server.js

const mongoose = require('mongoose')
const database = require('./models/index')
const City = database.City
const Country = database.Country
const Language = database.Language
const db = mongoose.connection;
const mongoURI = 'mongodb://localhost:27017/carmen';

mongoose.connect(mongoURI, { useNewUrlParser: true }, () => {
    console.log('the connection with mongod is established')
})

// Clue #1: We recently got word that someone fitting Carmen Sandiego's description has been
// traveling through Southern Europe. She's most likely traveling someplace where she won't be noticed,
// so find the least populated country in Southern Europe, and we'll start looking for her there.

// SOLUTION

// Country.find({region: "Southern Europe"}).sort('-population').exec((err, country) => {
//      console.log(country);
//     db.close();
// });

// Clue #2: Now that we're here, we have insight that Carmen was seen attending language classes in
// this country's officially recognized language. Check our databases and find out what language is
// spoken in this country, so we can call in a translator to work with you.

///////// we got the country code from the previous clue /////////

// SOLUTION
// Language.find({ countryCode: 'VAT' }, (err, lang) => {
//     console.log(lang);
//     db.close();
// });


// -- Clue #3: We have new news on the classes Carmen attended – our gumshoes tell us she's moved on
// -- to a different country, a country where people speak only the language she was learning. Find out which
// --  nearby country speaks nothing but that language.

///////// we got the language from the previous clue /////////

// SOLUTION
// Language.find({ language: 'Italian', percentage: 100}, (err, language) => {
//     console.log(language);
//     db.close();
// });


// -- Clue #4: We're booking the first flight out – maybe we've actually got a chance to catch her this time.
//  -- There are only two cities she could be flying to in the country. One is named the same as the country – that
//  -- would be too obvious. We're following our gut on this one; find out what other city in that country she might
//  --  be flying to.

///////// we got the code from the previous clue /////////

// SOLUTION
// Country.find({ code: 'SMR' }, (err, country) => {
//         console.log(country);
//         db.close();
// });

///////// we got the name from the above find method /////////

// SOLUTION
// City.find({ countrycode: "SMR", name: { $ne: 'San Marino' } }, (err, city) => {
//         console.log(city);
//         db.close();
// });


// -- Clue #5: Oh no, she pulled a switch – there are two cities with very similar names, but in totally different
// -- parts of the globe! She's headed to South America as we speak; go find a city whose name is like the one we were
// -- headed to, but doesn't end the same. Find out the city, and do another search for what country it's in. Hurry!

///////// we got the name from previous clue /////////

// SOLUTION
// City.find({ 'name': /^Serra/ }, (err, city) => {
//         console.log(city);
//         db.close();
//     });

///////// we got the code from the above find method /////////

// SOLUTION


// Country.find({ code: 'BRA' }, (err, country) => {
//     console.log(country);
//     db.close();
// });

// -- Clue #6: We're close! Our South American agent says she just got a taxi at the airport, and is headed towards
//  -- the capital! Look up the country's capital, and get there pronto! Send us the name of where you're headed and we'll
//  -- follow right behind you!

///////// we got the cityId from previous clue /////////

// SOLUTION


// City.find({ cityId: 211 }, (err, city) => {
//     console.log(city);
//     db.close();
// });


// -- Clue #7: She knows we're on to her – her taxi dropped her off at the international airport, and she beat us to
//  -- the boarding gates. We have one chance to catch her, we just have to know where she's heading and beat her to the
//  -- landing dock. Lucky for us, an informant told us that she couldn't afford a long distance ticket! Where ever she is, it has to be close! 
// -- And she's getting cocky. She left us a note, and I'm sure she thinks she's very clever, but
// -- if we can crack it, we can finally put her where she belongs – behind bars.

// -- Our playdate of late has been unusually fun –
// -- As an agent, I'll say, you've been a joy to outrun.
// -- And while the food here is great, and the people – so nice!
// -- I need a little more sunshine with my slice of life.
// -- So I'm off to add one to the population I find
// -- In a city of ninety-one thousand and now, eighty five.

// -- We're counting on you, gumshoe. Find out where she's headed, send us the info, and we'll be sure to meet her at the gates with bells on.


// SOLUTION

// City.find({ population: 91084 }, (err, city) => {
//     console.log(city);
//     db.close();
// });

// Where is Carmen?

///////// the above method will give us two cities one in the USA and the other in Turkey,  /////////
///////// since our previous clue pointed us to brazil we can tell that USA is closer than turkey to where we are /////////
///////// so the final answer is "Santa Monica" /////////