var https = require("https");
var os = require("os");
var http = require("http");
var url = require("url");
var fs = require("fs");
var path = require("path");
var childProcess = require("child_process");
var readline = require("readline");

var version = "UNKNOWN";
try {
  version = JSON.parse(fs.readFileSync(__dirname + "/mod.info")).version;
} catch (ex) {
  // Can't determine version
}
var configJSONS = {};
try {
  configJSONS = JSON.parse(fs.readFileSync(__dirname + "/../../../config.json")); // Read configuration JSON
} catch(ex) {
  //RedBrick will not care about configJSONS in SVR.JS 3.x and newer
  //SVR.JS 2.x and older will fail to start with broken configuration file anyway...
}

var exttointerpreteruser = {};
var scriptExts = [];
try {
  exttointerpreteruser = JSON.parse(fs.readFileSync(__dirname + "/../../../redbrick-interpreters.json"));
} catch (ex) {

}
try {
  scriptExts = JSON.parse(fs.readFileSync(__dirname + "/../../../redbrick-scriptexts.json"));
} catch (ex) {

}

var disableModExposeSupported = process.versions.svrjs && process.versions.svrjs.match(/^(?:Nightly-|(?:[4-9]|[123][0-9])[0-9]*\.|3\.(?:[1-9][0-9]+\.|9\.(?:[1-9])|4\.(?:(?:[3-9]|[12][0-9])[0-9]+|29)))/i);

function Mod() {}

Mod.prototype.callback = function (req, res, serverconsole, responseEnd, href, ext, uobject, search, defaultpage, users, page404, head, foot, fd, elseCallback, configJSON, callServerError, getCustomHeaders, origHref, redirect, parsePostData, authUser) {
  return function () {
    if (!configJSON) {
      configJSON = configJSONS;
    }

    function checkIfThereIsA401Rule() {
      var actually401 = false;

      function createRegex(regex) {
        var regexObj = regex.split("/");
        if (regexObj.length == 0) throw new Error("Invalid regex!");
        var modifiers = regexObj.pop();
        regexObj.shift();
        var searchString = regexObj.join("/");
        return new RegExp(searchString, modifiers);
      }

      if(configJSON.nonStandardCodes) {
        configJSON.nonStandardCodes.every(function (nonscode) {
          if (nonscode.scode == 401) {
            if (nonscode.regex && (req.url.match(createRegex(nonscode.regex)) || href.match(createRegex(nonscode.regex)))) {
              actually401 = true;
              return true;
            } else if (nonscode.url && (nonStandardCodes[i].url == href || (os.platform() == "win32" && nonStandardCodes[i].url.toLowerCase() == href.toLowerCase()))) {
              actually401 = true;
              return true;
            }
          }
          return false;
        });
      }
      return actually401;
    }

    if (!getCustomHeaders) {
      var bheaders = JSON.parse(JSON.stringify(configJSON.customHeaders));
    } else {
      var bheaders = getCustomHeaders();
    }

    bheaders["Content-Type"] = "text/html"; // HTML output

    if (!getCustomHeaders) {
      bheaders["Server"] =
        "SVR.JS/" +
        configJSON.version +
        " (" +
        os.platform()[0].toUpperCase() +
        os.platform().slice(1) +
        ")"; // Add Server header
    }

    var abheaders = JSON.parse(JSON.stringify(bheaders));

    function executeCGI(fname, req, res, dh, nEnv) {
      // Function to execute CGI scripts
      var env = JSON.parse(JSON.stringify(process.env));
      var nEnvKeys = Object.keys(nEnv);
      for (var i = 0; i < nEnvKeys.length; i++) {
        env[nEnvKeys[i]] = nEnv[nEnvKeys[i]];
      }
      var exttointerpreter = {
        ".pl": ["perl"],
        ".py": ["python"],
        ".sh": ["bash"],
        ".ksh": ["ksh"],
        ".csh": ["csh"],
        ".rb": ["ruby"],
        ".php": ["php-cgi"]
      };
      if (os.platform() == "win32") {
        exttointerpreter[".exe"] = [];
        exttointerpreter[".bat"] = ["cmd", "/c"];
        exttointerpreter[".vbs"] = ["cscript"];
      }

      fs.stat(fname, function (err, stats) {
        if (err) {
          if (!callServerError) {
            res.writeHead(500, {
              "Content-Type": "text/html",
              "Server": "RedBrick/" + version
            });
            res.end("<html><head></head><body><h1>RedBrick Error!</h1><p>Reason: " + err.message + "</p></body></html>");
          } else {
            callServerError(500, "RedBrick/" + version, err);
          }
          return;

