├── src
    ├── react-app-env.d.ts
    ├── assets
    │   ├── Kanit.ttf
    │   ├── user.png
    │   ├── gh-logo.png
    │   ├── codeforces_logo.png
    │   ├── index.ts
    │   └── loop.svg
    ├── models
    │   ├── LogicalOperator.ts
    │   ├── ProblemStatistics.ts
    │   └── Problem.ts
    ├── components
    │   ├── common
    │   │   └── Row.tsx
    │   ├── problems-section
    │   │   ├── EmptySection.tsx
    │   │   ├── ProblemsSection.tsx
    │   │   └── ProblemCard.tsx
    │   ├── header
    │   │   └── Header.tsx
    │   ├── snackbar
    │   │   ├── CancelButton.tsx
    │   │   └── Snackbar.tsx
    │   ├── options-button
    │   │   └── index.tsx
    │   ├── footer
    │   │   └── Footer.tsx
    │   ├── clear-button
    │   │   └── ClearButton.tsx
    │   ├── topics
    │   │   ├── Tag.tsx
    │   │   └── Topics.tsx
    │   ├── randomize-button
    │   │   ├── LoadingIndicator.tsx
    │   │   └── RandomizeButton.tsx
    │   ├── options
    │   │   └── Options.tsx
    │   ├── slider
    │   │   └── Slider.tsx
    │   └── home
    │   │   └── Home.tsx
    ├── setupTests.ts
    ├── App.test.tsx
    ├── App.tsx
    ├── index.css
    ├── index.tsx
    ├── services
    │   ├── data.ts
    │   ├── storage.ts
    │   └── problems.ts
    └── serviceWorker.ts
├── public
    ├── robots.txt
    ├── CRicon.png
    ├── manifest.json
    └── index.html
├── screenshots
    ├── SS1.PNG
    ├── SS2.png
    ├── SS3.png
    └── SS4.png
├── .gitignore
├── tsconfig.json
├── README.md
└── package.json


/src/react-app-env.d.ts:
--------------------------------------------------------------------------------
1 | /// <reference types="react-scripts" />
2 | 


--------------------------------------------------------------------------------
/public/robots.txt:
--------------------------------------------------------------------------------
1 | # https://www.robotstxt.org/robotstxt.html
2 | User-agent: *
3 | Disallow:
4 | 


--------------------------------------------------------------------------------
/public/CRicon.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/public/CRicon.png


--------------------------------------------------------------------------------
/screenshots/SS1.PNG:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/screenshots/SS1.PNG


--------------------------------------------------------------------------------
/screenshots/SS2.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/screenshots/SS2.png


--------------------------------------------------------------------------------
/screenshots/SS3.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/screenshots/SS3.png


--------------------------------------------------------------------------------
/screenshots/SS4.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/screenshots/SS4.png


--------------------------------------------------------------------------------
/src/assets/Kanit.ttf:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/src/assets/Kanit.ttf


--------------------------------------------------------------------------------
/src/assets/user.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/src/assets/user.png


--------------------------------------------------------------------------------
/src/models/LogicalOperator.ts:
--------------------------------------------------------------------------------
1 | type LogicalOperator = "AND" | "OR";
2 | 
3 | export default LogicalOperator;
4 | 


--------------------------------------------------------------------------------
/src/assets/gh-logo.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/src/assets/gh-logo.png


--------------------------------------------------------------------------------
/src/assets/codeforces_logo.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/KarimElghamry/Codeforces-Randomizer/HEAD/src/assets/codeforces_logo.png


--------------------------------------------------------------------------------
/src/models/ProblemStatistics.ts:
--------------------------------------------------------------------------------
1 | export interface ProblemStatistics {
2 |   contestId: number;
3 |   index: string;
4 |   solvedCount: number;
5 | }
6 | 


--------------------------------------------------------------------------------
/src/models/Problem.ts:
--------------------------------------------------------------------------------
1 | export interface Problem {
2 |   contestId: number;
3 |   index: string;
4 |   name: string;
5 |   type: string;
6 |   rating?: number;
7 |   tags: Array<string>;
8 | }
9 | 


--------------------------------------------------------------------------------
/src/components/common/Row.tsx:
--------------------------------------------------------------------------------
 1 | import styled from 'styled-components';
 2 | 
 3 | const Row = styled.div`
 4 |   display: flex;
 5 |   width: 100%;
 6 |   flex-direction: row;
 7 |   justify-content: center;
 8 |   align-items: center;
 9 | `;
10 | 
11 | export default Row;
12 | 


--------------------------------------------------------------------------------
/src/setupTests.ts:
--------------------------------------------------------------------------------
1 | // jest-dom adds custom jest matchers for asserting on DOM nodes.
2 | // allows you to do things like:
3 | // expect(element).toHaveTextContent(/react/i)
4 | // learn more: https://github.com/testing-library/jest-dom
5 | import '@testing-library/jest-dom/extend-expect';
6 | 


--------------------------------------------------------------------------------
/src/App.test.tsx:
--------------------------------------------------------------------------------
 1 | import React from 'react';
 2 | import { render } from '@testing-library/react';
 3 | import App from './App';
 4 | 
 5 | test('renders learn react link', () => {
 6 |   const { getByText } = render(<App />);
 7 |   const linkElement = getByText(/learn react/i);
 8 |   expect(linkElement).toBeInTheDocument();
 9 | });
10 | 


--------------------------------------------------------------------------------
/src/assets/index.ts:
--------------------------------------------------------------------------------
 1 | import codeforcesLogo from './codeforces_logo.png';
 2 | import userIcon from './user.png';
 3 | import githubLogo from './gh-logo.png';
 4 | import {ReactComponent as loopIcon} from './loop.svg';
 5 | 
 6 | export const images = {
 7 |   codeforcesLogo: codeforcesLogo,
 8 |   loopIcon: loopIcon,
 9 |   userIcon: userIcon,
10 |   githubLogo: githubLogo,
11 | };
12 | 


--------------------------------------------------------------------------------
/src/App.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import Home from './components/home/Home';
 3 | import {getPromblemsListFromStorage} from './services/storage';
 4 | 
 5 | const App: React.FC<{}> = (): ReactElement => {
 6 |   const problemsList = getPromblemsListFromStorage();
 7 |   return <Home initialProblemsList={problemsList}></Home>;
 8 | };
 9 | 
10 | export default App;
11 | 


--------------------------------------------------------------------------------
/src/index.css:
--------------------------------------------------------------------------------
 1 | @font-face {
 2 |   font-family: Kanit;
 3 |   src: url('../src/assets/Kanit.ttf');
 4 | }
 5 | 
 6 | html,
 7 | body {
 8 |   height: 100%;
 9 |   margin: 0px;
10 |   padding: 0px;
11 |   background-color: white;
12 |   font-family: Kanit;
13 |   -webkit-font-smoothing: antialiased;
14 |   -moz-osx-font-smoothing: grayscale;
15 | }
16 | 
17 | body {
18 |   display: flex;
19 |   flex-direction: column;
20 | }
21 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
 1 | # See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
 2 | 
 3 | # dependencies
 4 | /node_modules
 5 | /.pnp
 6 | .pnp.js
 7 | 
 8 | # testing
 9 | /coverage
10 | 
11 | # production
12 | /build
13 | 
14 | # misc
15 | .DS_Store
16 | .env.local
17 | .env.development.local
18 | .env.test.local
19 | .env.production.local
20 | 
21 | npm-debug.log*
22 | yarn-debug.log*
23 | yarn-error.log*
24 | 


