/*!
   * cookie-parser
   * Copyright(c) 2014 TJ Holowaychuk
   * Copyright(c) 2015 Douglas Christopher Wilson
   * MIT Licensed
   */
  
  'use strict';
  
  /**
   * Module dependencies.
   * @private
   */
  
  var cookie = require('cookie');
  var signature = require('cookie-signature');
  
  /**
   * Module exports.
   * @public
   */
  
  module.exports = cookieParser;
  module.exports.JSONCookie = JSONCookie;
  module.exports.JSONCookies = JSONCookies;
  module.exports.signedCookie = signedCookie;
  module.exports.signedCookies = signedCookies;
  
  /**
   * Parse Cookie header and populate `req.cookies`
   * with an object keyed by the cookie names.
   *
   * @param {string|array} [secret] A string (or array of strings) representing cookie signing secret(s).
   * @param {Object} [options]
   * @return {Function}
   * @public
   */
  
  function cookieParser(secret, options) {
    return function cookieParser(req, res, next) {
      if (req.cookies) {
        return next();
      }
  
      var cookies = req.headers.cookie;
      var secrets = !secret || Array.isArray(secret)
        ? (secret || [])
        : [secret];
  
      req.secret = secrets[0];
      req.cookies = Object.create(null);
      req.signedCookies = Object.create(null);
  
      // no cookies
      if (!cookies) {
        return next();
      }
  
      req.cookies = cookie.parse(cookies, options);
  
      // parse signed cookies
      if (secrets.length !== 0) {
        req.signedCookies = signedCookies(req.cookies, secrets);
        req.signedCookies = JSONCookies(req.signedCookies);
      }
  
      // parse JSON cookies
      req.cookies = JSONCookies(req.cookies);
  
      next();
    };
  }
  
  /**
   * Parse JSON cookie string.
   *
   * @param {String} str
   * @return {Object} Parsed object or undefined if not json cookie
   * @public
   */
  
  function JSONCookie(str) {
    if (typeof str !== 'string' || str.substr(0, 2) !== 'j:') {
      return undefined;
    }
  
    try {
      return JSON.parse(str.slice(2));
    } catch (err) {
      return undefined;
    }
  }
  
  /**
   * Parse JSON cookies.
   *
   * @param {Object} obj
   * @return {Object}
   * @public
   */
  
  function JSONCookies(obj) {
    var cookies = Object.keys(obj);
    var key;
    var val;
  
    for (var i = 0; i < cookies.length; i++) {
      key = cookies[i];
      val = JSONCookie(obj[key]);
  
      if (val) {
        obj[key] = val;
      }
    }
  
    return obj;
  }
  
  /**
   * Parse a signed cookie string, return the decoded value.
   *
   * @param {String} str signed cookie string
   * @param {string|array} secret
   * @return {String} decoded value
   * @public
   */
  
  function signedCookie(str, secret) {
    if (typeof str !== 'string') {
      return undefined;
    }
  
    if (str.substr(0, 2) !== 's:') {
      return str;
    }
  
    var secrets = !secret || Array.isArray(secret)
      ? (secret || [])
      : [secret];
  
    for (var i = 0; i < secrets.length; i++) {
      var val = signature.unsign(str.slice(2), secrets[i]);
  
      if (val !== false) {
        return val;
      }
    }
  
    return false;
  }
  
  /**
   * Parse signed cookies, returning an object containing the decoded key/value
   * pairs, while removing the signed key from obj.
   *
   * @param {Object} obj
   * @param {string|array} secret
   * @return {Object}
   * @public
   */
  
  function signedCookies(obj, secret) {
    var cookies = Object.keys(obj);
    var dec;
    var key;
    var ret = Object.create(null);
    var val;
  
    for (var i = 0; i < cookies.length; i++) {
      key = cookies[i];
      val = obj[key];
      dec = signedCookie(val, secret);
  
      if (val !== dec) {
        ret[key] = dec;
        delete obj[key];
      }
    }
  
    return ret;
  }