const { sep } = require('path')
const { homedir } = require('os')
const fs = require('fs')
const { canWrite } = require('./index.js')

let homedata = homedir()
let userdata = ""
let musicdata = ""

function checkPath(path){
  if (path === "") return ""
  if (!fs.existsSync(path)) return ""
  if (!canWrite(path)) return ""
  return path
}

function getConfigFolder(){
  if (userdata != "") return userdata
  if (process.env.XDG_CONFIG_HOME && userdata === ""){
    userdata = `${process.env.XDG_CONFIG_HOME}${sep}`
    userdata = checkPath(userdata)
  }
  if (process.env.APPDATA && userdata === ""){
    userdata = `${process.env.APPDATA}${sep}`
    userdata = checkPath(userdata)
  }
  if (process.platform == "darwin" && userdata === ""){
    userdata = `${homedata}/Library/Application Support/`
    userdata = checkPath(userdata)
  }
  if (userdata === ""){
    userdata = `${homedata}${sep}.config${sep}`
    userdata = checkPath(userdata)
  }

  if (userdata === "") userdata = `${process.cwd()}${sep}config${sep}`
  else userdata += `deemix${sep}`

  if (process.env.DEEMIX_DATA_DIR) userdata = process.env.DEEMIX_DATA_DIR
  return userdata
}

function getMusicFolder(){
  if (musicdata != "") return musicdata
  if (process.env.XDG_MUSIC_DIR && musicdata === ""){
    musicdata = `${process.env.XDG_MUSIC_DIR}${sep}`
    musicdata = checkPath(musicdata)
  }
  if (fs.existsSync(`${homedata}${sep}.config${sep}user-dirs.dirs`)){
    const userDirs = fs.readFileSync(`${homedata}${sep}.config${sep}user-dirs.dirs`).toString()
    musicdata = userDirs.match(/XDG_MUSIC_DIR="(.*)"/)[1]
    musicdata = musicdata.replace(/\$([A-Z_]+[A-Z0-9_]*)/ig, (_, envName) => process.env[envName])
    musicdata += sep
    musicdata = checkPath(musicdata)
  }
  if (process.platform == 'win32' && musicdata === ""){
    try {
      const { execSync } = require('child_process')
      const musicKeys = ["My Music", "{4BD8D571-6D19-48D3-BE97-422220080E43}"]
      let regData = execSync('reg.exe query "HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Shell Folders"').toString().split('\r\n')
      for (let i = 0; i < regData.length; i++){
        let line = regData[i]
        if (line === "") continue
        if (i == 1) continue
        line = line.split('    ')
        if (musicKeys.includes(line[1])){
          musicdata = line[3] + sep
          break;
        }
      }
      musicdata = checkPath(musicdata)
    } catch {/* empty */}
  }
  if (musicdata === ""){
    musicdata = `${homedata}${sep}Music${sep}`
    musicdata = checkPath(musicdata)
  }

  if (musicdata === "") musicdata = `${process.cwd()}${sep}music${sep}`
  else musicdata += `deemix Music${sep}`

  if (process.env.DEEMIX_MUSIC_DIR) musicdata = process.env.DEEMIX_MUSIC_DIR
  return musicdata
}

module.exports = {
  getConfigFolder,
  getMusicFolder
}