import { act, type ReactElement, useState } from "react";
import { createRoot, type Root } from "react-dom/client";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import { matchesRequiredPhrase } from "../src/confirmation.js";
import { ERROR_DETAILS_MAX_LENGTH, errorDetailsText } from "../src/feedback.js";
import {
  ConfirmationDialog,
  type ConfirmationDialogProps,
  Dialog,
  ErrorState,
  PageHeader,
  Skeleton,
  SkeletonGroup,
  type ToastApi,
  ToastProvider,
  useToasts,
} from "../src/index.js";
import { EKKLESIA_UI_STYLESHEET } from "../src/styles.js";
import { TOAST_MINIMUM_DURATION_MS, toastDuration } from "../src/toasts.js";

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

let container: HTMLDivElement;
let root: Root;

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

afterEach(() => {
  act(() => root.unmount());
  container.remove();
  vi.useRealTimers();
});

function render(node: ReactElement): void {
  act(() => root.render(node));
}

function byTestId(id: string): HTMLElement {
  const element = container.querySelector<HTMLElement>(`[data-testid="${id}"]`);
  if (!element) {
    throw new Error(`missing ${id}`);
  }
  return element;
}

function dialog(): HTMLElement {
  const element = container.querySelector<HTMLElement>('[role="dialog"]');
  if (!element) {
    throw new Error("no dialog");
  }
  return element;
}

function buttonNamed(name: string, scope: ParentNode = container): HTMLButtonElement {
  const button = [...scope.querySelectorAll("button")].find(
    (candidate) => (candidate.getAttribute("aria-label") ?? candidate.textContent) === name,
  );
  if (!button) {
    throw new Error(`no button ${name}`);
  }
  return button;
}

function press(element: Element, key: string, init: KeyboardEventInit = {}): KeyboardEvent {
  const event = new KeyboardEvent("keydown", { bubbles: true, cancelable: true, key, ...init });
  act(() => {
    element.dispatchEvent(event);
  });
  return event;
}

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

/** A page with a control that opens a confirmation, so opening, focus return, and the background
 * can all be observed. */
function ConfirmHarness(props: {
  readonly onConfirm?: () => void;
  readonly onCancel?: () => void;
  readonly dialog?: Partial<ConfirmationDialogProps>;
}): ReactElement {
  const [open, setOpen] = useState(false);
  return (
    <div>
      <button data-testid="background" type="button">
        Something behind
      </button>
      <button data-testid="opener" onClick={() => setOpen(true)} type="button">
        Delete display
      </button>
      <ConfirmationDialog
        confirmLabel="Delete display"
        description="Foyer-1 stops showing content and must be paired again to come back."
        onCancel={() => {
          props.onCancel?.();
          setOpen(false);
        }}
        onConfirm={() => {
          props.onConfirm?.();
          setOpen(false);
        }}
        open={open}
        title="Delete Foyer-1?"
        {...props.dialog}
      />
    </div>
  );
}

function openHarness(options: Parameters<typeof ConfirmHarness>[0] = {}): void {
  render(<ConfirmHarness {...options} />);
  const opener = byTestId("opener");
  act(() => opener.focus());
  act(() => opener.click());
}

describe("ConfirmationDialog", () => {
  it("is closed until asked, and opens as a named, described modal dialog", () => {
    render(<ConfirmHarness />);
    expect(container.querySelector('[role="dialog"]')).toBeNull();

    act(() => byTestId("opener").click());

    const element = dialog();
    expect(element.getAttribute("aria-modal")).toBe("true");
    expect(
      container.querySelector(`#${element.getAttribute("aria-labelledby")}`)?.textContent,
    ).toBe("Delete Foyer-1?");
    expect(
      container.querySelector(`#${element.getAttribute("aria-describedby")}`)?.textContent,
    ).toBe("Foyer-1 stops showing content and must be paired again to come back.");
  });

  it("confirms with its named action, and cancels with Cancel, without the other firing", () => {
    const onConfirm = vi.fn();
    const onCancel = vi.fn();
    openHarness({ onCancel, onConfirm });

