var mysql      = require('mysql');

var connection = mysql.createConnection({
  host     : 'localhost',
  port     : '13307',
  user     : 'root',
  password : '123456',
  database : 'mailbox'
});

var express    = require('express');
var app        = express();
var bodyParser = require('body-parser');

// 创建 application/x-www-form-urlencoded 编码解析
var urlencodedParser = bodyParser.urlencoded({ extended: false })

app.use(express.static('static'));

app.get('/', function (req, res) {
  var result_string = build_html_head('识别系统') + '<h2>欢迎来到识别系统！</h2>\r\n';

  result_string +='<table width="90%" class="table">\r\n';
  result_string +='<tr><th>用户名</th><th>密码</th><th>身份</th><th>备注</th></tr>\r\n';

  connection.query('SELECT * FROM mail;', function (error, results, fields) {
    if (error) {
      console.log('[SELECT ERROR] - ',error.message);
      return;
    }
    console.log('[SELECT SUCCESS]');
    for (var i = results.length - 1; i >= 0; i--) {
      result_string +='<tr>\r\n';
      result_string += ('  <td>'
        + results[i].name
        + '</td><td>'
        + results[i].passwd
        + '</td><td>'
        + results[i].id
        + '</td><td>'
        + results[i].msg
        +  '</td>\r\n');
      result_string +='</tr>\r\n';
    }
    result_string +='</table>\r\n';
    result_string +='<a class="link_button" href="form.html">注册用户</a>\r\n'

    result_string +='<div style="text-align: right;">\r\n';
    result_string +='<a class="link_button" href="welcome.html" >登陆界面</a>\r\n';
    result_string +='</div>\r\n';

    res.send(result_string + build_html_foot())
  });
})


// 文件上传接口
app.post('/fileUpload', function(req, res){
  // 上传的文件在req.files中
  const filename = req.files[0].path + pathLib.parse(req.files[0].originalname).ext
  console.log(filename);
  fs.rename(req.files[0].path, filename, function(err){
    if(err){
      res.send(err)
    }else{
     res.send('upload successfully')
     console.log('[上传成功]' + filename);
    }
  })
})


const session = require('express-session');
app.use(session({
    secret: 'your_secret_key', // 密钥用于会话加密
    resave: false,
    saveUninitialized: true,
    cookie: {
        maxAge: 60000 // 会话过期时间，单位是毫秒
    }
}));

//登录功能
app.post('/login', urlencodedParser, function(req, res) {
  var username = req.body.username;
  var password = req.body.passwd;
  
  // 查询数据库中是否存在匹配的用户名和密码
  connection.query('SELECT * FROM mail WHERE name = ? AND passwd = ?', [username, password], function(error, results, fields) {
    if (error) {
        console.log('[SELECT ERROR] - ', error.message);
        res.send('数据库查询错误！'); // 可以重定向到登录页面或其他处理方式
        return;
    }     
    if (results.length > 0) {
        // 登录成功
        //req.session.username = username; // 将用户名存储在session中
        res.redirect('/work1.html?username=' + username + '&userid=' + results[0].id); // 登录成功后重定向到首页或其他页面
    } else {
        // 登录失败，可以重定向到登录页面并显示错误信息
        console.log('[用户名或密码不正确]');
        res.send('<script>alert("用户名或密码不正确");window.location.href="welcome.html";</script>');  

    } 
  });
})

app.post('/idcheck', urlencodedParser, function(req, res) {
  var username = req.body.username;

  connection.query('SELECT id FROM mail WHERE name = ?', [username], function(error, results, fields) {
      if (error) {
          console.log('[SELECT ERROR] - ', error.message);
          res.send('数据库查询错误！');
          return;
      }

      if (results.length > 0 && results[0].id === 'admin') {
          res.send({ userid: 'admin' });
      } else {
          res.send({ userid: '' });
      }
  });
});


app.post('/insertrecord', urlencodedParser, function (req, res) {
  var insert_sql = 'INSERT INTO mail(name, passwd, id, msg) VALUES(?,?,?,?)';
  var insert_params = [req.body.name, req.body.passwd, req.body.id, req.body.msg];

  connection.query(insert_sql, insert_params, function(error, result) {
    if (error) {
      console.log('[INSERT ERROR] - ',error.message);
      return;
    }
    console.log('[INSERT SUCCESS]');
  });
  res.redirect('/');
})

function build_html_head(title) {
  var html_fragment = '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 '
    +'Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">\r\n';
  html_fragment += '<html lang="en">\r\n';
  html_fragment += '<head>\r\n';
  html_fragment += '  <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">\r\n';
  html_fragment += '  <title>' + title +'</title>\r\n';
  html_fragment += '  <link rel="stylesheet" href="style.css">\r\n';
  html_fragment += '</head>\r\n';
  html_fragment += '<body>\r\n';
  return html_fragment;
}

function build_html_foot() {
  return '</body>\r\n</html>';
}


var server = app.listen(8081, function () {

  var host = server.address().address
  var port = server.address().port

  connection.connect(function(err){
      if(err){
            console.log('[query] - :'+err);
          return;
      }
        console.log('[connection connect]  succeed!');
  });

  console.log("应用实例，访问地址为 http://%s:%s", host, port)
})