--------------------------------------------------------------------------------
/src/index.tsx:
--------------------------------------------------------------------------------
 1 | import React from 'react';
 2 | import ReactDOM from 'react-dom';
 3 | import './index.css';
 4 | import App from './App';
 5 | import * as serviceWorker from './serviceWorker';
 6 | 
 7 | ReactDOM.render(
 8 |   <React.StrictMode>
 9 |     <App />
10 |   </React.StrictMode>,
11 |   document.getElementById('root')
12 | );
13 | 
14 | // If you want your app to work offline and load faster, you can change
15 | // unregister() to register() below. Note this comes with some pitfalls.
16 | // Learn more about service workers: https://bit.ly/CRA-PWA
17 | serviceWorker.unregister();
18 | 


--------------------------------------------------------------------------------
/tsconfig.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "compilerOptions": {
 3 |     "target": "es5",
 4 |     "lib": [
 5 |       "dom",
 6 |       "dom.iterable",
 7 |       "esnext"
 8 |     ],
 9 |     "allowJs": true,
10 |     "skipLibCheck": true,
11 |     "esModuleInterop": true,
12 |     "allowSyntheticDefaultImports": true,
13 |     "strict": true,
14 |     "forceConsistentCasingInFileNames": true,
15 |     "module": "esnext",
16 |     "moduleResolution": "node",
17 |     "resolveJsonModule": true,
18 |     "isolatedModules": true,
19 |     "noEmit": true,
20 |     "jsx": "react"
21 |   },
22 |   "include": [
23 |     "src"
24 |   ]
25 | }
26 | 


--------------------------------------------------------------------------------
/public/manifest.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "short_name": "React App",
 3 |   "name": "Create React App Sample",
 4 |   "icons": [
 5 |     {
 6 |       "src": "favicon.ico",
 7 |       "sizes": "64x64 32x32 24x24 16x16",
 8 |       "type": "image/x-icon"
 9 |     },
10 |     {
11 |       "src": "logo192.png",
12 |       "type": "image/png",
13 |       "sizes": "192x192"
14 |     },
15 |     {
16 |       "src": "logo512.png",
17 |       "type": "image/png",
18 |       "sizes": "512x512"
19 |     }
20 |   ],
21 |   "start_url": ".",
22 |   "display": "standalone",
23 |   "theme_color": "#000000",
24 |   "background_color": "#ffffff"
25 | }
26 | 


--------------------------------------------------------------------------------
/src/components/problems-section/EmptySection.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import styled from 'styled-components';
 3 | 
 4 | const StyledEmptySecion = styled.div`
 5 |   display: flex;
 6 |   flex-direction: column;
 7 |   justify-content: center;
 8 |   align-items: center;
 9 |   width: 100%;
10 |   height: 100%;
11 | `;
12 | 
13 | const EmptySection: React.FC<{}> = (): ReactElement => {
14 |   return (
15 |     <StyledEmptySecion>
16 |       <div>Choose topics and press Randomize</div>
17 |       <div>to start adding problems</div>
18 |     </StyledEmptySecion>
19 |   );
20 | };
21 | 
22 | export default EmptySection;
23 | 


--------------------------------------------------------------------------------
/src/components/header/Header.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import styled from 'styled-components';
 3 | import * as assets from '../../assets';
 4 | 
 5 | const CenteredDiv = styled.div`
 6 |   text-align: center;
 7 |   font-size: 24px;
 8 |   font-weight: bold;
 9 | `;
10 | 
11 | const Header: React.FC = (): ReactElement => {
12 |   return (
13 |     <div style={{margin: '20px'}}>
14 |       <img
15 |         width={300}
16 |         height={35}
17 |         src={assets.images.codeforcesLogo}
18 |         alt=""
19 |       ></img>
20 |       <CenteredDiv>Randomizer</CenteredDiv>
21 |     </div>
22 |   );
23 | };
24 | 
25 | export default Header;
26 | 


--------------------------------------------------------------------------------
/public/index.html:
--------------------------------------------------------------------------------
 1 | <!DOCTYPE html>
 2 | <html lang="en">
 3 |   <head>
 4 |     <meta charset="utf-8" />
 5 |     <link rel="icon" href="%PUBLIC_URL%/CRicon.png" />
 6 |     <meta name="viewport" content="width=device-width, initial-scale=1" />
 7 |     <meta name="theme-color" content="#000000" />
 8 |     <meta
 9 |       name="Codeforces Randomizer"
10 |       content="Randomize problems based on choosen topics."
11 |     />
12 |     <link rel="manifest" href="%PUBLIC_URL%/manifest.json" />
13 | 
14 |     <title>Codeforces Randomizer</title>
15 |   </head>
16 |   <body>
17 |     <noscript>You need to enable JavaScript to run this app.</noscript>
18 |     <div id="root"></div>
19 |   </body>
20 | </html>
21 | 


--------------------------------------------------------------------------------
/src/components/snackbar/CancelButton.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import styled from 'styled-components';
 3 | 
 4 | interface Props {
 5 |   onClick: Function;
 6 | }
 7 | 
 8 | const StyleCancelButton = styled.div`
 9 |   font-family: 'Helvetica', 'Arial', sans-serif;
10 |   font-weight: bold;
11 |   background-color: white;
12 |   color: red;
13 |   margin-left: 5px;
14 |   width: 25px;
15 |   height: 25px;
16 |   border-radius: 12.5px;
17 |   display: flex;
18 |   justify-content: center;
19 |   align-items: center;
20 |   cursor: pointer;
21 | 
22 |   &:hover {
23 |     opacity: 0.8;
24 |   }
25 | `;
26 | 
27 | const CancelButton: React.FC<Props> = (props: Props): ReactElement => {
28 |   return (
29 |     <StyleCancelButton onClick={() => props.onClick()}>X</StyleCancelButton>
30 |   );
31 | };
32 | 
33 | export default CancelButton;
34 | 


--------------------------------------------------------------------------------
/src/components/options-button/index.tsx:
--------------------------------------------------------------------------------
 1 | import React from "react";
 2 | import styled from "styled-components";
 3 | import LogicalOperator from "../../models/LogicalOperator";
 4 | 
 5 | const Button = styled.div<{ isSelected: boolean }>`
 6 |   width: 50px;
 7 |   text-align: center;
 8 |   cursor: pointer;
 9 |   transition: 0.3s;
10 |   color: white;
11 |   background-color: ${(props) => (props.isSelected ? "#02b947" : "grey")};
12 | `;
13 | 
14 | type OptionsButtonProps = {
15 |   opertator: LogicalOperator;
16 |   isSelected: boolean;
17 |   onClick: (operator: LogicalOperator) => void;
18 | };
19 | 
20 | const OptionsButton = ({
21 |   opertator,
22 |   isSelected,
23 |   onClick,
24 | }: OptionsButtonProps) => {
25 |   return (
26 |     <Button isSelected={isSelected} onClick={() => onClick(opertator)}>
27 |       {opertator}
28 |     </Button>
29 |   );
30 | };
31 | 
32 | export default OptionsButton;
33 | 


