[WIP]: Cooldown

.env.example

@@ -1,17 +1,26 @@
-## if set to development, morgan middleware will log every request
+## if set to development, will briefly log every request
 NODE_ENV=production 
 
 ### optional properties. default shown. enable by removing # in front of them.
+## if using docker-compose.yml, make sure the port there is also the same as that in here.
 # PORT=3000
+#
 ## duration for which static files' cached copies are valid in the browser(eg: 1m, 3600, '2 days')
-# CACHE_PERIOD=1h 
+# CACHE_PERIOD=1y 
+#
 ## user agent and accept header that quora will see
-# AXIOS_USER_AGENT='axios/0.26.1'
-# AXIOS_ACCEPT='application/json, text/plain, */*'
+# USER_AGENT='Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36'
+# ACCEPT='text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'
+# ACCEPT_ENCODING='gzip, deflate, br, zstd'
+#
 ## for caching api responses using redis
-# REDIS_URL=localhost:6379 # if left unset, there'll be no caching
-# REDIS_TTL=3600
+# REDIS_URL= #localhost:6379 
+# REDIS_TTL=3600 # in seconds
+#
+## cooldown when rate-limited from upstream in milliseconds
+# RATE_LIMIT_COOLDOWN=7200000 # 2 hours
 
 ### for specific use-cases.
+#
 ## add any value here (e.g.: 1, true, 'por favor') if you're using any service where http is the preferred method(e.g.: tor, i2p). else leave it blank
-NO_UPGRADE=
+# NO_UPGRADE=

app.js

@@ -1,6 +1,3 @@
-////////////////////////////////////////////////////////
-//                      IMPORTS
-////////////////////////////////////////////////////////
 import express from 'express';
 import morgan from 'morgan';
 import helmet from 'helmet';
@@ -10,28 +7,24 @@ import viewRouter from './routes/viewRoutes.js';
 import apiRouter from './routes/apiRoutes.js';
 import globalErrorHandler from './controllers/errorController.js';
 import AppError from './utils/AppError.js';
+import { formatReq } from './middlewares/middlewares.js';
+import env from './utils/env.js';
 
-////////////////////////////////////////////////////////
-//            CREATING AND CONFIGURING APP
-////////////////////////////////////////////////////////
-// 0. CREATING APP
 const app = express();
 
-// 1. IMPORTANT MIDDLWARES
-app.use(compression()); // compressing responses
+app.use(compression());
 app.use(
   helmet({
     contentSecurityPolicy: {
       directives: {
         'block-all-mixed-content': null, // deprecated.
-        'upgrade-insecure-requests': process.env.NO_UPGRADE ? null : [],
+        'upgrade-insecure-requests': env.NO_UPGRADE ? null : [],
       },
     },
     crossOriginEmbedderPolicy: false,
   })
 ); // using sane headers on response
 
-// 2. SETTING VIEW ENGINE AND PATH TO STATIC ASSETS
 app.set('view engine', 'pug');
 const pathToViews = fileURLToPath(
   new URL('./views/pug/pages', import.meta.url)
@@ -42,33 +35,20 @@ const pathToPublicDirectory = fileURLToPath(
 );
 app.use(
   express.static(pathToPublicDirectory, {
-    maxAge: process.env.CACHE_PERIOD || '1h',
+    maxAge: env.CACHE_PERIOD,
   })
 );
+if (env.NODE_ENV === 'development') app.use(morgan('dev'));
 
-// 3. MISC MIDDLEWARES
-if (process.env.NODE_ENV === 'development') app.use(morgan('dev')); // for logging during development
-// middleware to add baseUrl to req object
-app.use((req, res, next) => {
-  req.urlObj = new URL(req.originalUrl, `${req.protocol}://${req.get('host')}`);
-  next();
-});
+app.use(formatReq);
 
-// 4. MIDDLWARES FOR ROUTES
 app.use('/', viewRouter);
 app.use('/api/v1/', apiRouter);
-
-////////////////////////////////////////////////////////
-//                 HANDLING ERRORS
-////////////////////////////////////////////////////////
 // for all other routes, throwing error
-app.all('*', (req, res, next) => {
+app.all('*', (req, _res, next) => {
   next(new AppError(`this route(${req.originalUrl}) doesn't exist`, 404));
 });
 
 app.use(globalErrorHandler);
 