    act(() => buttonNamed("Cancel", dialog()).click());
    expect(onCancel).toHaveBeenCalledTimes(1);
    expect(onConfirm).not.toHaveBeenCalled();
    expect(container.querySelector('[role="dialog"]')).toBeNull();

    act(() => byTestId("opener").click());
    act(() => buttonNamed("Delete display", dialog()).click());
    expect(onConfirm).toHaveBeenCalledTimes(1);
    expect(onCancel).toHaveBeenCalledTimes(1);
  });

  it("starts a simple confirmation on its action, ready for Enter", () => {
    openHarness();
    expect(document.activeElement?.textContent).toBe("Delete display");
    expect(document.activeElement?.className).toContain("ek-button--primary");
  });

  it("marks a destructive action by symbol and frame as well as colour, and starts on Cancel", () => {
    openHarness({ dialog: { tone: "destructive" } });

    const confirm = [...dialog().querySelectorAll("button")].find((button) =>
      button.textContent?.includes("Delete display"),
    );
    expect(confirm?.className).toContain("ek-button--danger");
    expect(confirm?.querySelector(".ek-confirmation__symbol")?.getAttribute("aria-hidden")).toBe(
      "true",
    );
    expect(dialog().className).toContain("ek-confirmation--destructive");
    expect(dialog().querySelector("h2 .ek-confirmation__symbol")).not.toBeNull();
    // The safe choice has focus, so a stray Enter cancels rather than destroys.
    expect(document.activeElement?.textContent).toBe("Cancel");
    expect(EKKLESIA_UI_STYLESHEET).toContain(".ek-confirmation__symbol::before");
  });

  it("requires the exact phrase before a typed confirmation can be confirmed", () => {
    const onConfirm = vi.fn();
    openHarness({ dialog: { requiredPhrase: "Foyer-1", tone: "destructive" }, onConfirm });
    const input = dialog().querySelector("input") as HTMLInputElement;
    const confirm = [...dialog().querySelectorAll("button")].find((button) =>
      button.textContent?.includes("Delete display"),
    ) as HTMLButtonElement;

    // Focus starts at the field, which is labelled with the phrase it wants.
    expect(document.activeElement).toBe(input);
    expect(input.labels?.[0]?.textContent).toBe("Type Foyer-1 to confirm");
    expect(input.getAttribute("autocapitalize")).toBe("off");
    expect(input.getAttribute("spellcheck")).toBe("false");
    expect(confirm.disabled).toBe(true);

    type(input, "foyer-1");
    expect(confirm.disabled).toBe(true);
    expect(input.getAttribute("aria-invalid")).toBe("true");
    act(() => {
      (input.form as HTMLFormElement).dispatchEvent(
        new Event("submit", { bubbles: true, cancelable: true }),
      );
    });
    expect(onConfirm).not.toHaveBeenCalled();

    type(input, " Foyer-1 ");
    expect(confirm.disabled).toBe(false);
    expect(input.getAttribute("aria-invalid")).toBeNull();
    // Enter in the field submits once it matches.
    act(() => {
      (input.form as HTMLFormElement).dispatchEvent(
        new Event("submit", { bubbles: true, cancelable: true }),
      );
    });
    expect(onConfirm).toHaveBeenCalledTimes(1);
  });

  it("forgets a typed phrase when it closes", () => {
    openHarness({ dialog: { requiredPhrase: "DELETE" } });
    type(dialog().querySelector("input") as HTMLInputElement, "DELETE");
    act(() => buttonNamed("Cancel", dialog()).click());

    act(() => byTestId("opener").click());

    expect((dialog().querySelector("input") as HTMLInputElement).value).toBe("");
  });

  it("matches a phrase exactly, forgiving only surrounding whitespace and Unicode composition", () => {
    expect(matchesRequiredPhrase("DELETE", "DELETE")).toBe(true);
    expect(matchesRequiredPhrase("  DELETE\n", "DELETE")).toBe(true);
    expect(matchesRequiredPhrase("delete", "DELETE")).toBe(false);
    expect(matchesRequiredPhrase("DELET", "DELETE")).toBe(false);
    expect(matchesRequiredPhrase("DELETE DELETE", "DELETE")).toBe(false);
    expect(matchesRequiredPhrase("Café", "Café")).toBe(true);
  });