--------------------------------------------------------------------------------
/src/services/data.ts:
--------------------------------------------------------------------------------
 1 | export const getTags: () => Array<string> = (): Array<string> => {
 2 |   const tags: Array<string> = [
 3 |     "2-sat",
 4 |     "binary search",
 5 |     "bitmasks",
 6 |     "brute force",
 7 |     "combinatorics",
 8 |     "constructive algorithms",
 9 |     "data structures",
10 |     "dfs and similar",
11 |     "divide and conquer",
12 |     "dp",
13 |     "dsu",
14 |     "expression parsing",
15 |     "fft",
16 |     "flow",
17 |     "games",
18 |     "geometry",
19 |     "graph matchings",
20 |     "graphs",
21 |     "greedy",
22 |     "hashing",
23 |     "implementation",
24 |     "interactive",
25 |     "math",
26 |     "matrices",
27 |     "number theory",
28 |     "probabilities",
29 |     "schedules",
30 |     "shortest paths",
31 |     "sortings",
32 |     "strings",
33 |     "ternary search",
34 |     "trees",
35 |     "two pointers",
36 |   ];
37 | 
38 |   return tags;
39 | };
40 | 
41 | export const minRating = 800;
42 | export const maxRating = 3500;
43 | 


--------------------------------------------------------------------------------
/src/services/storage.ts:
--------------------------------------------------------------------------------
 1 | import {Problem} from '../models/Problem';
 2 | import {ProblemStatistics} from '../models/ProblemStatistics';
 3 | 
 4 | export function getPromblemsListFromStorage(): Array<{
 5 |   problem: Problem;
 6 |   problemStatistics: ProblemStatistics;
 7 | }> {
 8 |   const result: string | null = localStorage.getItem('problemsList');
 9 |   if (!result) return [];
10 | 
11 |   const problemsList: Array<{
12 |     problem: Problem;
13 |     problemStatistics: ProblemStatistics;
14 |   }> = JSON.parse(result).problemsList;
15 |   return problemsList;
16 | }
17 | 
18 | export function setProblemsListToStorage(
19 |   list: Array<{problem: Problem; problemStatistics: ProblemStatistics}>
20 | ) {
21 |   const storageObject = {
22 |     problemsList: list,
23 |   };
24 | 
25 |   localStorage.setItem('problemsList', JSON.stringify(storageObject));
26 | }
27 | 
28 | export function clearProblemsList(): void {
29 |   localStorage.setItem('problemsList', JSON.stringify({problemsList: []}));
30 | }
31 | 


--------------------------------------------------------------------------------
/src/components/footer/Footer.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import styled from 'styled-components';
 3 | import {images} from '../../assets';
 4 | import Row from '../common/Row';
 5 | 
 6 | const StyledFooter = styled.div`
 7 |   width: 100%;
 8 |   background-color: #24292e;
 9 |   display: flex;
10 |   justify-content: center;
11 |   align-items: center;
12 |   color: white;
13 |   user-select: none;
14 | `;
15 | 
16 | const GithubLogo = styled.img`
17 |   width: 25px;
18 |   margin: 10px;
19 | `;
20 | 
21 | const githubProfileUrl: string = 'https://github.com/KarimElghamry';
22 | 
23 | const Footer: React.FC = (): ReactElement => {
24 |   return (
25 |     <StyledFooter>
26 |       <Row
27 |         style={{cursor: 'pointer', width: 'auto'}}
28 |         onClick={() => window.open(githubProfileUrl, '_blank')}
29 |       >
30 |         <GithubLogo src={images.githubLogo}></GithubLogo>
31 |         <div>KarimElghamry</div>
32 |       </Row>
33 |     </StyledFooter>
34 |   );
35 | };
36 | 
37 | export default Footer;
38 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # Codeforces Randomizer
 2 | 
 3 | Built using React, Styled components and Typescript.
 4 | 
 5 | deployed at: https://karimelghamry.github.io/Codeforces-Randomizer/
 6 | 
 7 | ### Show some :heart: and :star: the repo to support the project
 8 | 
 9 | ## How it works
10 | 
11 | - Select topics from the provided list (max 4).
12 | 
13 | - Adjust the range of ratings to your likings.
14 | 
15 | - Press `Randomize` to retrieve a random problem from Codeforces based on your inputs.
16 | 
17 | <p align='center'><img width="483px" src="screenshots/SS1.PNG"> <img height="310px" src="screenshots/SS2.png"></p> 
18 | <p align='center'><img class="temp" height="300px" src="screenshots/SS3.png">&emsp;&emsp;&emsp;&emsp;<img class="temp" height="300px" src="screenshots/SS4.png"></p>
19 | 
20 | ## Features
21 | 
22 | [✓] Ratings adjustment
23 | 
24 | [✓] All current Codeforces topics included
25 | 
26 | [✓] Automatically saves history local storage
27 | 
28 | [✓] Clear history on demand
29 | 
30 | ## Contribution
31 | 
32 | Feel free to to suggest further features/improvements by opening an issue or by submitting a pull request.
33 | 


--------------------------------------------------------------------------------
/src/components/clear-button/ClearButton.tsx:
--------------------------------------------------------------------------------
 1 | import React, { ReactElement } from "react";
 2 | import styled from "styled-components";
 3 | import Row from "../common/Row";
 4 | 
 5 | interface Props {
 6 |   onClick: Function;
 7 |   disabled: boolean;
 8 | }
 9 | 
10 | const StyledButton = styled.div<Props>`
11 |   width: 120px;
12 |   height: 35px;
13 |   margin: 15px;
14 |   display: flex;
15 |   visibility: ${(props) => (props.disabled ? "hidden" : "none")};
16 |   justify-content: space-evenly;
17 |   align-items: center;
18 |   background-color: red;
19 |   border: red solid 2px;
20 |   color: white;
21 |   font-weight: 600;
22 |   border-radius: 6px;
23 |   user-select: none;
24 |   cursor: pointer;
25 |   transition-duration: 0.3s;
26 |   transition-property: background-color, color;
27 | 
28 |   &:hover {
29 |     background-color: white;
30 |     color: red;
31 |   }
32 | `;
33 | 
34 | const ClearButton: React.FC<Props> = (props: Props): ReactElement => {
35 |   return (
36 |     <Row>
37 |       <StyledButton {...props} onClick={() => props.onClick()}>
38 |         Clear
39 |       </StyledButton>
40 |     </Row>
41 |   );
42 | };
43 | 
44 | export default ClearButton;
45 | 


--------------------------------------------------------------------------------
/src/components/topics/Tag.tsx:
--------------------------------------------------------------------------------
 1 | import React, { ReactElement } from "react";
 2 | import styled from "styled-components";
 3 | 
 4 | interface Props {
 5 |   selected: boolean;
 6 |   content: string;
 7 |   onClick: (selected: boolean, topic: string) => void;
 8 | }
 9 | 
10 | interface StyledProps {
11 |   selected: boolean;
12 | }
13 | 
14 | const StyledTag = styled.div<StyledProps>`
15 |   background-color: ${(props) => (props.selected ? "#33AC71" : "#00bcd4")};
16 |   border-radius: 2px;
17 |   color: white;
18 |   font-weight: 700;
19 |   min-width: 70px;
20 |   min-height: 30px;
21 |   margin: 5px;
22 |   user-select: none;
23 |   cursor: pointer;
24 |   display: inline-flex;
25 |   justify-content: center;
26 |   align-items: center;
27 |   transition-duration: 0.3s;
28 | `;
29 | 
30 | const Tag: React.FC<Props> = (props: Props): ReactElement => {
31 |   const selected: boolean = props.selected;
32 |   const content: string = props.content;
33 | 
34 |   return (
35 |     <StyledTag
36 |       selected={props.selected}
37 |       onClick={() => props.onClick(selected, content)}
38 |     >
39 |       <div style={{ margin: "5px" }}>{props.content}</div>
40 |     </StyledTag>
41 |   );
42 | };
43 | 
44 | export default Tag;
45 | 


