6. स्टेकिंग डीऐप(Dapp) कैसे बनाएं

git clone https://github.com/scaffold-eth/scaffold-eth-challenges.git challenge-1-decentralized-staking

cd challenge-1-decentralized-staking

git checkout challenge-1-decentralized-staking

yarn install

yarn start

yarn chain

yarn deploy

pragma solidity >=0.6.0 <0.7.0;

import "hardhat/console.sol";
import "./ExampleExternalContract.sol";

contract Staker {
  ExampleExternalContract public exampleExternalContract;
  
  constructor(address exampleExternalContractAddress) public {
      exampleExternalContract = ExampleExternalContract(exampleExternalContractAddress);
  }
  
}

mapping(address => uint256) public balances; 
mapping(address => uint256) public depositTimestamps;

uint256 public constant rewardRatePerSecond = 0.1 ether; 
uint256 public withdrawalDeadline = block.timestamp + 120 seconds; 
uint256 public claimDeadline = block.timestamp + 240 seconds; 
uint256 public currentBlock = 0;

event Stake(address indexed sender, uint256 amount); 
event Received(address, uint); 
event Execute(address indexed sender, uint256 amount);

function withdrawalTimeLeft() public view returns (uint256 withdrawalTimeLeft) {
    if( block.timestamp >= withdrawalDeadline) {
      return (0);
    } else {
      return (withdrawalDeadline - block.timestamp);
    }
  }

  function claimPeriodLeft() public view returns (uint256 claimPeriodLeft) {
    if( block.timestamp >= claimDeadline) {
      return (0);
    } else {
      return (claimDeadline - block.timestamp);
    }
  }

modifier withdrawalDeadlineReached( bool requireReached ) {
    uint256 timeRemaining = withdrawalTimeLeft();
    if( requireReached ) {
      require(timeRemaining == 0, "Withdrawal period is not reached yet");
    } else {
      require(timeRemaining > 0, "Withdrawal period has been reached");
    }
    _;
  }

  modifier claimDeadlineReached( bool requireReached ) {
    uint256 timeRemaining = claimPeriodLeft();
    if( requireReached ) {
      require(timeRemaining == 0, "Claim deadline is not reached yet");
    } else {
      require(timeRemaining > 0, "Claim deadline has been reached");
    }
    _;
  }

  modifier notCompleted() {
    bool completed = exampleExternalContract.completed();
    require(!completed, "Stake already completed!");
    _;
  }

// Stake function for a user to stake ETH in our contract
// हमारे कॉन्ट्रैक्ट में ETH को स्टेक करने के लिए एक उपयोगकर्ता के लिए स्टेक फंक्शन
  
  function stake() public payable withdrawalDeadlineReached(false) claimDeadlineReached(false) {
    balances[msg.sender] = balances[msg.sender] + msg.value;
    depositTimestamps[msg.sender] = block.timestamp;
    emit Stake(msg.sender, msg.value);
  }

/*
  Withdraw function for a user to remove their staked ETH inclusive
  of both the principle balance and any accrued interest
  */
/*
	 निकासी फंक्शन किसी भी उपयोगकर्ता के लिए अपने दाँव पर लगे (staked) ETH को वापिस लेने के लिए जिसमे
   दोनों यानि मूल शेष राशि और कोई भी अर्जित ब्याज शामिल है
*/
  
  function withdraw() public withdrawalDeadlineReached(true) claimDeadlineReached(false) notCompleted{
    require(balances[msg.sender] > 0, "You have no balance to withdraw!");
    uint256 individualBalance = balances[msg.sender];
    uint256 indBalanceRewards = individualBalance + ((block.timestamp-depositTimestamps[msg.sender])*rewardRatePerSecond);
    balances[msg.sender] = 0;

    // Transfer all ETH via call! (not transfer) cc: https://solidity-by-example.org/sending-ether
    (bool sent, bytes memory data) = msg.sender.call{value: indBalanceRewards}("");
    require(sent, "RIP; withdrawal failed :( ");
  }

/*
  Allows any user to repatriate "unproductive" funds that are left in the staking contract
  past the defined withdrawal period
  */
/*
	 परिभाषित निकासी अवधि के बाद किसी भी उपयोगकर्ता को "अनुत्पादक" निधियों (फंड्स) को प्रत्यावर्तित करने 
   की अनुमति देता है जो स्टेकिंग कॉन्ट्रैक्ट में बची हुई हैं
*/
  
  function execute() public claimDeadlineReached(true) notCompleted {
    uint256 contractBalance = address(this).balance;
    exampleExternalContract.complete{value: address(this).balance}();
  }

// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;

import "hardhat/console.sol";
import "./ExampleExternalContract.sol";

contract Staker {

  ExampleExternalContract public exampleExternalContract;

  mapping(address => uint256) public balances;
  mapping(address => uint256) public depositTimestamps;

  uint256 public constant rewardRatePerSecond = 0.1 ether;
  uint256 public withdrawalDeadline = block.timestamp + 120 seconds;
  uint256 public claimDeadline = block.timestamp + 240 seconds;
  uint256 public currentBlock = 0;

  // Events
  event Stake(address indexed sender, uint256 amount);
  event Received(address, uint);
  event Execute(address indexed sender, uint256 amount);

  // Modifiers
  /*
  Checks if the withdrawal period has been reached or not
	यह जाँचता है कि निकासी की अवधि पूरी हो गई है या नहीं
  */
  modifier withdrawalDeadlineReached( bool requireReached ) {
    uint256 timeRemaining = withdrawalTimeLeft();
    if( requireReached ) {
      require(timeRemaining == 0, "Withdrawal period is not reached yet");
    } else {
      require(timeRemaining > 0, "Withdrawal period has been reached");
    }
    _;
  }

  /*
  Checks if the claim period has ended or not
	जांचता है कि दावा अवधि समाप्त हो गई है या नहीं
  */
  modifier claimDeadlineReached( bool requireReached ) {
    uint256 timeRemaining = claimPeriodLeft();
    if( requireReached ) {
      require(timeRemaining == 0, "Claim deadline is not reached yet");
    } else {
      require(timeRemaining > 0, "Claim deadline has been reached");
    }
    _;
  }

  /*
  Requires that the contract only be complete 
यह सुनिश्चित करता है कि कॉन्ट्रैक्ट केवल एक बार पूरा हो!
  */
  modifier notCompleted() {
    bool completed = exampleExternalContract.completed();
    require(!completed, "Stake already completed!");
    _;
  }

  constructor(address exampleExternalContractAddress){
      exampleExternalContract = ExampleExternalContract(exampleExternalContractAddress);
  }

  // Stake function for a user to stake ETH in our contract
	// हमारे कॉन्ट्रैक्ट में ETH को दांव पर लगाने के लिए एक उपयोगकर्ता के लिए स्टेक फंक्शन
  function stake() public payable withdrawalDeadlineReached(false) claimDeadlineReached(false){
    balances[msg.sender] = balances[msg.sender] + msg.value;
    depositTimestamps[msg.sender] = block.timestamp;
    emit Stake(msg.sender, msg.value);
  }

  /*
  Withdraw function for a user to remove their staked ETH inclusive
  of both principal and any accrued interest
	
	निकासी फंक्शन किसी भी उपयोगकर्ता के लिए अपने दाँव पर लगे (staked) ETH को वापिस लेने के लिए जिसमे
  दोनों यानि मूल शेष राशि और कोई भी अर्जित ब्याज शामिल है
  */
  function withdraw() public withdrawalDeadlineReached(true) claimDeadlineReached(false) notCompleted{
    require(balances[msg.sender] > 0, "You have no balance to withdraw!");
    uint256 individualBalance = balances[msg.sender];
    uint256 indBalanceRewards = individualBalance + ((block.timestamp-depositTimestamps[msg.sender])*rewardRatePerSecond);
    balances[msg.sender] = 0;

    // Transfer all ETH via call! (not transfer) cc: https://solidity-by-example.org/sending-ether
    (bool sent, bytes memory data) = msg.sender.call{value: indBalanceRewards}("");
    require(sent, "RIP; withdrawal failed :( ");
  }

  /*
  Allows any user to repatriate "unproductive" funds that are left in the staking contract
  past the defined withdrawal period

	परिभाषित निकासी अवधि के बाद किसी भी उपयोगकर्ता को "अनुत्पादक" निधियों (फंड्स) को प्रत्यावर्तित करने 
  की अनुमति देता है जो स्टेकिंग कॉन्ट्रैक्ट में बची हुई हैं
  */
  function execute() public claimDeadlineReached(true) notCompleted {
    uint256 contractBalance = address(this).balance;
    exampleExternalContract.complete{value: address(this).balance}();
  }

