// @ts-ignore
import DhtNode from "@hyperswarm/dht-relay";
// @ts-ignore
import Stream from "@hyperswarm/dht-relay/ws";
// @ts-ignore
import createRoundRobin from "@derhuerst/round-robin-scheduler";
// @ts-ignore
import { Buffer } from "buffer";
// @ts-ignore
import { blake2b } from "libskynet";
// @ts-ignore
import { registryRead } from "libkmodule";
import { unpack } from "msgpackr";
const REGISTRY_DHT_KEY = "lumeweb-dht-node";
export default class DHT {
    _wsPool;
    _options;
    _relays = {};
    constructor(opts = {}) {
        // @ts-ignore
        opts.custodial = true;
        this._options = opts;
        this._wsPool = createRoundRobin();
    }
    ready() {
        return Promise.resolve();
    }
    get relays() {
        return Object.keys(this._relays);
    }
    async addRelay(pubkey) {
        let entry = await registryRead(Uint8Array.from(Buffer.from(pubkey, "hex")), hashDataKey(REGISTRY_DHT_KEY));
        if (entry[1] || !entry[0]?.exists) {
            return false;
        }
        let host;
        try {
            host = unpack(entry[0].entryData);
        }
        catch (e) {
            return false;
        }
        const [domain, port] = host.split(":");
        if (isNaN(parseInt(port))) {
            return false;
        }
        const connection = `wss://${domain}:${port}/`;
        this._wsPool.add(connection);
        this._relays[pubkey] = connection;
        return true;
    }
    removeRelay(pubkey) {
        if (!(pubkey in this._relays)) {
            return false;
        }
        this._wsPool.remove(this._relays[pubkey]);
        delete this._relays[pubkey];
        return true;
    }
    clearRelays() {
        this._wsPool = createRoundRobin();
        this._relays = {};
    }
    async isServerAvailable(connection) {
        return new Promise((resolve) => {
            const ws = new WebSocket(connection);
            ws.addEventListener("open", () => {
                ws.close();
                resolve(true);
            });
            ws.addEventListener("error", () => {
                resolve(false);
            });
        });
    }
    async connect(pubkey, options = {}) {
        const relay = await this.getAvailableRelay();
        if (!relay) {
            throw new Error("Failed to find an available relay");
        }
        const node = new DhtNode(new Stream(true, new WebSocket(relay)), this._options);
        await node.ready();
        return node.connect(pubkey, options);
    }
    async getAvailableRelay() {
        for (let i = 0; i < this._wsPool.length; i++) {
            const relay = this._wsPool.get();
            if (await this.isServerAvailable(relay)) {
                return relay;
            }
        }
        return false;
    }
}
export function hashDataKey(dataKey) {
    return blake2b(encodeUtf8String(dataKey));
}
function encodeUtf8String(str) {
    const byteArray = stringToUint8ArrayUtf8(str);
    const encoded = new Uint8Array(8 + byteArray.length);
    encoded.set(encodeNumber(byteArray.length));
    encoded.set(byteArray, 8);
    return encoded;
}
function stringToUint8ArrayUtf8(str) {
    return Uint8Array.from(Buffer.from(str, "utf-8"));
}
function encodeNumber(num) {
    const encoded = new Uint8Array(8);
    for (let index = 0; index < encoded.length; index++) {
        encoded[index] = num & 0xff;
        num = num >> 8;
    }
    return encoded;
}