<?php

require('AtomParser.php');

// create a bunch of 0's
function zero($num) {   
    $s = "";
    for($i = 0; $i < $num; $i++) {
        $s .= chr(0);
    }
    return $s;
}

//  Int2BigEndian 
// add 4 because the size takes up 4 bytes
function fb($str) {
    return pack("N", strlen($str)+4);
}

if(!function_exists('BigEndian2Int')) {
function BigEndian2Int($byteword) {
    $intvalue = 0;
    $bytewordlen = strlen($byteword);
    for ($i = 0; $i < $bytewordlen; $i++) {
        $intvalue += ord($byteword{$i}) * pow(256, ($bytewordlen - 1 - $i));
    }
    return (int)$intvalue;
} //function
} // if exists

function CreateUDTA($tags, $len) {

    $cnamdata = "data".zero(3).chr(1).zero(4).$tags['title'];
	$cnamdata = fb($cnamdata).$cnamdata;
    $cnam = "Šnam".$cnamdata;
	$cnam = fb($cnam).$cnam;

    $cartdata = "data".zero(3).chr(1).zero(4).$tags['artist'];
	$cartdata = fb($cartdata).$cartdata;
	$cart = "ŠART".$cartdata;
	$cart = fb($cart).$cart;

    $calbdata = "data".zero(3).chr(1).zero(4).$tags['album'];
	$calbdata = fb($calbdata).$calbdata;
    $calb = "Šalb".$calbdata;
	$calb = fb($calb).$calb;

    $gnredata = "data".zero(8).chr(0).chr($tags['genrenum']);
	$gnredata = fb($gnredata).$gnredata;
    $gnre = "gnre".$gnredata;
	$gnre = fb($gnre).$gnre;

    $trkndata = "data".zero(10).chr(0).chr($tags['track']).chr(0).chr($tags['track']).zero(2);
	$trkndata = fb($trkndata).$trkndata;
    $trkn = "trkn".$trkndata;
	$trkn = fb($trkn).$trkn;

    $diskdata = "data".zero(10).chr(0).chr(1).chr(0).chr(1);
	$diskdata = fb($diskdata).$diskdata;
    $disk = "disk".$diskdata;
	$disk = fb($disk).$disk;

    $cdaydata = "data".zero(3).chr(1).zero(4).$tags['year'];
	$cdaydata = fb($cdaydata).$cdaydata;
    $cday = "Šday".$cdaydata;
	$cday = fb($cday).$cday;

    $cpildata = "data".zero(3).chr(21).zero(5);
	$cpildata = fb($cpildata).$cpildata;
    $cpil = "cpil".$cpildata;
	$cpil = fb($cpil).$cpil;

    $tmpodata = "data".zero(3).chr(21).zero(6);
	$tmpodata = fb($tmpodata).$tmpodata;
    $tmpo = "tmpo".$tmpodata;
	$tmpo = fb($tmpo).$tmpo;

    $ctoodata = "data".zero(3).chr(1).zero(4)."iTunes v4.0, QuickTime 6.3";
	$ctoodata = fb($ctoodata).$ctoodata;
    $ctoo = "Štoo".$ctoodata;
	$ctoo = fb($ctoo).$ctoo;

	$ilst = "ilst".$cnam.$cart.$calb.$gnre.$trkn.$disk.$cday.$cpil.$tmpo.$ctoo;
	$ilst = fb($ilst).$ilst;

    $hdlr = "hdlr".zero(8)."mdirappl".zero(10);
	$hdlr = fb($hdlr).$hdlr;

	$dashmean = "mean".zero(4)."com.apple.iTunes";
	$dashmean = fb($dashmean).$dashmean;
        
	$dashname = "name".zero(4)."iTunNORM";
	$dashname = fb($dashname).$dashname;

    $dashdata = "data".zero(3).chr(1).zero(4)." 11111111 22222222 33333333 44444444";
    $dashdata = $dashdata." 55555555 66666666 77777777 88888888 99999999 00000000";
	$dashdata = fb($dashdata).$dashdata;

	$dash = "----".$dashmean.$dashname.$dashdata;
	$dash = fb($dash).$dash;

 	$meta = "meta".zero(4).$hdlr.$ilst.$dash;

    $freesize = $len - strlen($meta) - 8 - 12;
    if($freesize > 0) {
        $free = "free".zero($freesize);
        $free = fb($free).$free;
        $meta = $meta.$free;
    }

	$meta = fb($meta).$meta;

	$udta = "udta".$meta;
	$udta = fb($udta).$udta;

    return $udta;
} // create udta

// iTunes m4a header
function m4ahdr() {
    return zero(3).chr(32)."ftypm4a".chr(32).zero(4)."M4A".chr(32)."mp4isom".zero(4);
}

