//**************************************************************************
//**
//**	See jlquake.txt for copyright info.
//**
//**	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
//**  included (gnu.txt) GNU General Public License for more details.
//**
//**************************************************************************

/*****************************************************************************
 * name:		unzip.c
 *
 * desc:		IO on .zip files using portions of zlib 
 *
 * $Archive: /MissionPack/code/qcommon/unzip.c $
 *
 *****************************************************************************/

#include "core.h"
#include "unzip.h"


/* unzip.h -- IO for uncompress .zip files using zlib 
   Version 0.15 beta, Mar 19th, 1998,

   Copyright (C) 1998 Gilles Vollant

   This unzip package allow extract file from .ZIP file, compatible with PKZip 2.04g
     WinZip, InfoZip tools and compatible.
   Encryption and multi volume ZipFile (span) are not supported.
   Old compressions used by old PKZip 1.x are not supported

   THIS IS AN ALPHA VERSION. AT THIS STAGE OF DEVELOPPEMENT, SOMES API OR STRUCTURE
   CAN CHANGE IN FUTURE VERSION !!
   I WAIT FEEDBACK at mail info@winimage.com
   Visit also http://www.winimage.com/zLibDll/unzip.htm for evolution

   Condition of use and distribution are the same than zlib :

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.


*/
/* for more info about .ZIP format, see 
      ftp://ftp.cdrom.com/pub/infozip/doc/appnote-970311-iz.zip
   PkWare has also a specification at :
      ftp://ftp.pkware.com/probdesc.zip */

#if !defined(unix) && !defined(CASESENSITIVITYDEFAULT_YES) && \
                      !defined(CASESENSITIVITYDEFAULT_NO)
#define CASESENSITIVITYDEFAULT_NO
#endif


#ifndef UNZ_BUFSIZE
#define UNZ_BUFSIZE (65536)
#endif

#ifndef UNZ_MAXFILENAMEINZIP
#define UNZ_MAXFILENAMEINZIP (256)
#endif

#ifndef ALLOC
# define ALLOC(size) (Mem_Alloc(size))
#endif
#ifndef TRYFREE
# define TRYFREE(p) {if (p) Mem_Free(p);}
#endif

#define SIZECENTRALDIRITEM (0x2e)
#define SIZEZIPLOCALHEADER (0x1e)



/* ===========================================================================
     Read a byte from a gz_stream; update next_in and avail_in. Return EOF
   for end of file.
   IN assertion: the stream s has been sucessfully opened for reading.
*/

/*
static int unzlocal_getByte(FILE *fin,int *pi)
{
    unsigned char c;
	int err = fread(&c, 1, 1, fin);
    if (err==1)
    {
        *pi = (int)c;
        return UNZ_OK;
    }
    else
    {
        if (ferror(fin)) 
            return UNZ_ERRNO;
        else
            return UNZ_EOF;
    }
}
*/

/* ===========================================================================
   Reads a long in LSB order from the given gz_stream. Sets 
*/
static int unzlocal_getShort (FILE* fin, uLong *pX)
{
	short	v;

	fread( &v, sizeof(v), 1, fin );

	*pX = LittleShort( v);
	return UNZ_OK;

/*
    uLong x ;
    int i;
    int err;

    err = unzlocal_getByte(fin,&i);
    x = (uLong)i;
    
    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<8;
   
    if (err==UNZ_OK)
        *pX = x;
    else
        *pX = 0;
    return err;
*/
}

static int unzlocal_getLong (FILE *fin, uLong *pX)
{
	int		v;

	fread( &v, sizeof(v), 1, fin );

	*pX = LittleLong( v);
	return UNZ_OK;

/*
    uLong x ;
    int i;
    int err;

    err = unzlocal_getByte(fin,&i);
    x = (uLong)i;
    
    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<8;

    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<16;

    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<24;
   
    if (err==UNZ_OK)
        *pX = x;
    else
        *pX = 0;
    return err;
*/
}


/* My own strcmpi / strcasecmp */
static int strcmpcasenosensitive_internal (const char* fileName1,const char* fileName2)
{
	for (;;)
	{
		char c1=*(fileName1++);
		char c2=*(fileName2++);
		if ((c1>='a') && (c1<='z'))
			c1 -= 0x20;
		if ((c2>='a') && (c2<='z'))
			c2 -= 0x20;
		if (c1=='\0')
			return ((c2=='\0') ? 0 : -1);
		if (c2=='\0')
			return 1;
		if (c1<c2)
			return -1;
		if (c1>c2)
			return 1;
	}
}


#ifdef  CASESENSITIVITYDEFAULT_NO
#define CASESENSITIVITYDEFAULTVALUE 2
#else
#define CASESENSITIVITYDEFAULTVALUE 1
#endif

#ifndef STRCMPCASENOSENTIVEFUNCTION
#define STRCMPCASENOSENTIVEFUNCTION strcmpcasenosensitive_internal
#endif

