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

import { AccountData, Secp256k1HdWallet } from '@cosmjs/amino';
import { stringToPath } from '@cosmjs/crypto';

const getMnemonic = async (): Promise<string> => {
  const mnemonicStore = await getInternetCredentials('mnemonicServer');
  if (!mnemonicStore) {
    throw new Error('Mnemonic not found!');
  }

  const mnemonic = mnemonicStore.password;
  return mnemonic;
};

const getHDPath = (network: string, path: string): string => {
  return network === 'eth' ? `m/44'/60'/${path}` : `m/44'/118'/${path}`;
};

const getAddress = async (
  network: string,
  mnemonic: string,
  path: string,
): Promise<string> => {
  switch (network) {
    case 'eth':
      return HDNode.fromMnemonic(mnemonic).derivePath(`m/44'/60'/${path}`)
        .address;
    case 'cosmos':
      return (await getCosmosAccounts(mnemonic, `${path}`)).data.address;
    default:
      throw new Error('Invalid wallet type');
  }
};

const getCosmosAccounts = async (
  mnemonic: string,
  path: string,
): Promise<{ cosmosWallet: Secp256k1HdWallet; data: AccountData }> => {
  const cosmosWallet = await Secp256k1HdWallet.fromMnemonic(mnemonic, {
    hdPaths: [stringToPath(`m/44'/118'/${path}`)],
  });

  const accountsData = await cosmosWallet.getAccounts();
  const data = accountsData[0];

  return { cosmosWallet, data };
};

const accountInfoFromHDPath = async (
  hdPath: string,
): Promise<
  | { privKey: string; pubKey: string; address: string; network: string }
  | undefined
> => {
  const mnemonicStore = await getInternetCredentials('mnemonicServer');
  if (!mnemonicStore) {
    throw new Error('Mnemonic not found!');
  }

  const mnemonic = mnemonicStore.password;
  const hdNode = HDNode.fromMnemonic(mnemonic);
  const node = hdNode.derivePath(hdPath);

  const privKey = node.privateKey;
  const pubKey = node.publicKey;

  const parts = hdPath.split('/');
  const path = parts.slice(-3).join('/');
  const coinType = parts[2];

  let network: string;
  let address: string;

  switch (coinType) {
    case "60'":
      network = 'eth';
      address = node.address;
      break;
    case "118'":
      network = 'cosmos';
      address = (await getCosmosAccounts(mnemonic, path)).data.address;
      break;
    default:
      throw new Error('Invalid wallet type');
  }
  return { privKey, pubKey, address, network };
};

const getPathKey = async (
  network: string,
  accountId: number,
): Promise<{
  path: string;
  privKey: string;
  pubKey: string;
  address: string;
}> => {
  const pathKeyStore = await getInternetCredentials(
    `${network}:keyServer:${accountId}`,
  );

  if (!pathKeyStore) {
    throw new Error('Error while fetching counter');
  }

  const pathKeyVal = pathKeyStore.password;
  const pathkey = pathKeyVal.split(',');
  const path = pathkey[0];
  const privKey = pathkey[1];
  const pubKey = pathkey[2];
  const address = pathkey[3];

  return { path, privKey, pubKey, address };
};

const getGlobalCounter = async (
  network: string,
): Promise<{
  accountCounter: string;
  counterIds: number[];
  counterId: number;
}> => {
  const counterStore = await getInternetCredentials(`${network}:globalCounter`);

  if (!counterStore) {
    throw new Error('Error while fetching counter');
  }

  let accountCounter = counterStore.password;
  const counterIds = accountCounter.split(',').map(Number);
  const counterId = counterIds[counterIds.length - 1] + 1;

  return { accountCounter, counterIds, counterId };
};

const updateGlobalCounter = async (
  network: string,
): Promise<{ accountCounter: string; counterId: number }> => {
  const globalCounterData = await getGlobalCounter(network);
  const accountCounter = globalCounterData.accountCounter;
  const counterId = globalCounterData.counterId;
  const updatedAccountCounter = `${accountCounter},${counterId.toString()}`;

  await resetInternetCredentials(`${network}:globalCounter`);
  await setInternetCredentials(
    `${network}:globalCounter`,
    `${network}Global`,
    updatedAccountCounter,
  );

  return { accountCounter: updatedAccountCounter, counterId };
};

const getNextAccountId = async (network: string): Promise<number> => {
  const idStore = await getInternetCredentials(`${network}:accountIndices`);
  if (!idStore) {
    throw new Error('Account id not found');
  }

  const accountIds = idStore.password;
  const ids = accountIds.split(',').map(Number);
  return ids[ids.length - 1] + 1;
};

const updateAccountIndices = async (
  network: string,
  id: number,
): Promise<void> => {
  const idStore = await getInternetCredentials(`${network}:accountIndices`);
  if (!idStore) {
    throw new Error('Account id not found');
  }

  const updatedIndices = `${idStore.password},${id.toString()}`;
  await resetInternetCredentials(`${network}:accountIndices`);
  await setInternetCredentials(
    `${network}:accountIndices`,
    `${network}Counter`,
    updatedIndices,
  );
};

const resetKeyServers = async (prefix: string) => {
  const idStore = await getInternetCredentials(`${prefix}:accountIndices`);
  if (!idStore) {
    throw new Error('Account id not found.');
  }

  const accountIds = idStore.password;
  const ids = accountIds.split(',').map(Number);
  const id = ids[ids.length - 1];

  for (let i = 0; i <= id; i++) {
    await resetInternetCredentials(`${prefix}:keyServer:${i}`);
  }
};

export {
  accountInfoFromHDPath,
  getCosmosAccounts,
  getMnemonic,
  getPathKey,
  getNextAccountId,
  updateGlobalCounter,
  updateAccountIndices,
  getHDPath,
  getAddress,
  resetKeyServers,
};