        }
        if (stats.size == 0) {
          afterShebangCallback(false);
          return;
        }
        var s = fs.createReadStream(fname);
        s.on("error", function (err) {
          if (!callServerError) {
            res.writeHead(500, {
              "Content-Type": "text/html",
              "Server": "RedBrick/" + version
            });
            res.end("<html><head></head><body><h1>RedBrick Error!</h1><p>Reason: " + err.message + "</p></body></html>");
          } else {
            callServerError(500, "RedBrick/" + version, err);
          }
          return;
        }).on("open", function () {
          var rl = readline.createInterface({
            input: s,
          });

          rl.once("line", function (line) {
            rl.close();
            if (line.substr(0, 2) == "#!") {
              var args = line.substr(2).match(/(?:[^" ]|\\(?:.|$)|"[^"]*(?:"|$))+/g);
              if (!args) args = [];
              args = args.map(function (arg) {
                return arg.replace(/"/g, "");
              });
              afterShebangCallback(args);
            } else if (os.platform() != "win32" && line.substr(0, 4) == "\x7fELF") {
              afterShebangCallback("binary");
            } else {
              afterShebangCallback(false);
            }
          });
        });
      });

      function afterShebangCallback(passedArgs) {
        var ext = path.extname(fname);
        var args = [];
        var buffer = "";
        var stderr = "";
        var headerendline = -1;
        var cned = false;
        args.push(fname);
        if (passedArgs == "binary") {
          filename = (process.cwd() + (os.platform() == "win32" ? "\\" + fname.replace(/\//g, "\\") : "/" + fname)).replace(os.platform() == "win32" ? /\\+/ : /\/+/, os.platform() == "win32" ? "\\" : "/");
          args = [];
        } else if (passedArgs) {
          if (os.platform() == "win32") {
            args = passedArgs;
            args.push((process.cwd() + ("\\" + fname.replace(/\//g, "\\"))).replace(/\\+/, "\\"));
            filename = args.shift();
          } else {
            filename = (process.cwd() + (os.platform() == "win32" ? "\\" + fname.replace(/\//g, "\\") : "/" + fname)).replace(os.platform() == "win32" ? /\\+/ : /\/+/, os.platform() == "win32" ? "\\" : "/");
            args = [];
          }
        } else {
          args = exttointerpreteruser[ext];
          if (args === null) {
            elseCallback();
            return;
          } else if (!args) {
            args = exttointerpreter[ext];
            if (!args) {
              elseCallback();
              return;
            }
          }
          args.push((process.cwd() + (os.platform() == "win32" ? "\\" + fname.replace(/\//g, "\\") : "/" + fname)).replace(os.platform() == "win32" ? /\\+/ : /\/+/, os.platform() == "win32" ? "\\" : "/"));
          filename = args.shift();
        }

