mediastream test completed

.eslintrc.js

@@ -20,5 +20,10 @@ module.exports = {
     'react', 'react-hooks', 'jest'
   ],
   rules: {
+  },
+  settings: {
+    react: {
+      version: '17.0.2'
+    }
   }
 }

01-basic-cs/index.js

@@ -5,7 +5,20 @@ const assert = require('assert')
 
 const database = require('./database.json')
 
-const total = 0 // TODO
+// Combine all users's hats
+const allHats = _.flatMap(database, 'hats')
+
+// Obtain the frequency of each hat by its id
+const hatsFrequency = _.countBy(allHats, 'id')
+
+// Obtain a ordered array with the frequency of each hat
+const orderedHatsByFrequency = _.orderBy(_.toPairs(hatsFrequency), (pair) => pair[1], 'desc')
+
+// Get the first 3 elements
+const highers = _.take(orderedHatsByFrequency, 3)
+
+// Sume it
+const total = _.sumBy(highers, (el) => el[1])
 
 // Throws error on failure
 assert.equal(total, 23, `Invalid result: ${total} != 23`)
@@ -14,6 +27,6 @@ console.log('Success!')
 
 /**
  * Time and space complexity in O() notation is:
- *   - time complexity: TODO
- *   - space complexity: TODO
+ *   - time complexity: O(m log m) - m represents the array with the frequency, which is ordered
+ *   - space complexity: O(n)
  */

02-nodejs/docker-compose.yaml

@@ -0,0 +1,8 @@
+services:
+  mediastream:
+    image: mongo:5.0.0
+    container_name: mediastream-challenge
+    ports:
+      - 27017:27017
+    volumes:
+      - ./mongo:/data/db

02-nodejs/index.js

@@ -1,12 +1,40 @@
 'use strict'
 
 const express = require('express')
+const csv = require('fast-csv')
+const { Transform } = require('stream')
 
 const User = require('./models/User')
 
 // Setup Express.js app
 const app = express()
 
 // TODO: everything else
+app.get('/users', async (req, res) => {
+  try {
+    // Get all users from DB and select only the id, name and email
+    const dbUsers = await User.find({}).lean().select('-__v')
+
+    // Setup the headers to download
+    res.setHeader('Content-Type', 'text/csv')
+    res.setHeader('Content-Disposition', 'attachment filename=users.csv')
+
+    // Create a transform stream and in the _transform function add each register to the transform stream
+    const transformStream = new Transform({ objectMode: true })
+    transformStream._transform = function (user, _, done) {
+      this.push(user)
+      done()
+    }
+
+    // Finally use csv.write to generate the cvs file from our dbUsers
+    // and through the pipe connect it to the transform stream
+    csv.write(dbUsers, { headers: true })
+      .pipe(transformStream)
+      .pipe(res)
+  } catch (error) {
+    console.log(error)
+    res.status(500).send('Error while download the CSV file')
+  }
+})
 
 app.listen(3000)

03-react/src/App.js

@@ -1,11 +1,12 @@
+import React from 'react'
 import { BrowserRouter, Route, Switch } from 'react-router-dom'
-import Exercise from './components/pages/Exercise'
+import { MovieShop } from './pages/movies-shop/MovieShop'
 
 function App () {
   return (
     <BrowserRouter>
       <Switch>
-        <Route path="/" component={Exercise} exact />
+        <Route path="/" component={MovieShop} exact />
       </Switch>
     </BrowserRouter>
   )

03-react/src/components/MovieCard.js

@@ -0,0 +1,40 @@
+import React from 'react'
+import PropTypes from 'prop-types'
+
+export const MovieCard = ({ item, isInCart, addItem, removeItem }) => {
+  return (
+    <li key={item.id} className='movies__list-card'>
+      <ul>
+        <li>ID: {item.id}</li>
+        <li>Name: {item.name}</li>
+        <li>Price: ${item.price}</li>
+      </ul>
+      {
+        isInCart
+          ? (
+              <div className="movies__cart-card-quantity">
+                <button onClick={() => removeItem(item)}>
+                  -
+                </button>
+                <span>
+                  {item.quantity}
+                </span>
+                <button onClick={() => addItem(item)}>
+                  +
+                </button>
+              </div>
+            )
+          : (
+              <button onClick={() => addItem(item)}>Add to cart</button>
+            )
+      }
+    </li>
+  )
+}
+
+MovieCard.propTypes = {
+  item: PropTypes.object.isRequired,
+  isInCart: PropTypes.bool,
+  addItem: PropTypes.func.isRequired,
+  removeItem: PropTypes.func
+}

03-react/src/constants/index.js

@@ -0,0 +1,37 @@
+export const movies = [
+  {
+    id: 1,
+    name: 'Star Wars',
+    price: 20
+  },
+  {
+    id: 2,
+    name: 'Minions',
+    price: 25
+  },
+  {
+    id: 3,
+    name: 'Fast and Furious',
+    price: 10
+  },
+  {
+    id: 4,
+    name: 'The Lord of the Rings',
+    price: 5
+  }
+]
+
+export const discountRules = [
+  {
+    m: [3, 2],
+    discount: 0.25
+  },
+  {
+    m: [2, 4, 1],
+    discount: 0.5
+  },
+  {
+    m: [4, 2],
+    discount: 0.1
+  }
+]