/* 
   Compare two filename (fileName1,fileName2).
   If iCaseSenisivity = 1, comparision is case sensitivity (like strcmp)
   If iCaseSenisivity = 2, comparision is not case sensitivity (like strcmpi
                                                                or strcasecmp)
   If iCaseSenisivity = 0, case sensitivity is defaut of your operating system
        (like 1 on Unix, 2 on Windows)

*/
extern  int unzStringFileNameCompare (const char* fileName1,const char* fileName2,int iCaseSensitivity)
{
	if (iCaseSensitivity==0)
		iCaseSensitivity=CASESENSITIVITYDEFAULTVALUE;

	if (iCaseSensitivity==1)
		return String::Cmp(fileName1,fileName2);

	return STRCMPCASENOSENTIVEFUNCTION(fileName1,fileName2);
} 

#define BUFREADCOMMENT (0x400)

/*
  Locate the Central directory of a zipfile (at the end, just before
    the global comment)
*/
extern uLong unzlocal_SearchCentralDir(FILE *fin)
{
	unsigned char* buf;
	uLong uSizeFile;
	uLong uBackRead;
	uLong uMaxBack=0xffff; /* maximum size of global comment */
	uLong uPosFound=0;
	
	if (fseek(fin,0,SEEK_END) != 0)
		return 0;


	uSizeFile = ftell( fin );
	
	if (uMaxBack>uSizeFile)
		uMaxBack = uSizeFile;

	buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
	if (buf==NULL)
		return 0;

	uBackRead = 4;
	while (uBackRead<uMaxBack)
	{
		uLong uReadSize,uReadPos ;
		int i;
		if (uBackRead+BUFREADCOMMENT>uMaxBack) 
			uBackRead = uMaxBack;
		else
			uBackRead+=BUFREADCOMMENT;
		uReadPos = uSizeFile-uBackRead ;
		
		uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ? 
                     (BUFREADCOMMENT+4) : (uSizeFile-uReadPos);
		if (fseek(fin,uReadPos,SEEK_SET)!=0)
			break;

		if (fread(buf,(uInt)uReadSize,1,fin)!=1)
			break;

                for (i=(int)uReadSize-3; (i--)>0;)
			if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) && 
				((*(buf+i+2))==0x05) && ((*(buf+i+3))==0x06))
			{
				uPosFound = uReadPos+i;
				break;
			}

		if (uPosFound!=0)
			break;
	}
	TRYFREE(buf);
	return uPosFound;
}

extern unzFile unzReOpen (const char* path, unzFile file)
{
	unz_s *s;
	FILE * fin;

    fin=fopen(path,"rb");
	if (fin==NULL)
		return NULL;

	s=(unz_s*)ALLOC(sizeof(unz_s));
	Com_Memcpy(s, (unz_s*)file, sizeof(unz_s));

	s->file = fin;
	return (unzFile)s;	
}

/*
  Open a Zip file. path contain the full pathname (by example,
     on a Windows NT computer "c:\\test\\zlib109.zip" or on an Unix computer
	 "zlib/zlib109.zip".
	 If the zipfile cannot be opened (file don't exist or in not valid), the
	   return value is NULL.
     Else, the return value is a unzFile Handle, usable with other function
	   of this unzip package.
*/
extern unzFile unzOpen (const char* path)
{
	unz_s us;
	unz_s *s;
	uLong central_pos,uL;
	FILE * fin ;

	uLong number_disk;          /* number of the current dist, used for 
								   spaning ZIP, unsupported, always 0*/
	uLong number_disk_with_CD;  /* number the the disk with central dir, used
								   for spaning ZIP, unsupported, always 0*/
	uLong number_entry_CD;      /* total number of entries in
	                               the central dir 
	                               (same than number_entry on nospan) */

	int err=UNZ_OK;

    fin=fopen(path,"rb");
	if (fin==NULL)
		return NULL;

	central_pos = unzlocal_SearchCentralDir(fin);
	if (central_pos==0)
		err=UNZ_ERRNO;

	if (fseek(fin,central_pos,SEEK_SET)!=0)
		err=UNZ_ERRNO;

	/* the signature, already checked */
	if (unzlocal_getLong(fin,&uL)!=UNZ_OK)
		err=UNZ_ERRNO;

	/* number of this disk */
	if (unzlocal_getShort(fin,&number_disk)!=UNZ_OK)
		err=UNZ_ERRNO;

	/* number of the disk with the start of the central directory */
	if (unzlocal_getShort(fin,&number_disk_with_CD)!=UNZ_OK)
		err=UNZ_ERRNO;

	/* total number of entries in the central dir on this disk */
	if (unzlocal_getShort(fin,&us.gi.number_entry)!=UNZ_OK)
		err=UNZ_ERRNO;

