mongodbapi.js

const { MongoClient } = require('mongodb');

// Load environment variables from .env file
require('dotenv').config();

// Connection URI for MongoDB
var mongodbUri = 'mongodb://localhost:27017'
if (process.env.MONGODB_URI != undefined) {
    mongodbUri = process.env.MONGODB_URI;
}

// Database name
const dbName = 'newsstack';

// Create a new MongoClient
const mongodbClient = new MongoClient(mongodbUri);

var mongodbconnected = false;
var userscollection = null;

connectMongoDB();

function isMongoDBConnected() {
    return mongodbconnected;
}

async function connectMongoDB() {
    try {
        console.log("Trying to connect to MongoDB", mongodbUri, "..")
        // Connect to the MongoDB server
        await mongodbClient.connect();
    
        // Get a reference to the "newsstack" database
        const db = mongodbClient.db(dbName);
    
        // Create a new "users" collection
        userscollection = db.collection('users');
        mongodbconnected = true;

        console.log("Successfully connected to MongoDB", mongodbUri)
    } catch (error) {
        console.error("ERROR: Could not connect to MongoDB", mongodbUri, dbName, error)
        mongodbconnected = false;
    }
}

function closeMongoDBConnection() {
    if (mongodbconnected){
        // Close the client connection
        mongodbClient.close();
        mongodbconnected = false;
    }
}

async function isUserExisting(sub) {
    if (mongodbconnected) {
        const result = await userscollection.findOne({ _id: sub })

        if (result) {
            console.log("isUserExisting: found user")
            return true;
        } else {
            console.log("isUserExisting: did not find user")
            return false;
        }
    }
}

async function createUser(sub, usr_data) {
    if (mongodbconnected) {
        const currentDate = new Date();
        console.log("creating new user")
        try {
            // Insert a new document into the "users" collection
            const result = await userscollection.insertOne({
                _id: sub,
                lastLogin: currentDate.toString(),
                'user-data': usr_data,
                'ns-data': null,
            });
    
            console.log(`Document created with ID ${result.insertedId}`);
        } catch (err) {
            console.error(err);
        }
    }
}

async function getNewsStacks(sub) {
    if (mongodbconnected) {
        const filter = { _id: sub };
        const user = await userscollection.findOne(filter);
    
        if (user) {
            const ns_data = user['ns-data'];
            return ns_data;
        } else {
            console.log('User with sub ' + sub + ' not found');
        }
    }

    return null;
}

async function updateNewsStacks(sub, ns_data) {
    if (mongodbconnected) {
        const filter = { _id: sub };
        const update = { $set: { 'ns-data': ns_data } };

        const result = await userscollection.updateOne(filter, update);

        if (result.modifiedCount === 1) {
            console.log('ns-data field updated for user with sub ' + sub);
        } else {
            console.log('Error: User with sub ' + sub + ' not found');
        }
    }
}


async function getUserData(sub) {
    if (mongodbconnected) {
        const filter = { _id: sub };
        const user = await userscollection.findOne(filter);

        if (user) {
            const user_data = user['user-data'];
            return user_data;
        } else {
            console.log('User with sub ' + sub + ' not found');
        }
    }

    return null;
}


async function updateUserData(sub, user_data) {
    if (mongodbconnected) {
        if (await isUserExisting(sub)) {
            await createUser(sub, user_data);
        }
        else {
            const filter = { _id: sub };
            const update = { $set: { 'user-data': user_data } };

            const result = await userscollection.updateOne(filter, update);

            if (result.modifiedCount === 1) {
                console.log('user-data field updated for user with sub ' + sub);
            } else {
                console.log('Error: User with sub ' + sub + ' not found');
            }
        }
    }
}

async function updateLastLogin(sub) {
    if (mongodbconnected) {
        const currentDate = new Date();
        const filter = { _id: sub };
        const update = { $set: { lastLogin: currentDate.toString() } };

        const result = await userscollection.updateOne(filter, update);

        if (result.modifiedCount === 1) {
            console.log('lastLogin field updated for user with sub ' + sub);
        } else {
            console.log('Error: User with sub ' + sub + ' not found');
        }
    }
}


module.exports = { updateUserData, updateNewsStacks, updateLastLogin, getNewsStacks, isUserExisting, createUser, getUserData };