var http = require('http')
var fs = require('fs')

http.get("http://www.youtube.com/get_video_info?video_id=F_CvDj8pLo0", function(res) {
  //console.log("Got response: " + res.statusCode);
  var chunks = []
  res.on('data', function(chunk){chunks.push(chunk)
  }).on('end', function(){
    var data = Buffer.concat(chunks).toString()
	var videoInfo = parseVideoInfo(data)
	downloadVideo(videoInfo)
  })
}).on('error', function(e) {
  console.log("Got error: " + e.message)
});

function parseVideoInfo(videoInfo) {
	var rxUrlMap = /url_encoded_fmt_stream_map=([\]\[!"#$%'()*+,.\/:;<=>?@\^_`{|}~-\w]*)/
	urlmap = unescape(videoInfo.match(rxUrlMap)[1])
	//console.log(urlmap);
	var rxUrlG = /url=([\]\[!"#$%'()*+,.\/:;<=>?@\^_`{|}~-\w]*)/g
	var rxUrl  = /url=([\]\[!"#$%'()*+,.\/:;<=>?@\^_`{|}~-\w]*)/
	urls = urlmap.match(rxUrlG)
	urls = map(urls, function(s) {return s.match(rxUrl)[1]} )
	urls = map(urls, unescape)
	//console.log(urls[0])
	return { title:"test", urls: urls }
}

function downloadVideo(videoInfo) {
	var url = videoInfo.urls[0];
	var filename = videoInfo.title + ".flv"
	http.get(url,
	  function(res) {
		var stream = fs.createWriteStream(filename)
		res.pipe(stream)
	  })
	console.log("Downloading to "+filename);
}

function map (a,f) {
	for(i=0;i<a.length;i++){
		a[i]= f(a[i])
	}
	return a
}