3 files changed, 124 insertions, 1 deletions
diff --git a/src/connections/Discord/DiscordSettings.ts b/src/connections/Discord/DiscordSettings.ts
new file mode 100644
index 00000000..a8976f12
--- /dev/null
+++ b/src/connections/Discord/DiscordSettings.ts
@@ -0,0 +1,5 @@
+export class DiscordSettings {
+	enabled: boolean = false;
+	clientId: string | null = null;
+	clientSecret: string | null = null;
+}
\ No newline at end of file
diff --git a/src/connections/Discord/index.ts b/src/connections/Discord/index.ts
new file mode 100644
index 00000000..5a89860e
--- /dev/null
+++ b/src/connections/Discord/index.ts
@@ -0,0 +1,118 @@
+import fetch from "node-fetch";
+import {
+	Config,
+	ConnectedAccount,
+	ConnectionCallbackSchema,
+	DiscordApiErrors,
+	ConnectionLoader,
+} from "@fosscord/util";
+import Connection from "../../util/connections/Connection";
+import { DiscordSettings } from "./DiscordSettings";
+
+interface OAuthTokenResponse {
+	access_token: string;
+	token_type: string;
+	scope: string;
+	refresh_token?: string;
+	expires_in?: number;
+}
+
+interface UserResponse {
+	id: string;
+	username: string;
+	avatar_url: string | null;
+}
+
+export default class DiscordConnection extends Connection {
+	public readonly id = "discord";
+	public readonly authorizeUrl = "https://discord.com/oauth2/authorize";
+	public readonly tokenUrl = "https://discord.com/oauth2/token";
+	public readonly userInfoUrl = "https://discord.com/api/users/@me";
+	public readonly scopes = ["identify"];
+	settings: DiscordSettings = new DiscordSettings();
+
+	init(): void {
+		this.settings = ConnectionLoader.getConnectionConfig(
+			this.id,
+			this.settings,
+		) as DiscordSettings;
+	}
+
+	getAuthorizationUrl(userId: string): string {
+		const state = this.createState(userId);
+		const url = new URL(this.authorizeUrl);
+
+		url.searchParams.append("state", state);
+		url.searchParams.append("client_id", this.settings.clientId!);
+		url.searchParams.append("scope", this.scopes.join(" "));
+		url.searchParams.append("response_type", "code");
+		// controls whether, on repeated authorizations, the consent screen is shown
+		url.searchParams.append("consent", "none");
+
+		// 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`,
+		);
+
+		return url.toString();
+	}
+
+	getTokenUrl(code: string): string {
+		const url = new URL(this.tokenUrl);
+		url.searchParams.append("client_id", this.settings.clientId!);
+		url.searchParams.append("client_secret", this.settings.clientSecret!);
+		url.searchParams.append("grant_type", "authorization_code");
+		url.searchParams.append("code", code);
+		return url.toString();
+	}
+
+	async exchangeCode(state: string, code: string): Promise<string> {
+		this.validateState(state);
+		const url = this.getTokenUrl(code);
+
+		return fetch(url, {
+			method: "POST",
+			headers: {
+				Accept: "application/json",
+			},
+		})
+			.then((res) => res.json())
+			.then((res: OAuthTokenResponse) => 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 url = new URL(this.userInfoUrl);
+		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.id);
+
+		if (exists) return null;
+
+		return await this.createConnection({
+			user_id: userId,
+			external_id: userInfo.id,
+			friend_sync: params.friend_sync,
+			name: userInfo.username,
+			type: this.id,
+		})
+	}
+}
\ No newline at end of file
diff --git a/src/util/index.ts b/src/util/index.ts
index cb180ee8..9c0f7881 100644
--- a/src/util/index.ts
+++ b/src/util/index.ts
@@ -25,4 +25,4 @@ export * from "./dtos/index";
 export * from "./schemas";
 export * from "./imports";
 export * from "./config";
-export * from "./connections"
\ No newline at end of file
+export * from "./connections"