import React__default from 'react';

/**
 * Default slide duration for level transitions, in milliseconds — the default
 * of the `durationMs` prop.
 *
 * COUPLING: `durationMs` drives BOTH the `--push-menu-duration` custom
 * property (set inline on the root, read by the CSS transition) and the state
 * machine's `setTimeout`s (which settle the animation state, pop levels, and
 * schedule focus restoration). Do not override the custom property directly —
 * that changes only the visual duration while the state machine still settles
 * on `durationMs`, desyncing the two; pass `durationMs` instead. Under
 * `prefers-reduced-motion` the slide is skipped (the transition is applied
 * under `motion-safe:` only) but the state machine still waits the full
 * duration; the menu is simply "settled early" for those users, never broken.
 */
declare const PUSH_MENU_DURATION_MS = 300;
/** A node in the menu tree. Items with `links` drill in; items with `href` navigate. */
type PushMenuItem = {
    /** Unique across the whole tree — level ids and focus restoration track items by id. */
    id: string;
    /** Visible label. */
    title: string;
    /** Navigation target for leaf items. Ignored for drilling when `links` is non-empty. */
    href?: string;
    /** Child items. A non-empty array makes this item a drill-in button, not a link. */
    links?: PushMenuItem[];
};
/** One entry in the level stack — the root level plus one per drill-in. */
type PushMenuLevel = {
    id: string;
    title: string;
    /** 1 for the root level, incrementing per drill-in. */
    depth: number;
    items: PushMenuItem[];
    /** The item whose activation opened this level. Absent on the root level. */
    parentItem?: PushMenuItem;
};
/**
 * Collapses a trail of level titles into a single "A › B › C" string, keeping
 * the ends and eliding the middle once it outgrows `maxLength`. Exported so an
 * app can render the same trail outside the menu (e.g. in a sheet header).
 * Prefixed with "PushMenu" to avoid colliding with a future breadcrumb
 * component in the package barrel.
 *
 * `maxLength` is a HARD bound on the returned string, measured in UTF-16 units
 * (`String.length`) — the one exception is a single level, whose title is
 * returned verbatim because there is nothing to collapse. Callers rendering the
 * trail in a fixed-width slot can rely on that. Middle-elision is attempted
 * first because it reads better; when it does not fit, the full trail is
 * truncated from the end.
 */
declare function generatePushMenuBreadcrumb(levels: {
    title: string;
}[], maxLength?: number): string;
type PushMenuProps = Omit<React__default.ComponentPropsWithoutRef<'nav'>, 'children' | 'title'> & {
    /** The menu tree. Item ids must be unique across the whole tree. */
    navigation: PushMenuItem[];
    /**
     * The app's current pathname. Leaf links whose `href` matches get
     * `aria-current="page"` and the active treatment. Replaces the nswds-app
     * source's `usePathname()` — the design system is framework-free, so the
     * router value is passed in rather than read from next/navigation.
     */
    currentHref?: string;
    /** Root level title, shown in the header row. Also the default `aria-label`. */
    title?: string;
    /** Fired when a leaf item (link or child-less button) is activated. */
    onItemClick?: (item: PushMenuItem) => void;
    /** Fired after a forward/back slide settles on a level. */
    onNavigate?: (level: PushMenuLevel, history: PushMenuLevel[]) => void;
    /**
     * Renders a close button in the header row when provided. Unlike the
     * nswds-app source — which only offered close on sub-levels, leaving the
     * root level uncloseable — the button renders on every level.
     */
    onClose?: () => void;
    /** Show the "A › B › C" trail under the header on sub-levels. Defaults to `true`. */
    showBreadcrumbs?: boolean;
    /**
     * Slide duration in milliseconds, defaulting to `PUSH_MENU_DURATION_MS`
     * (300). Drives both the `--push-menu-duration` custom property and the
     * state machine's timeouts — tune the slide here, never by overriding the
     * custom property (see the coupling note on the constant).
     */
    durationMs?: number;
    /** Label for the Back button on sub-levels. Defaults to `'Back'`. */
    backLabel?: string;
    /** Accessible label for the close button. Defaults to `'Close menu'`. */
    closeLabel?: string;
    /**
     * Heading level for the per-level title, following `FooterNavColumn`'s
     * precedent (the nswds-app source used a `Heading` component this package
     * does not ship). Defaults to `2`; `1` is excluded because a menu panel
     * title is never the page's own title.
     */
    headingLevel?: 2 | 3 | 4 | 5 | 6;
    /**
     * Visually-hidden suffix appended to the accessible name of a row that
     * drills into a submenu. Defaults to `'submenu'`.
     *
     * The chevron is `aria-hidden`, so without this a drill-in row and a leaf
     * link are indistinguishable to a screen reader: both announce as
     * "<title>, button"/"link" with no hint that one replaces the panel and the
     * other leaves the page. Pass `null` to suppress it.
     */
    submenuLabel?: React__default.ReactNode;
    /**
     * Shown in place of the row list when a level has no items. Defaults to
     * "No navigation items available."; pass `null` to render an empty level.
     *
     * An empty `navigation` array is a legitimate runtime state — unpublished
     * content, a permission-filtered menu, a failed fetch — as distinct from the
     * malformed data `warnIfNavigationMalformed` reports to the console, which
     * is compiled out in production. Without a message the drawer opens onto a
     * blank panel whose only affordance is the close button.
