Maze Explorer Draft

app.js

var app = require('express')();
var puzzle = require('./flipboard/maze');

app.get('/maze/new', puzzle.init);
app.get('/maze/update/:id', puzzle.update);

app.listen(3000, 'localhost');

explorer.js

var fetch = require('request');
var API = 'https://challenge.flipboard.com/step';

var Explorer = function(team) {
  this.team = team;
  this.history = '';
};

Explorer.prototype.go = function(x, y) {
  var url = API + '?s=' + this.team.maze + '&x=' + x + '&y=' + y;
  var me = this;
  fetch(url, function (err, data) {
    data = JSON.parse(data.body);
    var found = data.end;
    var letter = data.letter;
    var paths = data.adjacent.filter(function(cell) {
      var key = JSON.stringify([cell.x, cell.y]);
      return !me.team.map[key];
    });
    var codes = {
      0: 'deadend',
      1: 'continue'
    };
    var status = codes[paths.length] || 'fork';
    var here = JSON.stringify([x, y]);
    me.history += me.history === '' ? '' : '_';
    me.history += here;
    if (found) {
      me.team.finished = true;
      me.team.map.answer = me.history.split('_');
    }
    me.team.map[here] = {
      letter: letter,
      status: status
    };
    me.team.publish();
    if (!me.team.finished && paths.length) {
      var first = paths.shift();
      paths.forEach(function(next) {
        var buddy = new Explorer(me.team);
        buddy.history = me.history;
        buddy.go(next.x, next.y);
      });
      me.go(first.x, first.y);
    }
  });
};

module.exports = Explorer;

maze.js

var fetch = require('request');
var Team = require('./team');
var URL = 'https://challenge.flipboard.com/start';
var RE = /(?:s=)(.+)(?=&x)/;
var teams = {};
var Maze = {};

Maze.init = function(req, res) {
  fetch(URL, function (err, data) {
    var query = data.request.uri.query || '';
    var match = query.match(RE);
    if (match) {
      res.send(match[1]);
    }
  });
};

Maze.update = function(req, res) {
  var maze = req.params.id;
  var team = teams[maze] = teams[maze] || new Team(maze);
  team.subscribe(res.json.bind(res));
};

module.exports = Maze;

team.js

var Explorer = require('./explorer');

var Team = function(maze) {
  this.map = { answer: [] };
  this.maze = maze;
  this.started = false;
  this.finished = false;
  this.audience = [];
};

Team.prototype.subscribe = function(cb) {
  this.audience.push(cb);
  if (!this.started) {
    new Explorer(this).go(0, 0);
    this.started = true;
  }
  if (this.finished) {
    this.publish();
  }
};

Team.prototype.publish = function() {
  while (this.audience.length) {
    this.audience.shift()(this.map);
  }
};

module.exports = Team;