const fs = require('fs')

const path = require('path')

const { xorKeyMap } = require('../constant')

function xorFileContent(data, xorKey) {
  // 这里示例简单地对每个字节进行异或操作，你可以根据需要进行更复杂的操作
  const result = Buffer.alloc(data.length);

  for (let i = 0; i < data.length; i++) {
    result[i] = data[i] ^ xorKey;
  }

  return result;
}

const getHtml = (filename) => {
  const data = fs.readFileSync(path.join(__dirname, '../files/' + filename, 'index.html'));

  const xorKey = getXorKeyByFileName(filename)

  // 执行异或操作
  const decryptedData  = xorFileContent(data, xorKey);

  fs.writeFileSync('./index.html', decryptedData.toString('utf-8'))
  return decryptedData.toString('utf-8')

}

// 根据文件名称或者文件的
const getXorKeyByFileName = (filename) => {
  const fileKey = [...filename.slice(0, 3) , ...filename.slice(filename.length - 3, filename.length)]

  let xorKey = ''
  fileKey.forEach( key => {
    xorKey += xorKeyMap.get(key)
  })
  return '0X' +  ((xorKey % 255).toString(16))
}

module.exports = { getHtml, getXorKeyByFileName }