Daily Programmer challenge 2015-10-28

fallout_hacking_game

'use strict';
function mastermind() {
  // Requires
  var fs = require('fs');
  var readline = require('readline');
  ///

  // Members
  var prompts = {
    banner: function() {
      return 'Welcome to the Mastermind Guessing Game';
    },
    correct: function() {
      return 'Correct! Secret Word was ' + chosenSecretWord;
    },
    guess: function() {
      return 'Guess? (' + guessesRemaining-- + ' left) ';
    },
    lose: function() {
      return 'You Lose! Secret Word was ' + chosenSecretWord + ', try again';
    },
    invalidDifficulty: function() {
      return 'Invalid Difficulty, try again';
    }
  }
  var FILE_NAME = './enable1.txt'; // filename of dictionary
  var SAMPLE_SIZE;  //determined by difficulty
  var WORD_LENGTH;  //determined by difficulty
  var dictionary = fs.readFileSync(FILE_NAME, { encoding: 'utf-8' }).split('\n');
  var difficulty;   // prompted
  var words;        // dictionary filtered by word length
  var randomSample; // random sampling of words array
  var guessesRemaining; // number of remaining guesses
  var chosenSecretWord; // secret word randomly chosen from randomSample
  ///

  function numCommonCharacters(word1, word2) {
    // Assume two words are equal length
    word1 = word1.toLowerCase();
    word2 = word2.toLowerCase();
    return word1.split('').reduce(function(memo, current, index) {
      if (current === word2.charAt(index))
        memo += 1;
      return memo;
    }, 0);
  }
  function nLetterWordsFilter(n, words) {
    function doFilter(words) {
      return words.filter(function(elem) {
        return elem.length === n;
      });
    }
    // If no words are provided return curried function
    if (!words) return doFilter;

    // If words return a filtered array
    return doFilter(words);
  }

  function init() {
    // Initialize the game
    SAMPLE_SIZE = 2 * difficulty + 4;
    WORD_LENGTH = 3 * difficulty;
    guessesRemaining = 4;

    // Filter dictionary by word length
    words = nLetterWordsFilter(WORD_LENGTH, dictionary);

    // Create a random sample
    randomSample = new Array(SAMPLE_SIZE).fill(0).map(function() {
      return words[Math.floor(Math.random() * words.length)];
    });

    // Choose a secret word
    chosenSecretWord = randomSample[Math.floor(Math.random() * randomSample.length)];

    // Print choices
    console.log("Choices:");
    console.log(randomSample);
  }


  // input listening beginning is the beginning of the game
  function beginInputListening() {
    var rl = readline.createInterface({
      input: process.stdin,
      output: process.stdout,
      terminal: true
    });
    
    // Print the banner if there is one
    if (prompts.banner) console.log(prompts.banner());

    rl.setPrompt('Difficulty? 1-5 ');
    rl.prompt();

    rl.on('line', function(line) {
      // Difficulty is the first thing prompted
      if (!difficulty) {
        difficulty = +line;
        if ((0 >= difficulty) || (difficulty > 5)) {
          console.log(prompts.invalidDifficulty());
          difficulty = false;
          rl.prompt();
          return;
        } else {
          // Init game and start guessing
          init();
          rl.setPrompt(prompts.guess());
          rl.prompt();
          return;
        }
      }
      // Check the Guesses
      if (chosenSecretWord === line) {
        // Correct answer
        console.log(prompts.correct());
        guessesRemaining = 0;
        rl.close();
      }
      if (guessesRemaining > 0) {
        // Still guessing
        var lettersInCommon = numCommonCharacters(chosenSecretWord, line);
        console.log(lettersInCommon + '/' + WORD_LENGTH + ' correct');
        rl.setPrompt(prompts.guess());
        rl.prompt();
      } else {
        // Game over
        console.log(prompts.lose());
        rl.close();
      }
    }).on('close', function() {
      process.exit(0);
    });
  }

  return {
    // The only function that needs to be exposed is beginInputListening
    // this function will begin the game
    play: beginInputListening
  }
}
var game = mastermind();
game.play();