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

run().catch(error => console.error(error.stack));

class Datum {
    id : BigInt;
    stationName : string;
    totalDocks: number;
  };
  
  const SSData: Datum[] = 
  [
    {
        "id" : BigInt(3898),
        "stationName": "E 63 St & 3 Ave",
        "totalDocks": 57
      },
    { 
      "id": BigInt(3899),
      "stationName": "Manhattan Av & Leonard St",
      "totalDocks": 18
    },
    {
      "id": BigInt(864691128455137547),
      "stationName": "Cypress Ave & Palmetto St",
      "totalDocks": 25,
    }
  
  ];
  
async function run() {
  const client = await MongoClient.connect('mongodb://localhost:27017/test', {
    useNewUrlParser: true
  });

  const db = client.db();
  await db.dropDatabase();

// Add a `toBSON()` function to enable MongoDB to store BigInts as strings
BigInt.prototype.toBSON = function() { return this.toString(); };

for (let i = 0; i < SSData.length; i++) {
    try {
      await db.collection('BigInt').update({id:SSData[i].id}, SSData[i], {upsert: true});
    }
    catch (e){
        console.error(e.toString());
    }
}

console.log('All records persisted'); 
  let recno = 0;
  try {
  const res = await db.collection('BigInt').find({});
  res.forEach(function(doc) {
    console.log('Document ' + ++recno + '. ' + JSON.stringify(doc))
  }
  )
  }
  catch(e) {
    console.error('Error in find ' + e.toString());
  }
}