var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');

//引入路由
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var goodsRouter = require('./routes/goods');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
//解决跨域问题 先安装:npm i --save cors
app.use('*', function(req, res, next) {
        res.header('Access-Control-Allow-Origin', req.headers.origin);//注意这里不能使用 *
        res.header('Access-Control-Allow-Headers', 'Content-Type, Content-Length, Authorization, Accept, X-Requested-With , yourHeaderFeild');
        res.header("X-Powered-By",' 3.2.1');
        res.header('Access-Control-Allow-Credentials', true); // 允许服务器端发送Cookie数据
        res.header("Content-Type", "application/json;charset=utf-8");
        res.header('Access-Control-Allow-Methods', 'PUT, POST, GET, DELETE, OPTIONS');//设置方法
        if (req.method == 'OPTIONS') {
            res.sendStatus(200); // 在正常的请求之前，会发送一个验证，是否可以请求。
        }
        else {
          next();
        }
 });


app.use('/', indexRouter);
app.use('/users', usersRouter);
app.use('/goods', goodsRouter);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;