        var wd = fname.split("/");
        wd[0] = "";
        wd[wd.length - 1] = "";
        wd = wd.join(os.platform() == "win32" ? "\\" : "/");
        var interpreter = childProcess.spawn(filename, args, {
          cwd: (process.cwd() + wd).replace(os.platform() == "win32" ? /\\+/ : /\/+/, os.platform() == "win32" ? "\\" : "/"),
          env: env
        });
        interpreter.on("error", (error) => {
          if (!callServerError) {
            res.writeHead(500, {
              "Content-Type": "text/html",
              "Server": "RedBrick/" + version
            });
            res.end("<html><head></head><body><h1>RedBrick Error!</h1><p>Reason: " + error.message + "</p></body></html>");
          } else {
            callServerError(500, "RedBrick/" + version, error);
          }
        });
        var dataHandler = function (data) {
          if (!cned) buffer += data.toString("latin1");
          var m = null;
          if (!cned) m = buffer.match(/(?:\r\n\r\n|\n\r\n\r|\n\n|\r\r)/);
          if (!cned && m) {
            cned = true;
            eol = m[0];
            headerendline = m.index;
            var bheaders = buffer.substr(0, headerendline).split(/(?:\r\n|\n\r|\n|\r)/);
            var bheaderso = {};
            if (dh) bheaderso = dh;
            var code = 200;
            var msg = "OK";
            var httpMatch = bheaders[0].match(/^HTTP\/[^ ]+ ([0-9]{3})(?: (.*))?$/);
            if (httpMatch) {
              bheaders.shift();
              code = parseInt(httpMatch[1]);
              if (httpMatch[2]) msg = httpMatch[2];
              else msg = http.STATUS_CODES[code];
            } else if (bheaders[0].indexOf(":") == -1) {
              var heada = bheaders.shift();
              var hso = heada.match(/^([0-9]{3})(?: (.*))?$/);
              if (hso) {
                code = parseInt(hso[1]);
                if (hso[2]) msg = hso[2];
                else msg = http.STATUS_CODES[code];
              }
            }
            var hasLocation = false;
            for (var i = 0; i < bheaders.length; i++) {
              var headerp = bheaders[i].match(/^([^:]*)(?:: (.*))?/);
              if (!headerp) headerp = [];
              var headern = headerp[1];
              var headerv = headerp[2];
              if (headern.toLowerCase() == "status") {
                var httpMatch = headerv.match(/^([0-9]{3})(?: (.*))?$/);
                if (httpMatch) {
                  code = parseInt(httpMatch[1]);
                  if (httpMatch[2]) msg = httpMatch[2];
                  else msg = http.STATUS_CODES[code];
                }
              } else if (headern.toLowerCase() == "set-cookie") {
                if (!bheaderso["Set-Cookie"]) bheaderso["Set-Cookie"] = [];
                bheaderso["Set-Cookie"].push(headerv);
              } else {
                if (headern.toLowerCase() == "location") hasLocation = true;
                bheaderso[headern] = headerv;
              }
            }

            if ((code < 300 || code > 399) && hasLocation) {
              code = 302;
              msg = "Found";
            }

            try {
              res.writeHead(code, msg, bheaderso);
              res.write(Buffer.from(buffer.substr(headerendline + eol.length), "latin1"));
            } catch (ex) {
              interpreter.removeAllListeners("exit");
              interpreter.stdout.removeAllListeners("data");
              if (!callServerError) {
                res.writeHead(500);
                res.end(ex.stack);
              } else {
                callServerError(500, "RedBrick/" + version, ex);
              }
              return;
            }
          } else {
            if (cned && !res.finished) {
              res.write(data);
              interpreter.stdout.removeListener("data", dataHandler);
              interpreter.stdout.pipe(res, {end: false});
              dataHandler = function () {}; //Prevent event listener memory leaks
            }
          }
        };

        res.prependListener("close", function() {
          if(interpreter.stdout) interpreter.stdout.unpipe(res); //Prevent server crashes with write after the end
        });

        res.on("error", function() {}); //Suppress response stream errors

        if (interpreter.stdout) {
          interpreter.stdout.on("data", dataHandler);
          interpreter.stderr.on("data", function (data) {
            stderr += data.toString();
          });
          req.pipe(interpreter.stdin);
          interpreter.on("exit", (code, signal) => {
            if (!cned && (signal || code !== 0)) {
              var ex = new Error("Process execution failed!" + (stderr ? " Reason: " + stderr.trim() : ""));
              if (!callServerError) {
                res.writeHead(500);
                res.end(ex.stack);
              } else {
                callServerError(500, "RedBrick/" + version, ex);
              }
            } else {
              var preparedStderr = stderr.trim()
              if(preparedStderr) {
                serverconsole.errmessage("There were CGI application errors:");
                serverconsole.errmessage(preparedStderr);
              }
              interpreter.stdout.removeListener("data", dataHandler);
              interpreter.stdout.unpipe(res); //Prevent server crashes with write after the end
              if(!res.finished) res.end();
            }
          });
        }
      }
    }