	/* total number of entries in the central dir */
	if (unzlocal_getShort(fin,&number_entry_CD)!=UNZ_OK)
		err=UNZ_ERRNO;

	if ((number_entry_CD!=us.gi.number_entry) ||
		(number_disk_with_CD!=0) ||
		(number_disk!=0))
		err=UNZ_BADZIPFILE;

	/* size of the central directory */
	if (unzlocal_getLong(fin,&us.size_central_dir)!=UNZ_OK)
		err=UNZ_ERRNO;

	/* offset of start of central directory with respect to the 
	      starting disk number */
	if (unzlocal_getLong(fin,&us.offset_central_dir)!=UNZ_OK)
		err=UNZ_ERRNO;

	/* zipfile comment length */
	if (unzlocal_getShort(fin,&us.gi.size_comment)!=UNZ_OK)
		err=UNZ_ERRNO;

	if ((central_pos<us.offset_central_dir+us.size_central_dir) && 
		(err==UNZ_OK))
		err=UNZ_BADZIPFILE;

	if (err!=UNZ_OK)
	{
		fclose(fin);
		return NULL;
	}

	us.file=fin;
	us.byte_before_the_zipfile = central_pos -
		                    (us.offset_central_dir+us.size_central_dir);
	us.central_pos = central_pos;
    us.pfile_in_zip_read = NULL;
	

	s=(unz_s*)ALLOC(sizeof(unz_s));
	*s=us;
//	unzGoToFirstFile((unzFile)s);	
	return (unzFile)s;	
}


/*
  Close a ZipFile opened with unzipOpen.
  If there is files inside the .Zip opened with unzipOpenCurrentFile (see later),
    these files MUST be closed with unzipCloseCurrentFile before call unzipClose.
  return UNZ_OK if there is no problem. */
extern int unzClose (unzFile file)
{
	unz_s* s;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;

    if (s->pfile_in_zip_read!=NULL)
        unzCloseCurrentFile(file);

	fclose(s->file);
	TRYFREE(s);
	return UNZ_OK;
}


/*
  Write info about the ZipFile in the *pglobal_info structure.
  No preparation of the structure is needed
  return UNZ_OK if there is no problem. */
extern int unzGetGlobalInfo (unzFile file,unz_global_info *pglobal_info)
{
	unz_s* s;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	*pglobal_info=s->gi;
	return UNZ_OK;
}


/*
   Translate date/time from Dos format to tm_unz (readable more easilty)
*/
static void unzlocal_DosDateToTmuDate (uLong ulDosDate, tm_unz* ptm)
{
    uLong uDate;
    uDate = (uLong)(ulDosDate>>16);
    ptm->tm_mday = (uInt)(uDate&0x1f) ;
    ptm->tm_mon =  (uInt)((((uDate)&0x1E0)/0x20)-1) ;
    ptm->tm_year = (uInt)(((uDate&0x0FE00)/0x0200)+1980) ;

    ptm->tm_hour = (uInt) ((ulDosDate &0xF800)/0x800);
    ptm->tm_min =  (uInt) ((ulDosDate&0x7E0)/0x20) ;
    ptm->tm_sec =  (uInt) (2*(ulDosDate&0x1f)) ;
}

/*
  Get Info about the current file in the zipfile, with internal only info
*/
static int unzlocal_GetCurrentFileInfoInternal (unzFile file,
                                                  unz_file_info *pfile_info,
                                                  unz_file_info_internal 
                                                  *pfile_info_internal,
                                                  char *szFileName,
												  uLong fileNameBufferSize,
                                                  void *extraField,
												  uLong extraFieldBufferSize,
                                                  char *szComment,
												  uLong commentBufferSize)
{
	unz_s* s;
	unz_file_info file_info;
	unz_file_info_internal file_info_internal;
	int err=UNZ_OK;
	uLong uMagic;
	long lSeek=0;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	if (fseek(s->file,s->pos_in_central_dir+s->byte_before_the_zipfile,SEEK_SET)!=0)
		err=UNZ_ERRNO;


	/* we check the magic */
	if (err==UNZ_OK) {
		if (unzlocal_getLong(s->file,&uMagic) != UNZ_OK)
			err=UNZ_ERRNO;
		else if (uMagic!=0x02014b50)
			err=UNZ_BADZIPFILE;
	}
	if (unzlocal_getShort(s->file,&file_info.version) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.version_needed) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.flag) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.compression_method) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.dosDate) != UNZ_OK)
		err=UNZ_ERRNO;

    unzlocal_DosDateToTmuDate(file_info.dosDate,&file_info.tmu_date);

	if (unzlocal_getLong(s->file,&file_info.crc) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.compressed_size) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.uncompressed_size) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_filename) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_file_extra) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.size_file_comment) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.disk_num_start) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&file_info.internal_fa) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info.external_fa) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&file_info_internal.offset_curfile) != UNZ_OK)
		err=UNZ_ERRNO;