--------------------------------------------------------------------------------
/src/assets/loop.svg:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="iso-8859-1"?>
 2 | <!-- Generator: Adobe Illustrator 16.0.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
 3 | <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
 4 | <svg version="1.1" id="Capa_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
 5 | 	 width="561px" height="561px" viewBox="0 0 561 561" style="enable-background:new 0 0 561 561;" xml:space="preserve">
 6 | <g>
 7 | 	<g id="loop">
 8 | 		<path d="M280.5,76.5V0l-102,102l102,102v-76.5c84.15,0,153,68.85,153,153c0,25.5-7.65,51-17.85,71.4l38.25,38.25
 9 | 			C471.75,357,484.5,321.3,484.5,280.5C484.5,168.3,392.7,76.5,280.5,76.5z M280.5,433.5c-84.15,0-153-68.85-153-153
10 | 			c0-25.5,7.65-51,17.85-71.4l-38.25-38.25C89.25,204,76.5,239.7,76.5,280.5c0,112.2,91.8,204,204,204V561l102-102l-102-102V433.5z"
11 | 			/>
12 | 	</g>
13 | </g>
14 | <g>
15 | </g>
16 | <g>
17 | </g>
18 | <g>
19 | </g>
20 | <g>
21 | </g>
22 | <g>
23 | </g>
24 | <g>
25 | </g>
26 | <g>
27 | </g>
28 | <g>
29 | </g>
30 | <g>
31 | </g>
32 | <g>
33 | </g>
34 | <g>
35 | </g>
36 | <g>
37 | </g>
38 | <g>
39 | </g>
40 | <g>
41 | </g>
42 | <g>
43 | </g>
44 | </svg>
45 | 


--------------------------------------------------------------------------------
/src/components/randomize-button/LoadingIndicator.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import styled, {keyframes} from 'styled-components';
 3 | 
 4 | interface CircleProps {
 5 |   color: string;
 6 | }
 7 | 
 8 | const BounceAnim = keyframes`
 9 | from{
10 |     bottom: 5px;
11 | }
12 | to{
13 |     bottom: 15px;
14 | }
15 | `;
16 | 
17 | const Circle = styled.div<CircleProps>`
18 |   position: absolute;
19 |   display: inline-block;
20 |   height: 10px;
21 |   width: 10px;
22 |   border-radius: 10px;
23 |   margin: 2px;
24 |   bottom: 5px;
25 |   background-color: ${(props) => props.color};
26 |   animation: ${BounceAnim} 0.5s cubic-bezier(0.3, 0, 0, 1) infinite;
27 |   animation-direction: alternate;
28 | 
29 |   &:nth-child(1) {
30 |     left: 30%;
31 |     animation-delay: 0s;
32 |   }
33 |   &:nth-child(2) {
34 |     left: 45%;
35 |     animation-delay: 0.2s;
36 |   }
37 |   &:nth-child(3) {
38 |     left: 60%;
39 |     animation-delay: 0.4s;
40 |   }
41 | `;
42 | 
43 | const StyledLoadingIndicator = styled.div`
44 |   position: relative;
45 |   height: 100%;
46 |   width: 100%;
47 | `;
48 | 
49 | const LoadingIndicator: React.FC = (): ReactElement => {
50 |   return (
51 |     <StyledLoadingIndicator>
52 |       <Circle color="#F9CD55"></Circle>
53 |       <Circle color="#198FCE"></Circle>
54 |       <Circle color="#B91D25"></Circle>
55 |     </StyledLoadingIndicator>
56 |   );
57 | };
58 | 
59 | export default LoadingIndicator;
60 | 


--------------------------------------------------------------------------------
/package.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "name": "codeforces-randomizer",
 3 |   "version": "0.1.0",
 4 |   "homepage": "https://KarimElghamry.github.io/Codeforces-Randomizer",
 5 |   "private": true,
 6 |   "dependencies": {
 7 |     "@testing-library/jest-dom": "^4.2.4",
 8 |     "@testing-library/react": "^9.5.0",
 9 |     "@testing-library/user-event": "^7.2.1",
10 |     "@types/axios": "^0.14.0",
11 |     "@types/jest": "^24.9.1",
12 |     "@types/node": "^12.12.47",
13 |     "@types/react": "^16.9.36",
14 |     "@types/react-dom": "^16.9.8",
15 |     "@types/styled-components": "^5.1.0",
16 |     "axios": "^0.19.2",
17 |     "react": "^16.13.1",
18 |     "react-dom": "^16.13.1",
19 |     "react-range": "^1.6.7",
20 |     "react-scripts": "3.4.1",
21 |     "styled-components": "^5.1.1",
22 |     "typescript": "^3.7.5"
23 |   },
24 |   "scripts": {
25 |     "start": "react-scripts --openssl-legacy-provider start",
26 |     "build": "react-scripts --openssl-legacy-provider build",
27 |     "test": "react-scripts test",
28 |     "eject": "react-scripts eject",
29 |     "predeploy": "npm run build",
30 |     "deploy": "gh-pages -d build"
31 |   },
32 |   "eslintConfig": {
33 |     "extends": "react-app"
34 |   },
35 |   "browserslist": {
36 |     "production": [
37 |       ">0.2%",
38 |       "not dead",
39 |       "not op_mini all"
40 |     ],
41 |     "development": [
42 |       "last 1 chrome version",
43 |       "last 1 firefox version",
44 |       "last 1 safari version"
45 |     ]
46 |   },
47 |   "devDependencies": {
48 |     "@types/react-rangeslider": "^2.2.2",
49 |     "gh-pages": "^3.0.0"
50 |   }
51 | }
52 | 


--------------------------------------------------------------------------------
/src/components/topics/Topics.tsx:
--------------------------------------------------------------------------------
 1 | import React, { ReactElement } from "react";
 2 | import styled from "styled-components";
 3 | import Tag from "./Tag";
 4 | import { getTags } from "../../services/data";
 5 | import Row from "../common/Row";
 6 | 
 7 | interface Props {
 8 |   selectedTopics: Array<string>;
 9 |   setSelectedTopics: Function;
10 | }
11 | 
12 | const Container = styled.div`
13 |   max-width: 650px;
14 |   min-width: 100px;
15 |   border: lightgray solid 1px;
16 |   border-radius: 10px;
17 |   margin: 10px;
18 |   margin-top: 5px;
19 |   padding: 10px;
20 |   display: block;
21 | `;
22 | 
23 | const tags: Array<string> = getTags();
24 | 
25 | const Topics: React.FC<Props> = ({
26 |   selectedTopics,
27 |   setSelectedTopics,
28 | }: Props): ReactElement => {
29 |   const handleTopicAddition = (selected: boolean, topic: string) => {
30 |     let newSelectedTopics: Array<string>;
31 |     if (selected) {
32 |       newSelectedTopics = selectedTopics.filter((val: string) => val !== topic);
33 |     } else {
34 |       newSelectedTopics = selectedTopics.concat(topic);
35 |     }
36 | 
37 |     setSelectedTopics(newSelectedTopics);
38 |   };
39 | 
40 |   return (
41 |     <Row>
42 |       <Container>
43 |         {tags.map((val: string) => {
44 |           const selected: boolean = selectedTopics.includes(val);
45 |           return (
46 |             <Tag
47 |               key={val}
48 |               selected={selected}
49 |               content={val}
50 |               onClick={handleTopicAddition}
51 |             ></Tag>
52 |           );
53 |         })}
54 |       </Container>
55 |     </Row>
56 |   );
57 | };
58 | 
59 | export default Topics;
60 | 