  /*
  READ-ONLY function to calculate the time remaining before the minimum staking period has passed
	केवल रीड-ओनली फंक्शन जो स्टेकिंग अवधि बीतने से पहले न्यूनतम शेष (बचा हुआ समय) समय की गणना कर सके 
  */
  function withdrawalTimeLeft() public view returns (uint256 withdrawalTimeLeft) {
    if( block.timestamp >= withdrawalDeadline) {
      return (0);
    } else {
      return (withdrawalDeadline - block.timestamp);
    }
  }

   /*
  READ-ONLY function to calculate the time remaining before the minimum staking period has passed
	रीड-ओनली फंक्शन जो स्टेकिंग अवधि बीतने से पहले न्यूनतम शेष(बचा हुआ समय) समय की गणना कर सके 
  */
  function claimPeriodLeft() public view returns (uint256 claimPeriodLeft) {
    if( block.timestamp >= claimDeadline) {
      return (0);
    } else {
      return (claimDeadline - block.timestamp);
    }
  }

  /*
  Time to "kill-time" on our local testnet
	हमारे स्थानीय टेस्टनेट पर "किल-टाइम" करने का समय
  */
  function killTime() public {
    currentBlock = block.timestamp;
  }

  /*
  \Function for our smart contract to receive ETH
	ETH प्राप्त करने के लिए हमारे स्मार्ट कॉन्ट्रैक्ट का फंक्शन
  cc: https://docs.soliditylang.org/en/latest/contracts.html#receive-ether-function
  */
  receive() external payable {
      emit Received(msg.sender, msg.value);
  }

}

<div style={{ padding: 8, marginTop: 16 }}>
    <div>Reward Rate Per Second:</div>
    <Balance balance={rewardRatePerSecond} fontSize={64} /> ETH
</div>

// ** keep track of a variable from the contract in the local React state:
// ** लॉकल रिएक्ट स्टेट (local React state) में कॉन्ट्रैक्ट से एक वेरिएबल का ट्रैक रखें:
  const claimPeriodLeft = useContractReader(readContracts, "Staker", "claimPeriodLeft");
  console.log("⏳ Claim Period Left:", claimPeriodLeft);

  const withdrawalTimeLeft = useContractReader(readContracts, "Staker", "withdrawalTimeLeft");
  console.log("⏳ Withdrawal Time Left:", withdrawalTimeLeft);

<div style={{ padding: 8, marginTop: 16, fontWeight: "bold" }}>
  <div>Claim Period Left:</div>
  {claimPeriodLeft && humanizeDuration(claimPeriodLeft.toNumber() * 1000)}
</div>

<div style={{ padding: 8, marginTop: 16, fontWeight: "bold"}}>
  <div>Withdrawal Period Left:</div>
  {withdrawalTimeLeft && humanizeDuration(withdrawalTimeLeft.toNumber() * 1000)}
</div>

import WalletConnectProvider from "@walletconnect/web3-provider";
//import Torus from "@toruslabs/torus-embed"
import WalletLink from "walletlink";
import { Alert, Button, Col, Menu, Row, List, Divider } from "antd";
import "antd/dist/antd.css";
import React, { useCallback, useEffect, useState } from "react";
import { BrowserRouter, Link, Route, Switch } from "react-router-dom";
import Web3Modal from "web3modal";
import "./App.css";
import { Account, Address, Balance, Contract, Faucet, GasGauge, Header, Ramp, ThemeSwitch } from "./components";
import { INFURA_ID, NETWORK, NETWORKS } from "./constants";
import { Transactor } from "./helpers";
import {
  useBalance,
  useContractLoader,
  useContractReader,
  useGasPrice,
  useOnBlock,
  useUserProviderAndSigner,
} from "eth-hooks";
import { useEventListener } from "eth-hooks/events/useEventListener";
import { useExchangeEthPrice } from "eth-hooks/dapps/dex";
// import Hints from "./Hints";
import { ExampleUI, Hints, Subgraph } from "./views";

import { useContractConfig } from "./hooks";
import Portis from "@portis/web3";
import Fortmatic from "fortmatic";
import Authereum from "authereum";
import humanizeDuration from "humanize-duration";

const { ethers } = require("ethers");
/*
    Welcome to 🏗 scaffold-eth !

    Code:
    https://github.com/austintgriffith/scaffold-eth

    Support:
    https://t.me/joinchat/KByvmRe5wkR-8F_zz6AjpA
    or DM @austingriffith on Twitter or Telegram

    You should get your own Infura.io ID and put it in `constants.js`
    (this is your connection to the main Ethereum network for ENS etc.)


