#!/usr/bin/perl
use strict;
use warnings;
use LWP::Simple;
use LWP::UserAgent;

# shamelessly reversed engineered from a python script :-) 

print "starting first page retrieval\n";
my $urlin  = shift || "http://youtube.com/watch?v=NeiLBET8Cdk";
my $content = get( $urlin  ) or die "argh : $!\n"; 
print "done first page retrieval : $urlin\n";

# print "$content" ;
# regex for 2 key text strings which identify the video file
# the second one $2 is unique for each download attempt
# $content =~ /player2\.swf\?video_id=([^&]+)&.*t=([^&]+)&/ ;

$content =~ /<title>(.*)<\/title>/ ;
my $infile = $1.'.flv' ;

$content =~ /watch_fullscreen\?video_id=([^&]+)&.*t=([^&]+)&/ ;
print $1, "\n" , $2, "\n";  

#http://www.youtube.com/get_video?video_id=p_YMigZmUuk&t=OEgsToPDskLRl9-iKyfQVcNT8xes2OIT
my $get_url = 'http://www.youtube.com/get_video?video_id='.$1.'&t='.$2;

print "gettin video file : $infile\n";

# don't buffer the prints to make the status update
$| = 1;

open(IN,"> $infile") or die "$_\n"; 

my $ua = LWP::UserAgent->new();
my $received_size = 0;
my $url = $get_url;
print "Fetching $url\n";
my $request_time = time;
my $last_update = 0;
my $response = $ua->get($url,
                        ':content_cb'     => \&callback,
                        ':read_size_hint' => 8192,
                       );
print "\n";
close IN;

#play the flv file with mplayer
# system( "mplayer $infile" );

#############################################

sub callback {
  my ($data, $response, $protocol) = @_;

  my $total_size = $response->header('Content-Length') || 0;
  $received_size += length $data;

  # write the $data to a filehandle or whatever should happen
  # with it here.
  print IN $data;

  my $time_now = time;

  # this to make the status only update once per second.
  return unless $time_now > $last_update or $received_size == $total_size;
  $last_update = $time_now;

  print "\rReceived $received_size bytes";
  printf " (%i%%)", (100/$total_size)*$received_size if $total_size;
  printf " %6.1f/bps", $received_size/(($time_now-$request_time)||1)
     if $received_size;
}

__END__