'use strict';

module.exports.create = function (deps, conf) {
  var app = require('express')();
  var domainMatches = require('../match-domain').match;

  // We handle both HTTPS and HTTP traffic on the same ports, and we want to redirect
  // any unencrypted requests to the same port they came from unless it came in on
  // the default HTTP port, in which case there wont be a port specified in the host.
  var redirecters = {};
  function redirectHttps(req, res, next) {
    var port = req.headers.host.split(':')[1];
    var redirecter = redirecters[port];
    if (!redirecter) {
      redirecter = redirecters[port] = require('redirect-https')({port: port});
    }
    redirecter(req, res, next);
  }

  function respond404(req, res) {
    res.writeHead(404);
    res.end('Not Found');
  }

  function createProxyRoute(mod) {
    // This is the easiest way to override the createConnections function the proxy
    // module uses, but take note the since we don't have control over where this is
    // called the extra options availabled will be different.
    var agent = new require('http').Agent({});
    agent.createConnection = deps.net.createConnection;

    var proxy = require('http-proxy').createProxyServer({
      agent: agent
    , target: 'http://' + mod.address
    , xfwd: true
    , toProxy: true
    });

    return function (req, res, next) {
      var hostname = req.headers.host.split(':')[0];
      var relevant = mod.domains.some(function (pattern) {
        return domainMatches(pattern, hostname);
      });

      if (relevant) {
        proxy.web(req, res);
      } else {
        next();
      }
    };
  }

  app.use(redirectHttps);

  (conf.http.modules || []).forEach(function (mod) {
    if (mod.name === 'proxy') {
      app.use(createProxyRoute(mod));
    }
    else {
      console.warn('unknown HTTP module', mod);
    }
  });

  app.use(respond404);
  return require('http').createServer(app);
};