oneuptime/CommonServer/Services/ShortLinkService.ts

import PostgresDatabase from '../Infrastructure/PostgresDatabase';
import Model from 'Model/Models/ShortLink';
import DatabaseService from './DatabaseService';
import { OnCreate } from '../Types/Database/Hooks';
import CreateBy from '../Types/Database/CreateBy';
import Text from 'Common/Types/Text';
import URL from 'Common/Types/API/URL';
import { LinkShortenerRoute } from 'Common/ServiceRoute';
import DatabaseConfig from '../DatabaseConfig';
import Route from 'Common/Types/API/Route';
import Hostname from 'Common/Types/API/Hostname';
import Protocol from 'Common/Types/API/Protocol';

export class Service extends DatabaseService<Model> {
    public constructor(postgresDatabase?: PostgresDatabase) {
        super(Model, postgresDatabase);
        this.hardDeleteItemsOlderThanInDays('createdAt', 3); //expire links in 3 days.
    }

    protected override async onBeforeCreate(
        createBy: CreateBy<Model>
    ): Promise<OnCreate<Model>> {
        createBy.data.shortId = Text.generateRandomText(8);

        return { createBy: createBy, carryForward: [] };
    }

    public async saveShortLinkFor(url: URL): Promise<Model> {
        const model: Model = new Model();
        model.link = url;
        return await this.create({ data: model, props: { isRoot: true } });
    }

    public async getShortenedUrl(model: Model): Promise<URL> {
        const host: Hostname = await DatabaseConfig.getHost();
        const httpProtocol: Protocol = await DatabaseConfig.getHttpProtocol();
        return new URL(
            httpProtocol,
            host,
            new Route(LinkShortenerRoute.toString()).addRoute(
                '/' + model.shortId?.toString()
            )
        );
    }

    public async getShortLinkFor(shortLinkId: string): Promise<Model | null> {
        return await this.findOneBy({
            query: {
                shortId: shortLinkId,
            },
            select: {
                _id: true,
                link: true,
            },
            props: {
                isRoot: true,
            },
        });
    }
}

export default new Service();