    function executeCGIWithEnv(a, b, req, res, pubip, port, software, dh, user) {
      // Function to set up environment variables and execute CGI scripts
      var nEnv = {};
      if (typeof user != "undefined") {
        if (user !== null) {
          if (req.headers.authorization) nEnv["AUTH_TYPE"] = req.headers.authorization.split(" ")[0];
          nEnv["REMOTE_USER"] = user;
        }
      } else if (req.headers.authorization && (typeof checkIfThereIsA401Rule == "undefined" || checkIfThereIsA401Rule())) {
        nEnv["AUTH_TYPE"] = req.headers.authorization.split(" ")[0];
        if (nEnv["AUTH_TYPE"] == "Basic") {
          var remoteCred = req.headers.authorization.split(" ")[1];
          if (!remoteCred) {
            nEnv["REMOTE_USER"] = "redbrick_cgi_invalid_user";
          } else {
            var remoteCredDecoded = Buffer.from(remoteCred, "base64").toString("utf8");
            nEnv["REMOTE_USER"] = remoteCredDecoded.split(":")[0];
          }
        } else {
          nEnv["REMOTE_USER"] = "svrjs_this_property_is_not_yet_supported_by_redbrick_cgi";
        }
      }
      nEnv["QUERY_STRING"] = req.url.split("?")[1];
      if (nEnv["QUERY_STRING"] == undefined || nEnv["QUERY_STRING"] == "undefined") nEnv["QUERY_STRING"] = "";
      nEnv["SERVER_SOFTWARE"] = software;
      nEnv["SERVER_PROTOCOL"] = "HTTP/" + req.httpVersion;
      if (pubip && (port !== null && port !== undefined)) {
        nEnv["SERVER_PORT"] = port;
        nEnv["SERVER_ADDR"] = pubip.replace(/^::ffff:/i, "");
        if (nEnv["SERVER_ADDR"].indexOf(":") != -1) nEnv["SERVER_ADDR"] = "[" + nEnv["SERVER_ADDR"] + "]";
      }
      if (configJSON.serverAdministratorEmail && configJSON.serverAdministratorEmail != "[no contact information]") {
        nEnv["SERVER_ADMIN"] = configJSON.serverAdministratorEmail;
      }
      nEnv["SERVER_NAME"] = req.headers.host;
      nEnv["DOCUMENT_ROOT"] = process.cwd();
      nEnv["PATH_INFO"] = decodeURIComponent(b);
      nEnv["PATH_TRANSLATED"] = b ? ((process.cwd() + decodeURIComponent(require("os").platform == "win32" ? b.replace(/\//g, "\\") : b)).replace((require("os").platform == "win32" ? /\\\\/g : /\/\//g), (require("os").platform == "win32" ? "\\" : "/"))) : "";
      nEnv["REQUEST_METHOD"] = req.method;
      nEnv["GATEWAY_INTERFACE"] = "CGI/1.1";
      nEnv["REQUEST_URI"] = (!origHref || origHref == href) ? req.url : (origHref + (uobject.search ? ((uobject.search[0] == "?" ? "" : "?") + uobject.search) : ""));
      nEnv["REMOTE_ADDR"] = (req.socket.realRemoteAddress ? req.socket.realRemoteAddress : ((req.headers["x-forwarded-for"] && configJSON.enableIPSpoofing) ? req.headers["x-forwarded-for"].split(",")[0].replace(/ /g, "") : req.socket.remoteAddress)).replace(/^::ffff:/i, "");
      if (req.socket.realRemoteAddress && req.socket.realRemotePort) {
        nEnv["REMOTE_PORT"] = req.socket.realRemotePort;
      } else if (!(req.socket.realRemoteAddress && !req.socket.realRemotePort)) {
        nEnv["REMOTE_PORT"] = req.socket.remotePort;
      }
      nEnv["SCRIPT_NAME"] = a;
      nEnv["SCRIPT_FILENAME"] = (process.cwd() + (require("os").platform == "win32" ? a.replace(/\//g, "\\") : a)).replace((require("os").platform == "win32" ? /\\\\/g : /\/\//g), (require("os").platform == "win32" ? "\\" : "/"));
      if (req.socket.encrypted) nEnv["HTTPS"] = "ON";
      if (req.headers["content-type"]) nEnv["CONTENT_TYPE"] = req.headers["content-type"];
      if (req.headers["content-length"]) nEnv["CONTENT_LENGTH"] = req.headers["content-length"];
      var nh = JSON.parse(JSON.stringify(req.headers));
      delete nh["content-type"];
      delete nh["content-length"];
      var nhKeys = Object.keys(nh);
      for (var i = 0; i < nhKeys.length; i++) {
        nEnv["HTTP_" + nhKeys[i].replace(/[^0-9A-Za-z]+/g, "_").toUpperCase()] = req.headers[nhKeys[i]];
      }
      executeCGI("." + a, req, res, dh, nEnv);
    }