     */
    emptyMessage?: React__default.ReactNode;
    /**
     * When the menu is below its root level, let Escape pop one level instead of
     * bubbling to an enclosing dialog. Defaults to `true`.
     *
     * A drill-down nested in a `Sheet` inherits the dialog's Escape-to-dismiss,
     * so a reader three levels deep loses both their position AND the drawer
     * from one keypress — and `navigateBack` is the only route back up (the
     * breadcrumb is decorative, and there is no swipe gesture). Popping one
     * level matches the back-out affordance the component actually offers.
     * Escape at the ROOT level always bubbles, so the drawer still closes the
     * way a dialog should. Set `false` for plain dialog semantics.
     */
    escapeGoesBack?: boolean;
    ref?: React__default.Ref<HTMLElement>;
};
/**
 * Multi-level slide-in-place drill-down menu ("push menu") for mobile
 * navigation, ported from nswds-app's `MultiLevelPushMenu`. Items with
 * children render as buttons that slide a new level in from the right; leaf
 * items render as links through `Link`, so apps can inject their framework
 * link component via `LinkProvider`. Fill height from its container — compose
 * it inside `SheetContent side="left"` for the classic mobile drawer.
 *
 * Accessibility contract (all improvements over the nswds-app source, which
 * got several of these wrong):
 *
 * - The root is a `nav` landmark named by `title` (override with `aria-label`).
 * - Non-current levels carry the `inert` attribute, so a hidden level's links
 *   are neither tabbable nor exposed to assistive tech. The app left every
 *   mounted level in the tab order, letting keyboard users tab into invisible
 *   history levels (WCAG 2.2, 2.4.3 Focus Order).
 * - Focus moves with the level change (2.4.3): drilling forward focuses the
 *   new level's Back button; going back focuses the item that opened the
 *   level just left, tracked by item id and restored after the slide settles.
 *   Without this, `inert` on the old level would silently drop focus to
 *   `<body>`. The Back button is the only POINTER route back (the breadcrumb
 *   is decorative), so it always renders on sub-levels — hiding it would make
 *   drill-down one-way.
 * - Escape below the root level pops ONE level rather than dismissing an
 *   enclosing dialog (`escapeGoesBack`, default true). Nested in a `Sheet` the
 *   inherited dialog behaviour discarded both the reader's position and the
 *   drawer on a single keypress; Escape at the root still closes normally.
 * - Row labels WRAP rather than truncate. Rows are `min-h-11` with
 *   `items-center`, so a long label grows its row instead of losing its tail —
 *   in a `w-3/4` drawer on a small phone the budget is roughly 25 characters,
 *   which real government labels ("Births, deaths and marriages") exceed. The
 *   level heading is the one exception (fixed-height header row) and carries a
 *   `title` attribute instead.
 * - Drill-in rows append a visually-hidden `submenuLabel` to their accessible
 *   name, so they no longer sound identical to leaf links.
 * - A single visually-hidden `aria-live="polite"` region at the root announces
 *   the current level's title, suffixed with the level number below the root.
 *   A live attribute on the per-level headings would not work: each level's
 *   heading is freshly mounted, and newly-mounted live regions are not
 *   reliably announced.
 * - Level lists are `<ul role="list">` — `list-style: none` strips list
 *   semantics in some screen reader/browser pairings (notably VoiceOver), and
 *   the explicit role restores them.
 * - Every row is at least 44px tall (2.5.8 Target Size); Back/close buttons
 *   inherit `Button`'s 44px touch target.
 * - During the slide, rows get `pointer-events-none` and the state machine
 *   ignores re-entrant navigation, but nothing is ever `disabled` — disabling
 *   the focused Back button mid-animation would eject keyboard focus.
 * - Slides are CSS transforms applied under `motion-safe:`, replacing the app's
 *   inline transition strings (which ignored reduced motion).
 *
 * Departures from the nswds-app source, beyond the above:
 *
 * - The footer/stats block (Level N, item counts, progress dots, lucide
 *   icons) is cut, along with its `showStats`/`showFooter` props: it was demo
 *   chrome for the sandbox, not part of a navigation component's job. The
 *   breadcrumb trail it hosted moves under the header row.
 * - The rendered "Navigation Error" fallback for MALFORMED data is replaced
 *   by a dev-only console warning (`warnIfNavigationMalformed`), mirroring
 *   button.tsx's `warnIfIconButtonUnlabelled`. An EMPTY level is a different
 *   case and does render — see `emptyMessage`. Empty is a legitimate runtime
 *   state rather than a programming error, and the console warning is compiled
 *   out in production regardless.
 * - The breadcrumb trail is `aria-hidden`: it repeats what the heading and
 *   live region already announce, and "›" separators read poorly in AT.
 *
 * The level stack is seeded from `navigation`/`title` on mount; pass a `key`
 * to remount (and reset to the root level) if either changes at runtime.
 */
declare function PushMenu({ navigation, currentHref, title, onItemClick, onNavigate, onClose, showBreadcrumbs, durationMs, backLabel, closeLabel, headingLevel, submenuLabel, emptyMessage, escapeGoesBack, className, style, 'aria-label': ariaLabel, ref, ...props }: PushMenuProps): React__default.JSX.Element | null;

export { PUSH_MENU_DURATION_MS, PushMenu, type PushMenuItem, type PushMenuLevel, type PushMenuProps, generatePushMenuBreadcrumb };