export type TreeItemKey = string | number;
export interface TreeStateOptions<T extends object, V extends TreeItemKey = string> {
    /** Items in the tree (controlled) */
    items?: T[];
    /** Default items in the tree (uncontrolled) */
    defaultItems?: T[];
    /** The currently selected keys in the tree (controlled). */
    selectedKeys?: V[];
    /** The default selected keys in the tree (uncontrolled). */
    defaultSelectedKeys?: V[];
    /** Handler that is called when the selection changes. */
    onSelectedKeysChange?: (selection: V[]) => void;
    /** A function that returns a unique key for an item object. */
    getKey: (item: T) => V;
    /** A function that returns the children for an item object. */
    getChildren: (item: T) => T[];
}
export interface TreeNode<T extends object, V extends TreeItemKey = string> {
    /** A unique key for the tree node. */
    key: V;
    /** The key of the parent node. */
    parentKey?: V | null;
    /** The value object for the tree node. */
    value: T;
    /** Children of the tree node. */
    children: TreeNode<T, V>[] | null;
}
export interface TreeState<T extends object, V extends TreeItemKey = string> {
    /** The root nodes in the tree. */
    nodes: TreeNode<T, V>[];
    /** The keys of the currently selected items in the tree. */
    selectedKeys: V[];
    /** Sets the selected keys. */
    setSelectedKeys(selection: V[]): void;
    /** Gets a node from the tree by key. */
    getItem(key: V): TreeNode<T, V> | undefined;
    /** Gets the position of a node in the tree. */
    getPosition(key: V): {
        parentKey: V | null;
        index: number;
    } | undefined;
    /** Appends items as children of a parent node. */
    append(parentKey: V | null, items: T[]): TreeDataState<T, V>;
    /** Replaces the children of a parent node with a new subtree. */
    replace(parentKey: V | null, items: T[]): TreeDataState<T, V>;
    /** Removes an item from the tree by its key. */
    remove(...keys: V[]): TreeDataState<T, V> | undefined;
    /** Moves an item within the tree. */
    move(key: V, toParentKey: V | null, index: number): TreeDataState<T, V>;
    /** Moves one or more items before a given key. */
    moveBefore(key: V, keys: V[]): TreeDataState<T, V>;
    /** Moves one or more items after a given key. */
    moveAfter(key: V, keys: V[]): TreeDataState<T, V>;
    /** Synchronizes the tree to the current items. */
    externalSync(): TreeDataState<T, V>;
}
export interface TreeDataState<T extends object, V extends TreeItemKey = string> {
    nodes: TreeNode<T, V>[];
    nodeMap: Map<V, TreeNode<T, V>>;
}
/**
 * Manages state for an immutable tree data structure, and provides convenience methods to update the data over time.
 */
export declare function useTreeState<T extends object, V extends TreeItemKey = string>({ items: itemsProp, defaultItems: initialItemsProp, selectedKeys: selectedKeysProp, defaultSelectedKeys: defaultSelectedKeysProp, getKey, getChildren, onSelectedKeysChange: onChange, }: TreeStateOptions<T, V>): TreeState<T, V>;
export declare const collectKeys: <T extends object, V extends TreeItemKey>(nodes: TreeNode<T, V>[]) => V[];