text: var express = require('express');
  var path = require('path');
  var favicon = require('serve-favicon');
  var cookieParser = require('cookie-parser');
  var bodyParser = require('body-parser');
  var helmet = require('helmet');
  var config = require('./core/config');
  var _ = require('lodash');
  var fs = require('fs');
  
  var routes = require('./routes/index');
  var auth = require('./routes/auth');
  var accessKeys = require('./routes/accessKeys');
  var sessions = require('./routes/sessions');
  var account = require('./routes/account');
  var users = require('./routes/users');
  var apps = require('./routes/apps');
  var AppError = require('./core/app-error');
  var log4js = require('log4js');
  var log = log4js.getLogger("cps:app");
  var app = express();
  app.use(helmet());
  app.disable('x-powered-by');
  // view engine setup
  app.set('views', path.join(__dirname, 'views'));
  app.set('view engine', 'pug');
  
  app.use(log4js.connectLogger(log4js.getLogger("http"), {level: log4js.levels.INFO, nolog:'\\.gif|\\.jpg|\\.js|\\.css$' }));
  
  app.use(bodyParser.json());
  app.use(bodyParser.urlencoded({ extended: false }));
  app.use(cookieParser());
  app.use(express.static(path.join(__dirname, 'public')));
  
  //use nginx in production
  if (app.get('env') === 'development') {
    log.debug("set Access-Control Header");
    app.all('*', function(req, res, next) {
      res.header("Access-Control-Allow-Origin", "*");
      res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization");
      res.header("Access-Control-Allow-Methods","PUT,POST,GET,PATCH,DELETE,OPTIONS");
      log.debug("use set Access-Control Header");
      next();
    });
  }
  
  log.debug("config common.storageType value: " + _.get(config, 'common.storageType'));
  
  if (_.get(config, 'common.storageType') === 'local') {
    var localStorageDir = _.get(config, 'local.storageDir');
    if (localStorageDir) {
  
      log.debug("config common.storageDir value: " + localStorageDir);
  
      if (!fs.existsSync(localStorageDir)) {
        var e = new Error(`Please create dir ${localStorageDir}`);
        log.error(e);
        throw e;
      }
      try {
        log.debug('checking storageDir fs.W_OK | fs.R_OK');
        fs.accessSync(localStorageDir, fs.W_OK | fs.R_OK);
        log.debug('storageDir fs.W_OK | fs.R_OK is ok');
      } catch (e) {
        log.error(e);
        throw e;
      }
      log.debug("static download uri value: " + _.get(config, 'local.public', '/download'));
      app.use(_.get(config, 'local.public', '/download'), express.static(localStorageDir));
    } else {
      log.error('please config local storageDir');
    }
  }
  
  app.use('/codepush/', routes);
  app.use('/codepush/auth', auth);
  app.use('/codepush/accessKeys', accessKeys);
  app.use('/codepush/sessions', sessions);
  app.use('/codepush/account', account);
  app.use('/codepush/users', users);
  app.use('/codepush/apps', apps);
  
  // development error handler
  // will print stacktrace
  if (app.get('env') === 'development') {
    app.use(function(req, res, next) {
      var err = new AppError.NotFound();
      res.status(err.status || 404);
      res.render('error', {
        message: err.message,
        error: err
      });
      log.error(err);
    });
    app.use(function(err, req, res, next) {
      if (err instanceof AppError.AppError) {
        res.send(err);
        log.debug(err);
      } else {
        res.status(err.status || 500);
        res.render('error', {
          message: err.message,
          error: err
        });
        log.error(err);
      }
    });
  } else {
    app.use(function(req, res, next) {
      var e = new AppError.NotFound();
      res.status(404).send(e);
      log.debug(e);
    });
    // production error handler
    // no stacktraces leaked to user
    app.use(function(err, req, res, next) {
      if (err instanceof AppError.AppError) {
        res.send(err);
      } else {
        var status = err.status || 500;
        var error = new AppError.AppError(`服务器繁忙，请稍后再试!`);
        error.status = status;
        res.status(status).send(error);
        log.error(err);
      }
    });
  }
  
  module.exports = app;
  