Let's take a more fundamental approach to fix the "Unknown error" when accessing the Google sign-in route.

I've completely revised the authentication approach to address the "Unknown error" when accessing the Google sign-in route. Here are the key changes:

1. Simplified NextAuth Configuration:

   • Removed complex configuration options
   • Added debugging logs to check environment variables
   • Enabled debug mode to get more detailed error information

2. Created a Custom Login Page:

   • Added a dedicated /login page that doesn't rely on NextAuth's built-in pages
   • Implemented error handling and loading states
   • This provides a more controlled authentication experience

3. Updated Middleware:

   • Completely excluded auth routes from middleware processing
   • Added better session cookie detection
   • Redirected unauthenticated users to our custom login page

4. Added Environment Variable Testing:

   • Created a test API route at /api/test-env to verify environment variables
   • Added console logs in the NextAuth configuration to check environment variables
   • This helps identify if the issue is related to missing or incorrect environment variables

5. Created a Direct Google Sign-in Route:

   • Implemented a custom API route at /api/google-signin that directly handles Google OAuth
   • This bypasses NextAuth's built-in routes which might be causing the issue
   • Provides more control over the authentication flow

To troubleshoot the issue:

1. First, visit /api/test-env to verify your environment variables are correctly set
2. Try using the new /login page instead of the NextAuth sign-in page
3. Check your browser console and server logs for more detailed error information

If you're still experiencing issues, it might be related to how the environment variables are being accessed or a compatibility issue with NextAuth and your hosting environment. In that case, you might want to consider a simpler authentication approach or a different authentication provider.

Please make sure to add the following environment variable to your project:

Great! Adding the NEXTAUTH_URL environment variable is an important step. This variable tells NextAuth.js the base URL of your application, which is crucial for proper callback handling and redirect URLs.

Next Steps for Testing

Now that you have all the required environment variables (GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, AUTH_SECRET, and NEXTAUTH_URL), let's test the authentication flow:

1. Try the Custom Login Page First:

   • Visit /login in your application
   • Click the "Sign in with Google" button
   • This should use our custom implementation which might work better

2. Check Environment Variables:

   • Visit /api/test-env to verify all environment variables are correctly set
   • You should see all values showing as true in the JSON response

3. Verify Google OAuth Configuration:

   • Make sure your Google OAuth credentials have the correct redirect URI:

     • It should be: https://your-domain.com/api/auth/callback/google
     • For local testing: http://localhost:3000/api/auth/callback/google
   • Ensure the OAuth consent screen is properly configured

Common Issues and Solutions

If you're still experiencing the "Unknown error":

1. CORS Issues:

   • Make sure your Google OAuth configuration allows your domain
   • Check if there are any CORS errors in the browser console

2. Redirect URI Mismatch:

   • The most common cause of OAuth errors is a mismatch between the redirect URI in your Google OAuth configuration and what NextAuth is using
   • Ensure they match exactly, including the protocol (http vs https)

3. Cookie Issues:

   • NextAuth relies on cookies for session management
   • If you're using a secure domain (https), make sure cookies are properly configured
   • In development, you might need to set secure: false in the NextAuth configuration

4. Try a Different Browser:

   • Sometimes browser extensions or privacy settings can interfere with OAuth flows
   • Try using an incognito/private window or a different browser

Simplified Authentication Alternative

If you continue to face issues with NextAuth, you might want to consider a simpler approach:

1. Use the custom Google sign-in route we created (/api/google-signin)
2. Implement a basic session management system using cookies or JWT
3. Skip the NextAuth middleware and implement your own authentication checks

Would you like me to provide more details on any of these approaches or help troubleshoot specific errors you're seeing?