const files = process.argv.slice(2);

 function main(){
   if (!files.length) {
     console.log('Please provide at least one .uc file to decode.')
     return
   }
   files.forEach(async name => {
     await decodeFile(name);
   })
 }

 function decodeFile(name){
   try {
     if (fs.statSync(name+'.mp3').isFile()){
       console.log('Skip ' + name);
       return Promise.resolve();
     }
   } catch (e) {}
   const fileIn = fs.createReadStream(name);
   const fileOut = fs.createWriteStream(name+'.mp3');

   console.log('Processing: ' + name);
   fileIn.on('data',(chunk) => {
     fileOut.write(Buffer.from([...chunk].map(d=>d^0xa3)))
   });

   return new Promise((res, rej)=>{
     fileIn.on('end',() => {
       console.log('Finished: ' + name);
       fileOut.end();
       res();
     })
   });
 }

 main();