/* Tower Toppler - Nebulus
 * Copyright (C) 2000-2012  Andreas Röver
 *
 * 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.
 */

#ifndef ARCHI_H
#define ARCHI_H

#include <SDL.h>

/* this module contains a simple archive access class. an archive
 * is a collection of zlib compressed files with a header defining
 * compressed, uncompressed size and the start of the data inside
 * the archive
 *
 * because the file gets decompressed in one run and saved inside a
 * memory block be careful not to create too big files
 */

class archive;

/* this class is used to handle the access to the different files inside
 * the archive(s)
 */
class file {

public:

  /* you need to give the archive with your file and
   * the name of the file you want to open to the
   * constructor
   */
  file(const archive *arc, const char *name);

  /* close the file and free memory
   */
  ~file();

  /* returns the size of the currently opened file
   */
  Uint32 size(void) { return fsize; }

  /* returns true if the current file is completely read
   */
  bool eof(void) { return bufferpos >= fsize; }

  /* reads up to size bytes into the buffer, returning in result
   * the real number read
   */
  Uint32 read(void *buf, Uint32 size);

  /* read one byte from currently opened file
   */
  Uint8 getbyte(void);

  /* read one word from currently opened file this read is endian save
   */
  Uint16 getword(void);

  /* chreates an RW operation type from this file */
  SDL_RWops *rwOps(void);

private:

  /* the buffer containing the uncompressed file data
   */
  Uint8* buffer;

  /* current position inside the file data
   */
  Uint32 bufferpos;

  /* size of the file
   */
  unsigned long fsize;

};

/* this class handles one archive, each archive can contain any number of
 * files with 0 terminated names.
 */
class archive {

public:

  /* opens the archive, you must give the FILE handle to the
   * file that is the archive to this constructor
   */
  archive(FILE *file);

  /* closes the archive and frees memory
   */
  ~archive();

  /* number of files inside the archive */
  Uint8 fileNumber(void) { return filecount; }

  /* name of the n-th file */
  const char * fname(Uint8 idx) { return files[idx].name; }

private:

  FILE *f;

  /* this structur contains all the information inside the
   * header for one file, it's used build an array of
   * files upon archive opening
   */
  typedef struct {
    char *name;
    Uint32 start, size, compress;
  } fileindex;

  /* the pointer to the file array
   */
  fileindex *files;

  /* number of files inside the archive
   */
  Uint8 filecount;

  /* the constructor for the archive file must access the files and
   * filecount members, so it must be a friend
   */
  friend file::file(const archive *arc, const char *name);
};

/* it is arguably, if this is the right place for this declaration, but
 * if you assume that everybody who wants to access an archive does need the
 * class definition and this global variable at the same time, it's not so wrong
 * either
 */
extern archive * dataarchive;

#endif