feat: implement user interface

Author: isharghura

src/items/services/UserService.ts

@@ -0,0 +1,22 @@
+import githubDiscordMap from "../../../data/githubDiscordMap.json";
+import { Err, Ok, Result } from "ts-results";
+
+export interface User {
+    githubUsername: string;
+    githubId: string;
+    discordId: string;
+}
+
+const users: User[] = Object.values(githubDiscordMap);
+
+export class UserService {
+    static async findUserByDiscordID(discordId: string): Promise<Result<User, Error>> {
+        const user = users.find((u) => u.discordId === discordId);
+        return user ? Ok(user) : Err(new Error("Could not find user with that DiscordID"));
+    }
+
+    static async findUserByGithubUsername(githubUsername: string): Promise<Result<User, Error>> {
+        const user = users.find((u) => u.githubUsername === githubUsername);
+        return user ? Ok(user) : Err(new Error("Could not find user with that GitHub username"));
+    }
+}