Audit.ts

import { values } from 'lodash';
import { format } from 'util';

export type AuditEntry = {
    action: AuditAction,
    type: string,
    id: string | number,
};

type InternalAuditEntry = {
    time: string,
} & AuditEntry;

export enum AuditAction {
    Read = 'read',
    Write = 'write',
    Remove = 'remove',
    Create = 'create',
}

export class Audit {
    entries: { [key: string]: InternalAuditEntry } = {};

    constructor(
        private requestId?: string,
        private principal?: string,
        private deviceId?: string,
    ) {
    }

    public async clear() {
        this.entries = {};
    }

    public async add(entry: AuditEntry) {
        const type = entry.type.replace(/ /ig, '_').toLocaleLowerCase();
        const key = `${type}:${entry.id}`;

        if (this.entries[key] != null) {
            // we don't override the time if it has been access more than once
            return;
        }

        this.entries[key] = {
            ...entry,
            type,
            time: new Date().toISOString(),
        };
    }

    /**
     * We don't want lambda to play with our log messages
     */
    public async dump() {
        values(this.entries).forEach((e) => {
            process.stdout.write(
                // tslint:disable-next-line: prefer-template
                format('AUDIT', e.time, this.requestId, this.deviceId, this.principal, e.action, e.type, e.id) + '\n',
            );
        });

        this.clear();
    }
}