Improve sidebar, new chat, and share dialog (#190)

app/(chat)/chat/[id]/page.tsx

@@ -0,0 +1,47 @@
+import { type Metadata } from 'next'
+import { notFound, redirect } from 'next/navigation'
+
+import { auth } from '@/auth'
+import { getChat } from '@/app/actions'
+import { Chat } from '@/components/chat'
+
+export interface ChatPageProps {
+  params: {
+    id: string
+  }
+}
+
+export async function generateMetadata({
+  params
+}: ChatPageProps): Promise<Metadata> {
+  const session = await auth()
+
+  if (!session?.user) {
+    return {}
+  }
+
+  const chat = await getChat(params.id, session.user.id)
+  return {
+    title: chat?.title.toString().slice(0, 50) ?? 'Chat'
+  }
+}
+
+export default async function ChatPage({ params }: ChatPageProps) {
+  const session = await auth()
+
+  if (!session?.user) {
+    redirect(`/sign-in?next=/chat/${params.id}`)
+  }
+
+  const chat = await getChat(params.id, session.user.id)
+
+  if (!chat) {
+    notFound()
+  }
+
+  if (chat?.userId !== session?.user?.id) {
+    notFound()
+  }
+
+  return <Chat id={chat.id} initialMessages={chat.messages} />
+}