chore: simplify next-auth (#80)

app/api/auth/[...nextauth]/route.ts

@@ -1 +1,2 @@
 export { GET, POST } from '@/auth'
+export const runtime = 'edge'

app/api/chat/route.ts

@@ -16,9 +16,9 @@ const openai = new OpenAIApi(configuration)
 export async function POST(req: Request) {
   const json = await req.json()
   const { messages, previewToken } = json
-  const session = await auth()
+  const userId = (await auth())?.user.id
 
-  if (session == null) {
+  if (!userId) {
     return new Response('Unauthorized', {
       status: 401
     })
@@ -38,31 +38,28 @@ export async function POST(req: Request) {
   const stream = OpenAIStream(res, {
     async onCompletion(completion) {
       const title = json.messages[0].content.substring(0, 100)
-      const userId = session?.user?.id
-      if (userId) {
-        const id = json.id ?? nanoid()
-        const createdAt = Date.now()
-        const path = `/chat/${id}`
-        const payload = {
-          id,
-          title,
-          userId,
-          createdAt,
-          path,
-          messages: [
-            ...messages,
-            {
-              content: completion,
-              role: 'assistant'
-            }
-          ]
-        }
-        await kv.hmset(`chat:${id}`, payload)
-        await kv.zadd(`user:chat:${userId}`, {
-          score: createdAt,
-          member: `chat:${id}`
-        })
+      const id = json.id ?? nanoid()
+      const createdAt = Date.now()
+      const path = `/chat/${id}`
+      const payload = {
+        id,
+        title,
+        userId,
+        createdAt,
+        path,
+        messages: [
+          ...messages,
+          {
+            content: completion,
+            role: 'assistant'
+          }
+        ]
       }
+      await kv.hmset(`chat:${id}`, payload)
+      await kv.zadd(`user:chat:${userId}`, {
+        score: createdAt,
+        member: `chat:${id}`
+      })
     }
   })