//  This may look like C code, but it is really -*- C++ -*-

//  ------------------------------------------------------------------
//  The Goldware Library
//  Copyright (C) 1990-1999 Odinn Sorensen
//  Copyright (C) 1999-2000 Alexander S. Aganichev
//  ------------------------------------------------------------------
//  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 program; if not, write to the Free
//  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
//  MA 02111-1307, USA
//  ------------------------------------------------------------------
//  $Id$
//  ------------------------------------------------------------------
//  CRC-16, CRC-32 and Hashing
//  ------------------------------------------------------------------

#include <gstrall.h>
#include <gcrcall.h>


//  ------------------------------------------------------------------
//  Split current value (val) into keyword (key) and new value
//  If "eql" is true, the '=' char is a keyword separator char.

void getkeyvaleql(char** key, char** val, bool eql) {
  
  // Skip leading whitespace
  char *p = strskip_wht(*val);

  // Get the keyword
  switch(*p) {

    // Strip "double" quotes
    case '\"':
      *key = ++p;
      do {
        p = strskip_to(p, '\"');
        if(not *p or (*(p-1) != '\\'))
          break;
        else
          p++;
      } while(*p);
      break;

    // Strip 'single' quotes
    case '\'':
      *key = ++p;
      do {
        p = strskip_to(p, '\'');
        if(not *p or (*(p-1) != '\\'))
          break;
        else
          p++;
      } while(*p);
      break;

    // Strip round brackets
    case '(': /*)*/
      *key = ++p;
      p = strskip_to(p, /*(*/ ')');
      break;

    // Get straight keyword
    default:
      *key = p;
      while(*p and not isspace(*p) and (*p != ',')) {
        if(eql and (*p == '='))
          break;
        p++;
      }
  }

  // Nul-terminate keyword and remove trailing comma if any
  if(*p) {
    if((*p != '\"') and (*p != '\'') and (*p != /*(*/ ')')) {
      char* q = p;
      while(*(--q) == ',')
        *q = NUL;
    }
    *p++ = NUL;
  }

  // Skip whitespace and '=' if any
  p = strskip_wht(p);
  if(eql and (*p == '='))
    p = strskip_wht(++p);

  // Get the value
  *val = p;

  // Handle comments, allowing ;'s in quoted strings
  while(*p and *p != ';') {
    if((*p == '\"') and (*(p-1) != '\\')) {
      p++;
      while(*p and not ((*p == '\"') and (*(p-1) != '\\')))
        p++;
    }
    if(*p)
      p++;
  }
  *p = NUL;

  // Trim whitespace from end of value
  p = *val;
  if(*p) {
    p = strskip_to(p, NUL);
    while((*(--p) <= ' ') and *p)
      *p = NUL;
  }
  strschg(*key, "\\\"", "\"");
}


//  ------------------------------------------------------------------
//  Split current value (val) into keyword (key) and new value

void getkeyval(char** key, char** val) {

  getkeyvaleql(key, val, false);
}


//  ------------------------------------------------------------------
//  Get keyword and value and calculate/return CRC16 of keyword

word getkeyvalcrc(char** key, char** val) {
  
  // First get keyword and value
  getkeyvaleql(key, val, false);

  // Init variables
  char* p = *key;
  word c = 0;

  // Calculate CRC16 of keyword
  while(*p)
    c = updCrc16((byte)g_toupper(*p++), c);

  // Return keyword CRC
  return c;
}


//  ------------------------------------------------------------------