Add ratelimits

Fixes #10

src/queries.ts

@@ -130,3 +130,8 @@ export const updateCronJobLastSuccess = {
 	name: "updateCronJobLastSuccess",
 	text: "UPDATE cron SET lastSuccess = now() WHERE jobName = $1"
 }
+
+export const getRateLimitStatus = {
+	name: "getRateLimitStatus",
+	text: "SELECT * FROM ratelimit_vw WHERE userid = $1"
+}

src/requests.ts

@@ -87,6 +87,7 @@ async function retrieveYoutubeMetadata(url: string) {
 }
 
 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)) {
@@ -95,11 +96,24 @@ export async function addRequest(url: string, requester: string): Promise<[numbe
 		}
 	}
 	if (!validUrl) return [400, "Invalid song URL."];
-	var result = await checkRequestExists(url)
-	if (result) {
-		console.log(result);
-		return [200,`Song already requested by ${result.rows[0].requester}. State: ${result.rows[0].state}`]
+
+	// 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 () => {