var EventEmitter = require('events').EventEmitter,

    fs = require('fs'),
    path = require('path'),
    util = require('util');

module.exports = (function () {
    function Walker() {
        EventEmitter.call(this);
    }

    util.inherits(Walker, EventEmitter);

    Walker.prototype.walk = function (from) {
        var root = path.resolve(from),

            callback = function (error, tree) {
                if (error !== null) {
                    return this.emit('error', error);
                }

                tree.forEach(function (leaf) {
                    var branch = path.join(root, leaf),

                        callback = function (error, stats) {
                            if (error !== null) {
                                return this.emit('error', error);
                            }

                            if (stats.isFile()) {
                                this.emit('file', branch);
                            } else if (stats.isDirectory()) {
                                this.walk(branch);
                            }
                        }.bind(this);

                    fs.stat(branch, callback);
                }, this);
            }.bind(this);

        this.emit('directory', root);

        fs.readdir(root, callback);

        return this;
    };

    return Walker;
}());