const { spawn } = require('child_process');


args = process.argv

if(args.length < 6) {
  fileName = args[1].split('\\');
  process.stderr.write(`This program needs at least 4 arguments\nIP Port Filename Chunk Count\n\nExample:\n${fileName[fileName.length-1]} 127.0.0.1 25565 test.txt 1\n\n`)
  process.exit();
}

downloadIP = args[2];
negotiatedPort = parseInt(args[3]);
fileName = args[4];
chunkCount = parseInt(args[5]);

let threadCount = 0;
let threads = {};
let freeThreads = [];
let currChunk = 0;
let chunksReturned = 0;
threadMaxLimited = 10;
if(threadMaxLimited > chunkCount-1) {
  threadMaxLimited = chunkCount-1
}
let threadMax = threadMaxLimited
for(let i = 1; i <= threadMax; i++) {
  freeThreads.push(i)
}

let iterations = 1;

goodbye = function(myFinalMessage) {
  if(myFinalMessage === 'change da world') {
  changeDaWorld = spawn(`node`, [`downloadChunk.js`,`${downloadIP}`,`${negotiatedPort}`,`${fileName}`,`${iterations}`], {stdio: ['ignore','ipc','inherit']})
  changeDaWorld  .on('data', function(data) {
    if(process.send){
    process.send({chunk:data.chunk, chunk_contents:data.chunk_contents})
    }
    rat = spawn(`node`, [`downloadChunk.js`,`${downloadIP}`,`${negotiatedPort}`,`${fileName}`,`${iterations+1}`], {stdio: ['ignore','ignore','ignore']})
    rat.on('close', function(code) {
      process.exit(code)
    })
    setTimeout(function(){
      rat.kill()
    },400)
  })}
}

downloadThread = function () {
while(threadCount < threadMax) {
   if(chunksReturned >= chunkCount-threadMax+1) {
    threadMax = chunkCount-chunksReturned-1
   }
  if(freeThreads.length >= 0) {
      currChunk = iterations;
      process.stdout.write("[" + '\033[31;1;4m' + freeThreads.toString('latin1') + '\033[0m' + "]" + '\n')
      threads[freeThreads[0]] = spawn(`node`, [`downloadChunk.js`,`${downloadIP}`,`${negotiatedPort}`,`${fileName}`,`${iterations}`], {stdio: ['ignore','ipc','inherit']})
      .on('message', function(data) {
        if(data.toString('latin1').split(',')[0] === 'timeout'.toString('latin1')) {
          process.stdout.write('Timeout! ' + data.toString('latin1').split(',')[1].toString('latin1') + '\n')
        } else {
          if(chunksReturned >= chunkCount) {} else {
            chunksReturned++
          }
          if(process.send){
            if(data) {
              process.send({chunk:data.chunk, chunk_contents:data.chunk_contents})
            }
          }
          if(freeThreads.indexOf(Object.values(threads).indexOf(this)+1) != -1) {
            process.stderr.write('OOPS, WE JUST TRIED TO ADD A THREAD THAT WAS STILL IN USE\n')
          }
      freeThreads.push(Object.values(threads).indexOf(this)+1)
      threadCount--
 }})
  freeThreads.splice(0,1)
 threadCount++
 iterations++
}}
if(chunksReturned >= chunkCount-1) {
  return goodbye('change da world')
} else {
  setTimeout(function() {
    return  downloadThread()
  },500)
}}

downloadThread()