continue scaffolding and refine the basic foundation

server/api/topics/[id]/messages/index.post.ts

@@ -0,0 +1,29 @@
+import { eq } from "drizzle-orm";
+import { messages, topics } from "~~/db/schema";
+
+export default defineEventHandler(async (event) => {
+    await protectRoute(event);
+
+    const db = useDrizzle();
+
+    const { id } = event.context.params!;
+
+    const [topic] = await db.select().from(topics).where(eq(topics.id, id));
+    if (topic === undefined || topic.userId !== event.context.user.id) {
+        throw createError({ statusCode: 404, statusMessage: 'Topic not found' });
+    }
+
+    const { content } = await readBody(event);
+    if (!content) {
+        throw createError({ statusCode: 400, statusMessage: 'No content provided' });
+    }
+
+    const [message] = await db.insert(messages).values({
+        topicId: topic.id,
+        userId: event.context.user.id,
+        content,
+        isUser: true,
+    }).returning();
+
+    return message;
+});