/*
 * Jon Lech Johansen <jon@nanocrew.net>
 */
using System;
using System.IO;
using System.Text;
using Microsoft.Win32;
using System.Windows.Forms;

class MainClass
{
    public static void Main( string[] args )
    {
        try
        {
            RegistryKey hklm = Registry.LocalMachine;
            hklm = hklm.OpenSubKey( "SOFTWARE\\GoogleVideoViewer\\VLC" );
            Object obp = hklm.GetValue( "InstallDir" );
            
            string file_path = String.Format( "{0}{1}plugins{2}libaccess_http_plugin.dll",
                                              obp, Path.DirectorySeparatorChar,
                                              Path.DirectorySeparatorChar );
            
            using( Stream s = new FileStream( file_path, FileMode.Open, 
                                              FileAccess.Read | FileAccess.Write ) )
            {
                int offset = 0;
                long file_pos = 0;
                int bytes_read = 0;
                byte[] buffer = new byte[ 65536 ];
                
                byte[] search_bytes = new byte[]
                {
                    0xBF, 0x40, 0x65, 0x00, 0x10,
                    0xE9, 0x36, 0xFC, 0xFF, 0xFF
                };
                
                while( ( bytes_read = s.Read( buffer, offset, buffer.Length - offset ) ) > 0 )
                {
                    for( int i = 0; i < bytes_read + offset - search_bytes.Length; i++ )
                    {
                        bool match = true;
                        
                        for( int j = 0; j < search_bytes.Length; j++ )
                        {
                            if( search_bytes[ j ] != buffer[ i + j ] )
                            {
                                match = false;
                                break;
                            }
                        }
                        
                        if( match )
                        {                           
                            s.Seek( file_pos + i - offset, SeekOrigin.Begin );
                            for( int j = 0; j < search_bytes.Length; j++ )
                                search_bytes[ j ] = 0x90;
                            s.Write( search_bytes, 0, search_bytes.Length );
                            MessageBox.Show( "GoogleVideoViewer was successfully patched", "GVVPatch" );
                            return;
                        }
                    }
          
                    file_pos = s.Position;

                    offset = search_bytes.Length;
                    for( int i = 0; i < offset; i++ )
                    {
                        buffer[ i ] = buffer[ buffer.Length - offset + i ];
                    }
                }
            }
            
            MessageBox.Show( "Error: Could not find bytes to patch. File already patched?", "GVVPatch" );
        }
        catch( Exception e )
        {
            MessageBox.Show( "Error: " + e.Message, "GVVPatch" );
        }
    }
}