/*
    $Id: udf_file.c,v 1.9 2006/04/11 05:47:58 rocky Exp $

    Copyright (C) 2005, 2006 Rocky Bernstein <rockyb@users.sourceforge.net>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
/* Access routines */

#include <cdio/bytesex.h>
#include "udf_private.h"
#include "udf_fs.h"

#ifdef HAVE_STRING_H
# include <string.h>
#endif

#include <stdio.h>  /* Remove when adding cdio/logging.h */

#define MIN(a, b) (a>b) ? (a) : (b)

const char *
udf_get_filename(const udf_dirent_t *p_udf_dirent)
{
  if (!p_udf_dirent) return NULL;
  if (!p_udf_dirent->psz_name) return "..";
  return p_udf_dirent->psz_name;
}

bool
udf_get_file_entry(const udf_dirent_t *p_udf_dirent, 
		   /*out*/ udf_file_entry_t *p_udf_fe)
{
  if (!p_udf_dirent) return false;
  memcpy(p_udf_fe, &p_udf_dirent->fe, sizeof(udf_file_entry_t));
  return true;
}

/*!
  Return the file id descriptor of the given file.
*/
bool udf_get_fileid_descriptor(const udf_dirent_t *p_udf_dirent, 
			       /*out*/ udf_fileid_desc_t *p_udf_fid)
{
  
  if (!p_udf_dirent) return false;
  if (!p_udf_dirent->fid) {
    /* FIXME do something about trying to get the descriptor. */
    return false;
  }
  memcpy(p_udf_fid, p_udf_dirent->fid, sizeof(udf_fileid_desc_t));
  return true;
}


/*!
  Return the number of hard links of the file. Return 0 if error.
*/
uint16_t udf_get_link_count(const udf_dirent_t *p_udf_dirent) 
{
  if (p_udf_dirent) {
    return uint16_from_le(p_udf_dirent->fe.link_count);
  }
  return 0; /* Error. Non-error case handled above. */
}

/*!
  Return the file length the file. Return 2147483647L if error.
*/
uint64_t udf_get_file_length(const udf_dirent_t *p_udf_dirent) 
{
  if (p_udf_dirent) {
    return uint64_from_le(p_udf_dirent->fe.info_len);
  }
  return 2147483647L; /* Error. Non-error case handled above. */
}

/*!
  Return true if the file is a directory.
*/
bool
udf_is_dir(const udf_dirent_t *p_udf_dirent)
{
  return p_udf_dirent->b_dir;
}

/**
  Attempts to read up to count bytes from UDF directory entry
  p_udf_dirent into the buffer starting at buf. buf should be a
  multiple of UDF_BLOCKSIZE bytes.

  If count is zero, read() returns zero and has no other results. If
  count is greater than SSIZE_MAX, the result is unspecified.

  If there is an error, cast the result to driver_return_code_t for 
  the specific error code.
*/
ssize_t
udf_read_block(const udf_dirent_t *p_udf_dirent, void * buf, size_t count)
{
  if (count == 0) return 0;
  else {
    const udf_t *p_udf = p_udf_dirent->p_udf;
    uint8_t data[UDF_BLOCKSIZE];
    const udf_file_entry_t *p_udf_fe = (udf_file_entry_t *) data;
    driver_return_code_t ret;
    const unsigned long int i_file_length = udf_get_file_length(p_udf_dirent);
    
    ret = udf_read_sectors(p_udf, data, p_udf_dirent->fe.unique_ID, 1);
    if (ret == DRIVER_OP_SUCCESS) {
      if (!udf_checktag(&p_udf_fe->tag, TAGID_FILE_ENTRY)) {
	uint32_t i_lba_start, i_lba_end;
	udf_get_lba( p_udf_fe, &i_lba_start, &i_lba_end);
	
	if ( (i_lba_end - i_lba_start+1) < count ) {
	  printf("Warning: don't know how to handle yet\n" );
	  count = i_lba_end - i_lba_start+1;
	} else {
	  const uint32_t i_lba = p_udf->i_part_start+i_lba_start;
	  ret = udf_read_sectors(p_udf, buf, i_lba, count);
	  if (DRIVER_OP_SUCCESS == ret) {
	    return MIN(i_file_length, count * UDF_BLOCKSIZE);
	  }
	}
	
      } else {
	return DRIVER_OP_ERROR;
      }
    }
    return ret;
  }
}