// write iTunes m4a heading to beginning of file
// take the moov atom starting at byte 32 and copy it to end
// change original moov atom to free atom
// change atomsize of new moov atom to accomodate new tags
function MOOVtoEnd($f, $len, $tags) {
    if(!isset($tags['moovpos']))
        return FALSE;

    $moovpos = $tags['moovpos'];

    fseek($f, $moovpos, SEEK_SET);    

    $AtomHeader = fread($f, 8);
    $atomsize = BigEndian2Int(substr($AtomHeader, 0, 4));
    $atomname =               substr($AtomHeader, 4, 4);

    if($moovpos == 32) {
        fseek($f, 0, SEEK_SET);         // move to beginning
        fwrite($f, m4ahdr());           // write a compliant header
    }

    fseek($f, $moovpos, SEEK_SET);  // move to start of moov atom
    $moov = fread($f, $atomsize);   // read entire moov atom

    fseek($f, $moovpos+4, SEEK_SET);// back to start of atom
    fwrite($f, "free");             // change moov atom to free

    fseek($f, 0, SEEK_END);         // move to end of file
    fwrite($f, pack("N", $atomsize+$len));  // write the new size
    fwrite($f, substr($moov, 4));   // write the moov atom
    return TRUE;
}

function parsepath($r, &$tags) {
    $a = pathinfo($r);

    $file = basename($a['basename'], ".".$a['extension']);

    $b = explode("\\", $a['dirname']);

    $i = count($b);

    $album = $b[$i-1];
    $artist = $b[$i-2];

	$trk = 10*($file{0}-"0") + $file{1}-"0";
	if(99 < $trk || $trk < 0) {
		$trk = 0;
	}
	$title = substr($file, 5);  
    
    $tags['artist'] = $artist;
    $tags['album'] = $album;
    $tags['track'] = $trk;
    $tags['title'] = $title;
}


// id3v1 codes plus one
function genrecode($gnre) {
    global $GenreList;

    for($i = 0; $i < count($GenreList); $i++) {
        if(strcasecmp($GenreList[$i], $gnre) == 0) {
            return $i+1;
        }
    }
    return 255;
}

function tagger($argc, $argv) {
//    global $debug;
  
// get the name of the infile from the command line and make sure it exists
    $infile = $argv[1];
    if(!is_file($infile)) {
        printf("File not found: %s\n", $infile);
        return FALSE;
    }

    $f = fopen($infile, "rb");

// read the existing tags
    ParseAtom($f, 0, filesize($infile), $tags);

// if auto, read tag fields from pathname.  
// cmd line tags override pathname, which is why this is before general cmd line read
    $changetags = 0;
    for($i = 2; $i < $argc; $i++) {
        if(strcmp($argv[$i], "--auto") == 0) {
            $changetags = 2;
            parsepath(realpath($infile), &$tags);
            break;
        }
    }

// read params from command line
    $back = 0;
    $remove = 0;
    for($i = 2; $i < $argc; $i++) {
        switch($argv[$i]) {
            case "--artist":
                $tags['artist'] = $argv[++$i];
                $changetags = 1;
                break;
            case "--album":
                $tags['album'] = $argv[++$i];
                $changetags = 1;
                break;
            case "--title":
                $tags['title'] = $argv[++$i];
                $changetags = 1;
                break;
            case "--track":
                $tags['track'] = $argv[++$i];
                $changetags = 1;
                break;
            case "--genre":
                $tags['genrename'] = $argv[++$i];
                $tags['genrenum'] = genrecode($argv[$i]);
                $changetags = 1;
                break;
            case "--year":
                $tags['year'] = $argv[++$i];
                $changetags = 1;
                break;
            case "--auto":
                $auto = 1;
                $changetags = 2;
                break;
            case "--back":
                $back = 1;
                break;
            case "--debug":
                $debug = 1;
                break;
            case "--remove";
                $remove = 1;
                break;
            default:
                printf("unknown field: %s\n", $argv[$i]);
                return FALSE;
        }  // switch
    }  // for 

// if remove, do it
    if($remove) {
        if(!isset($tags['udtapos'][0]))
            printf("no existing tags\n");    
        else {
            foreach($tags['udtapos'] as $key=>$val) {    // free existing tag
                fclose($f);
                $f = fopen($infile, 'r+b');
                fseek($f, $val+4, SEEK_SET);
                fwrite($f, "free");
            } // foreach
            fclose($f);
//            system("mp4creator60.exe -optimize \"$infile\"");
            $f = fopen($infile, 'rb');
            unset($tags);
            ParseAtom($f, 0, filesize($infile), $tags);
            fclose($f);
            printf("\n%s\n", $infile);
            printtags($tags);
        } // else 
        return TRUE;
    } // if remove