--------------------------------------------------------------------------------
/src/components/randomize-button/RandomizeButton.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import styled from 'styled-components';
 3 | import LoadingIndicator from './LoadingIndicator';
 4 | import {images} from '../../assets';
 5 | 
 6 | interface Props {
 7 |   isLoading: boolean;
 8 |   onClick: Function;
 9 | }
10 | 
11 | const StyledButton = styled.div<Props>`
12 |   padding: 2px;
13 |   width: 120px;
14 |   height: 35px;
15 |   display: flex;
16 |   justify-content: space-evenly;
17 |   align-items: center;
18 |   background-color: ${(props) => (props.isLoading ? 'white' : '#f7b708')};
19 |   color: white;
20 |   font-weight: 600;
21 |   border-radius: 6px;
22 |   user-select: none;
23 |   cursor: pointer;
24 |   transition-duration: 0.3s;
25 | 
26 |   &:hover {
27 |     background-color: ${(props) => (props.isLoading ? 'white' : '#33ac71')};
28 |   }
29 | `;
30 | 
31 | const LoopIcon = images.loopIcon;
32 | const StyledLoopIcon = styled(LoopIcon)`
33 |   height: 25px;
34 |   width: 25px;
35 |   fill: white;
36 | `;
37 | 
38 | const RandomizeButton: React.FC<Props> = (props: Props): ReactElement => {
39 |   return (
40 |     <StyledButton
41 |       isLoading={props.isLoading}
42 |       onClick={() => {
43 |         if (props.isLoading) return;
44 |         props.onClick();
45 |       }}
46 |     >
47 |       {props.isLoading ? (
48 |         <LoadingIndicator></LoadingIndicator>
49 |       ) : (
50 |         <React.Fragment>
51 |           <StyledLoopIcon></StyledLoopIcon>
52 |           <div>Randomize</div>
53 |         </React.Fragment>
54 |       )}
55 |     </StyledButton>
56 |   );
57 | };
58 | 
59 | RandomizeButton.defaultProps = {
60 |   isLoading: false,
61 | };
62 | 
63 | export default RandomizeButton;
64 | 


--------------------------------------------------------------------------------
/src/components/options/Options.tsx:
--------------------------------------------------------------------------------
 1 | import React, { ReactElement, useState } from "react";
 2 | import Slider from "../slider/Slider";
 3 | import { minRating, maxRating } from "../../services/data";
 4 | import RandomizeButton from "../randomize-button/RandomizeButton";
 5 | import styled from "styled-components";
 6 | import LogicalOperator from "../../models/LogicalOperator";
 7 | import OptionsButton from "../options-button";
 8 | import Row from "../common/Row";
 9 | 
10 | interface Props {
11 |   onRandomize: Function;
12 |   onOperatorSelect: (operator: LogicalOperator) => void;
13 |   operator: LogicalOperator;
14 | }
15 | 
16 | const Container = styled.div`
17 |   display: flex;
18 |   justify-content: center;
19 |   align-items: center;
20 |   flex-direction: column;
21 | `;
22 | 
23 | const operators: LogicalOperator[] = ["AND", "OR"];
24 | 
25 | const Options: React.FC<Props> = (props: Props): ReactElement => {
26 |   const [rating, setRating] = useState<{ min: number; max: number }>({
27 |     min: minRating,
28 |     max: maxRating,
29 |   });
30 |   const [isLoading, setIsLoading] = useState<boolean>(false);
31 | 
32 |   const randomizeProblem = async () => {
33 |     setIsLoading(true);
34 |     await props.onRandomize(rating);
35 |     setIsLoading(false);
36 |   };
37 |   return (
38 |     <Container>
39 |       <Row>
40 |         {operators.map((value) => (
41 |           <OptionsButton
42 |             opertator={value}
43 |             onClick={props.onOperatorSelect}
44 |             isSelected={props.operator === value}
45 |           />
46 |         ))}
47 |       </Row>
48 |       <Slider
49 |         minRating={rating.min}
50 |         maxRating={rating.max}
51 |         onChange={setRating}
52 |       ></Slider>
53 |       <RandomizeButton
54 |         isLoading={isLoading}
55 |         onClick={randomizeProblem}
56 |       ></RandomizeButton>
57 |     </Container>
58 |   );
59 | };
60 | 
61 | export default Options;
62 | 


--------------------------------------------------------------------------------
/src/components/problems-section/ProblemsSection.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement, useEffect} from 'react';
 2 | import ProblemCard from './ProblemCard';
 3 | import {ProblemStatistics} from '../../models/ProblemStatistics';
 4 | import {Problem} from '../../models/Problem';
 5 | import styled from 'styled-components';
 6 | import EmptySection from './EmptySection';
 7 | import Row from '../common/Row';
 8 | 
 9 | interface Props {
10 |   problemsList: Array<{problem: Problem; problemStatistics: ProblemStatistics}>;
11 | }
12 | 
13 | const StyleProblemsSection = styled.div`
14 |   margin-top: 20px;
15 |   height: 300px;
16 |   width: 500px;
17 |   overflow-y: scroll;
18 |   scrollbar-color: lightgray white;
19 |   scrollbar-width: thin;
20 | 
21 |   &::-webkit-scrollbar {
22 |     width: 8px;
23 |   }
24 | 
25 |   &::-webkit-scrollbar-track {
26 |     background-color: white;
27 |   }
28 | 
29 |   &::-webkit-scrollbar-thumb {
30 |     background-color: lightgray;
31 |     border-radius: 5px;
32 |   }
33 | 
34 |   @media screen and (max-width: 600px) {
35 |     width: 400px;
36 |   }
37 | `;
38 | 
39 | const ProblemsSection: React.FC<Props> = (props: Props): ReactElement => {
40 |   const problemsList = props.problemsList;
41 |   let wrapperRef: HTMLDivElement | null = null;
42 | 
43 |   useEffect(() => {
44 |     if (!wrapperRef) return;
45 | 
46 |     wrapperRef.scrollTo(0, 0);
47 |   }, [problemsList, wrapperRef]);
48 | 
49 |   return (
50 |     <Row>
51 |       <StyleProblemsSection ref={(ref) => (wrapperRef = ref)}>
52 |         {problemsList.length === 0 ? (
53 |           <EmptySection></EmptySection>
54 |         ) : (
55 |           problemsList
56 |             .map((val, index) => {
57 |               return (
58 |                 <ProblemCard
59 |                   key={index}
60 |                   problem={val.problem}
61 |                   problemStatistics={val.problemStatistics}
62 |                 ></ProblemCard>
63 |               );
64 |             })
65 |             .reverse()
66 |         )}
67 |       </StyleProblemsSection>
68 |     </Row>
69 |   );
70 | };
71 | 
72 | export default ProblemsSection;
73 | 


