Tic Tac Toe Node.Js Terminal Game

tic_tac_toe.js

#!/usr/bin/env node
const readline = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

// usage represents the help guide
function usage() {
  const usageText = `
  Tic Tac Toe application

  usage:
    tic tac toe <command>

    commands can be:

    new:      used to create a new tic tac toe
    help:     used to print the usage guide
  `
  console.log(usageText)
}

const args = process.argv
const new_board = [['-','-','-'],['-','-','-'],['-','-','-']];
let current_board;
let turn;

switch(args[2]) {
  case 'help':
    usage();
    break;
  default:
    getNewBoard();
}

//Initialises with new board
function getNewBoard(){
  current_board = new_board;
  turn = 0;
  console.log("New boad created");
  printTable();
  console.log("");
  getUserInput();
}

//Gets user Input
function getUserInput(){
  if(turn%2 === 0){
    userInput('O');
    // userOInput();
  }
  else{
    userInput('X');
    // userXInput();
  }
}

//Checks if board is Full
function checkIfBoardIsFull(){
  let isFull = true;
  current_board.forEach(row => {
    row.forEach(item => {
      if(item === '-'){
        isFull = false;
      }
    })
  });
  return isFull;
}

//Prints Table
function printTable(){
  current_board.forEach(row => {
    console.log(row);
  });
}

//Gets 2D coordinates
function getCoordinates(location) {
  location -= 1;
  let x = Math.floor(location/3);
  let y = location%3;
  return {x, y};
}

//Checks if the location is empty
function checkIfEmpty(x,y){
  return current_board[x][y] === '-';
}

//Enters the input in Table
function addInputToTable(location,input){
  if(location>9 || location<1){
    console.log('Invalid Input. Kindly enter between 1 to 9');
  }
  else{
    let {x, y} = getCoordinates(location);
    if(checkIfEmpty(x, y)){
      current_board[x][y] = input;
      turn+=1;
      printTable();
      console.log("");
      if(checkIfUserWon(x,y,input)){
        console.log(`User ${input} Won`);
        return 0;
      }
      if(checkIfBoardIsFull()){
        console.log("Board is Full. Game Over");
        return 0;
      }
    }
    else{
      console.log('Invalid Input. Kindly enter another empty location');
    }
  }
  return 1;
}

function checkStraightDiagonal(input){
  return (current_board[0][0] === input) && (current_board[1][1] === input) && (current_board[2][2] === input);
}

function checkCrossDiagonal(input){
  return (current_board[0][2] === input) && (current_board[1][1] === input) && (current_board[2][0] === input);
}

function checkRowsAndColums(x,y, input){
  return ((current_board[x][0] === input) && (current_board[x][1] === input) && (current_board[x][2] === input)) ||
  ((current_board[0][y] === input) && (current_board[1][y] === input) && (current_board[2][y] === input)); 
}

function checkIfUserWon(x,y, input){
  if(checkRowsAndColums(x,y, input)){
    return true;
  }
  else{
    if(x==1 && y==1){
      if(checkStraightDiagonal(input) || checkCrossDiagonal(input)){
        return true;
      }
    }
    else if(x===y){
      if(checkStraightDiagonal(input)){
        return true;
      }
    }
    else if(x+y === 2){
      if(checkCrossDiagonal(input)){
        return true;
      }
    }
  }  
}

function userInput(input) {
  readline.question(`User {input} print its value - `, location => {
    if(addInputToTable(location, input)){
      getUserInput();
    }
    else{
      readline.close();
    }
  });
}