    🌏 EXTERNAL CONTRACTS:
    You can also bring in contract artifacts in `constants.js`
    (and then use the `useExternalContractLoader()` hook!)
*/

/// 📡 What chain are your contracts deployed to?
const targetNetwork = NETWORKS.localhost; // <------- select your target frontend network (localhost, rinkeby, xdai, mainnet)

// 😬 Sorry for all the console logging
const DEBUG = true;
const NETWORKCHECK = true;

// 🛰 providers
if (DEBUG) console.log("📡 Connecting to Mainnet Ethereum");
// const mainnetProvider = getDefaultProvider("mainnet", { infura: INFURA_ID, etherscan: ETHERSCAN_KEY, quorum: 1 });
// const mainnetProvider = new InfuraProvider("mainnet",INFURA_ID);
//
// attempt to connect to our own scaffold eth rpc and if that fails fall back to infura...
// Using StaticJsonRpcProvider as the chainId won't change see https://github.com/ethers-io/ethers.js/issues/901
const scaffoldEthProvider = navigator.onLine
  ? new ethers.providers.StaticJsonRpcProvider("https://rpc.scaffoldeth.io:48544")
  : null;
const poktMainnetProvider = navigator.onLine
  ? new ethers.providers.StaticJsonRpcProvider(
      "https://eth-mainnet.gateway.pokt.network/v1/lb/611156b4a585a20035148406",
    )
  : null;
const mainnetInfura = navigator.onLine
  ? new ethers.providers.StaticJsonRpcProvider("https://mainnet.infura.io/v3/" + INFURA_ID)
  : null;
// ( ⚠️ Getting "failed to meet quorum" errors? Check your INFURA_ID

// 🏠 Your local provider is usually pointed at your local blockchain
const localProviderUrl = targetNetwork.rpcUrl;
// as you deploy to other networks you can set REACT_APP_PROVIDER=https://dai.poa.network in packages/react-app/.env
const localProviderUrlFromEnv = process.env.REACT_APP_PROVIDER ? process.env.REACT_APP_PROVIDER : localProviderUrl;
if (DEBUG) console.log("🏠 Connecting to provider:", localProviderUrlFromEnv);
const localProvider = new ethers.providers.StaticJsonRpcProvider(localProviderUrlFromEnv);

// 🔭 block explorer URL
const blockExplorer = targetNetwork.blockExplorer;

// Coinbase walletLink init
const walletLink = new WalletLink({
  appName: "coinbase",
});

// WalletLink provider
const walletLinkProvider = walletLink.makeWeb3Provider(`https://mainnet.infura.io/v3/${INFURA_ID}`, 1);

// Portis ID: 6255fb2b-58c8-433b-a2c9-62098c05ddc9
/*
  Web3 modal helps us "connect" external wallets:
*/
const web3Modal = new Web3Modal({
  network: "mainnet", // Optional. If using WalletConnect on xDai, change network to "xdai" and add RPC info below for xDai chain.
  cacheProvider: true, // optional
  theme: "light", // optional. Change to "dark" for a dark theme.
  providerOptions: {
    walletconnect: {
      package: WalletConnectProvider, // required
      options: {
        bridge: "https://polygon.bridge.walletconnect.org",
        infuraId: INFURA_ID,
        rpc: {
          1: `https://mainnet.infura.io/v3/${INFURA_ID}`, // mainnet // For more WalletConnect providers: https://docs.walletconnect.org/quick-start/dapps/web3-provider#required
          42: `https://kovan.infura.io/v3/${INFURA_ID}`,
          100: "https://dai.poa.network", // xDai
        },
      },
    },
    portis: {
      display: {
        logo: "https://user-images.githubusercontent.com/9419140/128913641-d025bc0c-e059-42de-a57b-422f196867ce.png",
        name: "Portis",
        description: "Connect to Portis App",
      },
      package: Portis,
      options: {
        id: "6255fb2b-58c8-433b-a2c9-62098c05ddc9",
      },
    },
    fortmatic: {
      package: Fortmatic, // required
      options: {
        key: "pk_live_5A7C91B2FC585A17", // required
      },
    },
    // torus: {
    //   package: Torus,
    //   options: {
    //     networkParams: {
    //       host: "https://localhost:8545", // optional
    //       chainId: 1337, // optional
    //       networkId: 1337 // optional
    //     },
    //     config: {
    //       buildEnv: "development" // optional
    //     },
    //   },
    // },
    "custom-walletlink": {
      display: {
        logo: "https://play-lh.googleusercontent.com/PjoJoG27miSglVBXoXrxBSLveV6e3EeBPpNY55aiUUBM9Q1RCETKCOqdOkX2ZydqVf0",
        name: "Coinbase",
        description: "Connect to Coinbase Wallet (not Coinbase App)",
      },
      package: walletLinkProvider,
      connector: async (provider, _options) => {
        await provider.enable();
        return provider;
      },
    },
    authereum: {
      package: Authereum, // required
    },
  },
});