--------------------------------------------------------------------------------
/src/components/snackbar/Snackbar.tsx:
--------------------------------------------------------------------------------
 1 | import React, { ReactElement, useEffect } from "react";
 2 | import styled from "styled-components";
 3 | import CancelButton from "./CancelButton";
 4 | 
 5 | interface SnackbarProps {
 6 |   visible: boolean;
 7 |   type?: string;
 8 |   content: string;
 9 |   onCancel: Function;
10 |   timeout: number;
11 | }
12 | 
13 | const StyledSnackbar = styled.div<SnackbarProps>`
14 |   background-color: ${(props) => (props.type === "error" ? "red" : "green")};
15 |   color: white;
16 |   opacity: ${(props) => (props.visible ? "0.9" : "0")};
17 |   visibility: ${(props) => (props.visible ? "none" : "hidden")};
18 |   position: fixed;
19 |   bottom: ${(props) => (props.visible ? "2.5vh" : "0")};
20 |   left: 0;
21 |   right: 0;
22 |   margin: auto;
23 |   padding-left: 15px;
24 |   padding-right: 15px;
25 |   width: fit-content;
26 |   height: 55px;
27 |   border-radius: 30px;
28 |   font-weight: 600;
29 |   font-size: 14px;
30 |   display: flex;
31 |   justify-content: space-evenly;
32 |   align-items: center;
33 |   user-select: none;
34 |   transition-duration: 0.5s;
35 | `;
36 | 
37 | const Snackbar: React.FC<SnackbarProps> = (
38 |   props: SnackbarProps
39 | ): ReactElement => {
40 |   const onCancel: Function = props.onCancel;
41 |   const visible: boolean = props.visible;
42 |   const timeout: number = props.timeout;
43 | 
44 |   useEffect(() => {
45 |     if (visible) {
46 |       const makeInvisible = setTimeout(() => onCancel(), timeout);
47 |       return () => clearTimeout(makeInvisible);
48 |     }
49 |   }, [visible, onCancel, timeout]);
50 | 
51 |   return (
52 |     <StyledSnackbar {...props}>
53 |       <div
54 |         style={{
55 |           maxLines: 1,
56 |           textOverflow: "ellipsis",
57 |           whiteSpace: "nowrap",
58 |           overflow: "hidden",
59 |           display: "block",
60 |           flex: "5",
61 |         }}
62 |       >
63 |         {props.content}
64 |       </div>
65 |       <CancelButton onClick={onCancel}></CancelButton>
66 |     </StyledSnackbar>
67 |   );
68 | };
69 | 
70 | Snackbar.defaultProps = {
71 |   type: "error",
72 | };
73 | 
74 | export default Snackbar;
75 | 


--------------------------------------------------------------------------------
/src/components/problems-section/ProblemCard.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import styled, {keyframes} from 'styled-components';
 3 | import {Problem} from '../../models/Problem';
 4 | import {ProblemStatistics} from '../../models/ProblemStatistics';
 5 | import {images} from '../../assets';
 6 | 
 7 | interface CardProps {
 8 |   problem: Problem;
 9 |   problemStatistics: ProblemStatistics;
10 | }
11 | 
12 | interface CellProps {
13 |   flex: number;
14 | }
15 | 
16 | const EnterAnim = keyframes`
17 | from{
18 |   margin-left: -50%;
19 | }
20 | to{
21 |   margin-left: 20px: 
22 | }
23 | `;
24 | 
25 | const StyledProblemCard = styled.div`
26 |   width: 90%;
27 |   min-height: 80px;
28 |   background-color: #f8f8f8;
29 |   margin: 20px;
30 |   display: flex;
31 |   justify-content: space-evenly;
32 |   align-items: center;
33 |   border-radius: 10px;
34 |   cursor: pointer;
35 |   user-select: none;
36 |   transition-duration: 0.3s;
37 |   animation: ${EnterAnim} 0.5s cubic-bezier(0.2, 0, 0, 1.2);
38 | 
39 |   &:hover {
40 |     background-color: lightgray;
41 |   }
42 | `;
43 | 
44 | const Cell = styled.div<CellProps>`
45 |   flex: ${(props) => props.flex};
46 |   display: flex;
47 |   justify-content: center;
48 |   align-items: center;
49 | `;
50 | 
51 | const ProblemCard: React.FC<CardProps> = (props: CardProps): ReactElement => {
52 |   const problem: Problem = props.problem;
53 |   const problemStats: ProblemStatistics = props.problemStatistics;
54 |   const baseUrl: string = 'https://codeforces.com/problemset/problem';
55 | 
56 |   const handleUrlRedirect = () => {
57 |     const redirectUrl: string = `${baseUrl}/${problem.contestId}/${problem.index}`;
58 |     window.open(redirectUrl, '_blank');
59 |   };
60 | 
61 |   return (
62 |     <StyledProblemCard
63 |       onClick={() => {
64 |         handleUrlRedirect();
65 |       }}
66 |     >
67 |       <Cell flex={1}>{`${problemStats.contestId}${problemStats.index}`}</Cell>
68 |       <Cell flex={2}>{`${problem.name}`}</Cell>
69 |       <Cell flex={1}>{`${
70 |         problem.rating === undefined ? 0 : problem.rating
71 |       }`}</Cell>
72 |       <Cell flex={1}>
73 |         <img src={images.userIcon} alt=""></img>
74 |         <span>{`x${problemStats.solvedCount}`}</span>
75 |       </Cell>
76 |     </StyledProblemCard>
77 |   );
78 | };
79 | 
80 | export default ProblemCard;
81 | 


--------------------------------------------------------------------------------
/src/components/slider/Slider.tsx:
--------------------------------------------------------------------------------
 1 | import React, {ReactElement} from 'react';
 2 | import {Range, getTrackBackground} from 'react-range';
 3 | import styled from 'styled-components';
 4 | import {minRating, maxRating} from '../../services/data';
 5 | 
 6 | interface TrackProps {
 7 |   values: Array<number>;
 8 |   min: number;
 9 |   max: number;
10 | }
11 | 
12 | interface SliderProps {
13 |   minRating: number;
14 |   maxRating: number;
15 |   onChange: Function;
16 | }
17 | 
18 | const Container = styled.div`
19 |   display: flex;
20 |   justify-content: center;
21 |   align-items: center;
22 |   flex-direction: column;
23 |   width: 250px;
24 |   margin: 20px;
25 | `;
26 | 
27 | const Track = styled.div<TrackProps>`
28 |   background: ${(props) =>
29 |     getTrackBackground({
30 |       values: props.values,
31 |       colors: ['#ccc', '#198FCE', '#ccc'],
32 |       min: props.min,
33 |       max: props.max,
34 |     })};
35 |   width: 100%;
36 |   height: 2px;
37 |   margin-bottom: 10px;
38 | `;
39 | 
40 | const Thumb = styled.div<{index: number}>`
41 |   display: flex;
42 |   justify-content: center;
43 |   align-items: center;
44 |   background-color: ${(props) => (props.index === 0 ? '#F8CC52' : '#BA1D25')};
45 |   height: 16px;
46 |   width: 16px;
47 |   border-radius: 16px;
48 | `;
49 | 
50 | const Indicator = styled.div<{isDragged: boolean}>`
51 |   height: 8px;
52 |   width: 8px;
53 |   border-radius: 6px;
54 |   background-color: ${(props) => (props.isDragged ? '#198FCE' : 'white')};
55 | `;
56 | 
57 | const Slider: React.FC<SliderProps> = (props: SliderProps): ReactElement => {
58 |   const values = [props.minRating, props.maxRating];
59 |   return (
60 |     <Container>
61 |       <Range
62 |         step={100}
63 |         min={minRating}
64 |         max={maxRating}
65 |         values={values}
66 |         onChange={(values) => props.onChange({min: values[0], max: values[1]})}
67 |         renderTrack={({props, children}) => (
68 |           <Track min={minRating} max={maxRating} values={values} {...props}>
69 |             {children}
70 |           </Track>
71 |         )}
72 |         renderThumb={({props, isDragged, index}) => {
73 |           return (
74 |             <Thumb {...props} index={index}>
75 |               <Indicator isDragged={isDragged}></Indicator>
76 |             </Thumb>
77 |           );
78 |         }}
79 |       />
80 |       <div>{`Rating: ${values[0]} - ${values[1]}`}</div>
81 |     </Container>
82 |   );
83 | };
84 | 
85 | export default Slider;
86 | 


