class SequentialQueue{	//if you want it to go backwards, too bad
	next(){
		return this.i++;
	}
	constructor(start = 0){
		this.i = start;
	}
}
const que = new SequentialQueue(0);
for(let i = 0; i < 10; i++){
	console.log(que.next());
}

//JavaScript program to swap two variables

//take input from the users
let a = prompt('Enter the first variable: ');
let b = prompt('Enter the second variable: ');

// XOR operator
a = a ^ b
b = a ^ b
a = a ^ b

console.log(`The value of a after swapping: ${a}`);
console.log(`The value of b after swapping: ${b}`);

require("dotenv").config();
const mongoose = require("mongoose");

const db = process.env.MONGO_URI;

const connectDB = async () => {
	try {
	await mongoose.connect(db, {
	useNewUrlParser: true,
	useUnifiedTopology: true,
	useFindAndModify: false,
	useCreateIndex: true
	});

	console.log("MongoDB Connected");
	} catch (err) {
	console.error(err.message);
	}
};

module.exports = connectDB;

class DoublyLinkedList {
  constructor() {
    this.nodes = [];
  }

  get size() {
    return this.nodes.length;
  }

  get head() {
    return this.size ? this.nodes[0] : null;
  }

  get tail() {
    return this.size ? this.nodes[this.size - 1] : null;
  }

  insertAt(index, value) {
    const previousNode = this.nodes[index - 1] || null;
    const nextNode = this.nodes[index] || null;
    const node = { value, next: nextNode, previous: previousNode };

    if (previousNode) previousNode.next = node;
    if (nextNode) nextNode.previous = node;
    this.nodes.splice(index, 0, node);
  }

  insertFirst(value) {
    this.insertAt(0, value);
  }

  insertLast(value) {
    this.insertAt(this.size, value);
  }

  getAt(index) {
    return this.nodes[index];
  }

  removeAt(index) {
    const previousNode = this.nodes[index - 1] || null;
    const nextNode = this.nodes[index + 1] || null;

    if (previousNode) previousNode.next = nextNode;
    if (nextNode) nextNode.previous = previousNode;

    return this.nodes.splice(index, 1);
  }

  clear() {
    this.nodes = [];
  }

  reverse() {
    this.nodes = this.nodes.reduce((acc, { value }) => {
      const nextNode = acc[0] || null;
      const node = { value, next: nextNode, previous: null };
      if (nextNode) nextNode.previous = node;
      return [node, ...acc];
    }, []);
  }

  *[Symbol.iterator]() {
    yield* this.nodes;
  }
}

const list = new DoublyLinkedList();

list.insertFirst(1);
list.insertFirst(2);
list.insertFirst(3);
list.insertLast(4);
list.insertAt(3, 5);

list.size;                      // 5
list.head.value;                // 3
list.head.next.value;           // 2
list.tail.value;                // 4
list.tail.previous.value;       // 5
[...list.map(e => e.value)];    // [3, 2, 1, 5, 4]

list.removeAt(1);               // 2
list.getAt(1).value;            // 1
list.head.next.value;           // 1
[...list.map(e => e.value)];    // [3, 1, 5, 4]

list.reverse();
[...list.map(e => e.value)];    // [4, 5, 1, 3]

list.clear();
list.size;                      // 0

function filePath(file){
  let folders = file.getParents();
  const parents = [];

  function makePathString(folderArray){
    let path = "";
    folderArray.forEach((folder)=>{
      path += "/" + folder.getName();
    });
    return path;
  }
  
  while (folders.hasNext()) {
    const folder = folders.next(); //This should hopefully remove that folder from the iterator
    parents.unshift(folder);
  }

  return makePathString(parents);
}

function myFunction() {
  const myEmail = Session.getEffectiveUser().getEmail();
  Logger.log("My email is " + myEmail);
  // Log the name of every file in the user's Drive.
  var fileIterator = DriveApp.getFiles();
  const files = []; //List of [File, size] entries
  const filesMaxSize = 10;
  while (fileIterator.hasNext()) {
    var file = fileIterator.next();

    const owner = file.getOwner();

    //Only files I own
    if((!(owner)) || (!(owner.getEmail)) || owner.getEmail() != myEmail){
      continue;
    }

    const entry = [file, file.getSize()];

    function slideUp(arr, index){
      //Let's keep sliding it up so we don't have to sort it at the end.
      for(let i = index; i > 0; --i){ //Stops at 1
        const nextFile = arr[i-1];

        if(nextFile[1] > entry[1]){
          break;
        }else{
          //Swap with the next file to slide the file up
          const temp = arr[i];
          arr[i] = arr[i - 1];
          arr[i - 1] = temp;
        }
      }
    }

    if(files.length < filesMaxSize){
      files.push(entry);

      slideUp(files, files.length - 1);
    }else{
      if(entry[1] > files[files.length - 1][1]){ //If it's bigger than the smallest file in the list.
        files[files.length - 1] = entry;  //Replace the smallest file

        slideUp(files, files.length - 1); //Slide it up
      }
    }
  }

  for(let i = 0; i < filesMaxSize; ++i){
    const file = files[i][0];
    const size = files[i][1];
    Logger.log(size + "\t" + filePath(file) + "/" + file.getName() + "\t" + file.getOwner().getName());
  }
}

const getURLParameters = url =>
(url.match(/([^?=&]+)(=([^&]*))/g) || []).reduce(
    (a, v) => (
      (a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a
    ),
    {}
);