  it("closes on Escape and returns focus to the control that opened it", () => {
    const onCancel = vi.fn();
    openHarness({ onCancel });

    const event = press(dialog(), "Escape");

    expect(event.defaultPrevented).toBe(true);
    expect(onCancel).toHaveBeenCalledTimes(1);
    expect(container.querySelector('[role="dialog"]')).toBeNull();
    expect(document.activeElement).toBe(byTestId("opener"));
  });

  it("does not close on Escape or Cancel while the confirmed action is in progress", () => {
    const onCancel = vi.fn();
    openHarness({ dialog: { busy: true }, onCancel });

    press(dialog(), "Escape");
    expect(onCancel).not.toHaveBeenCalled();
    expect(buttonNamed("Cancel", dialog()).disabled).toBe(true);
    expect(dialog().querySelector("form")?.getAttribute("aria-busy")).toBe("true");
  });

  it("keeps Tab and Shift+Tab inside the dialog", () => {
    openHarness({ dialog: { requiredPhrase: "DELETE" } });
    const input = dialog().querySelector("input") as HTMLInputElement;
    type(input, "DELETE");
    const cancel = buttonNamed("Cancel", dialog());
    const confirm = buttonNamed("Delete display", dialog());

    act(() => confirm.focus());
    expect(press(confirm, "Tab").defaultPrevented).toBe(true);
    expect(document.activeElement).toBe(input);

    expect(press(input, "Tab", { shiftKey: true }).defaultPrevented).toBe(true);
    expect(document.activeElement).toBe(confirm);

    // Between inner controls, the browser moves focus itself.
    act(() => input.focus());
    expect(press(input, "Tab").defaultPrevented).toBe(false);
    expect(cancel).toBeTruthy();
  });

  it("blocks the page behind: the scrim takes the pointer and nothing behind is in the tab loop", () => {
    openHarness();
    const scrim = dialog().parentElement as HTMLElement;
    expect(scrim.className).toBe("ek-dialog__scrim");

    const pointer = new MouseEvent("pointerdown", { bubbles: true, cancelable: true });
    act(() => {
      scrim.dispatchEvent(pointer);
    });
    expect(pointer.defaultPrevented).toBe(true);
    expect(container.querySelector('[role="dialog"]')).not.toBeNull();
    expect(dialog().contains(byTestId("background"))).toBe(false);

    // Tab from the last control wraps inside rather than reaching "Something behind".
    const last = buttonNamed("Delete display", dialog());
    act(() => last.focus());
    press(last, "Tab");
    expect(document.activeElement).not.toBe(byTestId("background"));
    expect(dialog().contains(document.activeElement)).toBe(true);
  });

  it("stops Escape at the dialog, so a drawer or menu around it stays open", () => {
    const outer = vi.fn();
    render(
      // biome-ignore lint/a11y/noStaticElementInteractions: a test stand-in for a drawer that closes on Escape.
      <div
        onKeyDown={(event) => {
          if (event.key === "Escape") {
            outer();
          }
        }}
      >
        <ConfirmHarness />
      </div>,
    );
    act(() => byTestId("opener").click());

    press(dialog(), "Escape");

    expect(outer).not.toHaveBeenCalled();
  });

  it("is operable with the keyboard alone", () => {
    const onConfirm = vi.fn();
    openHarness({ dialog: { requiredPhrase: "DELETE" }, onConfirm });
    const input = document.activeElement as HTMLInputElement;

    type(input, "DELETE");
    act(() => {
      (input.form as HTMLFormElement).requestSubmit();
    });

    expect(onConfirm).toHaveBeenCalledTimes(1);
  });
});

