Remote upload file to server B

I’m aware this might be some of the hardest coding to do ever, but thought of giving it a try.

Im basically trying to detect all (mp3) filetypes uploaded through the WordPress media upload and send them offsite, thus have them uploaded to a different server through (ftp connection).

Below is the code i started after hours of research and i think i’m stucked, honestly i don’t even know if i’m at a good point. I hope someone who has much more knowledge with WordPress/PHP can help me archive what i’m trying to do. I’m doing this to save the main server from been overloaded with big file sizes and limit it to images.

I would want the structure uploaded to Server B is: serverB.com/music/Year/month/file.mp3

The year and month should inherit from wordpress post date( ‘Y/m’ );

After it is uploaded the link that appears in wordpress should be that of serverB.com url to the file.

Thank you. Below is the code i started:

<?php
/* 
 * Change upload directory/server for mp3 files 
 * Only works in WordPress 3.3+
 */

add_filter('wp_handle_upload_prefilter', 'music_pre_upload');
add_filter('wp_handle_upload', 'music_post_upload');

function music_pre_upload($file){
add_filter('upload_dir', 'music_remote_upload_dir');
return $file;
}

function music_post_upload($fileinfo){
remove_filter('upload_dir', 'music_remote_upload_dir');
return $fileinfo;
}

function music_remote_upload_dir($path){    
$extension = substr(strrchr($_POST['name'],'.'),1);
if(!empty($path['error']) ||  $extension != 'mp3') { return $path; } // if other     filetype send to default uploads folder.

    /**
     * Change this to match your server
     * You only need to change the those with (*)
     * If marked with (-) its optional 
     */

    $post_date = '/' . date( 'Y/m' );

    $settings = array(
            'host'          =>        'host or IP',       // * the ftp-server hostname
            'user'          =>        'ftp-username',                // * ftp-user
            'pass'          =>        'ftp-pass',       // * ftp-password
            'cdn'           =>        'external-server.com',          // * This have to be a pointed domain or subdomain to the root of the uploads
            'path'          =>        '/music',                    // - ftp-path, default is root (/). Change here and add the dir on the ftp-server
            'date'          =>        $post_date          // Local post date
    );

    /**
     * Host-connection
     * Read about it here: http://php.net/manual/en/function.ftp-connect.php
     */

    if(function_exists('ftp_ssl_connect'))
     {

    $connection = ftp_ssl_connect( $settings['host'] );

     }
        else
     {
    $connection = ftp_connect( $settings['host'] );
     }

    /**
     * Login to ftp
     * Read about it here: http://php.net/manual/en/function.ftp-login.php
     */

    $login = ftp_login( $connection, $settings['user'], $settings['pass'] );

    /**
     * Check ftp-connection
     */

    if ( !$connection || !$login ) {
        die('Connection attempt failed, Check your settings');
    }

   ftp_pasv($resource, true); // To avoid rectify warning

   if( ftp_put( $connection, $settings['path'] . "/" . $settings['date'] . "/" . $file, FTP_BINARY ) ) {

      echo "successfully uploaded $filen";

        } else {

      echo "There was a problem while uploading $filen";
      }

      // close the connection
       ftp_close($conn_id); 



} // End function