2 files changed, 140 insertions, 0 deletions
diff --git a/src/connections/EpicGames/EpicGamesSettings.ts b/src/connections/EpicGames/EpicGamesSettings.ts
new file mode 100644
index 00000000..4820a88a
--- /dev/null
+++ b/src/connections/EpicGames/EpicGamesSettings.ts
@@ -0,0 +1,5 @@
+export class EpicGamesSettings {
+	enabled: boolean = false;
+	clientId: string | null = null;
+	clientSecret: string | null = null;
+}
diff --git a/src/connections/EpicGames/index.ts b/src/connections/EpicGames/index.ts
new file mode 100644
index 00000000..cffafc60
--- /dev/null
+++ b/src/connections/EpicGames/index.ts
@@ -0,0 +1,135 @@
+import {
+	Config,
+	ConnectedAccount,
+	ConnectionCallbackSchema,
+	ConnectionLoader,
+	DiscordApiErrors,
+} from "@fosscord/util";
+import fetch from "node-fetch";
+import Connection from "../../util/connections/Connection";
+import { EpicGamesSettings } from "./EpicGamesSettings";
+
+interface OAuthTokenResponse {
+	access_token: string;
+	token_type: string;
+	scope: string;
+	refresh_token?: string;
+	expires_in?: number;
+}
+
+export interface UserResponse {
+	accountId: string;
+	displayName: string;
+	preferredLanguage: string;
+}
+
+export interface EpicTokenResponse extends OAuthTokenResponse {
+	expires_at: string;
+	refresh_expires_in: number;
+	refresh_expires_at: string;
+	account_id: string;
+	client_id: string;
+	application_id: string;
+}
+
+export default class EpicGamesConnection extends Connection {
+	public readonly id = "epicgames";
+	public readonly authorizeUrl = "https://www.epicgames.com/id/authorize";
+	public readonly tokenUrl = "https://api.epicgames.dev/epic/oauth/v1/token";
+	public readonly userInfoUrl =
+		"https://api.epicgames.dev/epic/id/v1/accounts";
+	public readonly scopes = ["basic profile"];
+	settings: EpicGamesSettings = new EpicGamesSettings();
+
+	init(): void {
+		this.settings = ConnectionLoader.getConnectionConfig(
+			this.id,
+			this.settings,
+		) as EpicGamesSettings;
+	}
+
+	getAuthorizationUrl(userId: string): string {
+		const state = this.createState(userId);
+		const url = new URL(this.authorizeUrl);
+
+		url.searchParams.append("client_id", this.settings.clientId!);
+		// TODO: probably shouldn't rely on cdn as this could be different from what we actually want. we should have an api endpoint setting.
+		url.searchParams.append(
+			"redirect_uri",
+			`${
+				Config.get().cdn.endpointPrivate || "http://localhost:3001"
+			}/connections/${this.id}/callback`,
+		);
+		url.searchParams.append("response_type", "code");
+		url.searchParams.append("scope", this.scopes.join(" "));
+		url.searchParams.append("state", state);
+		return url.toString();
+	}
+
+	getTokenUrl(): string {
+		return this.tokenUrl;
+	}
+
+	async exchangeCode(state: string, code: string): Promise<string> {
+		this.validateState(state);
+
+		const url = this.getTokenUrl();
+
+		return fetch(url.toString(), {
+			method: "POST",
+			headers: {
+				Accept: "application/json",
+				Authorization: `Basic ${Buffer.from(
+					`${this.settings.clientId}:${this.settings.clientSecret}`,
+				).toString("base64")}`,
+				"Content-Type": "application/x-www-form-urlencoded",
+			},
+			body: new URLSearchParams({
+				grant_type: "authorization_code",
+				code,
+			}),
+		})
+			.then((res) => res.json())
+			.then((res: EpicTokenResponse) => res.access_token)
+			.catch((e) => {
+				console.error(
+					`Error exchanging token for ${this.id} connection: ${e}`,
+				);
+				throw DiscordApiErrors.INVALID_OAUTH_TOKEN;
+			});
+	}
+
+	async getUser(token: string): Promise<UserResponse[]> {
+		const { sub } = JSON.parse(
+			Buffer.from(token.split(".")[1], "base64").toString("utf8"),
+		);
+		const url = new URL(this.userInfoUrl);
+		url.searchParams.append("accountId", sub);
+		return fetch(url.toString(), {
+			method: "GET",
+			headers: {
+				Authorization: `Bearer ${token}`,
+			},
+		}).then((res) => res.json());
+	}
+
+	async handleCallback(
+		params: ConnectionCallbackSchema,
+	): Promise<ConnectedAccount | null> {
+		const userId = this.getUserId(params.state);
+		const token = await this.exchangeCode(params.state, params.code!);
+		const userInfo = await this.getUser(token);
+
+		const exists = await this.hasConnection(userId, userInfo[0].accountId);
+
+		if (exists) return null;
+
+		return await this.createConnection({
+			user_id: userId,
+			external_id: userInfo[0].accountId,
+			friend_sync: params.friend_sync,
+			name: userInfo[0].displayName,
+			type: this.id,
+		});
+	}
+}