/*  Importing this library provides react native with a secure random source.
For more information, "visit https://docs.ethers.org/v5/cookbook/react-native/#cookbook-reactnative-security" */
import 'react-native-get-random-values';
import '@ethersproject/shims';

import { Wallet, utils } from 'ethers';
import { HDNode } from 'ethers/lib/utils';
import { Alert } from 'react-native';
import {
  setInternetCredentials,
  getInternetCredentials,
  resetInternetCredentials,
} from 'react-native-keychain';

const generateWallet = async (): Promise<HDNode | undefined> => {
  try {
    const mnemonic = utils.entropyToMnemonic(utils.randomBytes(32));
    const hdNode = HDNode.fromMnemonic(mnemonic);
    const ethNode = hdNode.derivePath("m/44'/60'/0'/0/0");

    await setInternetCredentials('keyServer', 'key', ethNode.privateKey);
    await setInternetCredentials('mnemonicServer', 'mnemonic', mnemonic);

    return ethNode;
  } catch (error) {
    console.error('Error creating wallet ', error);
  }
};

const signMessage = async (message: string) => {
  try {
    const keyCred = await getInternetCredentials('keyServer');
    const wallet = keyCred && new Wallet(keyCred.password);
    const signature = wallet && (await wallet.signMessage(message));
    if (typeof signature === 'string') {
      Alert.alert('Message signature: ', signature);
    } else {
      Alert.alert('Message signing failed. Please try again.');
    }
  } catch (error) {
    console.error('Error signing transaction ', error);
  }
};

const resetWallet = async () => {
  await resetInternetCredentials('keyServer');
  await resetInternetCredentials('mnemonicServer');
};

export { generateWallet, signMessage, resetWallet };