/*
 *  misc.c
 *
 *  $Id: misc.c,v 1.13 2001/06/06 12:33:35 source Exp $
 *
 *  Miscellaneous functions
 *
 *  The iODBC driver manager.
 *  
 *  Copyright (C) 1995 by Ke Jin <kejin@empress.com> 
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <iodbc.h>

#include <sql.h>
#include <sqlext.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#ifdef _MAC
#include <getfpn.h>
#endif /* _MAC */


static int
upper_strneq (
    char *s1,
    char *s2,
    int n)
{
  int i;
  char c1, c2;

  for (i = 1; i < n; i++)
    {
      c1 = s1[i];
      c2 = s2[i];

      if (c1 >= 'a' && c1 <= 'z')
	{
	  c1 += ('A' - 'a');
	}
      else if (c1 == '\n')
	{
	  c1 = '\0';
	}

      if (c2 >= 'a' && c2 <= 'z')
	{
	  c2 += ('A' - 'a');
	}
      else if (c2 == '\n')
	{
	  c2 = '\0';
	}

      if ((c1 - c2) || !c1 || !c2)
	{
	  break;
	}
    }

  return (int) !(c1 - c2);
}


static char *			/* return new position in input str */
readtoken (
    char *istr,			/* old position in input buf */
    char *obuf)			/* token string ( if "\0", then finished ) */
{
  char *start = obuf;

  /* Skip leading white space */
  while (*istr == ' ' || *istr == '\t')
    istr++;

  for (; *istr && *istr != '\n'; istr++)
    {
      char c, nx;

      c = *(istr);
      nx = *(istr + 1);

      if (c == ';')
	{
	  for (; *istr && *istr != '\n'; istr++);
	  break;
	}
      *obuf = c;
      obuf++;

      if (nx == ';' || nx == '=' || c == '=')
	{
	  istr++;
	  break;
	}
    }
  *obuf = '\0';

  /* Trim end of token */
  for (; obuf > start && (*(obuf - 1) == ' ' || *(obuf - 1) == '\t');)
    *--obuf = '\0';

  return istr;
}


#if !defined(WINDOWS) && !defined(WIN32) && !defined(OS2) && !defined(_MAC)
#include <pwd.h>
#define UNIX_PWD
#endif

/*
 * Algorithm for resolving an odbc.ini reference
 * 
 * For UNIX :    1. Check for $ODBCINI variable, if exists return $ODBCINI.
 *               2. Check for $HOME/.odbc.ini or ~/.odbc.ini file, if exists 
 *                  return it.
 *               3. Check for SYS_ODBC_INI build variable, if exists return 
 *                  it. (ie : /etc/odbc.ini).
 *               4. No odbc.ini presence, return NULL.
 *
 * For WINDOWS, WIN32, OS2 :
 *               1. Check for the system odbc.ini file, if exists return it.
 *               2. No odbc.ini presence, return NULL.
 *
 * For VMS:      1. Check for $ODBCINI variable, if exists return $ODBCINI.
 *               2. Check for SYS$LOGIN:ODBC.INI file, if exists return it.
 *               3. No odbc.ini presence, return NULL.
 *
 * For Mac:      1. On powerPC, file is ODBC Preferences PPC
 *                  On 68k, file is ODBC Preferences
 *               2. Check for ...:System Folder:Preferences:ODBC Preferences 
 *                  file, if exists return it.
 *               3. No odbc.ini presence, return NULL.
 *
 * For MacX:     1. Check for $ODBCINI variable, if exists return $ODBCINI.
 *               2. Check for $HOME/.odbc.ini or ~/.odbc.ini file, if exists 
 *                  return it.
 *               3. Check for $HOME/Library/Preferences/ODBC.preference or 
 *                  ~/.odbc.ini file, if exists return it.
 *               4. Check for SYS_ODBC_INI build variable, if exists return 
 *                  it. (ie : /etc/odbc.ini).
 *               5. Check for /System/Library/Preferences/ODBC.preference 
 *                  file, if exists return it.
 *               6. No odbc.ini presence, return NULL.
 */
char *
_iodbcdm_getinifile (char *buf, int size)
{
#ifdef _MAC
  OSErr result;
  long fldrDid;
  short fldrRef;
#endif /* _MAC */
  int i, j;
  char *ptr;

