als-store/lib/name-params.js

Library for streamlined file management and advanced data caching, featuring intelligent file searching, dynamic cache control, and flexible file operations

const os = require('os')
const platform = os.platform()
const windowsInvalidChars = /[<>:"\/\\|?*\x00-\x1F]/g;
const windowsReservedNames = /^(con|prn|aux|nul|com[0-9]|lpt[0-9])(\.[^.]*)?$/i;
const isValidFilename = require('als-filename-validator')
function encode(value) {
   if (value === undefined) return ''
   if (value === null) return 'null'
   if (value === NaN) return 'NaN'
   if (typeof value !== 'string') return value.toString()
   value = value.replace(/\./g, '[.]')
   if (platform !== 'win32') return value

   value = value.replace(windowsInvalidChars, (char) => {
      return "_x" + char.charCodeAt(0).toString(16).toUpperCase();
   });

   value = value.replace(windowsReservedNames, (match) => {
      return "_r" + match.split('').map(c => c.charCodeAt(0).toString(16).toUpperCase()).join('');
   });

   return value;
}

function decode(value) {
   if (value === 'undefined' || value === '' || value === '[^]') return undefined
   if (value === 'null') return null
   if (value === 'NaN') return NaN
   if (typeof value !== 'string') return value
   value = value.replace(/\[\.\]/g, '.')
   value = value.replace(/^\[\^\]/, '')

   if (platform !== 'win32') return value
   
   value = value.replace(/_x([0-9A-F]{2})/g, (match, charCode) => {
      return String.fromCharCode(parseInt(charCode, 16));
   });

   value = value.replace(/_r([0-9A-F]+)/g, (match, hexString) => {
      let chars = [];
      for (let i = 0; i < hexString.length; i += 2) {
         chars.push(String.fromCharCode(parseInt(hexString.substr(i, 2), 16)));
      }
      return chars.join('');
   });

   return value;
}

function paramsToName(params) {
   if(params.length === 0) throw new Error('should be at lease one value')
   const keys = Object.keys(params)
   let name = keys.map(key => encode(params[key])).join('.')
   while (name.endsWith('.')) {name = name.slice(0, -1)} // remove dots in the end
   if (name === '' && keys.length === 1) name = '[^]'
   if (isValidFilename(name, platform)) return name
   else throw new Error(`${name} is not valid file name`)
}

function nameToParams(name) {
   return name.split(/(?<!\[\.)\.(?!\])/).map(v => decode(v))
}

module.exports = {nameToParams,paramsToName,encode,decode}