import React, { FC, useMemo } from 'react';
import { ConnectionProvider, WalletProvider } from '@solana/wallet-adapter-react';
import { WalletAdapterNetwork } from '@solana/wallet-adapter-base';
import { FakeWalletAdapter } from '@solana/wallet-adapter-wallets';
import {
    WalletModalProvider,
    WalletDisconnectButton,
    WalletMultiButton
} from '@solana/wallet-adapter-react-ui';
import { clusterApiUrl } from '@solana/web3.js';

// Default styles that can be overridden by your app
require('@solana/wallet-adapter-react-ui/styles.css');

export const Wallet: FC = () => {
    // The network can be set to 'devnet', 'testnet', or 'mainnet-beta'.
    const network = WalletAdapterNetwork.Devnet;

    // You can also provide a custom RPC endpoint.
    const endpoint = useMemo(() => clusterApiUrl(network), [network]);

    const wallets = useMemo(
        () => [
            /**
             * Select the wallets you wish to support, by instantiating wallet adapters here.
             *
             * Common adapters can be found in the npm package `@solana/wallet-adapter-wallets`.
             * That package supports tree shaking and lazy loading -- only the wallets you import
             * will be compiled into your application, and only the dependencies of wallets that
             * your users connect to will be loaded.
             */
            new FakeWalletAdapter(),
        ],
        []
    );

    return (
        <ConnectionProvider endpoint={endpoint}>
            <WalletProvider wallets={wallets} autoConnect>
                <WalletModalProvider>
                    <WalletMultiButton />
                    <WalletDisconnectButton />
                    { /* Your app's components go here, nested within the context providers. */ }
                </WalletModalProvider>
            </WalletProvider>
        </ConnectionProvider>
    );
};

import { WalletNotConnectedError } from '@solana/wallet-adapter-base';
import { useConnection, useWallet } from '@solana/wallet-adapter-react';
import { Keypair, SystemProgram, Transaction } from '@solana/web3.js';
import React, { FC, useCallback } from 'react';

export const SendSOLToRandomAddress: FC = () => {
    const { connection } = useConnection();
    const { publicKey, sendTransaction } = useWallet();

    const onClick = useCallback(async () => {
        if (!publicKey) throw new WalletNotConnectedError();

        // 890880 lamports as of 2022-09-01
        const lamports = await connection.getMinimumBalanceForRentExemption(0);

        const transaction = new Transaction().add(
            SystemProgram.transfer({
                fromPubkey: publicKey,
                toPubkey: Keypair.generate().publicKey,
                lamports,
            })
        );

        const {
            context: { slot: minContextSlot },
            value: { blockhash, lastValidBlockHeight }
        } = await connection.getLatestBlockhashAndContext();

        const signature = await sendTransaction(transaction, connection, { minContextSlot });

        await connection.confirmTransaction({ blockhash, lastValidBlockHeight, signature });
    }, [publicKey, sendTransaction, connection]);

    return (
        <button onClick={onClick} disabled={!publicKey}>
            Send SOL to a random address!
        </button>
    );
};