learn-request-queue/src/requests.ts

import * as queries from "./queries"
import * as youtube from "./youtube"
import { log, LogLevel } from "./logging"
import pg from "pg";
import db from "./db";

export async function getRequests(count: number, offset: number, sort: string) {
	var query = {
		text: "SELECT * FROM requests_vw \
			JOIN states ON requests_vw.state = states.state WHERE active \
			ORDER BY " + sort + " LIMIT $1 OFFSET $2",
		values: [count,offset]
	};
	return db.query(query)
	.then((result: pg.QueryResult) => result.rows);
};

export async function getRequestsVoted(count: number, offset: number, sort: string, user: number) {
	var query = {
		text: "SELECT * FROM get_requests_voted($3) \
			JOIN states ON get_requests_voted.state = states.state WHERE active \
			ORDER BY " + sort + " LIMIT $1 OFFSET $2",
		values: [count,offset,user]
	};
	return db.query(query)
	.then((result: pg.QueryResult) => result.rows);
};

export async function getRequestsTotal() {
	return db.query(queries.getRequestsTotal)
	.then((result: pg.QueryResult) => result.rows[0]["count"]);
};

export async function getAllRequests(count: number, offset: number, sort: string) {
	var query = {
		text: "SELECT * FROM requests_vw \
			ORDER BY " + sort + " LIMIT $1 OFFSET $2",
		values: [count,offset]
	};
	return db.query(query)
	.then((result: pg.QueryResult) => result.rows);
};

export async function getAllRequestsVoted(count: number, offset: number, sort: string, user: number) {
	var query = {
		text: "SELECT * FROM get_requests_voted($3) \
			ORDER BY " + sort + " LIMIT $1 OFFSET $2",
		values: [count,offset,user]
	};
	return db.query(query)
	.then((result: pg.QueryResult) => result.rows);
};

export async function getAllRequestsTotal() {
	return db.query(queries.getAllRequestsTotal)
	.then((result: pg.QueryResult) => result.rows[0]["count"]);
};

const validUrlRegexes = [
	/^https:\/\/www\.youtube\.com\/watch\?v=[a-zA-Z0-9_-]{11}$/
];

async function checkRequestExists(url: string) {
	var query = Object.assign(queries.checkRequestExists, { values: [url] });
	var result = await db.query(query);
	if (result.rowCount > 0) {
		return result;
	} else {
		return false;
	}
}

async function retrieveYoutubeMetadata(url: string) {
				var videoId = url.match(/^https:\/\/www\.youtube\.com\/watch\?v=([a-zA-Z0-9_-]{11})$/)![1];
				try {
					var ytResponse = await youtube.apiRequest('/videos', new URLSearchParams({ id: videoId, part: 'snippet' }));
					if (ytResponse) {
						var title = ytResponse['items'][0]['snippet']['title'];
						db.query(Object.assign(queries.updateRequestMetadata, { values: [url,title] }));
					}
				} catch(e) {
					log(LogLevel.ERROR,"Failed to fetch YouTube metadata");
					log(LogLevel.ERROR,"Video ID: " + videoId);
					log(LogLevel.ERROR,"Error info:");
					log(LogLevel.ERROR,e);
				}
}

export async function addRequest(url: string, requester: string): Promise<[number,string]> {
	// Check that URL is of an accepted format
	var validUrl = false;
	for (var regex of validUrlRegexes) {
		if (regex.test(url)) {
			validUrl = true;
			break;
		}
	}
	if (!validUrl) return [400, "Invalid song URL."];

	// Check whether the URL has already been requested
	var existsResult = await checkRequestExists(url)
	if (existsResult) {
		console.log(existsResult);
		return [200,`Song already requested by ${existsResult.rows[0].requester}. State: ${existsResult.rows[0].state}`]
	}

	// Check whether the user has hit their rate limit
	var rateLimitQuery = Object.assign(queries.getRateLimitStatus, { values: [requester] });
	var rateLimitResult = (await db.query(rateLimitQuery)).rows[0];
	if (rateLimitResult.status) {
		return [429,`You have reached your maximum of ${rateLimitResult.max} requests per day.
			Please try again later.\n
			Tip: Removing one of your requests from the past 24 hours by retracting your vote will allow you to replace it with another.`];
	}

	// Add the request
	var query = Object.assign(queries.addRequest, { values: [url,requester] });
	return db.query(query)
		.then(async () => {
			if (url.includes('youtube')){
				retrieveYoutubeMetadata(url);
			}
			return [201,"Song request added."] as [number,string];
		})
};

export async function updateRequestMetadata(url: string): Promise <[number,string]> {
	if (!checkRequestExists(url)) {
		return [400,"Request does not exist."];
	}
	if (url.includes('youtube')){
		retrieveYoutubeMetadata(url);
	}
	return [200,"Metadata update requested."];
}

export async function updateRequestState(url: string, state: string): Promise<[number,string]> {
	var query = Object.assign(queries.checkValidState, { values: [state] });
	var result = await db.query(query);
	if (result.rowCount == 0) {
		return [400,"Invalid state"]
	}

	if (!checkRequestExists(url)) {
		return [400,"Request does not exist."];
	}

	var query = Object.assign(queries.updateRequestState, { values: [url,state] });
	return db.query(query)
	.then(() => [200,"Song request state updated."] as [number,string]);
};

export async function updateRequestScoreModifier(url: string, scoreDiff: number): Promise<[number,string]> {
	var query = Object.assign(queries.updateRequestScoreModifier, { values: [url,scoreDiff] });
	return db.query(query)
		.then(() => [200,"Song request score updated."] as [number,string]);
};

export async function deleteRequest(url: string): Promise<[number,string]> {
	var query = Object.assign(queries.deleteRequest, { values: [url] });
	return db.query(query)
	.then(() => [200,"Song request deleted."] as [number,string]);
};

export async function addVote(url: string, user: string): Promise<[number,string]> {
	var query = Object.assign(queries.checkVoteExists, { values: [url,user] });
	var result = await db.query(query);
	if (result.rowCount > 0) {
		return [200,`Song already voted on`]
	}
	return db.query("CALL add_vote($1,$2)",[url,user])
		.then(() => [201,"Successfully cast vote."] as [number,string]);
};

export async function deleteVote(url: string, user: string): Promise<[number,string]> {
	return db.query("CALL delete_vote($1,$2)",[url,user])
		.then(() => [201,"Successfully retracted vote."] as [number,string]);
};