function App(props) {
  const mainnetProvider =
    poktMainnetProvider && poktMainnetProvider._isProvider
      ? poktMainnetProvider
      : scaffoldEthProvider && scaffoldEthProvider._network
      ? scaffoldEthProvider
      : mainnetInfura;

  const [injectedProvider, setInjectedProvider] = useState();
  const [address, setAddress] = useState();

  const logoutOfWeb3Modal = async () => {
    await web3Modal.clearCachedProvider();
    if (injectedProvider && injectedProvider.provider && typeof injectedProvider.provider.disconnect == "function") {
      await injectedProvider.provider.disconnect();
    }
    setTimeout(() => {
      window.location.reload();
    }, 1);
  };

  /* 💵 This hook will get the price of ETH from 🦄 Uniswap: */
  const price = useExchangeEthPrice(targetNetwork, mainnetProvider);

  /* 🔥 This hook will get the price of Gas from ⛽️ EtherGasStation */
  const gasPrice = useGasPrice(targetNetwork, "fast");
  // Use your injected provider from 🦊 Metamask or if you don't have it then instantly generate a 🔥 burner wallet.
  const userProviderAndSigner = useUserProviderAndSigner(injectedProvider, localProvider);
  const userSigner = userProviderAndSigner.signer;

  useEffect(() => {
    async function getAddress() {
      if (userSigner) {
        const newAddress = await userSigner.getAddress();
        setAddress(newAddress);
      }
    }
    getAddress();
  }, [userSigner]);

  // You can warn the user if you would like them to be on a specific network
  const localChainId = localProvider && localProvider._network && localProvider._network.chainId;
  const selectedChainId =
    userSigner && userSigner.provider && userSigner.provider._network && userSigner.provider._network.chainId;

  // For more hooks, check out 🔗eth-hooks at: https://www.npmjs.com/package/eth-hooks

  // The transactor wraps transactions and provides notificiations
  const tx = Transactor(userSigner, gasPrice);

  // Faucet Tx can be used to send funds from the faucet
  const faucetTx = Transactor(localProvider, gasPrice);

  // 🏗 scaffold-eth is full of handy hooks like this one to get your balance:
  const yourLocalBalance = useBalance(localProvider, address);

  // Just plug in different 🛰 providers to get your balance on different chains:
  const yourMainnetBalance = useBalance(mainnetProvider, address);

  const contractConfig = useContractConfig();

  // Load in your local 📝 contract and read a value from it:
  const readContracts = useContractLoader(localProvider, contractConfig);

  // If you want to make 🔐 write transactions to your contracts, use the userSigner:
  const writeContracts = useContractLoader(userSigner, contractConfig, localChainId);

  // EXTERNAL CONTRACT EXAMPLE:
  //
  // If you want to bring in the mainnet DAI contract it would look like:
  const mainnetContracts = useContractLoader(mainnetProvider, contractConfig);

  // If you want to call a function on a new block
  useOnBlock(mainnetProvider, () => {
    console.log(`⛓ A new mainnet block is here: ${mainnetProvider._lastBlockNumber}`);
  });

  // Then read your DAI balance like:
  const myMainnetDAIBalance = useContractReader(mainnetContracts, "DAI", "balanceOf", [
    "0x34aA3F359A9D614239015126635CE7732c18fDF3",
  ]);

  //keep track of contract balance to know how much has been staked total:
  const stakerContractBalance = useBalance(
    localProvider,
    readContracts && readContracts.Staker ? readContracts.Staker.address : null,
  );
  if (DEBUG) console.log("💵 stakerContractBalance", stakerContractBalance);

  const rewardRatePerSecond = useContractReader(readContracts, "Staker", "rewardRatePerSecond");
  console.log("💵 Reward Rate:", rewardRatePerSecond);

  // ** keep track of a variable from the contract in the local React state:
  const balanceStaked = useContractReader(readContracts, "Staker", "balances", [address]);
  console.log("💸 balanceStaked:", balanceStaked);

  // ** 📟 Listen for broadcast events
  const stakeEvents = useEventListener(readContracts, "Staker", "Stake", localProvider, 1);
  console.log("📟 stake events:", stakeEvents);

  const receiveEvents = useEventListener(readContracts, "Staker", "Received", localProvider, 1);
  console.log("📟 receive events:", receiveEvents);