--------------------------------------------------------------------------------
/src/services/problems.ts:
--------------------------------------------------------------------------------
 1 | import axios, { AxiosRequestConfig } from "axios";
 2 | import { Problem } from "../models/Problem";
 3 | import { ProblemStatistics } from "../models/ProblemStatistics";
 4 | import { getTags } from "./data";
 5 | import LogicalOperator from "../models/LogicalOperator";
 6 | 
 7 | const baseUrl: string = "https://codeforces.com/api/problemset.problems";
 8 | 
 9 | function getRandomInt(max: number): number {
10 |   return Math.floor(Math.random() * Math.floor(max));
11 | }
12 | 
13 | // codeforces API only allows for AND operations
14 | // OR operations are implemented manually
15 | async function getProblems(
16 |   topics: string[],
17 |   operator: LogicalOperator,
18 | ): Promise<[Problem[], ProblemStatistics[]]> {
19 |   let problems: Problem[] = [];
20 |   let problemsStatistics: ProblemStatistics[] = [];
21 | 
22 |   if (operator === "AND") {
23 |     const tags: string = topics.reduce(
24 |       (prev: string, current: string, _: number) => {
25 |         return prev + ";" + current;
26 |       },
27 |     );
28 | 
29 |     const response = await axios.get(baseUrl, {
30 |       params: {
31 |         tags: tags,
32 |       },
33 |     });
34 | 
35 |     if (response.data.status !== "OK") throw new Error("Invalid combination");
36 | 
37 |     problems = response.data.result.problems as Array<Problem>;
38 |     problemsStatistics = response.data.result
39 |       .problemStatistics as Array<ProblemStatistics>;
40 |   } else if (operator === "OR") {
41 |     for (const topic of topics) {
42 |       const response = await axios.get(baseUrl, {
43 |         params: {
44 |           tags: topic,
45 |         },
46 |       });
47 | 
48 |       if (response.data.status !== "OK") throw new Error("Invalid combination");
49 | 
50 |       problems = problems.concat(response.data.result.problems as Problem);
51 |       problemsStatistics = problemsStatistics.concat(
52 |         response.data.result.problemStatistics as ProblemStatistics,
53 |       );
54 |     }
55 |   }
56 | 
57 |   return [problems, problemsStatistics];
58 | }
59 | 
60 | export async function getRandomProblem(
61 |   topics: Array<string>,
62 |   ratings: { min: number; max: number },
63 |   operator: LogicalOperator,
64 | ): Promise<{ problem: Problem; problemStatistics: ProblemStatistics }> {
65 |   if (topics.length === 0)
66 |     topics = topics.concat(getTags()[getRandomInt(getTags().length)]);
67 | 
68 |   const [problems, problemsStatistics] = await getProblems(topics, operator);
69 | 
70 |   let filteredProblems: Array<number> = [];
71 |   problems.forEach((val: Problem, index: number) => {
72 |     if (!val.rating) val.rating = ratings.min;
73 | 
74 |     if (val.rating >= ratings.min && val.rating <= ratings.max)
75 |       filteredProblems = filteredProblems.concat(index);
76 |   });
77 | 
78 |   if (filteredProblems.length === 0)
79 |     throw new Error(
80 |       `No problems found for the entered combination. Try another combination.`,
81 |     );
82 | 
83 |   const probIndex: number =
84 |     filteredProblems[getRandomInt(filteredProblems.length)];
85 |   return {
86 |     problem: problems[probIndex],
87 |     problemStatistics: problemsStatistics[probIndex],
88 |   };
89 | }
90 | 


--------------------------------------------------------------------------------
/src/components/home/Home.tsx:
--------------------------------------------------------------------------------
  1 | import React, { ReactElement, useState } from "react";
  2 | import { Problem } from "../../models/Problem";
  3 | import { ProblemStatistics } from "../../models/ProblemStatistics";
  4 | import Header from "../header/Header";
  5 | import Topics from "../topics/Topics";
  6 | import Snackbar from "../snackbar/Snackbar";
  7 | import ProblemsSection from "../problems-section/ProblemsSection";
  8 | import { getRandomProblem } from "../../services/problems";
  9 | import {
 10 |   setProblemsListToStorage,
 11 |   clearProblemsList,
 12 | } from "../../services/storage";
 13 | import ClearButton from "../clear-button/ClearButton";
 14 | import Options from "../options/Options";
 15 | import styled from "styled-components";
 16 | import Footer from "../footer/Footer";
 17 | import LogicalOperator from "../../models/LogicalOperator";
 18 | 
 19 | interface Props {
 20 |   initialProblemsList: Array<{
 21 |     problem: Problem;
 22 |     problemStatistics: ProblemStatistics;
 23 |   }>;
 24 | }
 25 | 
 26 | const Container = styled.div`
 27 |   display: flex;
 28 |   justify-content: space-between;
 29 |   align-items: center;
 30 |   flex-direction: column;
 31 |   min-height: 100vh;
 32 |   width: 100%;
 33 | `;
 34 | 
 35 | const Home: React.FC<Props> = (props: Props): ReactElement => {
 36 |   const [errContent, setErrContent] = useState<string>("");
 37 |   const [visible, setVisible] = useState<boolean>(false);
 38 |   const [selectedTopics, setSelectedTopics] = useState<Array<string>>([]);
 39 |   const [operator, setOperator] = useState<LogicalOperator>("AND");
 40 |   const [problemsList, setProblemsList] = useState<
 41 |     Array<{ problem: Problem; problemStatistics: ProblemStatistics }>
 42 |   >(props.initialProblemsList);
 43 | 
 44 |   const triggerError: (content: string) => void = (content: string) => {
 45 |     setErrContent(content);
 46 |     setVisible(true);
 47 |   };
 48 | 
 49 |   const randomizeProblem: (ratings: {
 50 |     min: number;
 51 |     max: number;
 52 |   }) => void = async (ratings: { min: number; max: number }): Promise<void> => {
 53 |     try {
 54 |       const newProblem = await getRandomProblem(
 55 |         selectedTopics,
 56 |         ratings,
 57 |         operator,
 58 |       );
 59 |       const newProblemsList = problemsList.concat(newProblem);
 60 |       setProblemsListToStorage(newProblemsList);
 61 |       setProblemsList(newProblemsList);
 62 |     } catch (e) {
 63 |       triggerError(e.message);
 64 |     }
 65 |   };
 66 | 
 67 |   const clearProblemsHistory = (): void => {
 68 |     clearProblemsList();
 69 |     setProblemsList([]);
 70 |   };
 71 | 
 72 |   return (
 73 |     <Container>
 74 |       <Header></Header>
 75 | 
 76 |       <Topics
 77 |         selectedTopics={selectedTopics}
 78 |         setSelectedTopics={setSelectedTopics}
 79 |       ></Topics>
 80 |       <Options
 81 |         operator={operator}
 82 |         onOperatorSelect={(value: LogicalOperator) => setOperator(value)}
 83 |         onRandomize={randomizeProblem}
 84 |       ></Options>
 85 |       <ProblemsSection problemsList={problemsList}></ProblemsSection>
 86 | 
 87 |       <ClearButton
 88 |         onClick={clearProblemsHistory}
 89 |         disabled={problemsList.length === 0}
 90 |       ></ClearButton>
 91 | 
 92 |       <Footer></Footer>
 93 | 
 94 |       <Snackbar
 95 |         type="error"
 96 |         content={errContent}
 97 |         visible={visible}
 98 |         timeout={2000}
 99 |         onCancel={() => setVisible(false)}
100 |       ></Snackbar>
101 |     </Container>
102 |   );
103 | };
104 | 
105 | export default Home;
106 | 


