Add message actions (#482)

app/(chat)/actions.ts

@@ -1,8 +1,29 @@
 'use server';
 
+import { CoreMessage, CoreUserMessage, generateText } from 'ai';
 import { cookies } from 'next/headers';
 
+import { customModel } from '@/ai';
+
 export async function saveModelId(model: string) {
   const cookieStore = await cookies();
   cookieStore.set('model-id', model);
 }
+
+export async function generateTitleFromUserMessage({
+  message,
+}: {
+  message: CoreUserMessage;
+}) {
+  const { text: title } = await generateText({
+    model: customModel('gpt-3.5-turbo'),
+    system: `\n
+    - you will generate a short title based on the first message a user begins a conversation with
+    - ensure it is not more than 80 characters long
+    - the title should be a summary of the user's message
+    - do not use quotes or colons`,
+    prompt: JSON.stringify(message),
+  });
+
+  return title;
+}