  // ** keep track of a variable from the contract in the local React state:
  const claimPeriodLeft = useContractReader(readContracts, "Staker", "claimPeriodLeft");
  console.log("⏳ Claim Period Left:", claimPeriodLeft);

  const withdrawalTimeLeft = useContractReader(readContracts, "Staker", "withdrawalTimeLeft");
  console.log("⏳ Withdrawal Time Left:", withdrawalTimeLeft);


  // ** Listen for when the contract has been 'completed'
  const complete = useContractReader(readContracts, "ExampleExternalContract", "completed");
  console.log("✅ complete:", complete);

  const exampleExternalContractBalance = useBalance(
    localProvider,
    readContracts && readContracts.ExampleExternalContract ? readContracts.ExampleExternalContract.address : null,
  );
  if (DEBUG) console.log("💵 exampleExternalContractBalance", exampleExternalContractBalance);

  let completeDisplay = "";
  if (complete) {
    completeDisplay = (
      <div style={{padding: 64, backgroundColor: "#eeffef", fontWeight: "bold", color: "rgba(0, 0, 0, 0.85)" }} >
        -- 💀 Staking App Fund Repatriation Executed 🪦 --
        <Balance balance={exampleExternalContractBalance} fontSize={32} /> ETH locked!
      </div>
    );
  }

  /*
  const addressFromENS = useResolveName(mainnetProvider, "austingriffith.eth");
  console.log("🏷 Resolved austingriffith.eth as:", addressFromENS)
  */

  //
  // 🧫 DEBUG 👨🏻‍🔬
  //
  useEffect(() => {
    if (
      DEBUG &&
      mainnetProvider &&
      address &&
      selectedChainId &&
      yourLocalBalance &&
      yourMainnetBalance &&
      readContracts &&
      writeContracts &&
      mainnetContracts
    ) {
      console.log("_____________________________________ 🏗 scaffold-eth _____________________________________");
      console.log("🌎 mainnetProvider", mainnetProvider);
      console.log("🏠 localChainId", localChainId);
      console.log("👩‍💼 selected address:", address);
      console.log("🕵🏻‍♂️ selectedChainId:", selectedChainId);
      console.log("💵 yourLocalBalance", yourLocalBalance ? ethers.utils.formatEther(yourLocalBalance) : "...");
      console.log("💵 yourMainnetBalance", yourMainnetBalance ? ethers.utils.formatEther(yourMainnetBalance) : "...");
      console.log("📝 readContracts", readContracts);
      console.log("🌍 DAI contract on mainnet:", mainnetContracts);
      console.log("💵 yourMainnetDAIBalance", myMainnetDAIBalance);
      console.log("🔐 writeContracts", writeContracts);
    }
  }, [
    mainnetProvider,
    address,
    selectedChainId,
    yourLocalBalance,
    yourMainnetBalance,
    readContracts,
    writeContracts,
    mainnetContracts,
  ]);

  let networkDisplay = "";
  if (NETWORKCHECK && localChainId && selectedChainId && localChainId !== selectedChainId) {
    const networkSelected = NETWORK(selectedChainId);
    const networkLocal = NETWORK(localChainId);
    if (selectedChainId === 1337 && localChainId === 31337) {
      networkDisplay = (
        <div style={{ zIndex: 2, position: "absolute", right: 0, top: 60, padding: 16 }}>
          <Alert
            message="⚠️ Wrong Network ID"
            description={
              <div>
                You have <b>chain id 1337</b> for localhost and you need to change it to <b>31337</b> to work with
                HardHat.
                <div>(MetaMask -&gt; Settings -&gt; Networks -&gt; Chain ID -&gt; 31337)</div>
              </div>
            }
            type="error"
            closable={false}
          />
        </div>
      );
    } else {
      networkDisplay = (
        <div style={{ zIndex: 2, position: "absolute", right: 0, top: 60, padding: 16 }}>
          <Alert
            message="⚠️ Wrong Network"
            description={
              <div>
                You have <b>{networkSelected && networkSelected.name}</b> selected and you need to be on{" "}
                <Button
                  onClick={async () => {
                    const ethereum = window.ethereum;
                    const data = [
                      {
                        chainId: "0x" + targetNetwork.chainId.toString(16),
                        chainName: targetNetwork.name,
                        nativeCurrency: targetNetwork.nativeCurrency,
                        rpcUrls: [targetNetwork.rpcUrl],
                        blockExplorerUrls: [targetNetwork.blockExplorer],
                      },
                    ];
                    console.log("data", data);

