feat: 5 digit code ui

## What changed?

This Pull Request introduces an access code validation feature to the authentication process. Changes encompass backend route for access code validation, new frontend components for handling access code input, and integration of the access code verification in the signup flow.

### Backend:
- Added POST `/accesscode` route in `auth.ts` for validating access codes.

### Frontend:
- Created `AccessCode` component for access code input and validation.
- Added `AccessSignUp` component that integrates access code verification before signup.
- Updated `SignUp` component to check for valid access code on mount.
- Modified `SnowballAuth` to use new `AccessSignUp` instead of `SignUp`.
- Added `verifyAccessCode` utility function for code verification API call.

## How to test?
1. Run the backend and frontend projects.
2. Navigate to the signup page. You should be prompted to enter an access code.
3. Enter the code `444444` and proceed. Any other code should display an error message.
4. Verify that valid access code routes to the signup component.

## Why make this change?

This change improves authentication by adding an extra layer of security through access code verification.

packages/backend/src/routes/auth.ts

@@ -5,10 +5,13 @@ import { authenticateUser, createUser } from '../turnkey-backend';
 
 const router = Router();
 
+//
+// Access Code
+//
 router.post('/accesscode', async (req, res) => {
   console.log('Access Code', req.body);
   const { accesscode } = req.body;
-  if (accesscode === '444444') {
+  if (accesscode === '44444') {
     return res.send({ isValid: true });
   } else {
     return res.sendStatus(204);

packages/frontend/src/components/shared/VerifyCodeInput/VerifyCodeInput.tsx

@@ -0,0 +1,117 @@
+import { useEffect, useRef } from 'react';
+import { Input } from '../Input';
+
+export interface VerifyCodeInputProps {
+  code: string;
+  setCode: (code: string) => void;
+  submitCode: () => void;
+  loading: boolean;
+}
+
+export const VerifyCodeInput = ({
+  code,
+  setCode,
+  submitCode,
+  loading,
+}: VerifyCodeInputProps) => {
+  const inputRefs = useRef<(HTMLInputElement | null)[]>([]);
+
+  const handlePaste = (
+    e: React.ClipboardEvent<HTMLInputElement>,
+    i: number,
+  ) => {
+    e.preventDefault();
+    const pasteData = e.clipboardData.getData('text').replace(/\D/g, ''); // Only digits
+    if (pasteData.length > 0) {
+      let newCodeArray = code.split('');
+      for (let j = 0; j < pasteData.length && i + j < 6; j++) {
+        newCodeArray[i + j] = pasteData[j];
+      }
+      const newCode = newCodeArray.join('');
+      setCode(newCode);
+      const nextIndex = Math.min(i + pasteData.length, 5);
+      const nextInput = inputRefs.current[nextIndex];
+      if (nextInput) nextInput.focus();
+      if (!newCode.includes(' ')) {
+        submitCode();
+      }
+    }
+  };
+
+  const handleKeyDown = (
+    e: React.KeyboardEvent<HTMLInputElement>,
+    i: number,
+  ) => {
+    if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey) return;
+
+    if (e.key === 'Backspace') {
+      e.preventDefault();
+      const isEmpty = code[i] === ' ';
+      const newCode = !isEmpty
+        ? code.slice(0, i) + ' ' + code.slice(i + 1, 6)
+        : code.slice(0, i - 1) + ' ' + code.slice(i, 6);
+
+      setCode(newCode.slice(0, 6));
+
+      if (i === 0 || !isEmpty) return;
+      const prev = inputRefs.current[i - 1];
+      if (prev) prev.focus();
+      return;
+    }
+
+    if (!e.key.match(/[0-9]/)) return;
+
+    e.preventDefault(); // Prevent the default event to avoid duplicate input
+
+    const newCode = code.slice(0, i) + e.key + code.slice(i + 1, 6);
+    setCode(newCode);
+
+    if (i === 5) {
+      submitCode();
+      return;
+    }
+
+    const next = inputRefs.current[i + 1];
+    if (next) next.focus();
+  };
+
+  const handleChange = (e: React.ChangeEvent<HTMLInputElement>, i: number) => {
+    const value = e.target.value.slice(-1);
+    if (!value.match(/[0-9]/)) return;
+
+    const newCode = code.slice(0, i) + value + code.slice(i + 1, 6);
+    setCode(newCode);
+
+    if (i < 5) {
+      const next = inputRefs.current[i + 1];
+      if (next) next.focus();
+    }
+
+    if (!newCode.includes(' ')) {
+      submitCode();
+    }
+  };
+
+  useEffect(() => {
+    if (inputRefs.current[0]) {
+      inputRefs.current[0].focus();
+    }
+  }, []);
+
+  return (
+    <div className="flex gap-2">
+      {code.split('').map((char, i) => (
+        <Input
+          key={i}
+          value={char === ' ' ? '' : char}
+          ref={(el) => (inputRefs.current[i] = el)}
+          onChange={(e) => handleChange(e, i)}
+          onPaste={(e) => handlePaste(e, i)}
+          onKeyDown={(e) => handleKeyDown(e, i)}
+          disabled={!!loading}
+          style={{ textAlign: 'center' }} // Add this line to center text
+        />
+      ))}
+    </div>
+  );
+};

