/*
 * common.c -- miscellanious helper functions.
 *
 * Copyright (c) 2003, WiseGuys Internet B.V.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the
 * distribution.
 * 
 * - Neither the name of the WiseGuys Internet B.V. nor the names of
 * its contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "config.h"
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdarg.h>
#include <ctype.h>
#include "common_impl.h"

extern void wgmem_error( const char *fmt, ... )
{
        va_list ap;

	fprintf(stderr, "MEMERROR : ");
        va_start(ap, fmt);
        vfprintf(stderr, fmt, ap);
        va_end(ap);
}


extern void *wg_malloc( size_t size )
{
	void *result;
	if ( !size ) {
		wgmem_error( "Error mallocing 0 bytes.\n" );
	}

	result = malloc( size );
	if ( !result ) {
		wgmem_error( "Error while mallocing %u bytes.\n", size );
	}

	return result;
}

extern void *wg_calloc( size_t nmemb, size_t size )
{
	void *result;
	if ( !size || !nmemb ) {
		wgmem_error( "Error callocing 0 bytes.\n" );
	}

	result = calloc( nmemb, size );
	if ( !result ) {
		wgmem_error( "Error while callocing %u elements of %u bytes.\n", nmemb, size);
	}

	return result;
}

extern void *wg_zalloc( size_t size )
{
	void *result;

	if (!size) {
		wgmem_error( "Error zallocing 0 bytes.\n" );
	}

	result = calloc(1, size);
	if ( !result ) {
		wgmem_error( "Error while zallocing %u bytes.\n", size );
	}

	return result;
}

extern char* wg_strdup( const char *s )
{
	char *result = strdup( s );

	if ( !result ) {
		wgmem_error( "Error while strduping %u bytes.\n", strlen(s) );
	}

	return( result ); 
}

extern void* wg_realloc( void *ptr, size_t size ) 
{ 
	void *result;

	if (!size) {
		wgmem_error( "Error reallocing 0 bytes.\n" );
	}

	result = realloc( ptr, size );

	if ( !result ) {
		wgmem_error( "Error while reallocing %u bytes.\n", size );
	}

	return( result ); 
}

extern void wg_free( void *mem )
{
        if ( mem ) {
                free(mem);
        }
}

extern char *wg_getline( char *line, int size, FILE *fp )
{
        char *p;

        if ( fgets(line, size, fp) == NULL ) {
		return NULL;
	}
        
        /** kill term null **/
        if ( (p = strpbrk( line, "\n\r" )) ) {
                *p = '\0';
        }           
  
        return line;
}



/*
 * wg_split: split a line into segments, using whitespace-sequences as separators.
 *
 * ARGUMENTS:
 * - result:
 * 
 *  After the split, this array contains pointers to the start of each
 *  detected segment. Must be preallocated and at least as large as
 *  maxsegments. The pointers point into the dest buffer.
 * 
 * - dest: 
 * 
 *  String into which result points as an index. Must be preallocated, and
 *  at least as big as src. You can use src as dest, but in that case src
 *  is overwritten!
 * 
 * - src:  
 * 
 *  The string to split. Sequences of whitespace are treated as separators, unless
 *  escaped. There are two ways to escape: by using single quotes (anything
 *  between single quotes is treated as one segment), or by using a backslash
 *  to escape the next character. The backslash escape works inside quotation
 *  as well.
 * 
 *  Example:
 *  
 *  "It\'s   very\ easy   'to  use WiseGuys\' wg_split()' function" is split into:
 *  
 *  "It's"
 *  "very easy"
 *  "to  use WiseGuys' wg_split()"
 *  "function"
 *  
 * - maxsegments: 
 * 
 *  The maximum number of segments. If the splitter runs out of segments,
 *  the remainder of the string is stored in the last segment.
 *  
 * RETURN VALUE:
 * The number of segments found.
 */
unsigned int wg_split( char **result, char *dest, char *src, int maxsegments )
{
	char *p = src;
	char *w = dest;
	int cnt = 0;
	int state=0;