                    let switchTx;
                    // https://docs.metamask.io/guide/rpc-api.html#other-rpc-methods
                    try {
                      switchTx = await ethereum.request({
                        method: "wallet_switchEthereumChain",
                        params: [{ chainId: data[0].chainId }],
                      });
                    } catch (switchError) {
                      // not checking specific error code, because maybe we're not using MetaMask
                      try {
                        switchTx = await ethereum.request({
                          method: "wallet_addEthereumChain",
                          params: data,
                        });
                      } catch (addError) {
                        // handle "add" error
                      }
                    }

                    if (switchTx) {
                      console.log(switchTx);
                    }
                  }}
                >
                  <b>{networkLocal && networkLocal.name}</b>
                </Button>
              </div>
            }
            type="error"
            closable={false}
          />
        </div>
      );
    }
  } else {
    networkDisplay = (
      <div style={{ zIndex: -1, position: "absolute", right: 154, top: 28, padding: 16, color: targetNetwork.color }}>
        {targetNetwork.name}
      </div>
    );
  }

  const loadWeb3Modal = useCallback(async () => {
    const provider = await web3Modal.connect();
    setInjectedProvider(new ethers.providers.Web3Provider(provider));

    provider.on("chainChanged", chainId => {
      console.log(`chain changed to ${chainId}! updating providers`);
      setInjectedProvider(new ethers.providers.Web3Provider(provider));
    });

    provider.on("accountsChanged", () => {
      console.log(`account changed!`);
      setInjectedProvider(new ethers.providers.Web3Provider(provider));
    });

    // Subscribe to session disconnection
    provider.on("disconnect", (code, reason) => {
      console.log(code, reason);
      logoutOfWeb3Modal();
    });
  }, [setInjectedProvider]);

  useEffect(() => {
    if (web3Modal.cachedProvider) {
      loadWeb3Modal();
    }
  }, [loadWeb3Modal]);

  const [route, setRoute] = useState();
  useEffect(() => {
    setRoute(window.location.pathname);
  }, [setRoute]);

  let faucetHint = "";
  const faucetAvailable = localProvider && localProvider.connection && targetNetwork.name.indexOf("local") !== -1;

  const [faucetClicked, setFaucetClicked] = useState(false);
  if (
    !faucetClicked &&
    localProvider &&
    localProvider._network &&
    localProvider._network.chainId === 31337 &&
    yourLocalBalance &&
    ethers.utils.formatEther(yourLocalBalance) <= 0
  ) {
    faucetHint = (
      <div style={{ padding: 16 }}>
        <Button
          type="primary"
          onClick={() => {
            faucetTx({
              to: address,
              value: ethers.utils.parseEther("0.01"),
            });
            setFaucetClicked(true);
          }}
        >
          💰 Grab funds from the faucet ⛽️
        </Button>
      </div>
    );
  }

  return (
    <div className="App">
      {/* ✏️ Edit the header and change the title to your project name */}
      <Header />
      {networkDisplay}
      <BrowserRouter>
        <Menu style={{ textAlign: "center" }} selectedKeys={[route]} mode="horizontal">
          <Menu.Item key="/">
            <Link
              onClick={() => {
                setRoute("/");
              }}
              to="/"
            >
              Staker UI
            </Link>
          </Menu.Item>
          <Menu.Item key="/contracts">
            <Link
              onClick={() => {
                setRoute("/contracts");
              }}
              to="/contracts"
            >
              Debug Contracts
            </Link>
          </Menu.Item>
        </Menu>

        <Switch>
          <Route exact path="/">
            {completeDisplay}

            <div style={{ padding: 8, marginTop: 16 }}>
              <div>Staker Contract:</div>
              <Address value={readContracts && readContracts.Staker && readContracts.Staker.address} />
            </div>

            <Divider />

            <div style={{ padding: 8, marginTop: 16 }}>
              <div>Reward Rate Per Second:</div>
              <Balance balance={rewardRatePerSecond} fontSize={64} /> ETH
            </div>

            <Divider />

            <div style={{ padding: 8, marginTop: 16, fontWeight: "bold" }}>
              <div>Claim Period Left:</div>
              {claimPeriodLeft && humanizeDuration(claimPeriodLeft.toNumber() * 1000)}
            </div>

            <div style={{ padding: 8, marginTop: 16, fontWeight: "bold"}}>
              <div>Withdrawal Period Left:</div>
              {withdrawalTimeLeft && humanizeDuration(withdrawalTimeLeft.toNumber() * 1000)}
            </div>