	lSeek+=file_info.size_filename;
	if ((err==UNZ_OK) && (szFileName!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_filename<fileNameBufferSize)
		{
			*(szFileName+file_info.size_filename)='\0';
			uSizeRead = file_info.size_filename;
		}
		else
			uSizeRead = fileNameBufferSize;

		if ((file_info.size_filename>0) && (fileNameBufferSize>0))
			if (fread(szFileName,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		lSeek -= uSizeRead;
	}

	
	if ((err==UNZ_OK) && (extraField!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_file_extra<extraFieldBufferSize)
			uSizeRead = file_info.size_file_extra;
		else
			uSizeRead = extraFieldBufferSize;

		if (lSeek!=0) {
			if (fseek(s->file,lSeek,SEEK_CUR)==0)
				lSeek=0;
			else
				err=UNZ_ERRNO;
		}
		if ((file_info.size_file_extra>0) && (extraFieldBufferSize>0)) {
			if (fread(extraField,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		}
		lSeek += file_info.size_file_extra - uSizeRead;
	}
	else
		lSeek+=file_info.size_file_extra; 

	
	if ((err==UNZ_OK) && (szComment!=NULL))
	{
		uLong uSizeRead ;
		if (file_info.size_file_comment<commentBufferSize)
		{
			*(szComment+file_info.size_file_comment)='\0';
			uSizeRead = file_info.size_file_comment;
		}
		else
			uSizeRead = commentBufferSize;

		if (lSeek!=0) {
			if (fseek(s->file,lSeek,SEEK_CUR)==0)
				lSeek=0;
			else
				err=UNZ_ERRNO;
		}
		if ((file_info.size_file_comment>0) && (commentBufferSize>0)) {
			if (fread(szComment,(uInt)uSizeRead,1,s->file)!=1)
				err=UNZ_ERRNO;
		}
		lSeek+=file_info.size_file_comment - uSizeRead;
	}
	else
		lSeek+=file_info.size_file_comment;

	if ((err==UNZ_OK) && (pfile_info!=NULL))
		*pfile_info=file_info;

	if ((err==UNZ_OK) && (pfile_info_internal!=NULL))
		*pfile_info_internal=file_info_internal;

	return err;
}



/*
  Write info about the ZipFile in the *pglobal_info structure.
  No preparation of the structure is needed
  return UNZ_OK if there is no problem.
*/
extern int unzGetCurrentFileInfo (	unzFile file, unz_file_info *pfile_info,
									char *szFileName, uLong fileNameBufferSize,
									void *extraField, uLong extraFieldBufferSize,
									char *szComment, uLong commentBufferSize)
{
	return unzlocal_GetCurrentFileInfoInternal(file,pfile_info,NULL,
												szFileName,fileNameBufferSize,
												extraField,extraFieldBufferSize,
												szComment,commentBufferSize);
}

/*
  Set the current file of the zipfile to the first file.
  return UNZ_OK if there is no problem
*/
extern int unzGoToFirstFile (unzFile file)
{
	int err=UNZ_OK;
	unz_s* s;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	s->pos_in_central_dir=s->offset_central_dir;
	s->num_file=0;
	err=unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											 &s->cur_file_info_internal,
											 NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return err;
}


/*
  Set the current file of the zipfile to the next file.
  return UNZ_OK if there is no problem
  return UNZ_END_OF_LIST_OF_FILE if the actual file was the latest.
*/
extern int unzGoToNextFile (unzFile file)
{
	unz_s* s;	
	int err;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	if (!s->current_file_ok)
		return UNZ_END_OF_LIST_OF_FILE;
	if (s->num_file+1==s->gi.number_entry)
		return UNZ_END_OF_LIST_OF_FILE;

	s->pos_in_central_dir += SIZECENTRALDIRITEM + s->cur_file_info.size_filename +
			s->cur_file_info.size_file_extra + s->cur_file_info.size_file_comment ;
	s->num_file++;
	err = unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											   &s->cur_file_info_internal,
											   NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return err;
}

/*
  Get the position of the info of the current file in the zip.
  return UNZ_OK if there is no problem
*/
extern int unzGetCurrentFileInfoPosition (unzFile file, unsigned long *pos )
{
	unz_s* s;	

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;

	*pos = s->pos_in_central_dir;
	return UNZ_OK;
}

/*
  Set the position of the info of the current file in the zip.
  return UNZ_OK if there is no problem
*/
extern int unzSetCurrentFileInfoPosition (unzFile file, unsigned long pos )
{
	unz_s* s;	
	int err;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;

	s->pos_in_central_dir = pos;
	err = unzlocal_GetCurrentFileInfoInternal(file,&s->cur_file_info,
											   &s->cur_file_info_internal,
											   NULL,0,NULL,0,NULL,0);
	s->current_file_ok = (err == UNZ_OK);
	return UNZ_OK;
}