describe("Dialog", () => {
  it("traps focus, describes itself, and returns focus when it closes", () => {
    function Harness(): ReactElement {
      const [open, setOpen] = useState(false);
      return (
        <>
          <button data-testid="open" onClick={() => setOpen(true)} type="button">
            Open
          </button>
          <Dialog
            actions={
              <button onClick={() => setOpen(false)} type="button">
                Done
              </button>
            }
            description="Details about the dialog."
            onDismiss={() => setOpen(false)}
            open={open}
            title="Information"
          />
        </>
      );
    }
    render(<Harness />);
    act(() => byTestId("open").focus());
    act(() => byTestId("open").click());

    expect(document.activeElement).toBe(dialog());
    expect(
      container.querySelector(`#${dialog().getAttribute("aria-describedby")}`)?.textContent,
    ).toBe("Details about the dialog.");
    const done = buttonNamed("Done");
    act(() => done.focus());
    press(done, "Tab");
    expect(document.activeElement).toBe(done);

    act(() => done.click());
    expect(document.activeElement).toBe(byTestId("open"));
  });

  it("ignores Escape when the caller says dismissing is not safe", () => {
    const onDismiss = vi.fn();
    render(<Dialog dismissible={false} onDismiss={onDismiss} open title="Saving" />);

    press(dialog(), "Escape");

    expect(onDismiss).not.toHaveBeenCalled();
  });
});

function ToastHarness(props: { readonly onApi: (api: ToastApi) => void }): null {
  props.onApi(useToasts());
  return null;
}

function renderToasts(options: { readonly maxVisible?: number } = {}): ToastApi {
  let api: ToastApi | undefined;
  render(
    <ToastProvider {...options}>
      <ToastHarness
        onApi={(value) => {
          api = value;
        }}
      />
    </ToastProvider>,
  );
  if (!api) {
    throw new Error("no toast api");
  }
  return api;
}

function toastTitles(): string[] {
  return [...container.querySelectorAll(".ek-toast .ek-toast__title")].map(
    (title) => title.textContent?.replace(/^\S+\s/u, "") ?? "",
  );
}

describe("toasts", () => {
  it("renders a top-center region whose live regions exist before any toast arrives", () => {
    renderToasts();

    const region = container.querySelector(".ek-toast-region");
    expect(region?.tagName).toBe("SECTION");
    expect(region?.getAttribute("aria-label")).toBe("Notifications");
    expect(region?.querySelector('[role="status"][aria-live="polite"]')).not.toBeNull();
    expect(region?.querySelector('[role="alert"][aria-live="assertive"]')).not.toBeNull();
    expect(EKKLESIA_UI_STYLESHEET).toMatch(/\.ek-toast-region \{[^}]*position: fixed;[^}]*top:/su);
  });

  it("shows each severity with its symbol, errors assertively and the rest politely", () => {
    vi.useFakeTimers();
    const api = renderToasts();

    act(() => {
      api.show({ title: "Saved", tone: "success" });
      api.show({ title: "Heads up", tone: "info" });
      api.show({ title: "Storage is nearly full", tone: "warning" });
      api.show({ title: "The display could not be revoked", tone: "danger" });
    });

    const polite = container.querySelector('[aria-live="polite"]') as HTMLElement;
    const assertive = container.querySelector('[aria-live="assertive"]') as HTMLElement;
    expect(assertive.textContent).toContain("The display could not be revoked");
    expect(polite.textContent).not.toContain("could not be revoked");
    for (const tone of ["success", "info", "warning", "danger"]) {
      const toast = container.querySelector(`.ek-toast--${tone}`);
      expect(toast, tone).not.toBeNull();
      // Its own role would nest one live region in another.
      expect(toast?.getAttribute("role"), tone).toBeNull();
      expect(toast?.querySelector('[aria-hidden="true"]')?.textContent?.trim(), tone).not.toBe("");
    }
  });

  it("dismisses a routine toast on its own once there has been time to read it", () => {
    vi.useFakeTimers();
    const api = renderToasts();

    act(() => {
      api.show({ title: "Saved", tone: "success" });
    });
    act(() => {
      vi.advanceTimersByTime(TOAST_MINIMUM_DURATION_MS - 1);
    });
    expect(toastTitles()).toEqual(["Saved"]);

