pairing-approve");

    expect(
      platform.requests.find((r) => r.path === "/api/v1/device-pairing/approvals")?.body,
    ).toEqual({ code: PLATFORM_CODE, deviceName: "Foyer TV 2" });
    await eventually(() => query("device-device-2") !== null);
    expect(required("device-device-2-showing").textContent).toBe("Showing: Nothing yet");
  });

  it("chooses what a new platform display shows with the themed select, not a native one", async () => {
    const platform = await renderPage();
    await click("add-display");
    await type("device-pairing-code-input", PLATFORM_CODE);
    await submit("device-pairing-lookup");

    const dialog = required("add-display-dialog");
    expect(dialog.querySelector("select")).toBeNull();
    const shows = required("device-pairing-shows");
    expect(shows.getAttribute("role")).toBe("combobox");
    expect(shows.textContent).toBe("Nothing yet");
    await choose("device-pairing-shows", "Signage");
    expect(shows.textContent).toBe("Signage");
    await type("device-pairing-name", "Lobby screen");
    await submit("device-pairing-approve");

    expect(
      platform.requests.find((r) => r.path === "/api/v1/device-pairing/approvals")?.body,
    ).toEqual({ code: PLATFORM_CODE, deviceName: "Lobby screen", moduleId: "signage" });
    await eventually(() => query("device-device-2") !== null);
    expect(required("device-device-2-showing").textContent).toBe("Showing: Signage");
  });

  it("still pairs, showing nothing yet, when the display modules cannot be read", async () => {
    const platform = await renderPage({ modules: "fails" });
    await click("add-display");
    await type("device-pairing-code-input", PLATFORM_CODE);
    await submit("device-pairing-lookup");
    expect(query("device-pairing-shows")).toBeNull();
    await type("device-pairing-name", "Hall");
    await submit("device-pairing-approve");
    expect(
      platform.requests.find((r) => r.path === "/api/v1/device-pairing/approvals")?.body,
    ).toEqual({ code: PLATFORM_CODE, deviceName: "Hall" });
    // Without the module list the card neither guesses what it shows nor offers to change it.
    expect(query("device-device-1-showing")).toBeNull();
    expect(query("device-change-device-1")).toBeNull();
  });
});

describe("changing what a display shows (ADR 0065)", () => {
  it("moves a display from nothing to a module, between modules, and back, as the same display", async () => {
    const platform = await renderPage({ modules: [SIGNAGE, BULLETIN] });
    const puts = () =>
      platform.requests.filter((r) => r.method === "PUT").map((r) => [r.path, r.body]);

    // Nothing yet → Signage.
    await click("device-change-device-1");
    const dialog = required("device-change-dialog");
    expect(dialog.textContent).toContain("Change what Foyer TV shows");
    expect(dialog.querySelector("select")).toBeNull();
    expect(required("device-change-shows").textContent).toBe("Nothing yet");
    // Nothing to save until something changes.
    expect((required("device-change-save") as HTMLButtonElement).disabled).toBe(true);
    await choose("device-change-shows", "Signage");
    await click("device-change-save");
    expect(query("device-change-dialog")).toBeNull();
    expect(required("device-device-1-showing").textContent).toBe("Showing: Signage");
    expect(required("device-change-success").textContent).toBe("Foyer TV now shows Signage.");
    expect(document.activeElement).toBe(required("device-change-device-1"));

    // Signage → Bulletin.
    await click("device-change-device-1");
    expect(required("device-change-shows").textContent).toBe("Signage");
    await choose("device-change-shows", "Bulletin");
    await click("device-change-save");
    expect(required("device-device-1-showing").textContent).toBe("Showing: Bulletin");

    // Bulletin → nothing.
    await click("device-change-device-1");
    await choose("device-change-shows", "Nothing yet");
    await click("device-change-save");
    expect(required("device-device-1-showing").textContent).toBe("Showing: Nothing yet");
    expect(required("device-change-success").textContent).toContain("Foyer TV now shows nothing");

    expect(puts()).toEqual([
      ["/api/v1/devices/device-1/display", { moduleId: "signage" }],
      ["/api/v1/devices/device-1/display", { moduleId: "bulletin" }],
      ["/api/v1/devices/device-1/display", { moduleId: null }],
    ]);
    // Always the one display: no new identity, and the same name.
    expect(platform.devices.map((device) => device.id)).toEqual(["device-1"]);
    expect(container.querySelectorAll('[data-testid^="device-device-"]').length).toBeGreaterThan(0);
    expect(container.querySelectorAll('[data-testid="device-device-1"]')).toHaveLength(1);
  });

  it("closes on Cancel or Escape without changing anything", async () => {
    const platform = await renderPage();
    await click("device-change-device-1");
    await choose("device-change-shows", "Signage");
    await click("device-change-cancel");
    expect(query("device-change-dialog")).toBeNull();
    expect(platform.requests.some((r) => r.method === "PUT")).toBe(false);
    expect(required("device-device-1-showing").textContent).toBe("Showing: Nothing yet");
  });
});

/**
 * Removing a display (revoking its credential) strands that screen until someone re-pairs it in
 * person, so the page explains the consequence in its own dialog first — never with a
 * browser-native confirm (DESIGN §21). The interface says "remove"; only the platform says "revoke".
 */
describe("removing a display", () => {
  it("asks in a product dialog before removing, and does nothing on cancel", async () => {
    const confirm = vi.fn(() => true);
    Object.assign(window, { confirm });
    const platform = await renderPage();

    await click("device-revoke-device-1");
    const dialog = container.querySelector('[role="dialog"]');
    // Administrators remove a display; revoking its credential is the platform's word, not theirs.
    expect(dialog?.textContent).toContain("Remove display?");
    expect(dialog?.textContent).toContain("Foyer TV stops showing content");
    expect(dialog?.textContent).not.toMatch(/revok/iu);
    expect(dialog?.textContent).toContain("pairing code");

    await click("device-revoke-cancel");
    expect(container.querySelector('[role="dialog"]')).toBeNull();
    expect(platform.requests.some((r) => r.path.endsWith("/revoke"))).toBe(false);
    expect(confirm).not.toHaveBeenCalled();
  });

  it("takes a removed display off the list at once, and says what happened", async () => {
    const platform = await renderPage();

    await click("device-revoke-device-1");
    await click("device-revoke-confirm");
    await act(async () => settle());

    expect(platform.requests.filter((r) => r.path.endsWith("/revoke"))).toHaveLength(1);
    expect(container.querySelector('[role="dialog"]')).toBeNull();
    // Gone from the active list without a reload, though the server keeps it as history.
    expect(query("device-device-1")).toBeNull();
    expect(platform.devices[0]?.revoked).toBe(true);
    expect(required("device-list-empty")).not.toBeNull();
    expect(required("device-outcome").textContent).toContain("Display removed");
    expect(required("device-revoke-success").textContent).toContain("Foyer TV was removed");
    expect(container.textContent).not.toMatch(/revok/iu);
    // Its card is gone, so focus lands on what happened rather than on the page.
    expect(document.activeElement).toBe(required("device-outcome"));
  });
});