#ifdef _MAC
#  ifdef __POWERPC__
  j = STRLEN (":ODBC Preferences PPC") + 1;
#  else
  j = STRLEN (":ODBC Preferences") + 1;
#  endif /* __POWERPC__ */
#else
  j = STRLEN ("/odbc.ini") + 1;
#endif /* _MAC */

  if (size < j)
    return NULL;

#if !defined(UNIX_PWD)
#  ifdef _MAC
  result =
      FindFolder (kOnSystemDisk, kPreferencesFolderType, kDontCreateFolder,
      &fldrRef, &fldrDid);
  if (result != noErr)
    return NULL;
  ptr = get_full_pathname (fldrDid, fldrRef);

  i = (ptr) ? STRLEN (ptr) : 0;
  if (i == 0 || i > size - j)
    {
      if (ptr)
	free (ptr);
      return NULL;
    }

#    ifdef __POWERPC__
  STRCPY (buf, ptr);
  STRCAT (buf, ":ODBC Preferences PPC");
#    else
  STRCPY (buf, ptr);
  STRCAT (buf, ":ODBC Preferences");
#    endif /* __POWERPC__ */
  free (ptr);

  return buf;

#  else	/* else _MAC */

  /*
   *  On Windows, there is only one place to look
   */
  i = GetWindowsDirectory ((LPSTR) buf, size);

  if (i == 0 || i > size - j)
    return NULL;

  snprintf (buf + i, size - i, "/odbc.ini");

  return buf;
#  endif /* _MAC */
#else
  /*
   *  1. Check $ODBCINI environment variable
   */
  if ((ptr = getenv ("ODBCINI")) != NULL)
    {
      STRNCPY (buf, ptr, size);

      if (access (buf, R_OK) == 0)
	return buf;
    }

#ifdef VMS
  /*
   *  2a. VMS calls this HOME
   */
  STRNCPY (buf, "SYS$LOGIN:ODBC.INI", size);

  if (access (buf, R_OK) == 0)
    return buf;
#  else	/* else VMS */
  /*
   *  2b. Check either $HOME/.odbc.ini or ~/.odbc.ini
   */
  if ((ptr = getenv ("HOME")) == NULL)
    {
      ptr = (char *) getpwuid (getuid ());

      if (ptr != NULL)
	ptr = ((struct passwd *) ptr)->pw_dir;
    }

  if (ptr != NULL)
    {
      snprintf (buf, size, "%s/.odbc.ini", ptr);

      if (access (buf, R_OK) == 0)
	return buf;

#   ifdef _MACX
      /*
       * Try to check the ~/Library/Preferences/ODBC.preference
       */
      snprintf (buf, size, "%s" ODBC_INI_APP, ptr);

      if (access (buf, R_OK) == 0)
	return buf;
#   endif /* _MACX */
    }

#  endif /* VMS */

  /*
   *  3. Try SYS_ODBC_INI as the last resort
   */
  if ((ptr = getenv ("SYSODBCINI")) != NULL)
    {
      STRNCPY (buf, ptr, size);

      if (access (buf, R_OK) == 0)
	return buf;
    }

  STRNCPY (buf, SYS_ODBC_INI, size);

  if (access (buf, R_OK) == 0)
    return buf;

# ifdef _MACX
  /*
   * Try to check the /System/Library/Preferences/ODBC.preference
   */
  snprintf (buf, size, "/System%s", ODBC_INI_APP);

  if (access (buf, R_OK) == 0)
    return buf;
# endif	/* _MACX */

  /*
   *  No ini file found or accessable
   */
  return NULL;
#endif /* UNIX_PWD */
}


/* 
 *  read odbc init file to resolve the value of specified
 *  key from named or defaulted dsn section 
 */
char *
_iodbcdm_getkeyvalbydsn (
    char *dsn,
    int dsnlen,
    char *keywd,
    char *value,
    int size)
{
  char buf[1024];
  char dsntk[SQL_MAX_DSN_LENGTH + 3] = {'[', '\0'};
  char token[1024];		/* large enough */
  FILE *file;
  char pathbuf[1024];
  char *path;
  int nKeyWordLength = 0, nTokenLength = 0;