    act(() => {
      vi.advanceTimersByTime(5000);
    });
    expect(toastTitles()).toEqual([]);
  });

  it("never times a toast out in under three seconds, and gives longer messages longer", () => {
    const tooShort = toastDuration({ duration: 500, title: "Saved" }) as number;
    expect(tooShort).toBeGreaterThanOrEqual(TOAST_MINIMUM_DURATION_MS);
    expect(tooShort).toBeLessThan(TOAST_MINIMUM_DURATION_MS + 1000);
    const short = toastDuration({ title: "Saved", tone: "success" }) as number;
    const long = toastDuration({
      description:
        "The timeline was published to every screen in the Sanctuary and Foyer groups, and the next slide starts in a minute.",
      title: "Published",
      tone: "success",
    }) as number;
    expect(short).toBeGreaterThanOrEqual(TOAST_MINIMUM_DURATION_MS);
    expect(long).toBeGreaterThan(short);
    expect(toastDuration({ title: "Careful", tone: "warning" })).toBeGreaterThan(short);
  });

  it("keeps an error until it is dismissed, unless its caller gives it a duration", () => {
    vi.useFakeTimers();
    const api = renderToasts();

    act(() => {
      api.show({ title: "The display could not be revoked", tone: "danger" });
      api.show({ duration: 4000, title: "Enter a name", tone: "danger" });
    });
    act(() => {
      vi.advanceTimersByTime(60_000);
    });

    expect(toastTitles()).toEqual(["The display could not be revoked"]);
    expect(toastDuration({ title: "x", tone: "danger" })).toBe("persistent");
  });

  it("dismisses on its named dismiss control", () => {
    vi.useFakeTimers();
    const api = renderToasts();
    act(() => {
      api.show({ title: "The display could not be revoked", tone: "danger" });
    });

    act(() => buttonNamed("Dismiss notification: The display could not be revoked").click());

    expect(toastTitles()).toEqual([]);
  });

  it("dismisses programmatically by the id it returned", () => {
    vi.useFakeTimers();
    const api = renderToasts();
    let id = "";
    act(() => {
      id = api.show({ title: "Uploading", tone: "info" });
    });
    expect(id).toMatch(/^ek-toast-/u);

    act(() => api.dismiss(id));

    expect(toastTitles()).toEqual([]);
  });

  it("dismisses the focused toast on Escape and returns focus where it was", () => {
    vi.useFakeTimers();
    let api: ToastApi | undefined;
    render(
      <ToastProvider>
        <button data-testid="work" type="button">
          Work
        </button>
        <ToastHarness
          onApi={(value) => {
            api = value;
          }}
        />
      </ToastProvider>,
    );
    act(() => {
      api?.show({ title: "Saved", tone: "success" });
    });
    const work = byTestId("work");
    act(() => work.focus());
    const dismiss = buttonNamed("Dismiss notification: Saved");
    act(() => {
      dismiss.dispatchEvent(new FocusEvent("focusin", { bubbles: true, relatedTarget: work }));
      dismiss.focus();
    });

    press(dismiss, "Escape");

    expect(toastTitles()).toEqual([]);
    expect(document.activeElement).toBe(work);
  });

  it("stacks newest first, refreshes a duplicate, and never lets routine toasts displace an error", () => {
    vi.useFakeTimers();
    const api = renderToasts({ maxVisible: 2 });

    act(() => {
      api.show({ title: "Storage is unavailable", tone: "danger" });
      api.show({ title: "One", tone: "info" });
      api.show({ title: "Two", tone: "info" });
      api.show({ title: "Three", tone: "info" });
      api.show({ title: "Three", tone: "info" });
    });