/*
  Try locate the file szFileName in the zipfile.
  For the iCaseSensitivity signification, see unzipStringFileNameCompare

  return value :
  UNZ_OK if the file is found. It becomes the current file.
  UNZ_END_OF_LIST_OF_FILE if the file is not found
*/
extern int unzLocateFile (unzFile file, const char *szFileName, int iCaseSensitivity)
{
	unz_s* s;	
	int err;

	
	uLong num_fileSaved;
	uLong pos_in_central_dirSaved;


	if (file==NULL)
		return UNZ_PARAMERROR;

    if (String::Length(szFileName)>=UNZ_MAXFILENAMEINZIP)
        return UNZ_PARAMERROR;

	s=(unz_s*)file;
	if (!s->current_file_ok)
		return UNZ_END_OF_LIST_OF_FILE;

	num_fileSaved = s->num_file;
	pos_in_central_dirSaved = s->pos_in_central_dir;

	err = unzGoToFirstFile(file);

	while (err == UNZ_OK)
	{
		char szCurrentFileName[UNZ_MAXFILENAMEINZIP+1];
		unzGetCurrentFileInfo(file,NULL,
								szCurrentFileName,sizeof(szCurrentFileName)-1,
								NULL,0,NULL,0);
		if (unzStringFileNameCompare(szCurrentFileName,
										szFileName,iCaseSensitivity)==0)
			return UNZ_OK;
		err = unzGoToNextFile(file);
	}

	s->num_file = num_fileSaved ;
	s->pos_in_central_dir = pos_in_central_dirSaved ;
	return err;
}


/*
  Read the static header of the current zipfile
  Check the coherency of the static header and info in the end of central
        directory about this file
  store in *piSizeVar the size of extra info in static header
        (filename and size of extra field data)
*/
static int unzlocal_CheckCurrentFileCoherencyHeader (unz_s* s, uInt* piSizeVar,
													uLong *poffset_local_extrafield,
													uInt *psize_local_extrafield)
{
	uLong uMagic,uData,uFlags;
	uLong size_filename;
	uLong size_extra_field;
	int err=UNZ_OK;

	*piSizeVar = 0;
	*poffset_local_extrafield = 0;
	*psize_local_extrafield = 0;

	if (fseek(s->file,s->cur_file_info_internal.offset_curfile +
								s->byte_before_the_zipfile,SEEK_SET)!=0)
		return UNZ_ERRNO;


	if (err==UNZ_OK) {
		if (unzlocal_getLong(s->file,&uMagic) != UNZ_OK)
			err=UNZ_ERRNO;
		else if (uMagic!=0x04034b50)
			err=UNZ_BADZIPFILE;
	}
	if (unzlocal_getShort(s->file,&uData) != UNZ_OK)
		err=UNZ_ERRNO;
/*
	else if ((err==UNZ_OK) && (uData!=s->cur_file_info.wVersion))
		err=UNZ_BADZIPFILE;
*/
	if (unzlocal_getShort(s->file,&uFlags) != UNZ_OK)
		err=UNZ_ERRNO;

	if (unzlocal_getShort(s->file,&uData) != UNZ_OK)
		err=UNZ_ERRNO;
	else if ((err==UNZ_OK) && (uData!=s->cur_file_info.compression_method))
		err=UNZ_BADZIPFILE;

    if ((err==UNZ_OK) && (s->cur_file_info.compression_method!=0) &&
                         (s->cur_file_info.compression_method!=Z_DEFLATED))
        err=UNZ_BADZIPFILE;

	if (unzlocal_getLong(s->file,&uData) != UNZ_OK) /* date/time */
		err=UNZ_ERRNO;

	if (unzlocal_getLong(s->file,&uData) != UNZ_OK) /* crc */
		err=UNZ_ERRNO;
	else if ((err==UNZ_OK) && (uData!=s->cur_file_info.crc) &&
		                      ((uFlags & 8)==0))
		err=UNZ_BADZIPFILE;

	if (unzlocal_getLong(s->file,&uData) != UNZ_OK) /* size compr */
		err=UNZ_ERRNO;
	else if ((err==UNZ_OK) && (uData!=s->cur_file_info.compressed_size) &&
							  ((uFlags & 8)==0))
		err=UNZ_BADZIPFILE;

	if (unzlocal_getLong(s->file,&uData) != UNZ_OK) /* size uncompr */
		err=UNZ_ERRNO;
	else if ((err==UNZ_OK) && (uData!=s->cur_file_info.uncompressed_size) && 
							  ((uFlags & 8)==0))
		err=UNZ_BADZIPFILE;


	if (unzlocal_getShort(s->file,&size_filename) != UNZ_OK)
		err=UNZ_ERRNO;
	else if ((err==UNZ_OK) && (size_filename!=s->cur_file_info.size_filename))
		err=UNZ_BADZIPFILE;