packages/frontend/src/components/shared/VerifyCodeInput/index.ts

@@ -0,0 +1 @@
+export { VerifyCodeInput } from './VerifyCodeInput';

packages/frontend/src/pages/auth/AccessCode.tsx

@@ -6,7 +6,7 @@ import {
   LoaderIcon,
 } from 'components/shared/CustomIcon';
 import { WavyBorder } from 'components/shared/WavyBorder';
-import { Input } from 'components/shared/Input';
+import { VerifyCodeInput } from 'components/shared/VerifyCodeInput';
 import { verifyAccessCode } from 'utils/accessCode';
 
 type AccessMethod = 'accesscode' | 'passkey';
@@ -20,7 +20,7 @@ type AccessCodeProps = {
 export const AccessCode: React.FC<AccessCodeProps> = ({
   onCorrectAccessCode,
 }) => {
-  const [accessCode, setAccessCode] = useState('');
+  const [accessCode, setAccessCode] = useState('     ');
   const [error, setError] = useState<Err | null>();
   const [accessMethod, setAccessMethod] = useState<AccessMethod | false>(false);
 
@@ -28,6 +28,9 @@ export const AccessCode: React.FC<AccessCodeProps> = ({
     setAccessMethod('accesscode');
     try {
       const isValidAccessCode = await verifyAccessCode(accessCode);
+
+      // add a pause for ux
+      await new Promise((resolve) => setTimeout(resolve, 250));
       if (isValidAccessCode) {
         localStorage.setItem('accessCode', accessCode);
         onCorrectAccessCode();
@@ -43,7 +46,7 @@ export const AccessCode: React.FC<AccessCodeProps> = ({
   }
 
   const loading = accessMethod;
-  const isValidAccessCodeLength = accessCode.length === 6;
+  const isValidAccessCodeLength = accessCode.trim().length === 5;
 
   return (
     <div>
@@ -56,10 +59,11 @@ export const AccessCode: React.FC<AccessCodeProps> = ({
       <div className="self-stretch p-4 xs:p-6 flex-col justify-center items-center gap-8 flex">
         <div className="self-stretch flex-col gap-8 flex">
           <div className="flex-col justify-start items-start gap-2 inline-flex">
-            <Input
-              value={accessCode}
-              onChange={(e) => setAccessCode(e.target.value)}
-              disabled={!!loading}
+            <VerifyCodeInput
+              loading={!!loading}
+              code={accessCode}
+              setCode={setAccessCode}
+              submitCode={validateAccessCode}
             />
           </div>
           <Button
@@ -70,9 +74,7 @@ export const AccessCode: React.FC<AccessCodeProps> = ({
                 <ArrowRightCircleFilledIcon height="16" />
               )
             }
-            onClick={() => {
-              validateAccessCode();
-            }}
+            onClick={validateAccessCode}
             variant={'secondary'}
             disabled={!accessCode || !isValidAccessCodeLength || !!loading}
           >
@@ -82,7 +84,10 @@ export const AccessCode: React.FC<AccessCodeProps> = ({
             <div className="flex flex-col gap-3">
               <div className="justify-center items-center gap-2 inline-flex">
                 <div className="text-red-500 text-sm">
-                  Error: {error.message}
+                  Error: {error.message}.{' '}
+                  <a href="/signup" className="underline">
+                    Try again?
+                  </a>
                 </div>
               </div>
             </div>