--------------------------------------------------------------------------------
/src/serviceWorker.ts:
--------------------------------------------------------------------------------
  1 | // This optional code is used to register a service worker.
  2 | // register() is not called by default.
  3 | 
  4 | // This lets the app load faster on subsequent visits in production, and gives
  5 | // it offline capabilities. However, it also means that developers (and users)
  6 | // will only see deployed updates on subsequent visits to a page, after all the
  7 | // existing tabs open on the page have been closed, since previously cached
  8 | // resources are updated in the background.
  9 | 
 10 | // To learn more about the benefits of this model and instructions on how to
 11 | // opt-in, read https://bit.ly/CRA-PWA
 12 | 
 13 | const isLocalhost = Boolean(
 14 |   window.location.hostname === 'localhost' ||
 15 |     // [::1] is the IPv6 localhost address.
 16 |     window.location.hostname === '[::1]' ||
 17 |     // 127.0.0.0/8 are considered localhost for IPv4.
 18 |     window.location.hostname.match(
 19 |       /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
 20 |     )
 21 | );
 22 | 
 23 | type Config = {
 24 |   onSuccess?: (registration: ServiceWorkerRegistration) => void;
 25 |   onUpdate?: (registration: ServiceWorkerRegistration) => void;
 26 | };
 27 | 
 28 | export function register(config?: Config) {
 29 |   if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
 30 |     // The URL constructor is available in all browsers that support SW.
 31 |     const publicUrl = new URL(
 32 |       process.env.PUBLIC_URL,
 33 |       window.location.href
 34 |     );
 35 |     if (publicUrl.origin !== window.location.origin) {
 36 |       // Our service worker won't work if PUBLIC_URL is on a different origin
 37 |       // from what our page is served on. This might happen if a CDN is used to
 38 |       // serve assets; see https://github.com/facebook/create-react-app/issues/2374
 39 |       return;
 40 |     }
 41 | 
 42 |     window.addEventListener('load', () => {
 43 |       const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
 44 | 
 45 |       if (isLocalhost) {
 46 |         // This is running on localhost. Let's check if a service worker still exists or not.
 47 |         checkValidServiceWorker(swUrl, config);
 48 | 
 49 |         // Add some additional logging to localhost, pointing developers to the
 50 |         // service worker/PWA documentation.
 51 |         navigator.serviceWorker.ready.then(() => {
 52 |           console.log(
 53 |             'This web app is being served cache-first by a service ' +
 54 |               'worker. To learn more, visit https://bit.ly/CRA-PWA'
 55 |           );
 56 |         });
 57 |       } else {
 58 |         // Is not localhost. Just register service worker
 59 |         registerValidSW(swUrl, config);
 60 |       }
 61 |     });
 62 |   }
 63 | }
 64 | 
 65 | function registerValidSW(swUrl: string, config?: Config) {
 66 |   navigator.serviceWorker
 67 |     .register(swUrl)
 68 |     .then(registration => {
 69 |       registration.onupdatefound = () => {
 70 |         const installingWorker = registration.installing;
 71 |         if (installingWorker == null) {
 72 |           return;
 73 |         }
 74 |         installingWorker.onstatechange = () => {
 75 |           if (installingWorker.state === 'installed') {
 76 |             if (navigator.serviceWorker.controller) {
 77 |               // At this point, the updated precached content has been fetched,
 78 |               // but the previous service worker will still serve the older
 79 |               // content until all client tabs are closed.
 80 |               console.log(
 81 |                 'New content is available and will be used when all ' +
 82 |                   'tabs for this page are closed. See https://bit.ly/CRA-PWA.'
 83 |               );
 84 | 
 85 |               // Execute callback
 86 |               if (config && config.onUpdate) {
 87 |                 config.onUpdate(registration);
 88 |               }
 89 |             } else {
 90 |               // At this point, everything has been precached.
 91 |               // It's the perfect time to display a
 92 |               // "Content is cached for offline use." message.
 93 |               console.log('Content is cached for offline use.');
 94 | 
 95 |               // Execute callback
 96 |               if (config && config.onSuccess) {
 97 |                 config.onSuccess(registration);
 98 |               }
 99 |             }
100 |           }
101 |         };
102 |       };
103 |     })
104 |     .catch(error => {
105 |       console.error('Error during service worker registration:', error);
106 |     });
107 | }
108 | 
109 | function checkValidServiceWorker(swUrl: string, config?: Config) {
110 |   // Check if the service worker can be found. If it can't reload the page.
111 |   fetch(swUrl, {
112 |     headers: { 'Service-Worker': 'script' }
113 |   })
114 |     .then(response => {
115 |       // Ensure service worker exists, and that we really are getting a JS file.
116 |       const contentType = response.headers.get('content-type');
117 |       if (
118 |         response.status === 404 ||
119 |         (contentType != null && contentType.indexOf('javascript') === -1)
120 |       ) {
121 |         // No service worker found. Probably a different app. Reload the page.
122 |         navigator.serviceWorker.ready.then(registration => {
123 |           registration.unregister().then(() => {
124 |             window.location.reload();
125 |           });
126 |         });
127 |       } else {
128 |         // Service worker found. Proceed as normal.
129 |         registerValidSW(swUrl, config);
130 |       }
131 |     })
132 |     .catch(() => {
133 |       console.log(
134 |         'No internet connection found. App is running in offline mode.'
135 |       );
136 |     });
137 | }
138 | 
139 | export function unregister() {
140 |   if ('serviceWorker' in navigator) {
141 |     navigator.serviceWorker.ready
142 |       .then(registration => {
143 |         registration.unregister();
144 |       })
145 |       .catch(error => {
146 |         console.error(error.message);
147 |       });
148 |   }
149 | }
150 | 


--------------------------------------------------------------------------------