import * as secp from "@noble/secp256k1";
import * as bip39 from "bip39";
import { Buffer } from "buffer";
import * as cryptoJs from "crypto-js";

function isValidSeed(seed: string) {
  const hexRegex = /^[0-9a-fA-F]+$/;
  return hexRegex.test(seed) ? true : false;
}

function getPublicKey(privateKey: Buffer | string) {
  return "0x" + Buffer.from(secp.getPublicKey(privateKey, true)).toString("hex");
}

export function generatePublicKey(secret: string) {
  let privKey;

  if (bip39.validateMnemonic(secret)) {
    const seed = bip39.mnemonicToSeedSync(secret);
    privKey = new Uint8Array(seed).slice(0, 32);
  } else {
    privKey = secret;
    if (secret.startsWith("0x")) {
      privKey = secret.substring(2);
    }

    if (!isValidSeed(privKey) || privKey.length !== 64) {
      throw new Error("Invalid seed. Couldn't get public key from the provided seed.");
    }
  }

  return getPublicKey(privKey);
}

export function hexStringToArrayBuffer(hexString) {
  // remove the leading 0x
  hexString = hexString.replace(/^0x/, "");

  // ensure even number of characters
  if (hexString.length % 2 != 0) {
    console.log("WARNING: expecting an even number of characters in the hexString");
  }

  // check for some non-hex characters
  const bad = hexString.match(/[G-Z\s]/i);
  if (bad) {
    console.log("WARNING: found non-hex characters", bad);
  }

  // split the string into pairs of octets
  const pairs = hexString.match(/[\dA-F]{2}/gi);

  // convert the octets to integers
  const integers = pairs.map(function (s) {
    return parseInt(s, 16);
  });

  const array = new Uint8Array(integers);

  return array.buffer;
}

export function wordArrayToUint8Array(data: cryptoJs.lib.WordArray) {
  const dataArray = new Uint8Array(data.sigBytes);
  for (let i = 0x0; i < data.sigBytes; i++) {
    dataArray[i] = (data.words[i >>> 0x2] >>> (0x18 - (i % 0x4) * 0x8)) & 0xff;
  }
  return new Uint8Array(dataArray);
}