fixed a bit

app/api/join-team/route.js

@@ -0,0 +1,46 @@
+import { queryOne } from "../../../../lib/db";
+import { getServerSession } from "next-auth/next";
+import { authOptions } from "../../auth/[...nextauth]/route";
+
+export async function POST(request) {
+  const session = await getServerSession(authOptions);
+
+  if (!session) {
+    return new Response(JSON.stringify({ error: "Unauthorized" }), {
+      status: 401,
+    });
+  }
+
+  try {
+    const { teamCode } = await request.json();
+    if (!teamCode) {
+      return new Response(JSON.stringify({ error: "Team code is required" }), {
+        status: 400,
+      });
+    }
+
+    const team = await queryOne("SELECT id FROM teams WHERE code = ?", [
+      teamCode,
+    ]);
+
+    if (!team) {
+      return new Response(JSON.stringify({ error: "Invalid team code" }), {
+        status: 404,
+      });
+    }
+
+    await queryOne("UPDATE users SET team_id = ? WHERE id = ?", [
+      team.id,
+      session.user.id,
+    ]);
+
+    return new Response(JSON.stringify({ teamId: team.id }), {
+      status: 200,
+    });
+  } catch (error) {
+    console.error("Join team error:", error);
+    return new Response(JSON.stringify({ error: "Failed to join team" }), {
+      status: 500,
+    });
+  }
+}