// if we  are not changing tags, just report tag info and return
    if($changetags == 0) {
        if($debug) {
            $num = count($tags['atoms']);
            for($i = 0; $i < $num; $i++) 
                printf("%s%s (%s bytes at %s)\n", str_repeat('-',$tags['atoms'][$i]['level']-1), 
                    $tags['atoms'][$i]['name'], number_format($tags['atoms'][$i]['size']), 
                    number_format($tags['atoms'][$i]['pos']) );
        } // if debug
        printf("\n%s\n", $infile);
        if(isset($tags)) {
            printtags($tags);
        }
        else {
            printf("no tags\n");
        }
        fclose($f);
        return TRUE;
    } // no change


// if --noback on cmdline, then don't create a new file to write
// else write to oldfile.xyz
    if($back == 0) {
        $outfile = $infile;
    }
    else {
        $outfile = $infile.".xyz";
        copy($infile, $outfile);
    }
    
// do it
    $fdate = filemtime($outfile);  // remember file time
    $f = fopen($outfile, 'r+b');   

    $udta = CreateUDTA($tags, 0); // create a udta atom from tags

// is there an existing udta atom we can overwrite?
    $wrote = 0;
    if(isset($tags['udtapos'][0])) {
        for($i =0; $i < count($tags['udtapos']); $i++) {
            if((strlen($udta) < $tags['udtasize'][$i]) && !$wrote) {
                $udta = CreateUDTA($tags, $tags['udtasize'][$i]);
                fseek($f, $tags['udtapos'][$i], SEEK_SET);
                fwrite($f, $udta);
                $wrote = 1;
            } // if
            else {
                fseek($f, $tags['udtapos'][$i]+4, SEEK_SET);
                fwrite($f, "free");
            }
        } // for
    } // if isset {check udta's)

// is there a free atom under moov we can overwrite?
    $top = "";
    $num = count($tags['atoms']);
    for($i = 0; $i < $num; $i++) {  // loop through the atoms
        if(($tags['atoms'][$i]['level']-1) == 0) {  // check top level atoms
            $top = $tags['atoms'][$i]['name'];
            continue;
        }
        if(strcmp($top, "moov") == 0) // to see if they are moov
            if(($tags['atoms'][$i]['level']-1) == 1)
                if(strcmp($tags['atoms'][$i]['name'], "free") == 0) {
                    if((strlen($udta) < $tags['atoms'][$i]['size']) && !$wrote) {
                        $udta = CreateUDTA($tags, $tags['atoms'][$i]['size']);
                        fseek($f, $tags['atoms'][$i]['pos'], SEEK_SET);
                        fwrite($f, $udta);
                        $wrote = 1;
                        break;
                    } // found a place to write
                } // found a free
    }


// if we can't overwrite something, moov to the end and write the tags after it
    if(!$wrote) {
        $udta = CreateUDTA($tags, 750);
        if (MOOVtoEnd($f, strlen($udta), $tags) == FALSE) {
            return FALSE;
        }
        fwrite($f, $udta);
    }

    fclose($f);

// use mp4creator to clean up a bit
    if(!$wrote) {
        system("mp4creator60.exe -optimize \"$outfile\"");
        OptFree($infile, $tags);
    }

// keep old file time
    touch($outfile, $fdate);     

// read the new tags
    $f = fopen($outfile, "rb");
    unset($tags);
    ParseAtom($f, 0, filesize($outfile), $tags);

    printf("\n%s\n", $outfile);
    printtags($tags);

    fclose($f);

}

// main ------------------------------------------- //

    if($argc == 1) {
        print <<<END
Tagger for mp4's - uses iTunes format.  Tested only with QT created mp4's. 
Use at your own risk.  
Version 0.21  2003-07-27

Usage: tg <filename> Options
Wildcards are supported in filename

Options:
[none]      print existing tags
--debug     print existing tags and atom info
--remove    remove existing tags
--auto      parses filepath - must be in form "artist\album\\nn - title.ext"
--artist <value>
--album  <value>
--title  <value>
--track  <value>
--genre  <value> [id3v1 tags only]
--year   <value>
 
mp4creator must be available: 
    http://rarewares.hydrogenaudio.org/files/mp4creator60.EP.zip   
thanks to www.getid3.org and tag for inspiration
     
END;
}
    
    $filenames = glob($argv[1]);  // get  a list of all filenames matching cmd line pattern
    if(count($filenames) == 0) {
        printf("File not found: %s\n", $argv[1]);
        exit;
    }

    $parms = $argv;
    foreach($filenames as $fname) { 
        $parms[1] = realpath($fname);  
        tagger($argc, $parms);
    }

?>