OpenMediaCenter/src/pages/RandomPage/RandomPage.tsx

import React from 'react';
import style from './RandomPage.module.css';
import SideBar, {SideBarTitle} from '../../elements/SideBar/SideBar';
import Tag from '../../elements/Tag/Tag';
import PageTitle from '../../elements/PageTitle/PageTitle';
import VideoContainer from '../../elements/VideoContainer/VideoContainer';
import {APINode, callAPI} from '../../utils/Api';
import {TagType} from '../../types/VideoTypes';
import {VideoTypes} from '../../types/ApiTypes';
import {addKeyHandler, removeKeyHandler} from '../../utils/ShortkeyHandler';

interface state {
    videos: VideoTypes.VideoUnloadedType[];
    tags: TagType[];
}

interface GetRandomMoviesType {
    Videos: VideoTypes.VideoUnloadedType[];
    Tags: TagType[];
}

/**
 * Randompage shuffles random viedeopreviews and provides a shuffle btn
 */
class RandomPage extends React.Component<{}, state> {
    readonly LoadNR = 3;

    // random seed to load videos, remains page reload.
    seed = this.genRandInt();

    constructor(props: {}) {
        super(props);

        // get previously stored location from localstorage
        const storedseed = global.localStorage.getItem('randpageseed');
        if (storedseed != null) {
            this.seed = parseInt(storedseed, 10);
        }

        this.state = {
            videos: [],
            tags: []
        };

        this.keypress = this.keypress.bind(this);
    }

    genRandInt(): number {
        return Math.floor(Math.random() * 2147483647) + 1;
    }

    componentDidMount(): void {
        addKeyHandler(this.keypress);

        this.loadShuffledvideos(this.LoadNR);
    }

    componentWillUnmount(): void {
        removeKeyHandler(this.keypress);
    }

    render(): JSX.Element {
        return (
            <div>
                <PageTitle title='Random Videos' subtitle='4pc' />

                <SideBar>
                    <SideBarTitle>Visible Tags:</SideBarTitle>
                    {this.state.tags.map((m) => (
                        <Tag key={m.TagId} tagInfo={m} />
                    ))}
                </SideBar>

                {this.state.videos.length !== 0 ? (
                    <VideoContainer data={this.state.videos}>
                        <div className={style.Shufflebutton}>
                            <button onClick={(): void => this.shuffleclick()} className={style.btnshuffle}>
                                Shuffle
                            </button>
                        </div>
                    </VideoContainer>
                ) : (
                    <div>No Data found!</div>
                )}
            </div>
        );
    }

    /**
     * click handler for shuffle btn
     */
    shuffleclick(): void {
        this.genSeed();
        this.loadShuffledvideos(this.LoadNR);
    }

    genSeed(): void {
        this.seed = this.genRandInt();
        global.localStorage.setItem('randpageseed', this.seed.toString());
    }

    /**
     * load random videos from backend
     * @param nr number of videos to load
     */
    loadShuffledvideos(nr: number): void {
        callAPI<GetRandomMoviesType>(APINode.Video, {action: 'getRandomMovies', Number: nr, Seed: this.seed}, (result) => {
            this.setState({videos: []}); // needed to trigger rerender of main videoview
            this.setState({
                videos: result.Videos,
                tags: result.Tags
            });
        });
    }

    /**
     * key event handling
     * @param event keyevent
     */
    private keypress(event: KeyboardEvent): void {
        // bind s to shuffle
        if (event.key === 's') {
            this.genSeed();
            this.loadShuffledvideos(this.LoadNR);
        }
    }
}

export default RandomPage;