TyrealGray/Qin.js

//@flow
import Datastore from 'nedb';

type DBClientPropsType = {
    name: string,
};

class DBClient {
    _db: Datastore;
    _name: string;

    constructor(props: DBClientPropsType) {
        this._name = props.name;
        this._db = new Datastore({
            filename: `./${this._name}`,
            autoload: true,
        });
    }

    async _promiseDBQuery(
        dbCallback: (Object, (...arg: any) => any) => void,
        query: Object,
    ): Promise<any> {
        return new Promise((resolve, reject) => {
            dbCallback(query, (err, docs) => {
                if (err) {
                    return reject(err);
                }

                return resolve(docs);
            });
        });
    }

    async _get(query: Object): Promise<any> {
        return await this._promiseDBQuery((q, c) => this._db.find(q, c), query);
    }

    async _getOne(query: Object): Promise<any> {
        return await this._promiseDBQuery(
            (q, c) => this._db.findOne(q, c),
            query,
        );
    }

    async _upsert(query: Object, content: Object): Promise<any> {
        return new Promise((resolve, reject) => {
            this._db.update(
                query,
                { $set: content },
                { upsert: true },
                (err, numReplaced, affectedDocuments) => {
                    if (err) {
                        return reject(err);
                    }

                    return resolve(affectedDocuments);
                },
            );
        });
    }

    async query(query: Object): Promise<Object> {
        return await this._get(query);
    }

    async queryOne(query: Object): Promise<Object> {
        return await this._getOne(query);
    }

    async update(query: Object, content: Object): Promise<any> {
        return await this._upsert(query, content);
    }
}

export default DBClient;