    // Errors are listed first; then routine toasts, newest first, at most two of them.
    expect(toastTitles()).toEqual(["Storage is unavailable", "Three", "Two"]);
    expect(container.querySelectorAll(".ek-toast")).toHaveLength(3);
  });

  it("pauses while the pointer is over it, so a toast being read does not vanish", () => {
    vi.useFakeTimers();
    const api = renderToasts();
    act(() => {
      api.show({ title: "Saved", tone: "success" });
    });
    const region = container.querySelector(".ek-toast-region") as HTMLElement;

    act(() => {
      region.dispatchEvent(new MouseEvent("mouseover", { bubbles: true }));
    });
    act(() => {
      vi.advanceTimersByTime(30_000);
    });
    expect(toastTitles()).toEqual(["Saved"]);

    act(() => {
      region.dispatchEvent(new MouseEvent("mouseout", { bubbles: true }));
    });
    act(() => {
      vi.advanceTimersByTime(30_000);
    });
    expect(toastTitles()).toEqual([]);
  });

  it("clears every timer when the provider goes away", () => {
    vi.useFakeTimers();
    const api = renderToasts();
    act(() => {
      api.show({ title: "One", tone: "info" });
      api.show({ title: "Two", tone: "warning" });
    });
    expect(vi.getTimerCount()).toBe(2);

    act(() => root.unmount());

    expect(vi.getTimerCount()).toBe(0);
    root = createRoot(container);
  });

  it("is per React tree: outside a provider there is no toast API to reach for", () => {
    function Orphan(): null {
      useToasts();
      return null;
    }
    const consoleError = vi.spyOn(console, "error").mockImplementation(() => undefined);
    expect(() => render(<Orphan />)).toThrow("useToasts must be used inside a ToastProvider.");
    consoleError.mockRestore();
  });
});

describe("ErrorState", () => {
  it("leads with a plain message, and shows no disclosure when there is no detail", () => {
    render(<ErrorState description="Check the connection, then retry." title="Could not load" />);

    const element = container.querySelector(".ek-message--error") as HTMLElement;
    expect(element.getAttribute("role")).toBe("alert");
    expect(element.querySelector(".ek-message__title")?.textContent).toBe("Could not load");
    expect(element.querySelector("details")).toBeNull();
  });

  it("keeps technical detail and a reference collapsed behind a disclosure", () => {
    render(
      <ErrorState
        details={"STORAGE_PROVIDER_UNAVAILABLE\nThe object store did not answer within 5 s."}
        reference="req-7f3a"
        title="The image could not be uploaded"
      />,
    );

    const details = container.querySelector("details") as HTMLDetailsElement;
    expect(details.open).toBe(false);
    expect(details.querySelector("summary")?.textContent).toBe("Technical details");
    expect(details.querySelector("pre")?.textContent).toBe(
      "STORAGE_PROVIDER_UNAVAILABLE\nThe object store did not answer within 5 s.",
    );
    expect(details.querySelector("code")?.textContent).toBe("req-7f3a");
  });

  it("offers recovery and remedy actions beside the message", () => {
    const retry = vi.fn();
    render(
      <ErrorState
        actions={
          <>
            <button onClick={retry} type="button">
              Retry
            </button>
            <a href="/settings">Open storage settings</a>
          </>
        }
        title="Could not load"
      />,
    );

    act(() => buttonNamed("Retry").click());
    expect(retry).toHaveBeenCalledTimes(1);
    expect(container.querySelector(".ek-message__actions a")?.getAttribute("href")).toBe(
      "/settings",
    );
  });

  it("renders an arbitrary server string as inert, bounded text", () => {
    const hostile = `<img src=x onerror="alert(1)"><script>steal()</script>\u0007\u001b[31m${"x".repeat(5000)}`;
    render(<ErrorState details={hostile} title="Something went wrong" />);

    const pre = container.querySelector("pre") as HTMLElement;
    expect(container.querySelector("img")).toBeNull();
    expect(container.querySelector("script")).toBeNull();
    expect(pre.textContent?.startsWith('<img src=x onerror="alert(1)">')).toBe(true);
    expect(pre.textContent).not.toContain("\u0007");
    expect(pre.textContent?.length).toBe(ERROR_DETAILS_MAX_LENGTH + 1);
    expect(errorDetailsText("  line one\n\tline two  ")).toBe("line one\n\tline two");
  });

