#!/usr/bin/perl -w

use Proc::Daemon;
use DBI;
use Digest::SHA;
use File::Copy;

#TODO: put this into central configuration file
$database = 'yolanda';
$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';
$root = '/var/www/yolanda';

#TODO: deamonize by uncommenting this line
#Proc::Daemon::Init;

$LOG = "/dev/null";


#TODO: maybe keep file open the whole time ?
sub appendlog
{
    if (open(FILE, ">>$LOG"))
    {
        print FILE scalar(localtime)." ".$$."\n";
        print "------------------------------------\n";
        print join("\n",@_)."\n";
        print "------------------------------------\n\n";
        close FILE;
    }
}

sub interrupt
{
    appendlog(@_);
    die;
}

$dbh = DBI->connect("DBI:mysql:$database:$dbhost", $dbuser, $dbpass) or interrupt "could not connect to db";

#video status:
# 0 - new entry - nothing done yet
# 1 - valid public video
# 2 - error: invalid audio and/or video stream
# 3 - error: file not found
# 4 - error: file is not a video
# 5 - error: video is a duplicate

while(1)
{
    #get fresh video id from db
    my $sth = $dbh->prepare(qq{select id from uploaded where status = 0 limit 1}) or interrupt $dbh->errstr;
        
    $sth->execute() or interrupt $dbh->errstr;
    my ($id) = $sth->fetchrow_array();
    $sth->finish() or interrupt $dbh->errstr;
    
    if($id)
    {
        $info = `export SDL_VIDEODRIVER="dummy"; ffplay -stats -an -vn -nodisp /tmp/$id 2>&1`;
        
        if($info =~ /ignoring/)
        {
            appendlog "id: $id",
                "error: invalid stream",
                "ffplay msg: $info";
            
            #write status 2 to uploaded table
            $dbh->do(qq{update uploaded set status = ? where id = ?}, undef, 2, $id) or interrupt $dbh->errstr;
            unlink "/tmp/$id";
        }
        elsif ($info =~ /I\/O error occured/)
        {
            appendlog "id: $id",
                "error: file not found",
                "ffplay msg: $info";
            
            #write status 3 to uploaded table
            $dbh->do(qq{update uploaded set status = ? where id = ?}, undef, 3, $id) or interrupt $dbh->errstr;
            unlink "/tmp/$id";
        }
        elsif ($info =~ /Unknown format/ or $info =~ /could not find codec parameters/)
        {
            appendlog "id: $id",
                "error: file is of unknown format",
                "ffplay msg: $info";
            
            #write status 4 to uploaded table
            $dbh->do(qq{update uploaded set status = ? where id = ?}, undef, 4, $id) or interrupt $dbh->errstr;
            unlink "/tmp/$id";
        }
        else
        {
            $sha = new Digest::SHA(256);
            $sha->addfile("/tmp/$id");
            $sha = $sha->hexdigest;
            
            #check if this hash is already in database
            my $sth = $dbh->prepare(qq{select id from videos where hash = ? limit 1}) or interrupt $dbh->errstr;
            $sth->execute($sha) or interrupt $dbh->errstr;
            my ($resultid) = $sth->fetchrow_array();
            $sth->finish() or interrupt $dbh->errstr;
            
            #if so, then video is a duplicate (alternatively ALL HAIL QUANTUM COMPUTING)
            if($resultid)
            {
                appendlog  "id: $id",
                    "error: video already uploaded: $resultid";
                
                #write status 5 to uploaded table
                $dbh->do(qq{update uploaded set status = ? where id = ?}, undef, 5, $id) or interrupt $dbh->errstr;
                unlink "/tmp/$id";
            }
            else
            {
                ($container, $duration) = $info =~ /Input \#0, (\w+),.+?\n.+?Duration: (\d{2}:\d{2}:\d{2}\.\d)/;
                
