import { ReactNode, RefObject } from 'react';
import { CSSObject } from 'styled-components';
export type DirectoryExpandedItems = Set<string> | string[];
export type DirectoryVirtualizationConfig = {
    /**
     * External scroll container. Must be mounted (ref.current set) by the
     * time Directory mounts — onEndReached binds its scroll listener once
     * and does not retry when the element appears later.
     */
    viewportRef?: RefObject<HTMLElement | null>;
    rowHeight?: number;
    sectionHeight?: number;
    viewportHeight?: number;
    overscan?: number;
    threshold?: number;
};
export type DirectoryProps = {
    directoryData: DirectoryData[] | null;
    idPrefix?: string;
    activeItem?: string | null;
    onActiveItemChange?: (item: string | null) => void;
    defaultActiveItem?: string | null;
    iconOnlyMode?: boolean;
    showHierarchyLines?: boolean;
    hierarchyLineBorderRadius?: CSSObject['borderRadius'];
    expandedItems?: DirectoryExpandedItems;
    defaultExpandedItems?: DirectoryExpandedItems;
    onExpandedItemsChange?: (items: string[]) => void;
    onItemExpand?: (item: NavbarItem, itemPath: string) => void | Promise<void>;
    /**
     * Called when the viewport is scrolled within endReachedThreshold pixels
     * of the bottom (and re-checked when the content grows), for paged /
     * infinite loading.
     */
    onEndReached?: () => void | Promise<void>;
    /**
     * Distance in pixels from the bottom at which onEndReached fires.
     * @default 200
     */
    endReachedThreshold?: number;
    /**
     * When true, clicking a parent row selects it (updates activeItem) in
     * addition to toggling expansion, and parent rows can render as
     * selected. When false, only leaf rows can be selected.
     * @default false
     */
    enableParentSelection?: boolean;
    /**
     * When true, selecting an item also styles its ancestor chain as
     * `activePath` and every unrelated row as `muted`, so the branch you are
     * in reads at a glance. With nothing selected the tree renders exactly as
     * it does with this off.
     *
     * Requires a path-valued `activeItem` — a bare label (the backward-compat
     * match for id-less items) resolves no ancestors and degrades to
     * selected-only highlighting.
     *
     * Note: the default `muted` text colour is 4.49:1 (light) / 4.17:1 (dark),
     * just under the 4.5:1 WCAG AA floor; muted rows lift to the `hover` tier
     * on hover and focus-visible. Override `DIRECTORY` component tokens if
     * your product needs muted rows to clear AA at rest.
     *
     * @default false
     */
    highlightActivePath?: boolean;
    enableVirtualization?: boolean;
    virtualization?: DirectoryVirtualizationConfig;
};
export type DirectoryData = {
    label?: string;
    items?: NavbarItem[];
    isCollapsible?: boolean;
    defaultOpen?: boolean;
};
export type NavbarItem = {
    label: string;
    /**
     * Stable identifier used as this item's path segment (itemPath, expansion
     * state, virtualizer keys, data-id). Falls back to label when omitted or
     * empty — provide it when sibling labels can collide. Must not contain
     * "/" (the path separator). Items without an id also match a bare-label
     * activeItem for backward compatibility; items with an id match only
     * their id-based path.
     */
    id?: string;
    items?: NavbarItem[];
    leftSlot?: ReactNode;
    rightSlot?: ReactNode;
    onClick?: () => void;
    href?: string;
    isSelected?: boolean;
    /**
     * When true, the item appears in the Sidebar mobile navigation drawer.
     * Desktop always renders all items regardless of this flag.
     */
    showOnMobile?: boolean;
};
export type SectionProps = {
    section: DirectoryData;
    sectionIndex: number;
    onNavigateBetweenSections: (direction: 'up' | 'down', currentIndex: number) => void;
    idPrefix?: string;
    iconOnlyMode?: boolean;
    showHierarchyLines?: boolean;
    hierarchyLineBorderRadius?: CSSObject['borderRadius'];
    enableParentSelection?: boolean;
    highlightActivePath?: boolean;
};
export type NavItemProps = {
    item: NavbarItem;
    index: number;
    onNavigate: (direction: 'up' | 'down', currentIndex: number) => void;
    itemPath?: string;
    iconOnlyMode?: boolean;
    showHierarchyLines?: boolean;
    hierarchyLineBorderRadius?: CSSObject['borderRadius'];
    isLast?: boolean;
    isNested?: boolean;
    enableParentSelection?: boolean;
    highlightActivePath?: boolean;
    pathVerticalActive?: boolean;
    pathElbowActive?: boolean;
};
export type DirectoryFlatRow = {
    type: 'section';
    section: DirectoryData;
    sectionIndex: number;
} | {
    type: 'item';
    item: NavbarItem;
    sectionIndex: number;
    itemPath: string;
    depth: number;
    isLast: boolean;
    ancestorIsLast: boolean[];
};