/******************************************************************************
** Functions by Derrick Sobodash
** http://www.cinnamonpirate.com/
** Submitted to ROM Hacking.net on July 3, 2006
******************************************************************************/

/******************************************************************************
** apply_ppf()
*******************************************************************************
** syntax: void apply_ppf(string ppf_file, string bin_file)
*******************************************************************************
** Applies ppf_file to bin_file if both files exist.
******************************************************************************/

function apply_ppf($ppf_file, $bin_file)
{

  // Make sure the input is all valid
  if(!file_exists($ppf_file))
    die("Error: apply_ppf(): Unable to open $ppf_file\r\n\r\n");
  if(!file_exists($bin_file))
    die("Error: apply_ppf(): Unable to open $bin_file\r\n\r\n");

  // This is dirty code, it should be fixed later
  $ppfdump = file_read($ppf_file);
  if(strpos($ppfdump, "@BEGIN_FILE_ID"))
    $ppf_end = strpos($ppfdump, "@BEGIN_FILE_ID");
  else
    $ppf_end = filesize($ppf_file);
  unset($ppfdump);

  // Open the patch file as a stream
  $ppf = fopen($ppf_file, "rb");

  if(fread($ppf, 3) != "PPF")
    die("Error: apply_ppf(): Not a valid PPF patch\r\n\r\n");

  $magic = fread($ppf, 2);

  if(($magic == "10" || $magic == "20" || $magic == "30") && ord(fgetc($ppf)) == 0)
  {

    // Skip PPF internal info
    
    fseek($ppf, 56, SEEK_SET);

    // Open the binary file in read/write mode
    $fa = fopen($bin_file, "r+b");

    while($ftell($ppf) < $ppf_end)
    {

      fseek($fa, punpack(fread($ppf, 4)), SEEK_SET);
      $length = ord(fgetc($fa));
      fputs($fa, fread($ppf, $length));

    }

    fclose($fa);
    fclose($ppf);

  }

  else if(($magic == "20" || $magic == "30") && ord(fgetc($ppf)) == 1)
  {

    // Skip PPF internal info
    
    fseek($ppf, 56, SEEK_SET);

    // Open the binary file in read/write mode
    $fa = fopen($bin_file, "r+b");

    // Run the PPF file size check
    if(punpack(fread($ppf, 4)) != filesize($bin_file))
      die("Error: apply_ppf(): Target file size does not match patch requirement\r\n\r\n");

    // Run the PPF sector match check
    fseek($fa, 0x9320, SEEK_SET);
    $ppf_bin_block = fread($ppf, KBYTE);
    $org_bin_block = fread($fa, KBYTE);

    fseek($fa, 0, SEEK_SET);

    if($ppf_bin_block != $org_bin_block)
      die("Error: apply_ppf(): Target file sector \$9320 does not match patch requirement\r\n\r\n");

    // Unset variables and free up some RAM
    unset($ppf_bin_block, $org_bin_block);

    while($ftell($ppf) < $ppf_end)
    {

      fseek($fa, punpack(fread($ppf, 4)), SEEK_SET);
      $length = ord(fgetc($fa));
      fputs($fa, fread($ppf, $length));

    }

    fclose($fa);
    fclose($ppf);

  }

  else if($magic == "30" && ord(fgetc($ppf)) == 2)
  {

    // Skip PPF internal info
    
    fseek($ppf, 56, SEEK_SET);

    $imagetype = ord(fgetc($ppf));
    $blockcheck = ord(fgetc($ppf));
    $undodata = ord(fgetc($ppf));
    $dummy = fgetc($ppf);

    // Open the binary file in read/write mode
    $fa = fopen($bin_file, "r+b");

    // Run the PPF sector match check
    if($blockcheck != 0)
    {

      if($imagetype == 0)
        fseek($fa, 0x9320, SEEK_SET);
      else if($imagetype == 1)
        fseek($fa, 0x80a0, SEEK_SET);
      $ppf_bin_block = fread($ppf, KBYTE);
      $org_bin_block = fread($fa, KBYTE);

      fseek($fa, 0, SEEK_SET);

      if($ppf_bin_block != $org_bin_block)
        die("Error: apply_ppf(): Target file sector does not match patch requirement\r\n\r\n");

      // Unset variables and free up some RAM
      unset($ppf_bin_block, $org_bin_block);
    }

    while($ftell($ppf) < $ppf_end)
    {

      fseek($fa, punpack(fread($ppf, 8)), SEEK_SET);
      $length = ord(fread($ppf, 2));
      fputs($fa, fread($ppf, $length));

    }

    fclose($fa);
    fclose($ppf);

  }

  else
    die("Error: apply_ppf(): Unsupported PPF version\r\n\r\n");

}