-////////////////////////////////////////////////////////
-//                      EXPORTS
-////////////////////////////////////////////////////////
 export default app;

controllers/apiController.js

@@ -1,87 +1,42 @@
-/* eslint-disable no-unused-vars */
-////////////////////////////////////////////////////////
-//                     IMPORTS
-////////////////////////////////////////////////////////
-import getAxiosInstance from '../utils/getAxiosInstance.js';
+import axiosInstance from '../utils/axiosInstance.js';
 import catchAsyncErrors from '../utils/catchAsyncErrors.js';
-import getAnswers from '../fetchers/getAnswers.js';
-import getTopic from '../fetchers/getTopic.js';
-import getProfile from '../fetchers/getProfile.js';
-import getOrSetCache from '../utils/getOrSetCache.js';
-import { answersKey, profileKey, topicKey } from '../utils/cacheKeys.js';
 
-////////////////////////////////////////////////////////
-//                     EXPORTS
-////////////////////////////////////////////////////////
-export const about = (req, res, next) => {
+/** @type {import('express').RequestHandler} */
+export const about = (_req, res, _next) => {
   res.status(200).json({
     status: 'success',
-    message: `make a request. 
-    available endpoints are: '/slug', '/unanswered/slug', '/topic/slug', '/profile/slug'`,
+    message: `make a request. available endpoints are: '/slug', '/unanswered/slug', '/topic/slug', '/profile/slug'`,
   });
 };
 
-export const answers = catchAsyncErrors(async (req, res, next) => {
-  const {
-    urlObj,
-    params: { slug },
-    query: { lang },
-  } = req;
-
-  const data = await getOrSetCache(answersKey(urlObj), getAnswers, slug, lang);
-  res.status(200).json({ status: 'success', data });
-});
-
-export const topic = catchAsyncErrors(async (req, res, next) => {
-  const {
-    urlObj,
-    params: { slug },
-    query: { lang },
-  } = req;
-
-  const data = await getOrSetCache(topicKey(urlObj), getTopic, slug, lang);
-  res.status(200).json({ status: 'success', data });
-});
-
-export const profile = catchAsyncErrors(async (req, res, next) => {
-  const {
-    urlObj,
-    params: { name },
-    query: { lang },
-  } = req;
-
-  const data = await getOrSetCache(profileKey(urlObj), getProfile, name, lang);
-  res.status(200).json({ status: 'success', data });
-});
-
-export const unimplemented = (req, res, next) => {
+/** @type {import('express').RequestHandler} */
+export const unimplemented = (_req, res, _next) => {
   res.status(501).json({
     status: 'fail',
     message: "This route isn't yet implemented. Check back sometime later!",
   });
 };
 
-export const gone = (req, res, next) => {
+/** @type {import('express').RequestHandler} */
+export const gone = (_req, res, _next) => {
   res.status(501).json({
     status: 'fail',
     message: "This route doesn't exist anymore.",
   });
 };
 
 
-export const image = catchAsyncErrors(async (req, res, next) => {
+/** @type {import('express').RequestHandler} */
+export const image = catchAsyncErrors(async (req, res, _next) => {
   const { domain, path } = req.params;
   if (!domain.endsWith('quoracdn.net')) {
     return res.status(403).json({
       status: 'fail',
       message: 'Invalid domain',
     });
   }
-  // changing defaults for this particular endpoint
-  const axiosInstance = getAxiosInstance();
-  axiosInstance.defaults.baseURL = `https://${domain}/`;
 
-  const imageRes = await axiosInstance.get(path, { responseType: 'stream' });
+  const imageRes = await axiosInstance.get(path, { baseURL: `https://${domain}/`, responseType: 'stream' });
 
   res.set('Content-Type', imageRes.headers['content-type']);
   res.set('Cache-Control', 'public, max-age=315360000');

