<?php

/**
 * MusicDirector File Updater v0.1
 * Copyleft (C) 2008 BohwaZ - http://bohwaz.net/
 * Licensed under GNU/GPLv3, get the license at www.gnu.org
 */

/**
 * MusicDirector is a music software from eJay, similar to Acid.
 * It's great for a very low price (~10 euros or less), but it has a lot of flaws.
 * Like a lot of bugs and crashes (but it's normal for a windows software no ?),
 * and the file format used is very crappy : once you created a song with samples
 * from a directory, you can't move the samples from one path to another, the software
 * offers no way to relocate a sample file. Crap!
 *
 * But heres the solution, this tiny script will read and write to MDX files used
 * by MusicDirector to replace paths used for samples.
 *
 * You have to fill the path replacement array below with what you need, please note that
 * slashes will be replaced with backslashes (more convenient). Then run the script like this :
 *
 *  $ php music-director.php mysong.MDX
 *
 * It will show you the samples it found and the replacements it will do... if you add --replace
 * in the command-line, like this:
 *
 *  $ php music-director.php mysong.MDX --replace
 *
 * Note that it will not actually replace the original file but just create a new one called
 * mysong-replaced.mdx with the replaced paths.
 *
 * If you forgot where the samples were, just use the first command and it will show you the paths
 * MusicDirector tries to find.
 *
 */

$replace_paths = array(
    // Original path                        // Replaced path
    'G:/eJay/MusicDirectorPro/Samples/' =>  'Z:/studio/eJay/Samples/',
    'J:/musique/Samples/'               =>  'X:/musique/Samples/',
    'J:/Samples/'                       =>  'X:/Samples/',
    'G:/eJay/MusicDirectorPro/musicdirector/Import/'
                                        =>  'X:/musique/Files/MusicDirector/Import/',

);

// INTERNAL ROUTINE

// Each 10 samples (?)
$line_sequence = chr(1) . chr(128) . chr(86) . chr(64);

// Each sample (we ignore 8*NUL bytes here)
$sample_sequence = chr(240).chr(191);

// Samples list begins at byte 340
$begin_pos = 339;

$songs = array();
$files = array();
$view = true;

foreach ($_SERVER['argv'] as $key=>$arg)
{
    if ($key == 0) continue;

    if ($arg == '--replace')
    {
        $view = false;
        continue;
    }

    if (!file_exists($arg))
        die("File '$arg' doesn't exists.\n");

    if (is_dir($arg))
        continue;

    $files[] = $arg;
}

if (empty($files))
    die("Syntax: ".$_SERVER['argv'][0]." /home/me/MD_files/*\n");

foreach ($replace_paths as $old=>$new)
{
    unset($replace_paths[$old]);
    $old = str_replace('/', '\\', $old);
    $new = str_replace('/', '\\', $new);
    $replace_paths[$old] = $new;
}

echo "Extracting samples path from MDX files...\n";

foreach ($files as $file)
{
    if (!preg_match('!\.mdx$!i', $file) || preg_match('!\.replaced\.mdx$!i', $file))
        continue;

    $songs[$file] = array('samples' => array());

    $fp = fopen($file, 'rb');

    $songs[$file]['begin'] = fread($fp, $begin_pos);

    $content = fread($fp, filesize($file) - $begin_pos);
    fclose($fp);

    // Cut after the last sample
    $songs[$file]['offset'] = strrpos($content, $sample_sequence);
    $line = substr($content, 0, $songs[$file]['offset']);

    if (!$view) $songs[$file]['end'] = substr($content, $songs[$file]['offset']+2);

    $current = '';
    $chars = unpack("C*0", $line);

    foreach ($chars as $idx=>$char)
    {
        if ($char == 0 || $char == 19)
            continue;

        $current .= chr($char);

        if (substr($current, -4) == $line_sequence)
        {
            if ($current)
                $songs[$file]['samples'][] = substr($current, 0, -4);

            $current = '';
            continue;
        }
        elseif (substr($current, -2) == $sample_sequence)
        {
            if ($current)
                $songs[$file]['samples'][] = substr($current, 0, -2);

            $current = '';
            continue;
        }
    }

    if ($current)
        $songs[$file]['samples'][] = $current;
}

if ($view)
{
    echo "I'll replace those paths :\n\n";

    foreach ($songs as $file=>$song)
    {
        echo $file . "\n";

        foreach ($song['samples'] as &$sample)
        {
            echo "\t" . $sample . "\n";
            echo "\t  => ".strtr($sample, $replace_paths)."\n";
        }

        echo "\n";
    }

    die("Nothing done. Use --replace to replace paths in MDX files.\n");
}
else
{
    foreach ($songs as $file=>&$song)
    {
        $new_file = str_ireplace('.mdx', '.replaced.mdx', $file);

        $fp = fopen($new_file, 'wb');
        fwrite($fp, $song['begin']);

        foreach ($song['samples'] as &$sample)
        {
            fwrite($fp, strtr($sample, $replace_paths));
            // 8 * NUL + sample sequence
            fwrite($fp, chr(0).chr(0).chr(0).chr(0).chr(0).chr(0).chr(0).chr(0).$sample_sequence);
        }

        fwrite($fp, $song['end']);
        fclose($fp);

        echo "$file -> $new_file\n";
    }
}

?>