	*piSizeVar += (uInt)size_filename;

	if (unzlocal_getShort(s->file,&size_extra_field) != UNZ_OK)
		err=UNZ_ERRNO;
	*poffset_local_extrafield= s->cur_file_info_internal.offset_curfile +
									SIZEZIPLOCALHEADER + size_filename;
	*psize_local_extrafield = (uInt)size_extra_field;

	*piSizeVar += (uInt)size_extra_field;

	return err;
}
												
/*
  Open for reading data the current file in the zipfile.
  If there is no error and the file is opened, the return value is UNZ_OK.
*/
extern int unzOpenCurrentFile (unzFile file)
{
	int err=UNZ_OK;
	int Store;
	uInt iSizeVar;
	unz_s* s;
	file_in_zip_read_info_s* pfile_in_zip_read_info;
	uLong offset_local_extrafield;  /* offset of the static extra field */
	uInt  size_local_extrafield;    /* size of the static extra field */

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
	if (!s->current_file_ok)
		return UNZ_PARAMERROR;

    if (s->pfile_in_zip_read != NULL)
        unzCloseCurrentFile(file);

	if (unzlocal_CheckCurrentFileCoherencyHeader(s,&iSizeVar,
				&offset_local_extrafield,&size_local_extrafield)!=UNZ_OK)
		return UNZ_BADZIPFILE;

	pfile_in_zip_read_info = (file_in_zip_read_info_s*)
									    ALLOC(sizeof(file_in_zip_read_info_s));
	if (pfile_in_zip_read_info==NULL)
		return UNZ_INTERNALERROR;

	pfile_in_zip_read_info->read_buffer=(char*)ALLOC(UNZ_BUFSIZE);
	pfile_in_zip_read_info->offset_local_extrafield = offset_local_extrafield;
	pfile_in_zip_read_info->size_local_extrafield = size_local_extrafield;
	pfile_in_zip_read_info->pos_local_extrafield=0;

	if (pfile_in_zip_read_info->read_buffer==NULL)
	{
		TRYFREE(pfile_in_zip_read_info);
		return UNZ_INTERNALERROR;
	}

	pfile_in_zip_read_info->stream_initialised=0;
	
	if ((s->cur_file_info.compression_method!=0) &&
        (s->cur_file_info.compression_method!=Z_DEFLATED))
		err=UNZ_BADZIPFILE;
	Store = s->cur_file_info.compression_method==0;

	pfile_in_zip_read_info->crc32_wait=s->cur_file_info.crc;
	pfile_in_zip_read_info->crc32=0;
	pfile_in_zip_read_info->compression_method =
            s->cur_file_info.compression_method;
	pfile_in_zip_read_info->file=s->file;
	pfile_in_zip_read_info->byte_before_the_zipfile=s->byte_before_the_zipfile;

    pfile_in_zip_read_info->stream.total_out = 0;

	if (!Store)
	{
	  pfile_in_zip_read_info->stream.zalloc = (alloc_func)0;
	  pfile_in_zip_read_info->stream.zfree = (free_func)0;
	  pfile_in_zip_read_info->stream.opaque = (unsigned char*)0; 
      
	  err=inflateInit2(&pfile_in_zip_read_info->stream, -MAX_WBITS);
	  if (err == Z_OK)
	    pfile_in_zip_read_info->stream_initialised=1;
        /* windowBits is passed < 0 to tell that there is no zlib header.
         * Note that in this case inflate *requires* an extra "dummy" byte
         * after the compressed stream in order to complete decompression and
         * return Z_STREAM_END. 
         * In unzip, i don't wait absolutely Z_STREAM_END because I known the 
         * size of both compressed and uncompressed data
         */
	}
	pfile_in_zip_read_info->rest_read_compressed = 
            s->cur_file_info.compressed_size ;
	pfile_in_zip_read_info->rest_read_uncompressed = 
            s->cur_file_info.uncompressed_size ;

	
	pfile_in_zip_read_info->pos_in_zipfile = 
            s->cur_file_info_internal.offset_curfile + SIZEZIPLOCALHEADER + 
			  iSizeVar;
	
	pfile_in_zip_read_info->stream.avail_in = (uInt)0;


	s->pfile_in_zip_read = pfile_in_zip_read_info;
    return UNZ_OK;
}


/*
  Read bytes from the current file.
  buf contain buffer where data must be copied
  len the size of buf.