controllers/controller.js

@@ -0,0 +1,69 @@
+import catchAsyncErrors from '../utils/catchAsyncErrors.js';
+import { acceptedLanguages } from '../utils/constants.js';
+import getAnswers from '../fetchers/getAnswers.js';
+import getTopic from '../fetchers/getTopic.js';
+import getProfile from '../fetchers/getProfile.js';
+
+export const answers = catchAsyncErrors(async (req, res, next) => {
+  const { params: { slug }, query: { lang } } = req;
+
+  /** @type{Awaited<ReturnType<typeof getAnswers>>} */
+  let data = res.locals.data;
+  if (!data) data = await getAnswers(slug, lang);
+
+  const title = data.question.text[0].spans.map(span => span.text).join('');
+
+  res.locals.data = data;
+  res.locals.title = title;
+  res.locals.description = `Answers to ${title}`;
+
+  next();
+});
+
+export const topic = catchAsyncErrors(async (req, res, next) => {
+  const { params: { slug }, query: { lang } } = req;
+
+  /** @type{Awaited<ReturnType<typeof getTopic>>} */
+  let data = res.locals.data;
+  if (!data) data = await getTopic(slug, lang);
+
+  res.locals.data = data;
+  res.locals.title = data.name;
+  res.locals.description = `Information about ${data.name} topic.`;
+
+  next();
+});
+
+export const profile = catchAsyncErrors(async (req, res, next) => {
+  const { params: { name }, query: { lang } } = req;
+
+  /** @type{Awaited<ReturnType<typeof getProfile>>} */
+  let data = res.locals.data;
+  if (!data) data = await getProfile(name, lang);
+
+  res.locals.data = data;
+  res.locals.title = data.basic.name;
+  res.locals.description = `${data.basic.name}'s profile.`;
+
+  next();
+});
+
+const regex = /^https:\/\/(.{2,})\.quora\.com(\/.*)$/; // local helper constant
+export const redirect = (req, res, _next) => {
+  const url = req.originalUrl.replace('/redirect/', ''); // removing `/redirect/` part.
+  const match = regex.exec(url);
+
+  if (!match) return res.redirect('/');
+
+  const [_, subdomain, rest] = match; // eg: subdomain: 'es', rest: '/topic/linux?share=1'
+  let link;
+
+  if (acceptedLanguages.includes(subdomain))
+    // adding lang param
+    link = `${rest}${rest.includes('?') ? '&' : '?'}lang=${subdomain}`;
+  else if (subdomain === 'www')
+    link = rest; // doing nothing
+  else link = `/space/${subdomain}${rest}`; // gotta be a space url.
+
+  return res.redirect(link);
+};

controllers/errorController.js

@@ -1,28 +1,19 @@
-/* eslint-disable no-unused-vars */
-/* eslint-disable no-param-reassign */
-
-////////////////////////////////////////////////////////
-//                      IMPORTS
-////////////////////////////////////////////////////////
+import env from '../utils/env.js';
 import log from '../utils/log.js';
 
-////////////////////////////////////////////////////////
-//                    FUNCTIONS
-////////////////////////////////////////////////////////
 /**
- * @description function to send error responses to the client
- * @param {{}} err error object
- * @param {{}} req request object provided by express
- * @param {{}} res response object provided by express
- * @param {boolean} devMode if set to true, will send full stack trace to the client
+ * @param {Parameters<ErrorRequestHandler>['0']} err
+ * @param {Parameters<ErrorRequestHandler>['1']} req
+ * @param {Parameters<ErrorRequestHandler>['2']} res
+ * @param {boolean} devMode
  */
 const sendErrorResponse = (err, req, res, devMode = false) => {
   // 1. FOR API
   if (req.originalUrl.startsWith('/api/'))
     res.status(err.statusCode).json({
       status: err.status,
       message: err.message,
-      // only if devMode is true, will this stack trace get sent. using es6 spreading and short circuiting
+      // only if devMode is true, will this stack trace get sent
       ...(devMode && { stack: err.stack }),
     });
   // 2. FOR WEBPAGES
@@ -43,29 +34,23 @@ const sendErrorResponse = (err, req, res, devMode = false) => {
 };
 
 /**
- * @description function to handle all errors occuring in the app
- * @param {{}} err object containing full error
- * @param {{}} req request object in express
- * @param {{}} res response object in express
- * @param {function} next function to call next middleware in express
+ * @import { type ErrorRequestHandler } from "express";
+ * @description function to handle all errors occurring in the app
+ * @type {ErrorRequestHandler} 
  */
-
-const globalErrorHandler = (err, req, res, next) => {
+const globalErrorHandler = (err, req, res, _next) => {
   // since not all errors will be an instance of AppError class(as not errors will be manually thrown by us), we have to set sensible defaults before dealing with those errors
   err.statusCode = err.statusCode || 500;
   err.status = err.status || 'error';
   log(err, 'error');
 
-  if (process.env.NODE_ENV === 'development')
+  if (env.NODE_ENV === 'development') {
     sendErrorResponse(err, req, res, true);
-  else {
+  } else {
     // if error is not operational, sending a generic error message and not revealing full details in production mode
     if (err.name !== 'OperationalError') err.message = 'something went wrong!';
     sendErrorResponse(err, req, res);
   }
 };
 
-////////////////////////////////////////////////////////
-//                     EXPORTS
-////////////////////////////////////////////////////////
 export default globalErrorHandler;