import * as secp from "@noble/secp256k1";
import { KeyringPair } from "@polkadot/keyring/types";
import * as bip39 from "bip39";
import { Buffer } from "buffer";

export enum KPType {
  sr25519 = "sr25519",
  ed25519 = "ed25519",
}
export function sign(payload: string | Uint8Array, signer: KeyringPair) {
  const typePrefix = signer.type === KPType.sr25519 ? "s" : "e";
  const sig = signer.sign(payload);
  const prefix = Buffer.from(typePrefix).readUInt8(0);
  const sigPrefixed = new Uint8Array([prefix, ...sig]);

  return sigPrefixed;
}

export async function createShared(pubKey: Uint8Array, mnemonic: string) {
  const seed = await bip39.mnemonicToSeed(mnemonic);
  const privateKey = new Uint8Array(seed).slice(0, 32);
  const pointX = secp.getSharedSecret(privateKey, pubKey);
  const key = await secp.utils.sha256(pointX.slice(1, 33));
  return key;
}