            <Divider />

            <div style={{ padding: 8, fontWeight: "bold"}}>
              <div>Total Available ETH in Contract:</div>
              <Balance balance={stakerContractBalance} fontSize={64} />
            </div>

            <Divider />

            <div style={{ padding: 8,fontWeight: "bold" }}>
              <div>ETH Locked 🔒 in Staker Contract:</div>
              <Balance balance={balanceStaked} fontSize={64} />
            </div>

            <div style={{ padding: 8 }}>
              <Button
                type={"default"}
                onClick={() => {
                  tx(writeContracts.Staker.execute());
                }}
              >
                📡 Execute!
              </Button>
            </div>

            <div style={{ padding: 8 }}>
              <Button
                type={"default"}
                onClick={() => {
                  tx(writeContracts.Staker.withdraw());
                }}
              >
                🏧 Withdraw
              </Button>
            </div>

            <div style={{ padding: 8 }}>
              <Button
                type={balanceStaked ? "success" : "primary"}
                onClick={() => {
                  tx(writeContracts.Staker.stake({ value: ethers.utils.parseEther("0.5") }));
                }}
              >
                🥩 Stake 0.5 ether!
              </Button>
            </div>

            {/*
                🎛 this scaffolding is full of commonly used components
                this <Contract/> component will automatically parse your ABI
                and give you a form to interact with it locally
            */}

            {/* uncomment for a second contract:
            <Contract
              name="SecondContract"
              signer={userProvider.getSigner()}
              provider={localProvider}
              address={address}
              blockExplorer={blockExplorer}
              contractConfig={contractConfig}
            />
            */}
          </Route>
          <Route path="/contracts">
            <Contract
              name="Staker"
              signer={userSigner}
              provider={localProvider}
              address={address}
              blockExplorer={blockExplorer}
              contractConfig={contractConfig}
            />
            <Contract
              name="ExampleExternalContract"
              signer={userSigner}
              provider={localProvider}
              address={address}
              blockExplorer={blockExplorer}
              contractConfig={contractConfig}
            />
          </Route>
        </Switch>
      </BrowserRouter>

      <ThemeSwitch />

      {/* 👨‍💼 Your account is in the top right with a wallet at connect options */}
      <div style={{ position: "fixed", textAlign: "right", right: 0, top: 0, padding: 10 }}>
        <Account
          address={address}
          localProvider={localProvider}
          userSigner={userSigner}
          mainnetProvider={mainnetProvider}
          price={price}
          web3Modal={web3Modal}
          loadWeb3Modal={loadWeb3Modal}
          logoutOfWeb3Modal={logoutOfWeb3Modal}
          blockExplorer={blockExplorer}
        />
        {faucetHint}
      </div>

      <div style={{ marginTop: 32, opacity: 0.5 }}>
        {/* Add your address here */}
        Created by <Address value={"Your...address"} ensProvider={mainnetProvider} fontSize={16} />
      </div>

      <div style={{ marginTop: 32, opacity: 0.5 }}>
        <a target="_blank" style={{ padding: 32, color: "#000" }} href="https://github.com/scaffold-eth/scaffold-eth">
          🍴 Fork me!
        </a>
      </div>

      {/* 🗺 Extra UI like gas price, eth price, faucet, and support: */}
      <div style={{ position: "fixed", textAlign: "left", left: 0, bottom: 20, padding: 10 }}>
        <Row align="middle" gutter={[4, 4]}>
          <Col span={8}>
            <Ramp price={price} address={address} networks={NETWORKS} />
          </Col>

          <Col span={8} style={{ textAlign: "center", opacity: 0.8 }}>
            <GasGauge gasPrice={gasPrice} />
          </Col>
          <Col span={8} style={{ textAlign: "center", opacity: 1 }}>
            <Button
              onClick={() => {
                window.open("https://t.me/joinchat/KByvmRe5wkR-8F_zz6AjpA");
              }}
              size="large"
              shape="round"
            >
              <span style={{ marginRight: 8 }} role="img" aria-label="support">
                💬
              </span>
              Support
            </Button>
          </Col>
        </Row>

        <Row align="middle" gutter={[4, 4]}>
          <Col span={24}>
            {
              /*  if the local provider has a signer, let's show the faucet:  */
              faucetAvailable ? (
                <Faucet localProvider={localProvider} price={price} ensProvider={mainnetProvider} />
              ) : (
                ""
              )
            }
          </Col>
        </Row>
      </div>
    </div>
  );
}

export default App;