#include <stdlib.h>

/*
 * Everything down to the end of the next two functions is copied from the X sources.
 */

/*

Copyright 1985, 1986, 1987,1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.

*/

#include "xparsegeometry_repl.h"

/*
 *   XParseGeometry parses strings of the form
 *   "=<width>x<height>{+-}<xoffset>{+-}<yoffset>", where
 *   width, height, xoffset, and yoffset are unsigned integers.
 *   Example:  "=80x24+300-49"
 *   The equal sign is optional.
 *   It returns a bitmask that indicates which of the four values
 *   were actually found in the string.  For each value found,
 *   the corresponding argument is updated;  for each value
 *   not found, the corresponding argument is left unchanged.
 */

static int
ReadInteger(char *string, char **NextString)
{
    register int Result = 0;
    int Sign = 1;

    if (*string == '+')
        string++;
    else if (*string == '-')
    {
        string++;
        Sign = -1;
    }
    for (; (*string >= '0') && (*string <= '9'); string++)
    {
        Result = (Result * 10) + (*string - '0');
    }
    *NextString = string;
    if (Sign >= 0)
        return Result;
    else
        return -Result;
}

int XParseGeometry (
    const char *string,
    int *x,
    int *y,
    unsigned int *width,    /* RETURN */
    unsigned int *height)    /* RETURN */
{
    int mask = NoValue;
    register char *strind;
    unsigned int tempWidth = 0, tempHeight = 0;
    int tempX = 0, tempY = 0;
    char *nextCharacter;

    if ( (string == NULL) || (*string == '\0'))
      return mask;
    if (*string == '=')
        string++;  /* ignore possible '=' at beg of geometry spec */

    strind = (char *)string;
    if (*strind != '+' && *strind != '-' && *strind != 'x') {
        tempWidth = ReadInteger(strind, &nextCharacter);
        if (strind == nextCharacter)
            return 0;
        strind = nextCharacter;
        mask |= WidthValue;
    }

    if (*strind == 'x' || *strind == 'X') {
        strind++;
        tempHeight = ReadInteger(strind, &nextCharacter);
        if (strind == nextCharacter)
            return 0;
        strind = nextCharacter;
        mask |= HeightValue;
    }

    if ((*strind == '+') || (*strind == '-')) {
        if (*strind == '-') {
            strind++;
            tempX = -ReadInteger(strind, &nextCharacter);
            if (strind == nextCharacter)
                return 0;
            strind = nextCharacter;
            mask |= XNegative;
        }
        else
        {
            strind++;
            tempX = ReadInteger(strind, &nextCharacter);
            if (strind == nextCharacter)
                return 0;
            strind = nextCharacter;
        }
        mask |= XValue;
        if ((*strind == '+') || (*strind == '-')) {
            if (*strind == '-') {
                strind++;
                tempY = -ReadInteger(strind, &nextCharacter);
                if (strind == nextCharacter)
                    return 0;
                strind = nextCharacter;
                mask |= YNegative;
            }
            else
            {
                strind++;
                tempY = ReadInteger(strind, &nextCharacter);
                if (strind == nextCharacter)
                    return 0;
                strind = nextCharacter;
            }
            mask |= YValue;
        }
    }

    /* If strind isn't at the end of the string the it's an invalid
       geometry specification. */

    if (*strind != '\0') return 0;

    if (mask & XValue)
        *x = tempX;
    if (mask & YValue)
        *y = tempY;
    if (mask & WidthValue)
        *width = tempWidth;
    if (mask & HeightValue)
        *height = tempHeight;
    return mask;
}