const fs = require('fs');
const path = require('path');
const crypto = require('crypto');
const Koa = require('koa');
const Router = require('koa-router');
const koaBody = require('koa-body');
const send = require('koa-send');

const app = new Koa();
const router = new Router();
const SECRET = "?"


app.use(koaBody({
  multipart: true,
  formidable: {
      maxFileSize: 2000 * 1024 * 1024 
  }
}));


router.post('/uploadfile', async (ctx, next) => {
    const file = ctx.request.body.files.file;
    const reader = fs.createReadStream(file.path);
    let fileId = crypto.createHash('md5').update(file.name + Date.now() + SECRET).digest("hex");
    let filePath = path.join(__dirname, 'upload/') + fileId
    const upStream = fs.createWriteStream(filePath);
    reader.pipe(upStream)
    return ctx.body = "Upload success ~, your fileId is here：" + fileId;
  });


router.get('/downloadfile/:fileId', async (ctx, next) => {
  let fileId = ctx.params.fileId;
  ctx.attachment(fileId);
  try {
    await send(ctx, fileId, { root: __dirname + '/upload' });
  }catch(e){
    return ctx.body = "SCTF{no_such_file_~}"
  }
});


router.get('/', async (ctx, next) => {
  ctx.response.type = 'html';
  ctx.response.body = fs.createReadStream('index.html');
  
});

app.use(router.routes());
app.listen(3333, () => {
  console.log('This server is running at port: 3333')
})