feat: filter by country, improved pagination and minor fixes

Author: SysSn13

controllers/rankingsController.js

@@ -1,11 +1,14 @@
-const { isNumeric } = require("../helpers");
+const { isNumeric,generatePagination } = require("../helpers");
 const Contest = require("../models/contest");
 
 exports.get = async function (req, res) {
     try {
         let entries = 25;
         let { contestSlug, page } = req.params;
-        if (page == null) {
+        const country = req.query.country || "ALL";
+        const firstPage = req.query.firstPage;
+
+        if (firstPage || page == null) {
             page = "1";
         }
         if (!isNumeric(page)) {
@@ -18,32 +21,81 @@ exports.get = async function (req, res) {
             return;
         }
         let toSkip = (page - 1) * entries;
-        let contest = await Contest.findOne(
-            { _id: contestSlug },
-            {
-                rankings: { $slice: [toSkip, entries] },
-                title: 1,
-                user_num: 1,
-                rankings_fetched: 1,
-            }
-        );
-
+        let contest;
+        if(country!=="ALL"){
+            contest = await Contest.aggregate(
+                [
+                    {
+                        $project: {
+                            rankings_fetched:1,
+                            user_num:1,
+                            _id: 1,
+                            title: 1,
+                            rankings:1,
+                        },
+                    },
+                    { $match: { _id: contestSlug } },
+                    {$addFields:{
+                        "rankings":{
+                            $filter:{
+                                input:"$rankings",
+                                as:"ranking",
+                                cond:{$eq:["$$ranking.country_code",country]}
+                            }
+                        },
+                        
+                    }},
+                    {$addFields:{
+                        "user_num": {$size:"$rankings"},
+                    }},
+                    {$addFields:{
+                        "rankings":{
+                            $slice:["$rankings",toSkip,entries],
+                        }
+                    }}
+                ]);
+                if(contest && contest.length!==0){
+                    contest = contest[0]
+                }
+                else{
+                    contest = NULL;
+                }
+        }
+        else{
+            contest = await Contest.findOne(
+                { _id: contestSlug },
+                {
+                    rankings: { $slice: [toSkip, entries] },
+                    title: 1,
+                    user_num: 1,
+                    rankings_fetched: 1,
+                }
+            );
+        }
+        
         if (!contest || !contest.rankings_fetched) {
             res.sendStatus(404);
             return;
         }
         const totalPages = Math.ceil(contest.user_num / 25);
-        if (page > totalPages) {
+        if (totalPages>0 && page > totalPages) {
             res.sendStatus(404);
             return;
         }
+        const pages = generatePagination(totalPages,page);
+        const params = new URLSearchParams({
+            country,
+        });
         res.render("ranking", {
             contest,
             totalPages,
             page,
+            pages,
             searchResult: false,
             title: `${contest.title} | Leetcode Rating Predictor`,
+            params:params.toString()
         });
+          
     } catch (err) {
         console.error(err);
         res.sendStatus(500);

helpers.js

@@ -30,3 +30,29 @@ exports.getRemainingTime = (time) => {
 exports.isNumeric = (value) => {
     return /^\d+$/.test(value);
 };
+
+exports.generatePagination = (total,current)=>{
+    let result = []
+    let rem = 5;
+    let start = Math.max(current-(2+Math.max(0,2-(total-current))),1);
+    if(start>1){
+        result.push(1);
+    }
+    if(start>2){
+        result.push(-1);
+    }
+    for(let i=start;i<=current;i++){
+        result.push(i);
+    }
+    rem -= current-start+1;
+    for(let i=current+1;i<=current+rem && i<=total;i++){
+        result.push(i);
+    }
+    if(current+rem<total-1){
+        result.push(-1);
+    }
+    if(current+rem<total){
+        result.push(total);
+    }
+    return result;
+};

services/job-queues/jobScheduler.js

@@ -53,7 +53,7 @@ scheduler.process("updateUserDataScheduler", async (job, done) => {
 
     for (let i = 0; i < totalUsers; i += limit) {
         const date = new Date();
-        const hoursWindow = date.getHours() / 4;
+        const hoursWindow = Math.floor(date.getHours() / 4);
         const jobId = `updateUsers|${i}-${
             i + limit
         }|${hoursWindow}|${convertDateYYYYMMDD(date)}`;

services/users.js

@@ -448,7 +448,7 @@ const updateUsers = async (job) => {
         for (let i = 0; i < total; i += rateLimit) {
             let promises = [];
             for (let j = 0; j < rateLimit && i + j < total; j++) {
-                if (
+                if (users[i+j] && 
                     Date.now() - users[i + j].lastUpdated <
                     12 * 60 * 60 * 1000
                 ) {

views/layouts/layout.ejs

@@ -20,6 +20,7 @@
     <link rel="manifest" href="/site.webmanifest">
     <!-- Global site tag (gtag.js) - Google Analytics -->
     <script async src="https://www.googletagmanager.com/gtag/js?id=G-RYPSMF1X05"></script>
+    <script data-ad-client="ca-pub-7334877242717971" async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
     <script>
     window.dataLayer = window.dataLayer || [];
     function gtag(){dataLayer.push(arguments);}