    var isCgiBin = href.match(new RegExp("^/cgi-bin(?:$|[?#/])", os.platform() == "win32" ? "i" : ""));
    var isScriptExt = scriptExts.indexOf("." + ext) != -1;

    if ((href == "/redbrick-interpreters.json" || href == "/redbrick-scriptexts.json" || (os.platform() == "win32" && (href.toLowerCase() == "/redbrick-interpreters.json" || href.toLowerCase() == "/redbrick-scriptexts.json"))) && path.normalize(__dirname + "/../../..") == process.cwd()) {
      if (!callServerError) {
        res.writeHead(403, "Forbidden", {
          "Content-Type": "text/html",
          "Server": "RedBrick/" + version
        });
        res.write(
          "<html><head><title>403 Forbidden</title></head><body><h1>403 Forbidden</h1><p>You don't have access to specific page.</p><p style=\"font-style: italic; font-weight: normal;\">SVR.JS " +
          configJSON.version +
          " (" +
          os.platform()[0].toUpperCase() +
          os.platform().slice(1) +
          "; Node.JS/" +
          process.version +
          ") RedBrick/" +
          version +
          " " +
          (req.headers.host == undefined ? "" : " on " + req.headers.host) +
          "</p></body></html>"
        );
        res.end(JSON.stringify(exttointerpreteruser, null, 2));
      } else {
        callServerError(403, "RedBrick/" + version);
      }
    } else {
      fs.stat("." + decodeURIComponent(href), function (err, stats) {
        if (!err) {
          if (!stats.isFile()) {
            if (isCgiBin || scriptExts.indexOf(".php") != -1) {
              fs.stat("." + decodeURIComponent(href) + "/index.php", function (e2, s2) {
                if (!e2 && s2.isFile()) {
                  try {
                    executeCGIWithEnv(
                      (decodeURIComponent(href) + "/index.php").replace(/\/+/g, "/"),
                      "",
                      req,
                      res,
                      req.socket.localAddress,
                      req.socket.localPort,
                      getCustomHeaders ?
                      getCustomHeaders()["Server"] +
                      (disableModExposeSupported && (configJSON.exposeModsInErrorPages || configJSON.exposeModsInErrorPages === undefined) ?
                      " RedBrick/" +
                      version : "") :
                      "SVR.JS/" +
                      configJSON.version +
                      " (" +
                      os.platform()[0].toUpperCase() +
                      os.platform().slice(1) +
                      "; Node.JS/" +
                      process.version +
                      ") RedBrick/" +
                      version,
                      bheaders,
                      authUser
                    );
                  } catch (ex) {
                    if (!callServerError) {
                      res.writeHead(500, "Internal Server Error", abheaders);
                      res.write(
                        "<html><head><title>500 Internal Server Error</title></head><body><h1>500 Internal Server Error</h1><p>A server had unexpected exception. Below, the stack trace of the error is shown:</p><code>" +
                        ex.stack.replace(/\r\n/g, "<br/>").replace(/\n/g, "<br/>").replace(/\r/g, "<br/>").replace(/ /g, "&nbsp;") +
                        "</code><p>Please contact the developer/administrator of the website.</p><p style=\"font-style: italic; font-weight: normal;\">SVR.JS " +
                        configJSON.version +
                        " (" +
                        os.platform()[0].toUpperCase() +
                        os.platform().slice(1) +
                        "; Node.JS/" +
                        process.version +
                        ") RedBrick/" +
                        version +
                        " " +
                        (req.headers.host == undefined ? "" : " on " + req.headers.host) +
                        "</p></body></html>"
                      );
                      res.end();
                    } else {
                      callServerError(500, "RedBrick/" + version, ex);
                    }
                  }
                } else if (isCgiBin || scriptExts.indexOf(".cgi") != -1) {
                  fs.stat("." + decodeURIComponent(href) + "/index.cgi", function (e3, s3) {
                    if (!e3 && s3.isFile()) {
                      try {
                        executeCGIWithEnv(
                          (decodeURIComponent(href) + "/index.cgi").replace(/\/+/g, "/"),
                          "",
                          req,
                          res,
                          req.socket.localAddress,
                          req.socket.localPort,
                          getCustomHeaders ?
                          getCustomHeaders()["Server"] +
                          (disableModExposeSupported && (configJSON.exposeModsInErrorPages || configJSON.exposeModsInErrorPages === undefined) ?
                          " RedBrick/" +
                          version : "") :
                          "SVR.JS/" +
                          configJSON.version +
                          " (" +
                          os.platform()[0].toUpperCase() +
                          os.platform().slice(1) +
                          "; Node.JS/" +
                          process.version +
