Make chats private and fix redirection

app/chat/[id]/page.tsx

@@ -33,7 +33,7 @@ export default async function ChatPage({ params }: ChatPageProps) {
   const session = await auth()
 
   if (!session?.user) {
-    redirect('/sign-in')
+    redirect(`/sign-in?next=/chat/${params.id}`)
   }
 
   const chat = await getChat(params.id, session.user.id)
@@ -42,5 +42,9 @@ export default async function ChatPage({ params }: ChatPageProps) {
     notFound()
   }
 
+  if (chat?.userId !== session?.user?.id) {
+    notFound()
+  }
+
   return <Chat id={chat.id} initialMessages={chat.messages} />
 }

components/login-button.tsx

@@ -6,7 +6,7 @@ import { signIn } from 'next-auth/react'
 import { cn } from '@/lib/utils'
 import { Button, type ButtonProps } from '@/components/ui/button'
 import { IconGitHub, IconSpinner } from '@/components/ui/icons'
-
+import { useSearchParams } from 'next/navigation'
 interface LoginButtonProps extends ButtonProps {
   showGithubIcon?: boolean
   text?: string
@@ -19,13 +19,18 @@ export function LoginButton({
   ...props
 }: LoginButtonProps) {
   const [isLoading, setIsLoading] = React.useState(false)
+  const searchParams = useSearchParams()
+  const next = searchParams.get('next')
 
   return (
     <Button
       variant="outline"
       onClick={() => {
         setIsLoading(true)
-        signIn('github')
+        signIn('github', {
+          callbackUrl: `${window.location.origin}${next}`,
+          redirect: true
+        })
       }}
       disabled={isLoading}
       className={cn(className)}