chore: add mint button

examples/CRISP/client/.env.example

@@ -1,3 +1,5 @@
 VITE_ENCLAVE_API=http://127.0.0.1:4000
-VITE_TWITTER_SERVERLESS_API=
 VITE_WALLETCONNECT_PROJECT_ID=
+# A token with a public mint function. Also used as the fee token for Enclave. 
+# This is its default address in Hardhat node
+VITE_CRISP_TOKEN=0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0

examples/CRISP/client/src/components/Navbar.tsx

@@ -9,6 +9,7 @@ import Logo from '@/assets/icons/logo.svg'
 import { Link } from 'react-router-dom'
 import NavMenu from '@/components/NavMenu'
 import { ConnectKitButton } from 'connectkit'
+import useToken from '@/hooks/generic/useMintToken'
 
 const PAGES = [
   {
@@ -22,6 +23,8 @@ const PAGES = [
 ]
 
 const Navbar: React.FC = () => {
+  const { mintTokens, isMinting } = useToken()
+
   return (
     <nav className='absolute left-0 top-0 z-10 w-screen px-6 lg:px-9'>
       <div className='mx-auto max-w-screen-xl'>
@@ -34,6 +37,14 @@ const Navbar: React.FC = () => {
           </Link>
 
           <div className='flex items-center gap-2 md:gap-8'>
+            <button
+              disabled={isMinting}
+              onClick={mintTokens}
+              className='hover:text-twilight-blue-600 cursor-pointer font-bold text-slate-600 duration-300 ease-in-out hover:opacity-70 max-md:hidden'
+            >
+              Mint tokens
+            </button>
+
             {PAGES.map(({ label, path }) => (
               <Link
                 key={label}

examples/CRISP/client/src/hooks/generic/useMintToken.tsx

@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+//
+// This file is provided WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.
+
+import { iERC20Abi } from '@/utils/abi'
+import { useCallback, useState } from 'react'
+import { usePublicClient, useWalletClient } from 'wagmi'
+import { getChain } from '@/utils/methods'
+import { useNotificationAlertContext } from '@/context/NotificationAlert'
+import { ROUND_TOKEN } from '@/utils/constants'
+
+/**
+ * Hooks to interact with the token contract used to gatekeep access to voting rounds
+ */
+const useToken = () => {
+  const { showToast } = useNotificationAlertContext()
+  const [isMinting, setIsMinting] = useState<boolean>(false)
+
+  const { data: walletClient } = useWalletClient()
+  const publicClient = usePublicClient()
+
+  const mintTokens = useCallback(async () => {
+    if (!walletClient || !publicClient) {
+      showToast({
+        type: 'danger',
+        message: 'Wallet not connected',
+      })
+      return
+    }
+
+    const balance = await publicClient.readContract({
+      abi: iERC20Abi,
+      address: ROUND_TOKEN,
+      functionName: 'balanceOf',
+      args: [walletClient.account.address],
+    })
+
+    if (balance && balance > BigInt(0)) {
+      showToast({
+        type: 'info',
+        message: 'You already have tokens, no need to mint more',
+      })
+      return
+    }
+
+    setIsMinting(true)
+
+    try {
+      await walletClient.writeContract({
+        abi: iERC20Abi,
+        address: ROUND_TOKEN,
+        functionName: 'mint',
+        args: [walletClient.account.address, BigInt(1 * 1e18)],
+        chain: getChain(),
+      })
+      showToast({
+        type: 'success',
+        message: 'Tokens minted successfully',
+      })
+    } catch (error) {
+      console.log(error)
+      showToast({
+        type: 'danger',
+        message: 'Error minting tokens',
+      })
+    } finally {
+      setIsMinting(false)
+    }
+  }, [walletClient, showToast, publicClient])
+
+  return {
+    isMinting,
+    mintTokens,
+  }
+}
+
+export default useToken

examples/CRISP/client/src/utils/abi.ts

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+//
+// This file is provided WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.
+
+import { parseAbi } from 'viem'
+
+export const iERC20Abi = parseAbi([
+  'function balanceOf(address owner) view returns (uint256)',
+  'function mint(address to, uint256 amount) external',
+])

examples/CRISP/client/src/utils/constants.ts

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+//
+// This file is provided WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.
+
+export const ROUND_TOKEN = import.meta.env.VITE_CRISP_TOKEN

examples/CRISP/server/src/cli/approve.rs

@@ -25,7 +25,7 @@ pub async fn approve_token(
     amount: U256,
 ) -> Result<()> {
     use alloy::network::EthereumWallet;
-    use alloy::providers::{Provider, ProviderBuilder};
+    use alloy::providers::{ProviderBuilder};
     use alloy::signers::local::PrivateKeySigner;
 
     let token_address: Address = token_address.parse()?;