add Twitter connection

src/connections/Twitter/TwitterSettings.ts

@@ -0,0 +1,5 @@
+export class TwitterSettings {
+	enabled: boolean = false;
+	clientId: string | null = null;
+	clientSecret: string | null = null;
+}

src/connections/Twitter/index.ts

@@ -0,0 +1,222 @@
+import {
+	ApiError,
+	Config,
+	ConnectedAccount,
+	ConnectedAccountCommonOAuthTokenResponse,
+	ConnectionCallbackSchema,
+	ConnectionLoader,
+	DiscordApiErrors,
+} from "@fosscord/util";
+import fetch from "node-fetch";
+import RefreshableConnection from "../../util/connections/RefreshableConnection";
+import { TwitterSettings } from "./TwitterSettings";
+
+interface TwitterUserResponse {
+	data: {
+		id: string;
+		name: string;
+		username: string;
+		created_at: string;
+		location: string;
+		url: string;
+		description: string;
+		verified: string;
+	};
+}
+
+interface TwitterErrorResponse {
+	error: string;
+	error_description: string;
+}
+
+export default class TwitterConnection extends RefreshableConnection {
+	public readonly id = "twitter";
+	public readonly authorizeUrl = "https://twitter.com/i/oauth2/authorize";
+	public readonly tokenUrl = "https://api.twitter.com/2/oauth2/token";
+	public readonly userInfoUrl =
+		"https://api.twitter.com/2/users/me?user.fields=created_at%2Cdescription%2Cid%2Cname%2Cusername%2Cverified%2Clocation%2Curl";
+	public readonly scopes = ["users.read", "tweet.read"];
+	settings: TwitterSettings = new TwitterSettings();
+
+	init(): void {
+		this.settings = ConnectionLoader.getConnectionConfig(
+			this.id,
+			this.settings,
+		) as TwitterSettings;
+	}
+
+	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);
+		url.searchParams.append("code_challenge", "challenge"); // TODO: properly use PKCE challenge
+		url.searchParams.append("code_challenge_method", "plain");
+		return url.toString();
+	}
+
+	getTokenUrl(): string {
+		return this.tokenUrl;
+	}
+
+	async exchangeCode(
+		state: string,
+		code: string,
+	): Promise<ConnectedAccountCommonOAuthTokenResponse> {
+		this.validateState(state);
+
+		const url = this.getTokenUrl();
+
+		return fetch(url.toString(), {
+			method: "POST",
+			headers: {
+				Accept: "application/json",
+				"Content-Type": "application/x-www-form-urlencoded",
+				Authorization: `Basic ${Buffer.from(
+					`${this.settings.clientId!}:${this.settings.clientSecret!}`,
+				).toString("base64")}`,
+			},
+			body: new URLSearchParams({
+				grant_type: "authorization_code",
+				code: code,
+				client_id: this.settings.clientId!,
+				redirect_uri: `${
+					Config.get().cdn.endpointPrivate || "http://localhost:3001"
+				}/connections/${this.id}/callback`,
+				code_verifier: "challenge", // TODO: properly use PKCE challenge
+			}),
+		})
+			.then((res) => {
+				if (!res.ok) {
+					throw new ApiError("Failed to exchange code", 0, 400);
+				}
+
+				return res.json();
+			})
+			.then(
+				(
+					res: ConnectedAccountCommonOAuthTokenResponse &
+						TwitterErrorResponse,
+				) => {
+					if (res.error) throw new Error(res.error_description);
+					return res;
+				},
+			)
+			.catch((e) => {
+				console.error(
+					`Error exchanging code for ${this.id} connection: ${e}`,
+				);
+				throw DiscordApiErrors.GENERAL_ERROR;
+			});
+	}
+
+	async refreshToken(
+		connectedAccount: ConnectedAccount,
+	): Promise<ConnectedAccountCommonOAuthTokenResponse> {
+		if (!connectedAccount.token_data?.refresh_token)
+			throw new Error("No refresh token available.");
+		const refresh_token = connectedAccount.token_data.refresh_token;
+
+		const url = this.getTokenUrl();
+
+		return fetch(url.toString(), {
+			method: "POST",
+			headers: {
+				Accept: "application/json",
+				"Content-Type": "application/x-www-form-urlencoded",
+				Authorization: `Basic ${Buffer.from(
+					`${this.settings.clientId!}:${this.settings.clientSecret!}`,
+				).toString("base64")}`,
+			},
+			body: new URLSearchParams({
+				grant_type: "refresh_token",
+				refresh_token,
+				client_id: this.settings.clientId!,
+				redirect_uri: `${
+					Config.get().cdn.endpointPrivate || "http://localhost:3001"
+				}/connections/${this.id}/callback`,
+				code_verifier: "challenge", // TODO: properly use PKCE challenge
+			}),
+		})
+			.then((res) => {
+				if (!res.ok) {
+					throw new ApiError("Failed to exchange code", 0, 400);
+				}
+
+				return res.json();
+			})
+			.then(
+				(
+					res: ConnectedAccountCommonOAuthTokenResponse &
+						TwitterErrorResponse,
+				) => {
+					if (res.error) throw new Error(res.error_description);
+					return res;
+				},
+			)
+			.catch((e) => {
+				console.error(
+					`Error exchanging code for ${this.id} connection: ${e}`,
+				);
+				throw DiscordApiErrors.GENERAL_ERROR;
+			});
+	}
+
+	async getUser(token: string): Promise<TwitterUserResponse> {
+		const url = new URL(this.userInfoUrl);
+		return fetch(url.toString(), {
+			method: "GET",
+			headers: {
+				Authorization: `Bearer ${token}`,
+			},
+		})
+			.then((res) => {
+				if (!res.ok) {
+					throw new ApiError("Failed to fetch user", 0, 400);
+				}
+
+				return res.json();
+			})
+			.then((res: TwitterUserResponse & TwitterErrorResponse) => {
+				if (res.error) throw new Error(res.error_description);
+				return res;
+			})
+			.catch((e) => {
+				console.error(
+					`Error fetching user for ${this.id} connection: ${e}`,
+				);
+				throw DiscordApiErrors.GENERAL_ERROR;
+			});
+	}
+
+	async handleCallback(
+		params: ConnectionCallbackSchema,
+	): Promise<ConnectedAccount | null> {
+		const userId = this.getUserId(params.state);
+		const tokenData = await this.exchangeCode(params.state, params.code!);
+		const userInfo = await this.getUser(tokenData.access_token);
+
+		const exists = await this.hasConnection(userId, userInfo.data.id);
+
+		if (exists) return null;
+
+		return await this.createConnection({
+			token_data: { ...tokenData, fetched_at: Date.now() },
+			user_id: userId,
+			external_id: userInfo.data.id,
+			friend_sync: params.friend_sync,
+			name: userInfo.data.name,
+			type: this.id,
+		});
+	}
+}