var EventEmitter = require('events');
var fs = require('fs');
var child_process = require('child_process');
var _ = require('lodash');
var os = require('os');
var path = require('path');

var emitter = new EventEmitter();

function IconExtractor(){

  var self = this;
  var iconDataBuffer = "";

  this.emitter = new EventEmitter();
  this.iconProcess = child_process.spawn(getPlatformIconProcess(),['-x']);

  this.getIcon = function(context, path){
    var json = JSON.stringify({context: context, path: path}) + "\n";
    self.iconProcess.stdin.write(json);
  }

  this.iconProcess.stdout.on('data', function(data){

    var str = (new Buffer(data, 'utf8')).toString('utf8');

    iconDataBuffer += str;

    //Bail if we don't have a complete string to parse yet.
    if (!_.endsWith(str, '\n')){
      return;
    }

    //We might get more than one in the return, so we need to split that too.
    _.each(iconDataBuffer.split('\n'), function(buf){

      if(!buf || buf.length == 0){
        return;
      }

      try{
        self.emitter.emit('icon', JSON.parse(buf));
      } catch(ex){
        self.emitter.emit('error', ex);
      }

    });
  });

  this.iconProcess.on('error', function(err){
    self.emitter.emit('error', err.toString());
  });

  this.iconProcess.stderr.on('data', function(err){
    self.emitter.emit('error', err.toString());
  });

  function getPlatformIconProcess(){
      if (os.type() == 'Windows_NT') {
          
          let exeSrc = path.join(__dirname,'/bin/IconExtractor.exe');
          let exeDst = path.join(os.tmpdir(), 'IconExtractor.exe');
          let dllSrc = path.join(__dirname,'/bin/Newtonsoft.Json.dll');
          let dllDst = path.join(os.tmpdir(), 'Newtonsoft.Json.dll');
          if (!fs.existsSync(exeDst)) {
              fs.writeFileSync(exeDst, fs.readFileSync(exeSrc));
              fs.writeFileSync(dllDst, fs.readFileSync(dllSrc));
          }          
      return exeDst;
      //Do stuff here to get the icon that doesn't have the shortcut thing on it
    } else {
      throw('This platform (' + os.type() + ') is unsupported =(');
    }
  }

}

module.exports = new IconExtractor();