	if ( maxsegments == 0 ) {
		return 0;
	}

	maxsegments--;

	while (cnt < maxsegments && *p) {

		switch (state) {
		case 0:
			/*** Skip spaces ***/
			while ( isspace((int) *p) ) {
				p++;
			}
			state = 1;

		case 1: 
			/*** Start segment ***/
			result[cnt] = w;
			cnt++;
			state = 2;

		case 2:
			/*** Unquoted segment ***/
			while (*p) {
				if ( isspace((int) *p) ) {
					*w++ = '\0';
					p++;
					state = 0;
					break;
				}				
				else if ( *p == '\'' ) {
					/*** Start quotation ***/
					p++;
					state = 3;
					break;
				}
				else if ( *p == '\\' && p[1] ) {
					/*** Escape ***/
					p++;
					*w++ = *p++;
				}
				else {
					*w++ = *p++;
				}
			}
			break;

		case 3:
			/*** Inside quotes ***/
			while (*p) {
				if (*p == '\'') {
					p++;
					break;
				}
				else if ( *p == '\\' && p[1] ) {
					/*** Escape ***/
					p++;
					*w++ = *p++;
				}
				else {
					*w++ = *p++;
				}
			}
			state = 2;
			break;

		}
	}

	if ( !*p ) {
		*w = '\0';
		return cnt;
	}

	/*** We ran out of segments; copy the remainder of the string into last segment ***/
	result[cnt++] = w;
	while (*p) {
		*w++ = *p++;
	}
	*w = '\0';
	return cnt;
}


extern void wg_timerstart(wgtimer_t *t)
{
#ifdef HAVE_GETTIMEOFDAY
        gettimeofday( &(t->start), NULL );
#endif
}


extern uint4 wg_timerstop(wgtimer_t *t)
{
#ifdef HAVE_GETTIMEOFDAY
	uint4 result;
        gettimeofday( &(t->stop), NULL );
        result = (t->stop.tv_sec - t->start.tv_sec) * 1000000 +
                 (t->stop.tv_usec - t->start.tv_usec);

	t->start.tv_sec = t->stop.tv_sec;
	t->start.tv_usec = t->stop.tv_usec;

	return result;
#else
	return 0;
#endif
}


/**
 * wg_strgmov -- a guarded strcpy() variation
 * 
 * copies src to dest (including terminating zero), and returns
 * pointer to position of terminating zero in dest. The function is
 * guaranteed not to write past destlimit. If the copy couldn't be
 * finished, the function returns NULL after restoring the first 
 * character in dest for your convenience (since this is usually a zero).  
 */
char *wg_strgmov( char *dest, const char *src, const char *destlimit )
{
	char tmp, *w;
	
	if ( !dest || dest >= destlimit ) {
		return NULL;
	}

	tmp = *dest;
	w = dest;

	while ( *src ) {

		*w++ = *src++;

		if ( w == destlimit ) {
			/*** restore old situation ***/
			*dest = tmp;
			return NULL;
		}
	}

	*w = '\0';
	return w;

}

/*
 * wg_trim() -- remove whitespace surrounding a string. 
 *
 * Example: "   bla   bla   bla   " becomes "bla   bla   bla" after trimming.
 *
 * ARGUMENTS
 * - dest : After the trim, this will point to the trimmed string.
 *          Must be preallocated and at least as big as src. You can
 *          use src as dest.
 * - src : Points to the string to be trimmed.
 *
 * RETURNS:
 * dest
 */
char *wg_trim( char *dest, const char *src )
{
	char *lastnonspace = &dest[-1];
	const char *p = src;
	char *w = dest;
	
	while ( isspace((int)*p) ) {
		p++;
	}
	while (*p) {
		if ( !isspace((int)*p) ) {
			lastnonspace = w;
		}
		*w++ = *p++;
	}
	lastnonspace[1] = '\0';

	return dest;
}