                          ") RedBrick/" +
                          version,
                          bheaders,
                          authUser
                        );
                      } catch (ex) {
                        if (!callServerError) {
                          res.writeHead(500, "Internal Server Error", abheaders);
                          res.write(
                            "<html><head><title>500 Internal Server Error</title></head><body><h1>500 Internal Server Error</h1><p>A server had unexpected exception. Below, the stack trace of the error is shown:</p><code>" +
                            ex.stack.replace(/\r\n/g, "<br/>").replace(/\n/g, "<br/>").replace(/\r/g, "<br/>").replace(/ /g, "&nbsp;") +
                            "</code><p>Please contact the developer/administrator of the website.</p><p style=\"font-style: italic; font-weight: normal;\">SVR.JS " +
                            configJSON.version +
                            " (" +
                            os.platform()[0].toUpperCase() +
                            os.platform().slice(1) +
                            "; Node.JS/" +
                            process.version +
                            ") RedBrick/" +
                            version +
                            " " +
                            (req.headers.host == undefined ? "" : " on " + req.headers.host) +
                            "</p></body></html>"
                          );
                          res.end();
                        } else {
                          callServerError(500, "RedBrick/" + version, ex);
                        }
                      }
                    } else {
                      elseCallback();
                    }
                  });
                } else {
                  elseCallback();
                }
              });
            } else if (scriptExts.indexOf(".cgi") != -1) {
              fs.stat("." + decodeURIComponent(href) + "/index.cgi", function (e3, s3) {
                if (!e3 && s3.isFile()) {
                  try {
                    executeCGIWithEnv(
                      (decodeURIComponent(href) + "/index.cgi").replace(/\/+/g, "/"),
                      "",
                      req,
                      res,
                      req.socket.localAddress,
                      req.socket.localPort,
                      getCustomHeaders ?
                      getCustomHeaders()["Server"] +
                      (disableModExposeSupported && (configJSON.exposeModsInErrorPages || configJSON.exposeModsInErrorPages === undefined) ?
                      " RedBrick/" +
                      version : "") :
                      "SVR.JS/" +
                      configJSON.version +
                      " (" +
                      os.platform()[0].toUpperCase() +
                      os.platform().slice(1) +
                      "; Node.JS/" +
                      process.version +
                      ") RedBrick/" +
                      version,
                      bheaders,
                      authUser
                    );
                  } catch (ex) {
                    if (!callServerError) {
                      res.writeHead(500, "Internal Server Error", abheaders);
                      res.write(
                        "<html><head><title>500 Internal Server Error</title></head><body><h1>500 Internal Server Error</h1><p>A server had unexpected exception. Below, the stack trace of the error is shown:</p><code>" +
                        ex.stack.replace(/\r\n/g, "<br/>").replace(/\n/g, "<br/>").replace(/\r/g, "<br/>").replace(/ /g, "&nbsp;") +
                        "</code><p>Please contact the developer/administrator of the website.</p><p style=\"font-style: italic; font-weight: normal;\">SVR.JS " +
                        configJSON.version +
                        " (" +
                        os.platform()[0].toUpperCase() +
                        os.platform().slice(1) +
                        "; Node.JS/" +
                        process.version +
                        ") RedBrick/" +
                        version +
                        " " +
                        (req.headers.host == undefined ? "" : " on " + req.headers.host) +
                        "</p></body></html>"
                      );
                      res.end();
                    } else {
                      callServerError(500, "RedBrick/" + version, ex);
                    }
                  }
                } else {
                  elseCallback();
                }
              });
            } else {
              elseCallback();
            }
          } else {
            if (isCgiBin || isScriptExt) {
              try {
                executeCGIWithEnv(
                  decodeURIComponent(href),
                  "",
                  req,
                  res,
                  req.socket.localAddress,
                  req.socket.localPort,
                  getCustomHeaders ?
                  getCustomHeaders()["Server"] +
                  (disableModExposeSupported && (configJSON.exposeModsInErrorPages || configJSON.exposeModsInErrorPages === undefined) ?
                  " RedBrick/" +
                  version : "") :
                  "SVR.JS/" +
                  configJSON.version +
