almrooth/ramverk2

'use strict';

/**
* Module handling simple CRUD on MongoDB
*/

const MongoClient = require('mongodb').MongoClient;
const ObjectId = require('mongodb').ObjectId;


/**
* Export module
*
* @param {string} dsn of DB
* @param {string} collection to use
*
* @return {function} The module
*/
module.exports = (dsn, collection) => {
    /**
    * Create and return connection to DB
    *
    * @async
    *
    * @return {object} Connection and collection
    */
    async function connect() {
        try {
            const db    = await MongoClient.connect(dsn);
            const col   = await db.collection(collection);

            return { db, col };
        } catch (error) {
            throw error;
        }
    }


    return {
        /**
        * Get all items in collection
        *
        * @async
        *
        * @return {array} The items in collection
        */
        async index() {
            try {
                const { db, col } = await connect();
                const res = await col.find().toArray();

                await db.close();
                return res;
            } catch (error) {
                throw error;
            }
        },


        /**
        * Insert item
        *
        * @async
        *
        * @param {object} item the item to insert
        *
        * @return {object} Inserted item
        */
        async create(item) {
            try {
                const { db, col } = await connect();

                const res = await col.insertOne(item);

                await db.close();
                return res.ops[0];
            } catch (error) {
                throw error;
            }
        },


        /**
        * Get item by id
        *
        * @async
        *
        * @param {string} id of item
        *
        * @return {object} Requested item
        */
        async read(id) {
            try {
                const { db, col } = await connect();
                const res = await col.findOne({ _id: ObjectId(id)});

                await db.close();
                return res;
            } catch (error) {
                throw error;
            }
        },


        /**
        * Update item by id
        *
        * @async
        *
        * @param {string} id of item
        * @param {object} item keys and values to upadate
        *
        * @return {object} Updated item
        */
        async update(id, item) {
            try {
                const { db, col } = await connect();

                const res = await col.findOneAndUpdate({ _id: ObjectId(id)}, { $set: item });

                await db.close();
                return res;
            } catch (error) {
                throw error;
            }
        },


        /**
        * Delete item by id
        *
        * @async
        *
        * @param {string} id of item
        *
        * @return {object} Deleted item
        */
        async delete(id) {
            try {
                const { db, col } = await connect();

                const res = await col.findOneAndDelete({ _id: ObjectId(id) });

                await db.close();
                return res;
            } catch (error) {
                throw error;
            }
        }
    };
};