'use strict';

module.exports.create = function (deps) {
  var PromiseA = require('bluebird');
  var request = PromiseA.promisify(require('request'));
  var pending = {};

  function checkPublicAddr(host) {
    return request({
      method: 'GET'
    , url: host+'/api/org.oauth3.tunnel/checkip'
    , json: true
    }).then(function (result) {
      if (!result.body) {
        return PromiseA.reject(new Error('No response body in request for public address'));
      }
      if (result.body.error) {
        var err = new Error(result.body.error.message);
        return PromiseA.reject(Object.assign(err, result.body.error));
      }
      return result.body.address;
    });
  }

  function checkSinglePort(host, address, port) {
    var crypto = require('crypto');
    var token   = crypto.randomBytes(8).toString('hex');
    var keyAuth = crypto.randomBytes(32).toString('hex');
    pending[token] = keyAuth;

    var opts = {
      address: address
    , port: port
    , token: token
    , keyAuthorization: keyAuth
    , iat: Date.now()
    };

    return request({
      method: 'POST'
    , url: host+'/api/org.oauth3.tunnel/loopback'
    , json: opts
    })
    .then(function (result) {
      delete pending[token];
      if (!result.body) {
        return PromiseA.reject(new Error('No response body in loopback request for port '+port));
      }
      // If the loopback requests don't go to us then there are all kinds of ways it could
      // error, but none of them really provide much extra information so we don't do
      // anything that will break the PromiseA.all out and mask the other results.
      if (result.body.error) {
        console.log('error on remote side of port '+port+' loopback', result.body.error);
      }
      return !!result.body.success;
    }, function (err) {
      delete pending[token];
      throw err;
    });
  }

  function loopback(provider) {
    return deps.OAUTH3.discover(provider).then(function (directives) {
      return checkPublicAddr(directives.api).then(function (address) {
        console.log('checking to see if', address, 'gets back to us');
        var ports = require('./servers').listeners.tcp.list();
        return PromiseA.all(ports.map(function (port) {
          return checkSinglePort(directives.api, address, port);
        }))
        .then(function (values) {
          console.log(pending);
          var result = {error: null, address: address};
          ports.forEach(function (port, ind) {
            result[port] = values[ind];
          });
          return result;
        });
      });
    });
  }

  loopback.server = require('http').createServer(function (req, res) {
    var parsed = require('url').parse(req.url);
    var token = parsed.pathname.replace('/.well-known/cloud-challenge/', '');
    if (pending[token]) {
      res.setHeader('Content-Type', 'text/plain');
      res.end(pending[token]);
    } else {
      res.statusCode = 404;
      res.end();
    }
  });

  return loopback;
};