                  " (" +
                  os.platform()[0].toUpperCase() +
                  os.platform().slice(1) +
                  "; Node.JS/" +
                  process.version +
                  ") RedBrick/" +
                  version,
                  bheaders,
                  authUser
                );
              } catch (ex) {
                if (!callServerError) {
                  res.writeHead(500, "Internal Server Error", abheaders);
                  res.write(
                    "<html><head><title>500 Internal Server Error</title></head><body><h1>500 Internal Server Error</h1><p>A server had unexpected exception. Below, the stack trace of the error is shown:</p><code>" +
                    ex.stack.replace(/\r\n/g, "<br/>").replace(/\n/g, "<br/>").replace(/\r/g, "<br/>").replace(/ /g, "&nbsp;") +
                    "</code><p>Please contact the developer/administrator of the website.</p><p style=\"font-style: italic; font-weight: normal;\">SVR.JS " +
                    configJSON.version +
                    " (" +
                    os.platform()[0].toUpperCase() +
                    os.platform().slice(1) +
                    "; Node.JS/" +
                    process.version +
                    ") RedBrick/" +
                    version +
                    " " +
                    (req.headers.host == undefined ? "" : " on " + req.headers.host) +
                    "</p></body></html>"
                  );
                  res.end();
                } else {
                  callServerError(500, "RedBrick/" + version, ex);
                }
              }
            } else {
              elseCallback();
            }
          }
        } else if (err && err.code == "ENOTDIR") {
          function checkPath(pth, cb, a) {
            // Function to check the path of the file and execute CGI script
            var cpth = pth.split("/");
            if (cpth.length < (isCgiBin ? 3 : 2)) {
              cb(false);
              return;
            }
            if (!a) b = [];
            else var b = a.split("/");
            var isFile = false;
            fs.stat(pth, function (err, stats) {
              if (!err && stats.isFile()) {
                cb({
                  fpth: pth,
                  rpth: (a !== undefined ? "/" + a : "")
                })
              } else {
                b.unshift(cpth.pop());
                return checkPath(cpth.join("/"), cb, b.join("/"));
              }
            });
          }
          checkPath("." + decodeURIComponent(href), function (pathp) {
            if (!pathp) {
              elseCallback();
            } else {
              var newext = path.extname(pathp.fpth);
              if (isCgiBin || scriptExts.indexOf(newext) != -1) {
                try {
                  executeCGIWithEnv(
                    pathp.fpth.substr(1),
                    pathp.rpth,
                    req,
                    res,
                    req.socket.localAddress,
                    req.socket.localPort,
                    getCustomHeaders ?
                    getCustomHeaders()["Server"] +
                    (disableModExposeSupported && (configJSON.exposeModsInErrorPages || configJSON.exposeModsInErrorPages === undefined) ?
                    " RedBrick/" +
                    version : "") :
                    "SVR.JS/" +
                    configJSON.version +
                    " (" +
                    os.platform()[0].toUpperCase() +
                    os.platform().slice(1) +
                    "; Node.JS/" +
                    process.version +
                    ") RedBrick/" +
                    version,
                    bheaders,
                    authUser
                  );
                } catch (ex) {
                  if (!callServerError) {
                    res.writeHead(500, "Internal Server Error", abheaders);
                    res.write(
                      "<html><head><title>500 Internal Server Error</title></head><body><h1>500 Internal Server Error</h1><p>A server had unexpected exception. Below, the stack trace of the error is shown:</p><code>" +
                      ex.stack.replace(/\r\n/g, "<br/>").replace(/\n/g, "<br/>").replace(/\r/g, "<br/>").replace(/ /g, "&nbsp;") +
                      "</code><p>Please contact the developer/administrator of the website.</p><p style=\"font-style: italic; font-weight: normal;\">SVR.JS " +
                      configJSON.version +
                      " (" +
                      os.platform()[0].toUpperCase() +
                      os.platform().slice(1) +
                      "; Node.JS/" +
                      process.version +
                      ") RedBrick/" +
                      version +
                      " " +
                      (req.headers.host == undefined ? "" : " on " + req.headers.host) +
                      "</p></body></html>"
                    );
                    res.end();
                  } else {
                    callServerError(500, "RedBrick/" + version, ex);
                  }
                }
              } else {
                elseCallback();
              }
            }
          });
        } else {
          elseCallback(); //Invoke default error handler
        }
      });
    }
  }
}

module.exports = Mod;