mharj/mharj-jwt-util

import * as fs from 'fs';
import {type CertRecords, isCertRecords} from '../interfaces/CertRecords';
import {type ILoggerLike, type ISetOptionalLogger} from '@avanio/logger-like';
import {CertCache} from './CertCache';

interface IProps {
    fileName?: string;
    pretty?: boolean;
}

const initialCerts: CertRecords = {
    _ts: 0,
    certs: {},
};

export class FileCertCache extends CertCache implements ISetOptionalLogger {
    private file: string;
    private pretty: boolean;
    private logger: ILoggerLike | undefined;

    constructor({fileName, pretty}: IProps = {}, logger?: ILoggerLike) {
        super();
        this.logger = logger;
        this.logger?.info('jwt-util FileCertCache registered');
        this.file = fileName ?? './certCache.json';
        this.pretty = pretty ?? false;
    }

    public setLogger(logger: ILoggerLike | undefined) {
        this.logger = logger;
    }

    protected async init(): Promise<void> {
        this.logger?.debug('jwt-util FileCertCache:init()');
        // write empty record file if file not exists
        if (!fs.existsSync(this.file)) {
            await fs.promises.writeFile(this.file, JSON.stringify(initialCerts, undefined, this.pretty ? 2 : undefined));
        }
        // watch file changes
        fs.watch(this.file, async (eventType) => {
            if (this.updateCallback && eventType === 'change') {
                this.logger?.debug('jwt-util FileCertCache:watch ()=> change');
                const data = JSON.parse((await fs.promises.readFile(this.file)).toString()) as CertRecords;
                this.handleUpdate(data);
            }
        });
    }

    protected async load(): Promise<CertRecords> {
        this.logger?.debug('jwt-util FileCertCache:load()');
        if (!fs.existsSync(this.file)) {
            return initialCerts;
        }
        try {
            const data = JSON.parse((await fs.promises.readFile(this.file)).toString()) as unknown;
            // validate JSON cert records or use initialCerts
            return isCertRecords(data) ? data : initialCerts;
        } catch (_err) {
            return initialCerts;
        }
    }

    protected save(certs: CertRecords): Promise<void> {
        this.logger?.debug('jwt-util FileCertCache:save()');
        return fs.promises.writeFile(this.file, JSON.stringify(certs, undefined, this.pretty ? 2 : undefined));
    }
}