import Node from './Node';
export declare type CountCallback = (err, count?: number) => void;
export declare type NodeCallback = (err, node?: Node) => void;
export declare type NodesCallback = (err, nodes?: Node[]) => void;
/**
 * Database Class. Interface to Node Embedded Database (NeDB).
 *
 * @class Database
 * @memberof jibo.kb
 * @param {string} filename Full path filename to NeDB file.
 * @internal
 */
export default class Database {
    filename: string;
    nodes: any;
    constructor(filename: string);
    /** Attach to the NeDB filename given in constructor. File is
     * compacted upon opening, or created if it doesn't exist.
     *
     * @method jibo.kb.Database#init
     * @param {Function} callback Called when done compacting/creating/attaching.
     * @internal
     */
    init(callback: CountCallback): void;
    /** Load node of given id. Returns null (via callback) if
     * not found.
     *
     * @method jibo.kb.Database#load
     * @param {string} id ID of node to load.
     * @param {Function} callback Called with (err, node). Node (and err) is null if not found.
     * @internal
     */
    load(id: string, callback: NodeCallback): void;
    /** Load one node of a given type. Used to find the 'root' node.
     *
     * @method jibo.kb.Database#loadNodeOfType
     * @param {string} nodeType Node type to load.
     * @param {Function} callback Called with (err, node). Node (and err) is null if not found.
     * @internal
     */
    loadNodeOfType(nodeType: string, callback: NodeCallback): void;
    /** Load every node (in this kb slice) of a given type.
     *
     * @method jibo.kb.Database#loadNodesOfType
     * @param {string} nodeType Node type to load.
     * @param {Function} callback Called with (err, nodes) where nodes
     * is an array of the found nodes.
     * @internal
     */
    loadNodesOfType(nodeType: string, callback: NodesCallback): void;
    /** Save a given node.
     *
     * @method jibo.kb.Database#save
     * @param {jibo.kb.Node} node The node to be saved.
     * @param {Function} callback Called with (err, node) when finished.
     * @internal
     */
    save(node: Node, callback: NodeCallback): void;
    /** Remove a node from this kb slice.
     *
     * @method jibo.kb.Database#remove
     * @param {string|jibo.kb.Node} idOrNode Id string or Node object to be removed.
     * @param {Function} callback Called with (err, numRemoved) when finished.
     * @internal
     */
    remove(idOrNode: string | Node, callback: CountCallback): void;
    /** Convert an idOrNode parameter to an id if it's a node.
     *
     * @method jibo.kb.Database#_toId
     * @param {string|jibo.kb.Node} ID string, or node with an ._id property.
     * @returns {string} ID
     * @private
     * @internal
     */
    private _toId(idOrNode);
}