%%	options

copyright owner	=	Dirk Krause
copyright year	=	2015-xxxx
license		=	bsd


%%	header

/**	@file
	String operations for path names
	(wchar_t characters).
*/

#ifndef DK4CONF_H_INCLUDED
#include "dk4conf.h"
#endif

#ifndef DK4TYPES_H_INCLUDED
#include "dk4types.h"
#endif

#ifndef DK4ERROR_H_INCLUDED
#include "dk4error.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif

/**	Check whether a file name is an absolute path.
	CRT on Windows: Not used.
	@param	path	Path name to check.
	@return	1 for absolute path, 0 for other path.
*/
int
dk4pathw_is_absolute(const wchar_t *path);

/**	Check whether a file name is a relative path.
	CRT on Windows: Not used.
	@param	path	Path name to check.
	@return	1 for absolute path, 0 for other path.
*/
int
dk4pathw_is_relative(const wchar_t *path);

/**	Append path filename to path name already stored in buffer.
	CRT on Windows: Optional, disabling CRT degrades performance.
	@param	buffer		Buffer already containing a path.
	@param	sz		Buffer size.
	@param	filename	Relative file name to append to buffer.
	@param	erp		Error report, may be NULL.
	@return	1 on success, 0 on error.
	
	Error codes:
	- DK4_E_INVALID_ARGUMENTS<br>
	  if buffer or filename is NULL or sz is 0,
	- DK4_E_MATH_OVERFLOW<br>
	  if filename is too long,
	- DK4_E_MEMORY<br>
	  if allocation of a filename copy fails,
	- DK4_E_SYNTAX<br>
	  if too many .. in filename,
	- DK4_E_BUFFER_TOO_SMALL<br>
	  if buffer size is too small.
*/
int
dk4pathw_append(
  wchar_t *buffer, size_t sz, const wchar_t *filename, dk4_er_t *erp
);

/**	Find pointer to suffix.
	CRT on Windows: Not used.
	@param	filename	File name to find suffix for.
	@param	erp		Error report, may be NULL.
	@return	Pointer to suffix dot if found, NULL otherwise.
	
	Error codes:
	- DK4_E_INVALID_ARGUMENTS<br>
	  if filename is NULL,
	- DK4_E_NOT_FOUND<br>
	  if the file name does not contain a suffix.
*/
wchar_t *
dk4pathw_get_suffix(const wchar_t *filename, dk4_er_t *erp);

/**	Correct file name separators from slash to backslash on Windows,
	vice versa on other systems.
	CRT on Windows: Not used.
	@param	filename	File name to correct.
*/
void
dk4pathw_correct_sep(wchar_t *filename);

/**	Check whether file name needs expansion on Windows.
	CRT on Windows: Not used.
	@param	filename	File name to check.
	@return	1 if expansion is necessary, 0 otherwise.
*/
int
dk4pathw_must_expand(const wchar_t *filename);

#ifdef __cplusplus
}
#endif



%%	module


#include "dk4pathw.h"
#include "dk4mem.h"
#include "dk4strw.h"

#if DK4_HAVE_STRING_H
#ifndef STRING_H_INCLUDED
#include <string.h>
#define	STRING_H_INCLUDED 1
#endif
#endif

#if DK4_HAVE_WCHAR_H
#ifndef WCHAR_H_INCLUDED
#include <wchar.h>
#define	WCHAR_H_INCLUDED 1
#endif
#endif


/**	Constant keywords used by the dk4pathw module.
*/
static const wchar_t * const dk4pathw_kw[] = {
#if DK4_HAVE_BACKSLASH_AS_SEP
/* 0 */	L"\\",
/* 1 */ L"/",
#else
/* 0 */ L"/",
/* 1 */ L"\\",
#endif
/* 2 */ L".",
/* 3 */ L"..",
/* 4 */ L":"
};



/**	Get last character from a string.
	@param	str	String to test.
	@return	Last character from string.
*/
static
wchar_t
dk4pathw_lastchar(const wchar_t *str)
{
  wchar_t	back	=	'\0';
  if (str) { while (L'\0' != *str) { back = *(str++); } }
  return back;
}



int
dk4pathw_is_absolute(const wchar_t *path)
{
  int		back	=	0;
#if DK4_ON_WINDOWS
  wchar_t	c;
#endif
  if (NULL != path) {
#if DK4_ON_WINDOWS
    c = *path;
    if ( *(dk4pathw_kw[0]) == c ) {
      back = 1;
    } else {
      if (((L'a' <= c) && (L'z' >= c)) || ((L'A' <= c) && (L'Z' >= c))) {
        if ( *(dk4pathw_kw[4]) == path[1] ) {
	  c = path[2];
	  if ( ( *(dk4pathw_kw[0]) == c ) || ( L'\0' == c ) ) {
	    back = 1;
	  }
	}
      }
    }
#else
    if ( *(dk4pathw_kw[0]) == *path ) {
      back = 1;
    }
#endif
  }
  return back;
}