  return the number of byte copied if somes bytes are copied
  return 0 if the end of file was reached
  return <0 with error code if there is an error
    (UNZ_ERRNO for IO error, or zLib error for uncompress error)
*/
extern int unzReadCurrentFile  (unzFile file, void *buf, unsigned len)
{
	int err=UNZ_OK;
	uInt iRead = 0;
	unz_s* s;
	file_in_zip_read_info_s* pfile_in_zip_read_info;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
    pfile_in_zip_read_info=s->pfile_in_zip_read;

	if (pfile_in_zip_read_info==NULL)
		return UNZ_PARAMERROR;


	if ((pfile_in_zip_read_info->read_buffer == NULL))
		return UNZ_END_OF_LIST_OF_FILE;
	if (len==0)
		return 0;

	pfile_in_zip_read_info->stream.next_out = (Byte*)buf;

	pfile_in_zip_read_info->stream.avail_out = (uInt)len;
	
	if (len>pfile_in_zip_read_info->rest_read_uncompressed)
		pfile_in_zip_read_info->stream.avail_out = 
		  (uInt)pfile_in_zip_read_info->rest_read_uncompressed;

	while (pfile_in_zip_read_info->stream.avail_out>0)
	{
		if ((pfile_in_zip_read_info->stream.avail_in==0) &&
            (pfile_in_zip_read_info->rest_read_compressed>0))
		{
			uInt uReadThis = UNZ_BUFSIZE;
			if (pfile_in_zip_read_info->rest_read_compressed<uReadThis)
				uReadThis = (uInt)pfile_in_zip_read_info->rest_read_compressed;
			if (uReadThis == 0)
				return UNZ_EOF;
			if (s->cur_file_info.compressed_size == pfile_in_zip_read_info->rest_read_compressed)
				if (fseek(pfile_in_zip_read_info->file,
						  pfile_in_zip_read_info->pos_in_zipfile + 
							 pfile_in_zip_read_info->byte_before_the_zipfile,SEEK_SET)!=0)
					return UNZ_ERRNO;
			if (fread(pfile_in_zip_read_info->read_buffer,uReadThis,1,
                         pfile_in_zip_read_info->file)!=1)
				return UNZ_ERRNO;
			pfile_in_zip_read_info->pos_in_zipfile += uReadThis;

			pfile_in_zip_read_info->rest_read_compressed-=uReadThis;
			
			pfile_in_zip_read_info->stream.next_in = 
                (Byte*)pfile_in_zip_read_info->read_buffer;
			pfile_in_zip_read_info->stream.avail_in = (uInt)uReadThis;
		}

		if (pfile_in_zip_read_info->compression_method==0)
		{
			uInt uDoCopy,i ;
			if (pfile_in_zip_read_info->stream.avail_out < 
                            pfile_in_zip_read_info->stream.avail_in)
				uDoCopy = pfile_in_zip_read_info->stream.avail_out ;
			else
				uDoCopy = pfile_in_zip_read_info->stream.avail_in ;
				
			for (i=0;i<uDoCopy;i++)
				*(pfile_in_zip_read_info->stream.next_out+i) =
                        *(pfile_in_zip_read_info->stream.next_in+i);
					
//			pfile_in_zip_read_info->crc32 = crc32(pfile_in_zip_read_info->crc32,
//								pfile_in_zip_read_info->stream.next_out,
//								uDoCopy);
			pfile_in_zip_read_info->rest_read_uncompressed-=uDoCopy;
			pfile_in_zip_read_info->stream.avail_in -= uDoCopy;
			pfile_in_zip_read_info->stream.avail_out -= uDoCopy;
			pfile_in_zip_read_info->stream.next_out += uDoCopy;
			pfile_in_zip_read_info->stream.next_in += uDoCopy;
            pfile_in_zip_read_info->stream.total_out += uDoCopy;
			iRead += uDoCopy;
		}
		else
		{
			uLong uTotalOutBefore,uTotalOutAfter;
			const Byte *bufBefore;
			uLong uOutThis;
			int flush=Z_SYNC_FLUSH;

			uTotalOutBefore = pfile_in_zip_read_info->stream.total_out;
			bufBefore = pfile_in_zip_read_info->stream.next_out;

			/*
			if ((pfile_in_zip_read_info->rest_read_uncompressed ==
			         pfile_in_zip_read_info->stream.avail_out) &&
				(pfile_in_zip_read_info->rest_read_compressed == 0))
				flush = Z_FINISH;
			*/
			err=inflate(&pfile_in_zip_read_info->stream,flush);

			uTotalOutAfter = pfile_in_zip_read_info->stream.total_out;
			uOutThis = uTotalOutAfter-uTotalOutBefore;
			
