The Lost Eurovision Song Contest

mongoimport --uri "mongodb+srv://<db_username>@eurovision.<your_cluster_id>.mongodb.net/esc" -c contestants --type csv --file ~/<path_to_file>/contestants.csv --headerline

2021-05-15T12:42:27.154+0200        connected to: mongodb+srv://[**REDACTED**]@eurovision.12abc.mongodb.net/esc
2021-05-15T12:42:30.089+0200        1603 document(s) imported successfully. 0 document(s) failed to import.

function createSongList(songs) {
    let response = "";
    let arrayLength = songs.length;
    for (var i = 0; i < arrayLength; i++) {
        let song = songs[i];
        // shorten youtube links
        youtube_short = song["youtube_url"].replace("https://youtube.com/watch?v=", "youtu.be/");
        response = response + song["to_country"] + ": " + youtube_short + "\n";
    }
    response.trim();
    return response;
}

function formatResults(results) {
    let response = "";
    let arrayLength = results.length;
    for (var i = 0; i < arrayLength; i++) {
        response = response + "Place " + (i+1) + ": " + results[i]["_id"] + "\n";
    }
    response.trim();
    return response;
}

exports.handler = function(context, event, callback) {
    
    const MongoClient = require('mongodb').MongoClient;
    const CryptoJS = require("crypto-js");
    const client = new MongoClient(context.MDB_URI); // Set up MongoClient
    const dbName = 'esc';                            // Database name
    const incoming_message = event.Body.trim()       // Remove extra whitespace

    // Connect to the datbase
    client.connect(function(err) {
        const db = client.db(dbName);
        const contestants_collection = db.collection('contestants');
        const votes_collection = db.collection('votes')
        let pipeline;

        let year = incoming_message.substring(0,4);
        let country;

        if (!isNaN(year)) {                         //  If it is a year
            if (incoming_message.length == 4) {     // send list of songs for 
                pipeline = [
                    { "$match": {"year": parseInt(year)} }
                ];
                contestants_collection.aggregate(pipeline).toArray(function(err, docs) {
                    let twiml = new Twilio.twiml.MessagingResponse();
                    let response;
                    if (docs && docs.length) {
                        response = createSongList(docs);
                        } else {
                        response = "Sorry! There is nothing in the database " + 
                            "for the year " + token + ". Please try a " +  
                            "different year (1956 - 2021).";
                    }
                        twiml.message(response);
                        callback(null, twiml);
                    client.close();
                });
                
            } else if (incoming_message.length > 4) {      // we have a country
                country = incoming_message.substring(5);   

                // create hash of phone number
                let hash = CryptoJS.MD5(event.From).toString();
                
                contestants_collection.findOne({
                // Check if there is an entry for the specified year and country
                    year: parseInt(year),
                    to_country: country
                }, function (err, doc) {
                    if (doc) {
                        // vote (overwrite if needed)
                        votes_collection.update({
                            "year": year,
                            "voter" : hash,
                        }, {
                            "$set": { "country": country }
                        }, {
                            "upsert": true
                        }, function(err, res) {
                            // send text to confirm vote
                            let twiml = new Twilio.twiml.MessagingResponse();
                            twiml.message("Thank you. Your vote for " + country +
                                " was registered. You can only vote once for " + year + ". If you" +
                                " vote again, your previous vote will no longer count. To" +
                                " get the current voting results, reply with \"Results " +
                                year + "\".");
                            callback(null, twiml);
                            client.close();                        
                        });
                    } else {
                        let twiml = new Twilio.twiml.MessagingResponse();
                        twiml.message("We could not find an entry for " + country + " in " + year + ". Sorry.");
                        callback(null, twiml);
                        client.close();
                    }
                });            
                
            } else {
                let twiml = new Twilio.twiml.MessagingResponse();
                twiml.message("Sorry. It looks like you tried to vote but the" +
                " input wasn't formatted in a way the service understood. " + 
                "Please try again and send a message with \"" +
                "2020 Country\". (for example: \"2020 Germany\").")
                callback(null, twiml);
                client.close();
            }

        } else {                                    // we have text
            if (incoming_message.startsWith("Results")
                && !isNaN(incoming_message.substring(8))) {  // send results
                let year = incoming_message.substring(8);
                votes_collection.aggregate([
                    { "$match": { "year": year } },
                    { "$group": { "_id": "$country", "count": { "$sum": 1 } } },
                    { "$sort": { "count": -1 } },
                    { "$limit": 10}
                ]).toArray(function(err, docs){
                    if (docs) {
                        console.log(docs);
                        let twiml = new Twilio.twiml.MessagingResponse();
                        let results = formatResults(docs);
                        twiml.message("The current top 10 for The Lost " + 
                            "Eurovision (" + incoming_message.substring(8) +
                            ") are:\n" + results)
                        callback(null, twiml);
                        client.close();
                    }                    
                })

            } else {
                let twiml = new Twilio.twiml.MessagingResponse();
                twiml.message("Welcome to The Lost Eurovision - unofficially " +
                    "hosted by Twilio. Reply with \"2020\" (or another year) " +
                    "to get the list of participants. To vote send a message " +
                    "with \"2020 Country\". (for example: \"2020 Germany\"). " +
                    "To get the current voting results, reply with " +
                    "\"Results 2020\"")
                callback(null, twiml);
                client.close();
            }
        }
    });
};

mongodb+srv://<db_username>:<db_password>@eurovision.<your_cluster_id>.mongodb.net/esc?retryWrites=true&w=majority