/* $Id: chm_lib.h,v 1.10 2002/10/09 01:16:33 jedwin Exp $ */
/***************************************************************************
 *             chm_lib.h - CHM archive manipulation routines               *
 *                           -------------------                           *
 *                                                                         *
 *  author:     Jed Wing <jedwin@ugcs.caltech.edu>                         *
 *  version:    0.3                                                        *
 *  notes:      These routines are meant for the manipulation of microsoft *
 *              .chm (compiled html help) files, but may likely be used    *
 *              for the manipulation of any ITSS archive, if ever ITSS     *
 *              archives are used for any other purpose.                   *
 *                                                                         *
 *              Note also that the section names are statically handled.   *
 *              To be entirely correct, the section names should be read   *
 *              from the section names meta-file, and then the various     *
 *              content sections and the "transforms" to apply to the data *
 *              they contain should be inferred from the section name and  *
 *              the meta-files referenced using that name; however, all of *
 *              the files I've been able to get my hands on appear to have *
 *              only two sections: Uncompressed and MSCompressed.          *
 *              Additionally, the ITSS.DLL file included with Windows does *
 *              not appear to handle any different transforms than the     *
 *              simple LZX-transform.  Furthermore, the list of transforms *
 *              to apply is broken, in that only half the required space   *
 *              is allocated for the list.  (It appears as though the      *
 *              space is allocated for ASCII strings, but the strings are  *
 *              written as unicode.  As a result, only the first half of   *
 *              the string appears.)  So this is probably not too big of   *
 *              a deal, at least until CHM v4 (MS .lit files), which also  *
 *              incorporate encryption, of some description.               *
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU Lesser General Public License as        *
 *   published by the Free Software Foundation; either version 2.1 of the  *
 *   License, or (at your option) any later version.                       *
 *                                                                         *
 ***************************************************************************/

#ifndef INCLUDED_CHMLIB_H
#define INCLUDED_CHMLIB_H

#ifdef __cplusplus
extern "C" {
#endif

/* RWE 6/12/1002 */
#ifdef PPC_BSTR
#include <wtypes.h>
#endif

#ifdef WIN32
#ifdef __MINGW32__
#define __int64 long long
#endif
typedef unsigned __int64 LONGUINT64;
typedef __int64          LONGINT64;
#else
typedef unsigned long long LONGUINT64;
typedef long long          LONGINT64;
#endif

/* the two available spaces in a CHM file                      */
/* N.B.: The format supports arbitrarily many spaces, but only */
/*       two appear to be used at present.                     */
#define CHM_UNCOMPRESSED (0)
#define CHM_COMPRESSED   (1)

/* structure representing an ITS (CHM) file stream             */
struct chmFile;

/* structure representing an element from an ITS file stream   */
#define CHM_MAX_PATHLEN  (512)
struct chmUnitInfo
{
    LONGUINT64         start;
    LONGUINT64         length;
    int                space;
    int                flags;
    char               path[CHM_MAX_PATHLEN+1];
};

#define CHM_EXTERNAL_STREAM_SUPPORT 1

#ifdef CHM_EXTERNAL_STREAM_SUPPORT
/* external stream interface */
struct chmExternalFileStream {
    /** returns file size, in bytes, if opened successfully */
    LONGUINT64 (*open)(struct chmExternalFileStream * instance);
    /** reads bytes to buffer */
    LONGINT64 (*read)( struct chmExternalFileStream * instance, unsigned char * buf, LONGUINT64 pos, LONGINT64 len );
    /** closes file */
    int (*close)(struct chmExternalFileStream * instance);
};
#endif /*CHM_EXTERNAL_STREAM_SUPPORT*/

/* open an ITS archive */
#ifdef CHM_EXTERNAL_STREAM_SUPPORT
struct chmFile* chm_open(struct chmExternalFileStream * stream);
#else /*CHM_EXTERNAL_STREAM_SUPPORT*/
#ifdef PPC_BSTR
/* RWE 6/12/2003 */
struct chmFile* chm_open(BSTR filename);
#else
struct chmFile* chm_open(const char *filename);
#endif
#endif /*CHM_EXTERNAL_STREAM_SUPPORT*/

/* close an ITS archive */
void chm_close(struct chmFile *h);

/* methods for ssetting tuning parameters for particular file */
#define CHM_PARAM_MAX_BLOCKS_CACHED 0
void chm_set_param(struct chmFile *h,
                   int paramType,
                   int paramVal);

/* resolve a particular object from the archive */
#define CHM_RESOLVE_SUCCESS (0)
#define CHM_RESOLVE_FAILURE (1)
int chm_resolve_object(struct chmFile *h,
                       const char *objPath,
                       struct chmUnitInfo *ui);

/* retrieve part of an object from the archive */
LONGINT64 chm_retrieve_object(struct chmFile *h,
                              struct chmUnitInfo *ui,
                              unsigned char *buf,
                              LONGUINT64 addr,
                              LONGINT64 len);

/* enumerate the objects in the .chm archive */
typedef int (*CHM_ENUMERATOR)(struct chmFile *h,
                              struct chmUnitInfo *ui,
                              void *context);
#define CHM_ENUMERATE_NORMAL    (1)
#define CHM_ENUMERATE_META      (2)
#define CHM_ENUMERATE_SPECIAL   (4)
#define CHM_ENUMERATE_FILES     (8)
#define CHM_ENUMERATE_DIRS      (16)
#define CHM_ENUMERATE_ALL       (31)
#define CHM_ENUMERATOR_FAILURE  (0)
#define CHM_ENUMERATOR_CONTINUE (1)
#define CHM_ENUMERATOR_SUCCESS  (2)
int chm_enumerate(struct chmFile *h,
                  int what,
                  CHM_ENUMERATOR e,
                  void *context);

int chm_enumerate_dir(struct chmFile *h,
                      const char *prefix,
                      int what,
                      CHM_ENUMERATOR e,
                      void *context);

#ifdef __cplusplus
}
#endif

#endif /* INCLUDED_CHMLIB_H */
