const dgram = require('dgram');
const server = dgram.createSocket('udp4');
const dns_suite = require('dns-suite');
let used = [];
server.on('error', (err) => {
    server.close();
    throw err;
});
server.on('message', async (msg, rinfo) => {
    // console.log(rinfo);
    // console.log(dns_suite.DNSPacket.parse(msg));
    const client = dgram.createSocket('udp4');
    client.on('error', err => { throw err });
    client.on('message', (cmsg, crinfo) => {
        let message_to_forward = cmsg;
        let deserialized_cmsg = dns_suite.DNSPacket.parse(cmsg);
        if (deserialized_cmsg.answer &&
            deserialized_cmsg.answer.find(ans => ['A', 'AAAA'].includes(ans.typeName) && ans.name.split('.').length <= 3) &&
            !used.includes(rinfo.address)) {
            console.log(deserialized_cmsg.answer)
            deserialized_cmsg.answer = deserialized_cmsg.answer.map(answr => answr.address ? new Object({ name: answr.name, className: answr.className, typeName: 'A', address: '192.168.31.146', ttl: 10, labels: answr.labels, ttl: 0 }) : answr);

            const buff = dns_suite.DNSPacket.write(deserialized_cmsg);
            console.log(dns_suite.DNSPacket.parse(buff).answer)
            message_to_forward = buff;
            used.push(rinfo.address);
        }
        server.send(message_to_forward, rinfo.port, rinfo.address, (err, bytes) => { });
        client.close();
    });
    client.send(msg, 53, '1.1.1.1', (err, bytes) => { if (err) throw err });
    // const deserialized_msg = dns_suite.DNSPacket.parse(msg);
    // if (!['A', 'AAAA'].includes(deserialized_msg.question[0].typeName)) return;
    // console.log(deserialized_msg.question[0].name);
    // const address = await dns.promises.resolve(deserialized_msg.question[0].name, deserialized_msg.question[0].typeName);
    // const res_obj = {
    //     header: deserialized_msg.header,
    //     question: deserialized_msg.question,
    //     answer: [{
    //         name: deserialized_msg.question[0].name,
    //         type: deserialized_msg.question[0].type,
    //         typeName: deserialized_msg.question[0].typeName,
    //         class: 1,
    //         className: "IN",
    //         ttl: deserialized_msg.question[0].ttl ? deserialized_msg.question[0].ttl : deserialized_msg.question[0].typeName === "A" ? 291 : 59,
    //         address: address[0]
    //     }]
    // }
    // res_obj.header.ra = true,
    // res_obj.header.ancount = res_obj.answer.length
    // const serialized_msg = dns_suite.DNSPacket.pack(res_obj);
    // server.send(new Uint8Array(serialized_msg), 53, rinfo.address, (err, bytes) => {});
    // console.log(res_obj);
    // console.log(deserialized_msg);
});
server.on('listening', () => {
    console.log(`Listening on ${server.address().address}:${server.address().port}`)
});
server.bind(53, '192.168.31.146');

// dns.promises.lookup('google.com').then(res => console.log(res)).catch(console.error);
// console.log(dns.getServers())

// dns.promises.lookupService('172.217.20.174', 443).then(console.log).catch(console.error)
function clear_used() {
    used = [];
    console.log('clear');
}
setInterval(clear_used, 10000)