From cfcb6c6b64c214fa84e9dccbc6db1c869954dfcb Mon Sep 17 00:00:00 2001
From: Ajay Ramachandran <dev@ajay.app>
Date: Sun, 23 May 2021 16:53:35 -0400
Subject: [PATCH] Add reputation system

---
 src/middleware/queryCacher.ts |  2 +-
 src/middleware/redisKeys.ts   |  7 +++++-
 src/middleware/reputation.ts  | 45 +++++++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 src/middleware/reputation.ts

diff --git a/src/middleware/queryCacher.ts b/src/middleware/queryCacher.ts
index e1f9f09..ec48114 100644
--- a/src/middleware/queryCacher.ts
+++ b/src/middleware/queryCacher.ts
@@ -3,7 +3,7 @@ import { Logger } from "../utils/logger";
 import { skipSegmentsHashKey, skipSegmentsKey } from "./redisKeys";
 import { Service, VideoID, VideoIDHash } from "../types/segments.model";
 
-async function get<T>(fetchFromDB: () => Promise<T[]>, key: string): Promise<T[]> {
+async function get<T>(fetchFromDB: () => Promise<T>, key: string): Promise<T> {
     const {err, reply} = await redis.getAsync(key);
 
     if (!err && reply) {
diff --git a/src/middleware/redisKeys.ts b/src/middleware/redisKeys.ts
index 920b2da..5234a51 100644
--- a/src/middleware/redisKeys.ts
+++ b/src/middleware/redisKeys.ts
@@ -1,4 +1,5 @@
 import { Service, VideoID, VideoIDHash } from "../types/segments.model";
+import { UserID } from "../types/user.model";
 import { Logger } from "../utils/logger";
 
 export function skipSegmentsKey(videoID: VideoID, service: Service): string {
@@ -10,4 +11,8 @@ export function skipSegmentsHashKey(hashedVideoIDPrefix: VideoIDHash, service: S
     if (hashedVideoIDPrefix.length !== 4) Logger.warn("Redis skip segment hash-prefix key is not length 4! " + hashedVideoIDPrefix);
     
     return "segments." + service + "." + hashedVideoIDPrefix;
-} 
\ No newline at end of file
+} 
+
+export function userKey(userID: UserID): string {
+    return "user." + userID;
+}
\ No newline at end of file
diff --git a/src/middleware/reputation.ts b/src/middleware/reputation.ts
new file mode 100644
index 0000000..99bda65
--- /dev/null
+++ b/src/middleware/reputation.ts
@@ -0,0 +1,45 @@
+import { db } from "../databases/databases";
+import { UserID } from "../types/user.model";
+import { QueryCacher } from "./queryCacher";
+import { userKey } from "./redisKeys";
+
+interface ReputationDBResult {
+    totalSubmissions: number,
+    downvotedSubmissions: number,
+    upvotedSum: number,
+    oldUpvotedSubmissions: number
+}
+
+export async function getReputation(userID: UserID) {
+    const pastDate = Date.now() - 1000 * 1000 * 60 * 60 * 24 * 45; // 45 days ago
+    const fetchFromDB = () => db.prepare("get", 
+            `SELECT COUNT(*) AS "totalSubmissions",
+                SUM(CASE WHEN "votes" < 0 THEN 1 ELSE 0 END) AS "downvotedSubmissions",
+                SUM(CASE WHEN "votes" > 0 THEN "votes" ELSE 0 END) AS "upvotedSum",
+                SUM(CASE WHEN "timeSubmitted" < ? AND "votes" > 0 THEN 1 ELSE 0 END) AS "oldUpvotedSubmissions"
+            FROM "sponsorTimes" WHERE "userID" = ?`, [pastDate, userID]) as Promise<ReputationDBResult>;
+
+    const result = await QueryCacher.get(fetchFromDB, userKey(userID));
+
+    // Grace period
+    if (result.totalSubmissions < 5) {
+        return 0;
+    }
+
+    const downvoteRatio = result.downvotedSubmissions / result.totalSubmissions;
+    if (downvoteRatio > 0.3) {
+        return convertRange(downvoteRatio, 0.3, 1, -0.5, -1.5);
+    }
+
+    if (result.oldUpvotedSubmissions < 3 || result.upvotedSum < 5) {
+        return 0
+    }
+
+    return convertRange(Math.min(result.upvotedSum, 50), 5, 50, 0, 15);
+}
+
+function convertRange(value: number, currentMin: number, currentMax: number, targetMin: number, targetMax: number): number {
+    const currentRange = currentMax - currentMin;  
+    const targetRange = targetMax - targetMin;
+    return ((value - currentMin) / currentRange) * targetRange + targetMin;
+}
\ No newline at end of file