Implement Twitch API connector

src/app.ts

@@ -1,9 +1,12 @@
 import * as config from "./config";
 import * as requests from "./requests";
+import * as twitch from "./twitch";
+import { URLSearchParams } from "url";
 import { QueryResult } from "pg";
 import express from "express";
 import session from "express-session";
 import pgSessionStore from "connect-pg-simple";
+import fetch, { Response as FetchResponse } from "node-fetch";
 import db from "./db";
 import errorHandler from "./errors";
 
@@ -14,9 +17,12 @@ app.use(session({
 	secret: config.sessionSecret,
 	saveUninitialized: false,
 	resave: false,
-	store: new (pgSessionStore(session))()
+	store: new (pgSessionStore(session))({
+		pool: db
+	})
 }));
 
+// API
 app.get("/api/getRequests", async (request, response) => {
 	var requestCount = ( request.query.count ? parseInt(request.query.count as string, 10) : 5 );
 	requests.getRequests(requestCount).then((val: QueryResult) => response.send(val))
@@ -101,6 +107,26 @@ app.post("/api/deleteRequest", async (request, response) => {
 	.catch((e: any) => errorHandler(request,response,e));
 });
 
+// Twitch callback
+app.get("/callback", async (request, response) => {
+	var authcode = request.query.code as string;
+	var tokenResponse = await fetch("https://id.twitch.tv/oauth2/token", { method: "POST", body: new URLSearchParams({
+		client_id: config.twitchClientId,
+		client_secret: config.twitchSecret,
+		code: authcode,
+		grant_type: "authorization_code",
+		redirect_uri: `${config.urlPrefix}/callback`
+	})}).then((res: FetchResponse) => res.json() as Promise<twitch.TokenResponse>)
+	.catch((e: any) => errorHandler(request,response,e));
+	if (typeof request.session == 'undefined') throw new Error('Session is undefined');
+	if (typeof tokenResponse == 'undefined') throw new Error('tokenResponse is undefined');
+	request.session.tokenpair = { access_token: tokenResponse.access_token, refresh_token: tokenResponse.refresh_token };
+	request.session.user = (await twitch.apiRequest(request.session.tokenpair,"GET","/users")).data[0];
+	response.redirect(307, '/');
+});
+
+//app.get("/session", (request, response) => { response.send(request.session); });
+
 const server = app.listen(config.port, () => {
   console.log(`Listening on port ${config.port}`);
 });

src/config.ts

@@ -4,6 +4,18 @@ if (!process.env.PORT) {
 }
 export const port: number = parseInt(process.env.PORT as string, 10);
 
+if (!process.env.URL_PREFIX) {
+	console.log("Missing environment variable URL_PREFIX");
+	process.exit(1);
+}
+export const urlPrefix: string = process.env.URL_PREFIX;
+
+if (!process.env.TWITCH_CLIENTID) {
+	console.log("Missing environment variable TWITCH_CLIENTID");
+	process.exit(1);
+}
+export const twitchClientId: string = process.env.TWITCH_CLIENTID;
+
 if (!process.env.TWITCH_SECRET) {
 	console.log("Missing environment variable TWITCH_SECRET");
 	process.exit(1);

src/twitch.ts

@@ -0,0 +1,25 @@
+import * as config from "./config";
+import fetch, { Response as FetchResponse } from "node-fetch";
+
+export interface TokenResponse {
+	access_token: string;
+	refresh_token: string;
+	token_type: string;
+	expires_in: number;
+}
+
+export interface TokenPair {
+	access_token: string;
+	refresh_token: string;
+}
+
+export async function apiRequest(tokens: TokenPair, method: string, endpoint: string): Promise<any>;
+export async function apiRequest(tokens: TokenPair, method: string, endpoint: string, query: string): Promise<any>;
+export async function apiRequest(tokens: TokenPair, method: string, endpoint: string, query?: string,) {
+	var headers = {
+		"Authorization": "Bearer " + tokens.access_token,
+		"Client-ID": config.twitchClientId
+	};
+	return fetch("https://api.twitch.tv/helix" + endpoint, { method: method, headers: headers})
+		.then(async (res: FetchResponse) => res.json());
+}