learn-request-queue/src/app.ts

import * as config from "./config";
import * as requests from "./requests";
import * as twitch from "./twitch";
import * as queries from "./queries";
import { URLSearchParams } from "url";
import express from "express";
import session from "express-session";
import pg from "pg";
import pgSessionStore from "connect-pg-simple";
import fetch, { Response as FetchResponse } from "node-fetch";
import db from "./db";
import errorHandler from "./errors";

// Ensure that any API token we have is valid - if not, destroy the session,
// logging out the user. Should be called before checking whether a user is
// logged in.
async function validateApiToken(session: Express.Session) {
	if (session.tokenpair && ! (await twitch.isApiTokenValid(session.tokenpair))) {
		session.destroy(()=>{});
	}
}

const app = express();
app.use(express.static('public'));
app.use(express.urlencoded({extended: false}));
app.use(session({
	secret: config.sessionSecret,
	saveUninitialized: false,
	resave: false,
	store: new (pgSessionStore(session))({
		pool: db
	})
}));

// API
app.get("/api/getRequests", async (request, response) => {
	if (!request.session) {
		throw new Error ("Missing request.session")
	}
	var requestCount = ( request.query.count ? parseInt(request.query.count as string, 10) : 5 );
	await validateApiToken(request.session);
	if (request.session.user) {
		requests.getRequestsVoted(requestCount,request.session.user.id).then((val: Array<any>) => response.send(val))
			.catch((e: any) => errorHandler(request,response,e));
	} else {
		requests.getRequests(requestCount).then((val: Array<any>) => response.send(val))
			.catch((e: any) => errorHandler(request,response,e));
	}
});

app.get("/api/getAllRequests", async (request, response) => {
	if (!request.session) {
		throw new Error ("Missing request.session")
	}
	var requestCount = ( request.query.count ? parseInt(request.query.count as string, 10) : 5 );
	await validateApiToken(request.session);
	if (request.session.user) {
		requests.getAllRequestsVoted(requestCount,request.session.user.id).then((val: Array<any>) => response.send(val))
			.catch((e: any) => errorHandler(request,response,e));
	} else {
		requests.getAllRequests(requestCount).then((val: Array<any>) => response.send(val))
			.catch((e: any) => errorHandler(request,response,e));
	}
});

app.post("/api/addRequest", async (request, response) => {
	response.type('text/plain');
	if (request.session) await validateApiToken(request.session);
	if (!request.session || !request.session.user) {
		response.status(401);
		response.send("Must be logged in");
		return;
	}
	var banned = await db.query(queries.checkBan).then((result: pg.QueryResult) => result.rowCount > 0);
	if (banned) {
		response.status(401);
		response.send("You are banned; you may not add new requests.");
		return;
	}
	if (!request.body.url) {
		response.status(400);
		response.send("Missing url");
		return;
	}
	var url = request.body.url as string;
	var requester = request.session.user.id;
	requests.addRequest(url,requester).then((val: [number,string]) => {
		response.status(val[0]);
		response.send(val[1]);
	})
	.catch((e: any) => errorHandler(request,response,e));
});

app.post("/api/updateRequestState", async (request, response) => {
	if (request.session) await validateApiToken(request.session);
	if (!request.session || !request.session.user) {
		response.status(401);
		response.send("Must be logged in");
		return;
	}
	var streamerid = await db.query(queries.getStreamerId).then((result: pg.QueryResult) => result.rows[0]['userid']);
	if (request.session.user.id != streamerid) {
		response.status(401);
		response.send("You are not the streamer");
		return;
	}
	if (!request.body.url) {
		response.status(400);
		response.send("Missing url");
		return;
	}
	if (!request.body.state) {
		response.status(400);
		response.send("Missing state");
		return;
	}
	var url = request.body.url as string;
	var state = request.body.state as string;
	response.type('text/plain');
	requests.updateRequestState(url,state).then((val: [number,string]) => {
		response.status(val[0]);
		response.send(val[1]);
	})
	.catch((e: any) => errorHandler(request,response,e));
});

app.post("/api/updateRequestScore", async (request, response) => {
	if (request.session) await validateApiToken(request.session);
	if (!request.session || !request.session.user) {
		response.status(401);
		response.send("Must be logged in");
		return;
	}
	var streamerid = await db.query(queries.getStreamerId).then((result: pg.QueryResult) => result.rows[0]['userid']);
	if (request.session.user.id != streamerid) {
		response.status(401);
		response.send("You are not the streamer");
		return;
	}
	if (!request.body.url) {
		response.status(400);
		response.send("Missing url");
		return;
	}
	if (!request.body.scoreDiff) {
		response.status(400);
		response.send("Missing scoreDiff");
		return;
	}
	var url = request.body.url as string;
	var scoreDiff = parseInt(request.body.scoreDiff as string, 10);
	response.type('text/plain');
	requests.updateRequestScore(url,scoreDiff).then((val: [number,string]) => {
		response.status(val[0]);
		response.send(val[1]);
	})
	.catch((e: any) => errorHandler(request,response,e));
});

app.post("/api/deleteRequest", async (request, response) => {
	if (request.session) await validateApiToken(request.session);
	if (!request.session || !request.session.user) {
		response.status(401);
		response.send("Must be logged in");
		return;
	}
	var streamerid = await db.query(queries.getStreamerId).then((result: pg.QueryResult) => result.rows[0]['userid']);
	if (request.session.user.id != streamerid) {
		response.status(401);
		response.send("You are not the streamer");
		return;
	}
	if (!request.body.url) {
		response.status(400);
		response.send("Missing url");
		return;
	}
	var url = request.body.url as string;
	response.type('text/plain');
	requests.deleteRequest(url).then((val: [number,string]) => {
		response.status(val[0]);
		response.send(val[1]);
	})
	.catch((e: any) => errorHandler(request,response,e));
});