#define DSN_NOMATCH	0
#define DSN_NAMED	1
#define DSN_DEFAULT	2

  int dsnid = DSN_NOMATCH;
  int defaultdsn = DSN_NOMATCH;

  if (dsn == NULL || *dsn == 0)
    {
      dsn = "default";
      dsnlen = STRLEN (dsn);
    }

  if (dsnlen == SQL_NTS)
    {
      dsnlen = STRLEN (dsn);
    }

  if (dsnlen <= 0 || keywd == NULL || buf == 0 || size <= 0)
    {
      return NULL;
    }

  if (dsnlen > sizeof (dsntk) - 2)
    {
      return NULL;
    }

  value[0] = '\0';
  nKeyWordLength = STRLEN (keywd);

  STRNCAT (dsntk, dsn, dsnlen);
  STRCAT (dsntk, "]");

  dsnlen = dsnlen + 2;

  path = _iodbcdm_getinifile (pathbuf, sizeof (pathbuf));

  if (path == NULL)
    {
      return NULL;
    }

  file = (FILE *) fopen (path, "r");

  if (file == NULL)
    {
      return NULL;
    }

  for (;;)
    {
      char *str;

      str = fgets (buf, sizeof (buf), file);

      if (str == NULL)
	  break;

      if (*str == '[')
	{
	  if (upper_strneq (str, "[default]", STRLEN ("[default]")))
	    {
	      /* we only read first dsn default dsn
	       * section (as well as named dsn).
	       */
	      if (defaultdsn == DSN_NOMATCH)
		{
		  dsnid = DSN_DEFAULT;
		  defaultdsn = DSN_DEFAULT;
		}
	      else
		  dsnid = DSN_NOMATCH;

	      continue;
	    }
	  else if (upper_strneq (str, dsntk, dsnlen))
	    {
	      dsnid = DSN_NAMED;
	    }
	  else
	    {
	      dsnid = DSN_NOMATCH;
	    }

	  continue;
	}
      else if (dsnid == DSN_NOMATCH)
	{
	  continue;
	}

      str = readtoken (str, token);

      if (token)
	nTokenLength = STRLEN (token);
      else
	nTokenLength = 0;

      if (upper_strneq (keywd, token, nTokenLength > nKeyWordLength ? nTokenLength : nKeyWordLength))
	{
	  str = readtoken (str, token);

	  if (!STREQ (token, "="))
	    /* something other than = */
	    {
	      continue;
	    }

	  str = readtoken (str, token);

	  if (STRLEN (token) > size - 1)
	    {
	      break;
	    }

	  STRNCPY (value, token, size);
	  /* copy the value(i.e. next token) to buf */

	  if (dsnid != DSN_DEFAULT)
	    {
	      break;
	    }
	}
    }

  fclose (file);

  return (*value) ? value : NULL;
}


char *
_iodbcdm_getkeyvalinstr (
    char *cnstr,
    int cnlen,
    char *keywd,
    char *value,
    int size)
{
  char token[1024] = {'\0'};
  int flag = 0;

  if (cnstr == NULL || value == NULL
      || keywd == NULL || size < 1)
    {
      return NULL;
    }

  if (cnlen == SQL_NTS)
    {
      cnlen = STRLEN (cnstr);
    }

  if (cnlen <= 0)
    {
      return NULL;
    }

  for (;;)
    {
      cnstr = readtoken (cnstr, token);

      if (*token == '\0')
	  break;

      if (STREQ (token, ";"))
	{
	  flag = 0;
	  continue;
	}

      switch (flag)
	{
	case 0:
	  if (upper_strneq (token, keywd, STRLEN (keywd)))
	      flag = 1;
	  break;

	case 1:
	  if (STREQ (token, "="))
	      flag = 2;
	  break;

	case 2:
	  if (size < STRLEN (token) + 1)
	      return NULL;
	  STRNCPY (value, token, size);
	  return value;

	default:
	  break;
	}
    }

  return NULL;
}


#if 0
int
SQLGetPrivateProfileString (
    char *lpszSection,
    char *lpszEntry,
    char *lpszDefault,
    char *RetBuffer,
    int cbRetBuffer,
    char *lpzFilename)
{
  char *value;

  value = _iodbcdm_getkeyvalbydsn (
      lpszSection, SQL_NTS,
      lpszEntry, RetBuffer, cbRetBuffer);

  if (value == NULL)
    strncpy (RetBuffer, lpszDefault, cbRetBuffer);

  return strlen (RetBuffer);
}
#endif