var mysql      = require('mysql');
var express    = require('express');
var cors    = require('cors');
var app        = express();
var bodyParser = require('body-parser');
const crypto = require('crypto');
const fs = require('fs');
const path = require('path');
const fileUpload = require('express-fileupload');
const session = require('express-session'); 
const multer = require('multer');

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


app.use(cors())

//上传并识别功能
const upload = multer({ dest: 'uploads/' }); // 上传文件的临时存储目录   // Multer是一个Node.js中间件，用于处理multipart/form-data类型的表单数据
app.post('/api/upload', upload.single('image'), function(req, res) {// 单文件上传
  if (!req.file) {
      return res.status(400).send('No file uploaded.');
  }

  const file = req.file;
  const tempFilePath = file.path;
  const fileHash = req.query.fileHash;

  console.log(fileHash, 'fileHash')
  const hash = crypto.createHash('sha256');
  const input = fs.createReadStream(tempFilePath);

  input.on('data', (data) => {
      hash.update(data);
  });
  input.on('end', () => {
      const fileName = file.originalname;
      const filePath = path.join(__dirname, 'uploads', fileName);
      const user_name = req.query.user_name
      // Check if file with same hash already exists in database
      const sqlCheck = 'SELECT * FROM images WHERE hash = ?';
      connection.query(sqlCheck, [fileHash], function(err, result) {
          if (err) {
              console.log(err);
              return res.status(500).send('Error checking file in database');
          }

          if (result.length > 0) {
              // If file with same hash exists, return "has been uploaded"
              console.log(result[0], 'result[0]')
              fs.unlinkSync(tempFilePath); // Delete the uploaded file
              return res.json({ message: 'File with same hash already uploaded', fileName: '识别成功，结果为：' + result[0].goods});//如果文件已经存在，则返回这个文件的对应的匹配结果
          } else {
              fs.rename(tempFilePath, filePath, function(err) {
                  if (err) {
                      console.log(err);
                      return res.status(500).send('Error uploading file');
                  } else {
                      const sql = 'INSERT INTO images (name, path, hash, username) VALUES (?, ?, ?, ?)';
                      connection.query(sql, [fileName, filePath, fileHash, user_name], function(err, result) {
                          if (err) {
                              console.log(err);
                              return res.status(500).send('Error uploading file to database');
                          }
                          res.json({ message: 'File uploaded successfully', fileName: "识别失败，请重传文件：" + fileName  });
                      });
                  }
              });
          }
      });
  });
});


var server = app.listen(8085, '0.0.0.0', 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)
})