int
dk4pathw_is_relative(const wchar_t *path)
{
  int		back	=	0;
  if (NULL != path) {
    if (NULL != dk4strw_chr(path, *(dk4pathw_kw[0]))) {
      if (0 == dk4pathw_is_absolute(path)) {
        back = 1;
      }
    }
  }
  return back;
}



int
dk4pathw_append(
  wchar_t *buffer, size_t sz, const wchar_t *filename, dk4_er_t *erp
)
{
  wchar_t	*pc;			/* Current path part to append */
  wchar_t	*pn;			/* Next part to append */
  wchar_t	*pd;			/* Part to delete */
  wchar_t	*mycp	=	NULL;	/* Private copy */
#if DK4_ON_WINDOWS
  int		 ischr;
#endif
  int		 back	=	0;	/* Function result */
  int		 failed	=	0;	/* Definitely failed */
  wchar_t	 lch;			/* Last character from string */

  if ((NULL != buffer) && (NULL != filename) && (0 < sz)) {
    mycp = dk4strw_dup(filename, erp);
    if (NULL != mycp) {
      pc = mycp;
      while ((NULL != pc) && (0 == failed)) {
        pn = dk4strw_chr(pc, *(dk4pathw_kw[0]));
	if (NULL != pn) { *(pn++) = L'\0'; }
	if (0 != dk4strw_cmp(pc, dk4pathw_kw[2])) {
	  if (0 == dk4strw_cmp(pc, dk4pathw_kw[3])) {	/* Remove from buffer */
	    pd = dk4strw_rchr(buffer, *(dk4pathw_kw[0]));
	    if (NULL != pd) {
	      *pd = L'\0';
	      if (0 < dk4strw_len(&(pd[1]))) {
#if DK4_ON_WINDOWS
	        if (2 == dk4strw_len(buffer)) {
	          ischr = 0;
	          if ((L'A' <= buffer[0]) && (L'Z' >= buffer[0])) {
		    ischr = 1;
		  }
		  if ((L'a' <= buffer[0]) && (L'z' >= buffer[0])) {
		    ischr = 1;
		  }
		  if (1 == ischr) {
		    if (L':' == buffer[1]) {
		      buffer[2] = *(dk4pathw_kw[0]);
		      buffer[3] = L'\0';
		    }
		  }
	        }
#else
	        if (0 == dk4strw_len(buffer)) {
	          *pd = *(dk4pathw_kw[0]);
		  pd++;
		  *pd = L'\0';
	        }
#endif
	      } else {
	        failed = 1;
		dk4error_set_simple_error_code(erp, DK4_E_SYNTAX);
	      }
	    } else {
	      failed = 1;
	      dk4error_set_simple_error_code(erp, DK4_E_SYNTAX);
	    }
	  } else {					/* Add to buffer */
	    lch = dk4pathw_lastchar(buffer);
	    if (lch != *(dk4pathw_kw[0])) {
	      if (0 != dk4strw_cat_s(buffer, sz, dk4pathw_kw[0], erp)) {
	        if (0 == dk4strw_cat_s(buffer, sz, pc, erp)) {
	          failed = 1;
	        }
	      } else {
	        failed = 1;
	      }
	    } else {
	      if (0 == dk4strw_cat_s(buffer, sz, pc, erp)) {
	        failed = 1;
	      }
	    }
	  }
	}
	pc = pn;
      }
      if (0 == failed) {
        back = 1;
      }
      dk4mem_release(mycp);
    }
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  }
  return back;
}



wchar_t *
dk4pathw_get_suffix(const wchar_t *filename, dk4_er_t *erp)
{
  const wchar_t	*back	= NULL;
  if (NULL != filename) {
    while (L'\0' != *filename) {
      if ((L'\\' == *filename) || (L'/' == *filename)) {
        back = NULL;
      } else {
        if (L'.' == *filename) {
	  back = filename;
	}
      }
      filename++;
    }
  } else {
    dk4error_set_simple_error_code(erp, DK4_E_INVALID_ARGUMENTS);
  }
  return ((wchar_t *)back);
}



void
dk4pathw_correct_sep(wchar_t *filename)
{
  if (NULL != filename) {
    while (L'\0' != *filename) {
#if DK4_HAVE_BACKSLASH_AS_SEP
      if (L'/' == *filename) { *filename = L'\\'; }
#else
      if (L'\\' == *filename) { *filename = L'/'; }
#endif
      filename++;
    }
  }
}



int
dk4pathw_must_expand(const wchar_t *filename)
{
#if DK4_ON_WINDOWS
  int back = 0;
  if (NULL != filename) {
    if (L'\\' == filename[0]) {
      if (L'\\' == filename[1]) {
        if (L'?' == filename[2]) {
	  if (L'\\' == filename[3]) {
	    filename = &(filename[4]);
	  }
	}
      }
    }
    while((L'\0' != *filename) && (0 == back)) {
      if (L'*' == *filename) {
        back = 1;
      } else {
        if (L'?' == *filename) {
	  back = 1;
	} else {
	  filename++;
	}
      }
    }
  }
  return back;
#else
  return 0;
#endif
}