'use strict';

module.exports.create = function (defaults) {
  var handlers =  {
    getOptions: function () {
      return defaults;
    }
    //
    // set,get,remove challenges
    //
    // Note: this is fine for a one-off CLI tool
    // but a webserver using node-cluster or multiple
    // servers should use a database of some sort
  , _challenges: {}
  , set: function (args, domain, token, secret, cb) {
      handlers._challenges[token] = secret;
      cb(null);
    }
  , get: function (args, domain, token, cb) {
      // TODO keep in mind that, generally get args are just args.domains
      // and it is disconnected from the flow of setChallenge and removeChallenge
      cb(null, handlers._challenges[token]);
    }
  , remove: function (args, domain, token, cb) {
      delete handlers._challenges[token];
      cb(null);
    }

  , loopback: function (defaults, domain, challenge, done) {
      var hostname = domain + (defaults.loopbackPort ? ':' + defaults.loopbackPort : '');
      var urlstr = 'http://' + hostname + '/.well-known/acme-challenge/' + key;

      require('http').get(urlstr, function (res) {
        if (200 !== res.statusCode) {
          done(new Error("local loopback failed with statusCode " + res.statusCode));
          return;
        }
        var chunks = [];
        res.on('data', function (chunk) {
          chunks.push(chunk);
        });
        res.on('end', function () {
          var str = Buffer.concat(chunks).toString('utf8').trim();
          done(null, str);
        });
      }).setTimeout(defaults.loopbackTimeout, function () {
        done(new Error("loopback timeout, could not reach server"));
      }).on('error', function (err) {
        done(err);
      });
    }

  , test: function (args, domain, challenge, keyAuthorization, done) {
      var me = this;
      var key = keyAuthorization || challenge;

      me.set(args, domain, challenge, key, function (err) {
        if (err) { done(err); return; }

        myDefaults.loopbackPort = args.loopbackPort;
        myDefaults.webrootPath = args.webrootPath;
        me.loopback(args, domain, challenge, function (err, _key) {
          if (err) { done(err); return; }

          if (key !== _key) {
            err = new Error("keyAuthorization [original] '" + key + "'"
              + " did not match [result] '" + _key + "'");
            return;
          }

          me.remove(myDefaults, domain, challenge, function (_err) {
            if (_err) { done(_err); return; }

            done(err);
          });
        });
      });
    }

  };


  return handlers;
};