// https://flaviocopes.com/node-mongodb/

const mongo = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017';

mongo.connect(url, {
    useNewUrlParser: true,
    useUnifiedTopology: true
  }, (err, client) => {
  if (err) {
    console.error(err)
    return
  }

  if (client) {
      random_read(client);
  }
});

function random_read(client) {
    const db = client.db('write_test');
    const collection = db.collection('test_queue');

    let s = new Date();
    collection.find({scraped: true}).toArray((err, items) => {
        let e = new Date();

        if (err) console.error(err);

        if (items) {
            console.log(`Found ${items.length} items in ${e-s}ms`);
        }

        client.close();
    });
}

/**
 * Inserting 500000 items takes 5149ms
 * Inserting 100000 items takes 1073ms
 */
function bulk_insert(client) {
    const db = client.db('write_test');

    const collection = db.collection('test_queue');

    let urls = [];
    let n = 200000;

    for (let i = 0; i < n; i++) {
        urls.push({
            url: `https://someurltoscrape-${i}.com`,
            scraped: Math.random() > .9,
        });
    }

    let s = new Date();

    collection.insertMany(urls, (err, result) => {
        if (err) console.error(err);

        //console.log(result);
        let e = new Date();
        console.log(`Inserting ${n} items takes ${e-s}ms`);
        client.close();
    });
}