                #these two regexes have to be applied seperately because nobody knows which stream (audio or video) comes first
                ($audio) = $info =~ /Audio: (\w+)/;
                ($video, $width, $height, $fps) = $info =~ /Video: ([\w\d]+),.+?(\d+)x(\d+),.+?(\d+\.\d+) fps/;
                
                if(!$audio or !$video or !$duration)
                {
                    appendlog "id: $id",
                        "error: error: stream is missing or video is corrupt",
                        "audio: $audio",
                        "video: $video",
                        "duration: $duration",
                        "ffplay msg: $info";
                    
                    #write status 2 to uploaded table
                    $dbh->do(qq{update uploaded set status = ? where id = ?}, undef, 2, $id) or interrupt $dbh->errstr;
                    unlink "/tmp/$id";
                }
                else
                {
                    $filesize = -s "/tmp/$id";
                    
                    #convert hh:mm:ss.s duration to full seconds - thanks perl for making this so damn easy!
                    #don't want to know how this would look in python or php... hell I don't even have to create extra variables!
                    $duration =~ /^(\d{2}):(\d{2}):(\d{2})\.(\d)$/;
                    $duration = int($1*3600 + $2*60 + $3 + $4/10 + .5);
                    
                    #create thumbnail
                    $thumbnailsec = int($duration/3 + .5);
                    
                    #the width/height calculation could of course be much shorter but less readable then
                    #all thumbs have equal height
                    $tnmaxheight = 120;
                    $tnheight = $tnmaxheight;
                    $tnwidth = int($tnheight*($width/$height)/2 + .5)*2;
                    
                    system "ffmpeg -i /tmp/$id -vcodec mjpeg -vframes 1 -an -f rawvideo -ss $thumbnailsec -s ".$tnwidth."x$tnheight $root/video-stills/$id";
                    
                    $vmaxheight = 640;
                    
                    #check if the upload already is in the right format and smaller/equal max-width/height
                    if ($container eq 'ogg' and $video eq 'theora' and $audio eq 'vorbis' and $height <= $vmaxheight)
                    {
                        appendlog $id, "file already is ogg-theora/vorbis";
                        
                        #add video to videos table
                        $dbh->do(qq{insert into videos select id, title, description, userid, timestamp, creator,
                                                subject, source, language, coverage, rights, license, ?, ?, ?, ?, ?, ?, 0, 0
                                                from uploaded where id = ?}, undef, $filesize, $duration, $width,
                                                $height, $fps, $sha, $id) or interrupt $dbh->errstr;
                        
                        #move video
                        move "/tmp/$id", "$root/videos/$id";
                    }
                    else #encode video
                    {
                        #video height is either ther maximum video height
                        #or when the original is smaller than that the original height
                        #check for multiple by 8
                        $vheight = $vmaxheight <= $height ? $vmaxheight : int($height/8 + .5)*8;
                        $vwidth = int($vheight*($width/$height)/8 + .5)*8;
                        
                        $abitrate = 64;
                        $vbitrate = int(($filesize*8) / $duration + .5) - $abitrate;
                        
                        #TODO: add metadata information
                        system "ffmpeg2theora --optimize --videobitrate $vbitrate --audiobitrate $abitrate --sharpness 0 --width $vwidth --height $vheight --output $root/videos/$id /tmp/$id";
                        
                        appendlog $id, $audio, $video, $vwidth, $vheight, $fps, $duration, $sha;
                        
                        $filesize = -s "$root/videos/$id";
                        
                        #add video to videos table
                        $dbh->do(qq{insert into videos select id, title, description, userid, timestamp, creator,
                                                subject, source, language, coverage, rights, license, ?, ?, ?, ?, ?, ?, 0, 0
                                                from uploaded where id = ?}, undef, $filesize, $duration, $vwidth,
                                                $vheight, $fps, $sha, $id) or interrupt $dbh->errstr;
                        
                        #delete temp file
                        unlink "/tmp/$id";
                    }
                    
                    #create torrent file
                    
                    
                    #delete from uploaded table
                    $dbh->do(qq{delete from uploaded where id = ?}, undef, $id) or interrupt $dbh->errstr;
                }
            }
        }
    }
    else
    {
        #TODO: maybe make this event-driven by using the kernels has-this-file-changed-interface ?
        sleep 10;
    }
}