import Connection from "./connection";
import _sodium from "libsodium-wrappers";

window.currentConnection = undefined;

export function setConn(conn) {
  window.currentConnection = conn;
}

export function getConn() {
  return window.currentConnection;
}

export function close() {
  getConn()?.close();
  setConn(undefined);
}

export function newConn() {
  window.currentConnection?.close();
  const conn = new Connection();
  setConn(conn);
  return conn;
}

let sodium;
export async function verify(signed, pk) {
  if (!sodium) {
    await _sodium.ready;
    sodium = _sodium;
  }
  if (typeof pk == 'string') {
    pk = decodeBase64(pk);
  }
  return sodium.crypto_sign_open(signed, pk);
}

export function decodeBase64(pk) {
  return sodium.from_base64(pk, sodium.base64_variants.ORIGINAL);
}

export function genBoxKeyPair() {
  const pair = sodium.crypto_box_keypair();
  const sk = pair.privateKey;
  const pk = pair.publicKey;
  return [sk, pk];
}

export function genSecretKey() {
  return sodium.crypto_secretbox_keygen();
}

export function seal(unsigned, theirPk, ourSk) {
  const nonce = Uint8Array.from(Array(24).fill(0));
  return sodium.crypto_box_easy(unsigned, nonce, theirPk, ourSk);
}

function makeOnce(value) {
  var byteArray = Array(24).fill(0);

  for (var index = 0; index < byteArray.length && value > 0; index++) {
    var byte = value & 0xff;
    byteArray[index] = byte;
    value = (value - byte) / 256;
  }

  return Uint8Array.from(byteArray);
};

export function encrypt(unsigned, nonce, key) {
  return sodium.crypto_secretbox_easy(unsigned, makeOnce(nonce), key);
}

export function decrypt(signed, nonce, key) {
  return sodium.crypto_secretbox_open_easy(signed, makeOnce(nonce), key);
}