//			pfile_in_zip_read_info->crc32 = 
//                crc32(pfile_in_zip_read_info->crc32,bufBefore,
//                        (uInt)(uOutThis));

			pfile_in_zip_read_info->rest_read_uncompressed -=
                uOutThis;

			iRead += (uInt)(uTotalOutAfter - uTotalOutBefore);
            
			if (err==Z_STREAM_END)
				return (iRead==0) ? UNZ_EOF : iRead;
			if (err!=Z_OK) 
				break;
		}
	}

	if (err==Z_OK)
		return iRead;
	return err;
}


/*
  Give the current position in uncompressed data
*/
extern long unztell (unzFile file)
{
	unz_s* s;
	file_in_zip_read_info_s* pfile_in_zip_read_info;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
    pfile_in_zip_read_info=s->pfile_in_zip_read;

	if (pfile_in_zip_read_info==NULL)
		return UNZ_PARAMERROR;

	return (long)pfile_in_zip_read_info->stream.total_out;
}


/*
  return 1 if the end of file was reached, 0 elsewhere 
*/
extern int unzeof (unzFile file)
{
	unz_s* s;
	file_in_zip_read_info_s* pfile_in_zip_read_info;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
    pfile_in_zip_read_info=s->pfile_in_zip_read;

	if (pfile_in_zip_read_info==NULL)
		return UNZ_PARAMERROR;
	
	if (pfile_in_zip_read_info->rest_read_uncompressed == 0)
		return 1;
	else
		return 0;
}



/*
  Read extra field from the current file (opened by unzOpenCurrentFile)
  This is the static-header version of the extra field (sometimes, there is
    more info in the static-header version than in the central-header)

  if buf==NULL, it return the size of the static extra field that can be read

  if buf!=NULL, len is the size of the buffer, the extra header is copied in
	buf.
  the return value is the number of bytes copied in buf, or (if <0) 
	the error code
*/
extern int unzGetLocalExtrafield (unzFile file,void *buf,unsigned len)
{
	unz_s* s;
	file_in_zip_read_info_s* pfile_in_zip_read_info;
	uInt read_now;
	uLong size_to_read;

	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
    pfile_in_zip_read_info=s->pfile_in_zip_read;

	if (pfile_in_zip_read_info==NULL)
		return UNZ_PARAMERROR;

	size_to_read = (pfile_in_zip_read_info->size_local_extrafield - 
				pfile_in_zip_read_info->pos_local_extrafield);

	if (buf==NULL)
		return (int)size_to_read;
	
	if (len>size_to_read)
		read_now = (uInt)size_to_read;
	else
		read_now = (uInt)len ;

	if (read_now==0)
		return 0;
	
	if (fseek(pfile_in_zip_read_info->file,
              pfile_in_zip_read_info->offset_local_extrafield + 
			  pfile_in_zip_read_info->pos_local_extrafield,SEEK_SET)!=0)
		return UNZ_ERRNO;

	if (fread(buf,(uInt)size_to_read,1,pfile_in_zip_read_info->file)!=1)
		return UNZ_ERRNO;

	return (int)read_now;
}

/*
  Close the file in zip opened with unzipOpenCurrentFile
  Return UNZ_CRCERROR if all the file was read but the CRC is not good
*/
extern int unzCloseCurrentFile (unzFile file)
{
	int err=UNZ_OK;

	unz_s* s;
	file_in_zip_read_info_s* pfile_in_zip_read_info;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;
    pfile_in_zip_read_info=s->pfile_in_zip_read;

	if (pfile_in_zip_read_info==NULL)
		return UNZ_PARAMERROR;

/*
	if (pfile_in_zip_read_info->rest_read_uncompressed == 0)
	{
		if (pfile_in_zip_read_info->crc32 != pfile_in_zip_read_info->crc32_wait)
			err=UNZ_CRCERROR;
	}
*/

	TRYFREE(pfile_in_zip_read_info->read_buffer);
	pfile_in_zip_read_info->read_buffer = NULL;
	if (pfile_in_zip_read_info->stream_initialised)
		inflateEnd(&pfile_in_zip_read_info->stream);

	pfile_in_zip_read_info->stream_initialised = 0;
	TRYFREE(pfile_in_zip_read_info);

    s->pfile_in_zip_read=NULL;

	return err;
}


/*
  Get the global comment string of the ZipFile, in the szComment buffer.
  uSizeBuf is the size of the szComment buffer.
  return the number of byte copied or an error code <0
*/
extern int unzGetGlobalComment (unzFile file, char *szComment, uLong uSizeBuf)
{
	unz_s* s;
	uLong uReadThis ;
	if (file==NULL)
		return UNZ_PARAMERROR;
	s=(unz_s*)file;

	uReadThis = uSizeBuf;
	if (uReadThis>s->gi.size_comment)
		uReadThis = s->gi.size_comment;

	if (fseek(s->file,s->central_pos+22,SEEK_SET)!=0)
		return UNZ_ERRNO;

	if (uReadThis>0)
    {
      *szComment='\0';
	  if (fread(szComment,(uInt)uReadThis,1,s->file)!=1)
		return UNZ_ERRNO;
    }

	if ((szComment != NULL) && (uSizeBuf > s->gi.size_comment))
		*(szComment+s->gi.size_comment)='\0';
	return (int)uReadThis;
}
