mjackson/mach

var Connection = require('../Connection');
var Location = require('../Location');

/**
 * Standard ports for HTTP protocols.
 */
var STANDARD_PORTS = {
  'http:': '80',
  'https:': '443'
};

function ensureTrailingColon(string) {
  return string[string.length - 1] === ':' ? string : string + ':';
}

/**
 * Creates a new Location object that is reverse-proxy aware.
 */
function createLocation(nodeRequest) {
  var headers = nodeRequest.headers;

  var protocol;
  if (process.env.HTTPS === 'on' || headers['x-forwarded-ssl'] === 'on' || headers['font-end-https'] === 'on') {
    protocol = 'https:';
  } else if (headers['x-url-scheme']) {
    protocol = ensureTrailingColon(headers['x-url-scheme']);
  } else if (headers['x-forwarded-protocol']) {
    protocol = ensureTrailingColon(headers['x-forwarded-protocol'].split(',')[0]);
  } else if (headers['x-forwarded-proto']) {
    protocol = ensureTrailingColon(headers['x-forwarded-proto'].split(',')[0]);
  } else {
    protocol = 'http:';
  }

  var host;
  if (headers['x-forwarded-host']) {
    var hosts = headers['x-forwarded-host'].split(/,\s?/);
    host = hosts[hosts.length - 1];
  } else if (headers['host']) {
    host = headers['host'];
  } else if (process.env.SERVER_NAME) {
    host = process.env.SERVER_NAME;
  }

  var hostParts = host.split(':', 2);
  var hostname = hostParts[0];
  var port = hostParts[1] || headers['x-forwarded-port'];

  if (port == null) {
    if (headers['x-forwarded-host']) {
      port = STANDARD_PORTS[protocol];
    } else if (headers['x-forwarded-proto']) {
      port = STANDARD_PORTS[headers['x-forwarded-proto'].split(',')[0]];
    }
  }

  var path = nodeRequest.url;

  return new Location({
    protocol: protocol,
    hostname: hostname,
    port: port,
    path: path
  });
}

/**
 * Creates a mach.Connection from the given node.js HTTP request and
 * server (optional) objects. This is a low-level method that is not
 * generally needed by application-level code.
 */
function createConnection(nodeRequest) {
  var conn = new Connection({
    version: nodeRequest.httpVersion,
    method: nodeRequest.method,
    location: createLocation(nodeRequest),
    headers: nodeRequest.headers,
    content: nodeRequest,
    remoteHost: nodeRequest.connection.remoteAddress,
    remotePort: nodeRequest.connection.remotePort
  });

  nodeRequest.on('close', function () {
    conn.onClose();
  });

  return conn;
}

module.exports = createConnection;