import { HashFunction, Proof, Node } from "./types";
/**
 * A Merkle tree is a tree in which every leaf node is labelled with the cryptographic hash of a
 * data block, and every non-leaf node is labelled with the cryptographic hash of the labels of its child nodes.
 * It allows efficient and secure verification of the contents of large data structures.
 * The MerkleTree class is a TypeScript implementation of Merkle tree and it provides all the functions to create
 * efficient trees and to generate and verify proofs of membership.
 */
export default class MerkleTree {
    static readonly maxDepth = 32;
    private _root;
    private readonly _nodes;
    private readonly _zeroes;
    private readonly _hash;
    private readonly _depth;
    /**
     * Initializes the Merkle tree with the hash function, the depth and the zero value to use for zeroes.
     * @param hash Hash function.
     * @param depth Tree depth.
     * @param zeroValue Zero values for zeroes.
     */
    constructor(hash: HashFunction, depth: number, zeroValue: Node);
    /**
     * Returns the root hash of the tree.
     * @returns Root hash.
     */
    get root(): Node;
    /**
     * Returns the depth of the tree.
     * @returns Tree depth.
     */
    get depth(): number;
    /**
     * Returns the leaves of the tree.
     * @returns List of leaves.
     */
    get leaves(): Node[];
    /**
     * Returns the zeroes nodes of the tree.
     * @returns List of zeroes.
     */
    get zeroes(): Node[];
    /**
     * Inserts a new leaf in the tree.
     * @param leaf New leaf.
     */
    insert(leaf: Node): void;
    /**
     * Deletes a leaf from the tree. It does not remove the leaf from
     * the data structure. It set the leaf to be deleted to a zero value.
     * @param index Index of the leaf to be deleted.
     */
    delete(index: number): void;
    /**
     * Creates a proof of membership.
     * @param index Index of the proof's leaf.
     * @returns Proof object.
     */
    createProof(index: number): Proof;
    /**
     * Verifies a proof and return true or false.
     * @param proof Proof to be verified.
     * @returns True or false.
     */
    verifyProof(proof: Proof): boolean;
    /**
     * Returns the index of a leaf. If the leaf does not exist it returns -1.
     * @param leaf Tree leaf.
     * @returns Index of the leaf.
     */
    indexOf(leaf: Node): number;
    /**
     * Provides a bottom-up tree traversal where for each level it calls a callback.
     * @param index Index of the leaf.
     * @param callback Callback with tree level, index of node in that level and direction (left node: true, right node: false).
     */
    private forEachLevel;
}