Add api/item/filter proxy request

src/routes/api/item/filter/+server.ts

@@ -0,0 +1,23 @@
+import type { ErrorMessage } from "$lib/api";
+import { filter, type ItemFilter, type Item } from "$lib/entities";
+import type { RequestHandler } from "./$types";
+
+function isErrorMessage(value: any): value is ErrorMessage {
+  return value && typeof value.message === 'string';
+}
+
+export const POST: RequestHandler = async ({ request, cookies }): Promise<Response> => {
+  const session = cookies.get('session')
+
+  if (!session) {
+    throw new Response(JSON.stringify("no cookies"), { status: 401 })
+  }
+
+  const data: ItemFilter = await request.json();
+  const result = await filter<ItemFilter, Item>("item", data, session);
+  if (isErrorMessage(result)) {
+    return new Response(JSON.stringify(result), { status: 500 })
+  }
+  return new Response(JSON.stringify(result), { status: 200 })
+}
+