fix: resolve NGINX redirect issue and related server bugs (#6)

nginx/default.conf

@@ -9,7 +9,11 @@ server {
            root /var/www/html/muhzi.com;
 	}
     location ~* "^/[0-9a-z@]{5,15}$"  {
-         rewrite ^/(.*)$ http://muhzi.com:7000/api/item/$1 redirect;
+        proxy_pass         http://127.0.0.1:7000;
+        rewrite ^/(.*)$    /api/item/$1 break;
+        proxy_set_header   Host              $host;
+        proxy_set_header   X-Real-IP         $remote_addr;
+        proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
     }
 }
 

nginx/shortener_default.conf

@@ -1,21 +1,27 @@
-server {
-        listen 80; 
-        listen [::]:80;
-        index index.html index.htm index.nginx-debian.html;
-        server_name shortener.muhzi.com;
-        root /var/www/html/shortener;
-        location / {
-           root /var/www/html/shortener;
-        }
-        location /v1/ {
-         proxy_set_header Host $host;
-         proxy_set_header X-Real-IP $remote_addr;
-         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-         proxy_set_header Host $http_host;
-         proxy_set_header X-NginX-Proxy true;
-         proxy_pass http://127.0.0.1:7000/;
-         proxy_redirect off;
-       }
-
-}
-u
+server {
+        listen 80; 
+        listen [::]:80;
+        index index.html index.htm index.nginx-debian.html;
+        server_name shortener.muhzi.com;
+        root /var/www/html/shortener;
+        location / {
+           root /var/www/html/shortener;
+        }
+        location /v1/ {
+         proxy_set_header Host $host;
+         proxy_set_header X-Real-IP $remote_addr;
+         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+         proxy_set_header Host $http_host;
+         proxy_set_header X-NginX-Proxy true;
+         proxy_pass http://127.0.0.1:7000/;
+         proxy_redirect off;
+       }
+        location ~* "^/[0-9a-z@]{5,15}$"  {
+            proxy_pass         http://127.0.0.1:7000;
+            rewrite ^/(.*)$    /api/item/$1 break;
+            proxy_set_header   Host              $host;
+            proxy_set_header   X-Real-IP         $remote_addr;
+            proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
+        }
+
+}

server/config/constants.js

@@ -1,4 +1,4 @@
 module.exports = {
   mongoURI: "mongodb://localhost/url-shortner",
-  errorUrl: "https://muhzi.com/error"
+  errorUrl: "http://localhost/error"
 };

server/routes/urlshorten.js

@@ -5,55 +5,94 @@ const constants = require('../config/constants');
 const shortCode = require('../middlewares/uniqueUrlCode');
 
 const cache = require('../services/cache');
+
 module.exports = app => {
+  // GET  /api/item/:code  —  redirect to the original URL
   app.get('/api/item/:code', async (req, res) => {
     const urlCode = req.params.code;
-    const item = await UrlShorten.findOne({ urlCode: urlCode });
-    if (item) {
-      return res.redirect(item.originalUrl);
-    } else {
+
+    try {
+      // 1. Check Redis cache first (avoids a DB round-trip on every redirect)
+      let urlData = await cache.getFromCache('urlCode', urlCode);
+
+      if (!urlData) {
+        // 2. Fall back to MongoDB
+        urlData = await UrlShorten.findOne({ urlCode }).exec();
+
+        // 3. Populate cache for next time
+        if (urlData) {
+          cache.addToCache('urlCode', urlCode, urlData);
+        }
+      }
+
+      if (urlData) {
+        return res.redirect(urlData.originalUrl);
+      } else {
+        return res.redirect(constants.errorUrl);
+      }
+    } catch (err) {
+      // Cache or DB error — still try a plain DB lookup so the redirect works
+      try {
+        const urlData = await UrlShorten.findOne({ urlCode }).exec();
+        if (urlData) return res.redirect(urlData.originalUrl);
+      } catch (_) { /* intentional */ }
       return res.redirect(constants.errorUrl);
     }
   });
 
+  // POST /api/item  —  shorten a URL
   app.post('/api/item', async (req, res) => {
     const { shortBaseUrl, originalUrl } = req.body;
-    if (validUrl.isUri(shortBaseUrl)) {
-    } else {
+
+    if (!validUrl.isUri(shortBaseUrl)) {
       return res.status(404).json('Invalid Base Url format');
     }
 
+    if (!validUrl.isUri(originalUrl)) {
+      return res.status(401).json('Invalid Original Url.');
+    }
+
     const updatedAt = new Date();
     const queryOptions = { originalUrl };
-    if (validUrl.isUri(originalUrl)) {
+
+    try {
       let urlData;
+
+      // Check Redis cache
       try {
-        // Find the item is in the cache
         urlData = await cache.getFromCache('originalUrl', JSON.stringify(queryOptions));
-        if (!urlData) {
-          // Find the item is in the database
-          urlData = await UrlShorten.findOne(queryOptions).exec();
-        }
+      } catch (_) {
+        // Redis unavailable — skip cache, fall through to DB
+        urlData = null;
+      }
 
-        if (urlData) {
-          res.status(200).json(urlData);
-        } else {
-          const urlCode = shortCode.generate();
-          shortUrl = shortBaseUrl + '/' + urlCode;
-          const itemToBeSaved = { originalUrl, shortUrl, urlCode, updatedAt };
-
-          // Add the item to db
-          const item = new UrlShorten(itemToBeSaved);
-          await item.save();
-          // Add the item to cache
-          cache.addToCache('originalUrl', JSON.stringify(queryOptions), itemToBeSaved);
-          res.status(200).json(itemToBeSaved);
-        }
-      } catch (err) {
-        res.status(401).json('Invalid User Id');
+      if (!urlData) {
+        // Check MongoDB
+        urlData = await UrlShorten.findOne(queryOptions).exec();
       }
-    } else {
-      return res.status(401).json('Invalid Original Url.');
+
+      if (urlData) {
+        return res.status(200).json(urlData);
+      }
+
+      // Brand-new URL — generate a short code and persist
+      const urlCode = shortCode.generate();
+      const shortUrl = shortBaseUrl + '/' + urlCode;     // fixed: was undeclared
+      const itemToBeSaved = { originalUrl, shortUrl, urlCode, updatedAt };
+
+      const item = new UrlShorten(itemToBeSaved);
+      await item.save();
+
+      // Add to cache (best-effort; ignore Redis errors)
+      try {
+        cache.addToCache('originalUrl', JSON.stringify(queryOptions), itemToBeSaved);
+        cache.addToCache('urlCode', urlCode, itemToBeSaved);
+      } catch (_) { /* intentional */ }
+
+      return res.status(200).json(itemToBeSaved);
+    } catch (err) {
+      console.error('POST /api/item error:', err);
+      return res.status(500).json('Internal server error');
     }
   });
 };

server/services/cache.js

@@ -6,7 +6,9 @@ const keys = require('../config/redis');
 const client = redis.createClient(keys.redisUrl);
 client.hget = util.promisify(client.hget);
 
-client.on('error', function(err) {});
+client.on('error', function(err) {
+  console.error('[Redis] Connection error:', err.message);
+});
 // eslint-disable-next-line
 const exec = mongoose.Query.prototype.exec;