import type { ReactNode } from 'react';
export type TreeNode<T = unknown> = {
    id: string;
    label: ReactNode;
    icon?: ReactNode;
    data?: T;
    /**
     * Present (even as an empty array) means this node's children are
     * already known - eager mode relies entirely on this and never calls
     * `loadChildren`. Leave it undefined for a node whose children haven't
     * been fetched yet (lazy mode).
     */
    children?: TreeNode<T>[];
    /**
     * Only consulted while `children` is undefined and `loadChildren` is
     * given: says whether this node is expected to have children at all.
     * Defaults to true (assume expandable) so a node the caller hasn't
     * inspected yet still shows a toggle; set it to false for a node you
     * already know is a leaf, to skip showing a toggle for it entirely.
     */
    hasChildren?: boolean;
};
/** Fetches one node's children. Called once per node, the first time it's expanded (and again on retry after a failed load). Presence of this prop on TreeView is what switches it into lazy mode. */
export type LoadTreeChildren<T = unknown> = (node: TreeNode<T>) => Promise<TreeNode<T>[]>;
export type TreeViewProps<T = unknown> = {
    /** Top-level nodes. In eager mode every node's full subtree must already be present via `children`. In lazy mode only the nodes you already know about need to be here - deeper levels arrive via `loadChildren`. */
    data: TreeNode<T>[];
    /** Omit for eager mode. Provide for lazy mode. */
    loadChildren?: LoadTreeChildren<T>;
    /** Uncontrolled initial expanded ids. Ignored if `expandedIds` is given. */
    defaultExpandedIds?: string[];
    /** Controlled expanded ids - pass together with `onExpandedIdsChange` to own the expand/collapse state yourself (e.g. to sync it with a URL). */
    expandedIds?: string[];
    onExpandedIdsChange?: (ids: string[]) => void;
    selectedId?: string;
    onSelectNode?: (node: TreeNode<T>) => void;
    /** Customize how a node's row content renders; defaults to `node.icon` + `node.label`. */
    renderLabel?: (node: TreeNode<T>) => ReactNode;
    /** Allows node labels to wrap onto multiple lines. Set to false to truncate them to one line. */
    wrapLabels?: boolean;
    emptyMessage?: ReactNode;
    /** Formats the error shown under a node whose `loadChildren` call rejected. */
    loadErrorMessage?: (error: unknown, node: TreeNode<T>) => ReactNode;
    className?: string;
    'data-testid'?: string;
};