chunithm: Save and load user duel list

src/chunithm/handler/getUserDuel.ts

@@ -1,14 +1,23 @@
 import { Repositories } from "../repo";
 import { GetUserDuelRequest } from "../request/getUserDuel";
 import { GetUserDuelResponse } from "../response/getUserDuel";
+import { readAimeId } from "../proto/base";
+import { writeUserDuelList } from "../proto/userDuelList";
 
 export default async function getUserDuel(
   rep: Repositories,
   req: GetUserDuelRequest
 ): Promise<GetUserDuelResponse> {
+  const aimeId = readAimeId(req.userId);
+  // Get all duel entities if the client specifies to.
+  const duelId = req.isAllDuel ? undefined : parseInt(req.duelId);
+
+  const profileId = await rep.userData().lookup(aimeId);
+  const items = await rep.userDuelList().load(profileId, duelId);
+
   return {
     userId: req.userId,
-    length: "0",
-    userDuelList: [],
+    length: items.length.toString(),
+    userDuelList: items.map(writeUserDuelList),
   };
 }