app.post("/api/addVote", async (request,response) => {
	response.type('text/plain');
	if (request.session) await validateApiToken(request.session);
	if (!request.session || !request.session.user) {
		response.status(401);
		response.send("Must be logged in");
		return;
	}
	var banned = await db.query(queries.checkBan).then((result: pg.QueryResult) => result.rowCount > 0);
	if (banned) {
		response.status(401);
		response.send("You are banned; you may not vote on requests.");
		return;
	}
	if (!request.body.url) {
		response.status(400);
		response.send("Missing url");
		return;
	}
	var url = request.body.url as string;
	var user = request.session.user.id;
	requests.addVote(url,user).then((val: [number,string]) => {
		response.status(val[0]);
		response.send(val[1]);
	})
	.catch((e: any) => errorHandler(request,response,e));
});

app.post("/api/deleteVote", async (request,response) => {
	response.type('text/plain');
	if (request.session) await validateApiToken(request.session);
	if (!request.session || !request.session.user) {
		response.status(401);
		response.send("Must be logged in");
		return;
	}
	if (!request.body.url) {
		response.status(400);
		response.send("Missing url");
		return;
	}
	var url = request.body.url as string;
	var user = request.session.user.id;
	requests.deleteVote(url,user).then((val: [number,string]) => {
		response.status(val[0]);
		response.send(val[1]);
	})
	.catch((e: any) => errorHandler(request,response,e));
});

// Twitch callback
app.get("/callback", async (request, response) => {
	if (request.query.error) {
		response.redirect(307, '/');
		return;
	}
	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: `${config.urlPrefix}/callback`
	})}).then((res: FetchResponse) => res.json() as Promise<twitch.TokenPair>)
	.catch((e: any) => errorHandler(request,response,e));
	if (typeof request.session == 'undefined') throw new Error('Session is undefined');
	if (typeof tokenResponse == 'undefined') throw new Error('tokenResponse is undefined');
	request.session.tokenpair = { access_token: tokenResponse.access_token, refresh_token: tokenResponse.refresh_token };
	request.session.user = (await twitch.apiRequest(request.session.tokenpair,"/users")).data[0];
	var query = Object.assign(queries.updateUser,{ values: [request.session.user.id,request.session.user.display_name,request.session.user.profile_image_url] });
	db.query(query);
	var streamerid = await db.query(queries.getStreamerId).then((result: pg.QueryResult) => result.rows[0]['userid']);
	if (typeof (tokenResponse as any).scope != 'undefined') { // Scopes requested - update streamer info
		if (request.session.user.id == streamerid) {
			var query = Object.assign(queries.updateStreamer,{ values: [request.session.user.id,JSON.stringify(request.session.tokenpair)] });
			db.query(query);
		}
	} else if (request.session.user.id == streamerid) {
		response.redirect(307, `https://id.twitch.tv/oauth2/authorize?client_id=${config.twitchClientId}&redirect_uri=${config.urlPrefix}/callback&response_type=code&scope=channel:read:subscriptions moderation:read`);
		return;
	}
	response.redirect(307, '/');
});

// Frontend templates
app.get("/", async (request, response) => {
	if (request.session) await validateApiToken(request.session);
	var streamerInfo = await db.query(queries.getStreamerInfo).then((result: pg.QueryResult) => result.rows[0]);
	if (!request.session || !request.session.user) {
		response.render('main.eta', {
			loggedIn: false,
			clientId: config.twitchClientId,
			urlPrefix: config.urlPrefix,
			streamerName: streamerInfo['displayname'],
			streamerProfilePicture: streamerInfo['imageurl']
		});
	} else {
		response.render('main.eta', {
			loggedIn: true,
			userName: request.session.user.display_name,
			userProfilePicture: request.session.user.profile_image_url,
			streamerName: streamerInfo['displayname'],
			streamerProfilePicture: streamerInfo['imageurl']
		});
	}
});

// Streamer Panel
//app.get("/streamer/", async (request, response) => {
//
//});

// Logout
app.get("/logout", async (request, response) => request.session!.destroy(() => response.redirect(307, '/')));

async function processBannedUsers() {
	console.log("processBannedUsers run at " + new Date().toISOString());
	var streamer = await db.query(queries.getStreamerIdToken).then((result: pg.QueryResult) => result.rows[0]);
	if (streamer['tokenpair'] != null) {
		var response = await twitch.apiRequest(streamer['tokenpair'],"/moderation/banned?broadcaster_id=" + streamer['userid']);
		var dbconn = await db.connect();
		try {
			await dbconn.query('BEGIN');
			for (var ban of response.data) {
				if (ban.expires_at == '') dbconn.query(Object.assign(queries.insertBan,{ values: [ban.user_id] }))
			}
			await dbconn.query('COMMIT');
		} catch (e) {
			await dbconn.query('ROLLBACK');
		} finally {
			dbconn.release();
		}
	}
	setTimeout(processBannedUsers,3600000+Math.floor(Math.random()*900000)) // Run every 1-1.25 hours to balance load
}

processBannedUsers();

app.listen(config.port, () => {
  console.log(`Listening on port ${config.port}`);
});