  it("can be part of a page's initial content without being announced", () => {
    render(<ErrorState announce={false} title="Not available" />);

    expect(container.querySelector(".ek-message--error")?.getAttribute("role")).toBeNull();
  });
});

describe("Skeleton", () => {
  it("is a busy, labelled region announced once, with every placeholder hidden from it", () => {
    render(
      <SkeletonGroup label="Loading displays">
        <Skeleton shape="circle" width="2rem" />
        <Skeleton width="60%" />
        <Skeleton shape="block" />
      </SkeletonGroup>,
    );

    const group = container.querySelector(".ek-skeleton-group") as HTMLElement;
    expect(group.getAttribute("role")).toBe("status");
    expect(group.getAttribute("aria-busy")).toBe("true");
    expect(container.querySelector(`#${group.getAttribute("aria-labelledby")}`)?.textContent).toBe(
      "Loading displays",
    );
    const placeholders = [...group.querySelectorAll(".ek-skeleton")] as HTMLElement[];
    expect(placeholders).toHaveLength(3);
    for (const placeholder of placeholders) {
      expect(placeholder.getAttribute("aria-hidden")).toBe("true");
      expect(placeholder.textContent).toBe("");
    }
    expect(placeholders[0]?.style.height).toBe("2rem");
    // No percentage, no progress: there is none to report.
    expect(group.textContent).toBe("Loading displays");
  });

  it("stops moving for a person who asked for reduced motion", () => {
    const reduced = EKKLESIA_UI_STYLESHEET.slice(
      EKKLESIA_UI_STYLESHEET.indexOf("@media (prefers-reduced-motion: reduce)"),
    );
    expect(reduced).toMatch(/\.ek-skeleton[,\s]/u);
    expect(reduced).toContain("animation: none");
  });
});

describe("PageHeader", () => {
  it("names the page with its one h1 and keeps page actions beside it", () => {
    render(<PageHeader actions={<button type="button">Add display</button>} title="Displays" />);

    expect(container.querySelector("h1")?.textContent).toBe("Displays");
    expect(container.querySelector(".ek-page-header__actions button")?.textContent).toBe(
      "Add display",
    );
    expect(container.querySelector(".ek-page-header__back")).toBeNull();
  });

  it("puts a Back link above the title when Back is a real place", () => {
    const onBack = vi.fn();
    render(
      <PageHeader
        back={{ href: "/signage", label: "Back to Signage", onBack }}
        title="Add display"
      />,
    );

    const back = container.querySelector(".ek-page-header__back") as HTMLAnchorElement;
    expect(back.tagName).toBe("A");
    expect(back.getAttribute("href")).toBe("/signage");
    expect(back.textContent).toBe("←Back to Signage");
    expect(back.querySelector('[aria-hidden="true"]')?.textContent).toBe("←");
    const copy = back.parentElement as HTMLElement;
    expect([...copy.children].indexOf(back)).toBeLessThan(
      [...copy.children].indexOf(copy.querySelector("h1") as Element),
    );

    const click = new MouseEvent("click", { bubbles: true, button: 0, cancelable: true });
    act(() => {
      back.dispatchEvent(click);
    });
    expect(click.defaultPrevented).toBe(true);
    expect(onBack).toHaveBeenCalledTimes(1);

    const newTab = new MouseEvent("click", {
      bubbles: true,
      button: 0,
      cancelable: true,
      ctrlKey: true,
    });
    act(() => {
      back.dispatchEvent(newTab);
    });
    expect(newTab.defaultPrevented).toBe(false);
    expect(onBack).toHaveBeenCalledTimes(1);
  });

  it("renders Back as a button when it has no address", () => {
    const onBack = vi.fn();
    render(<PageHeader back={{ label: "Back", onBack }} title="Details" />);

    const back = container.querySelector(".ek-page-header__back") as HTMLButtonElement;
    expect(back.tagName).toBe("BUTTON");
    expect(back.type).toBe("button");
    act(() => back.click());
    expect(onBack).toHaveBeenCalledTimes(1);
  });
});