#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <gclib/mem.h>
#include <gclib/strfuncs.h>
#include <gclib/utils.h>

#define is_valid_drive(d)	((d)>='a' && (d)<='z' || (d)>='A' && (d)<='Z')

/*
 * Gets the last component of the filename. If filename ends with a directory
 * separator it gets the component before the last slash. If filename consists
 * only of directory separators (and on Windows, possibly a drive letter), a
 * single separator is returned. If filename is empty, it gets ".".
 */
char *path_get_basename(const char *filename)
{
    ssize_t base,last_nonslash;
    size_t len;
    char *retval;
    if (*filename=='\0')
        return str_dup(".");
    last_nonslash=strlen(filename)-1;
    while (last_nonslash>=0 && GC_IS_DIR_SEPARATOR(filename[last_nonslash]))
	last_nonslash--;
    if (last_nonslash<0)
	/* string only containing slashes */
    return str_dup(GC_DIR_SEPARATOR_S);
#ifdef WIN32
    if (last_nonslash==1 && is_valid_drive(filename[0]) && filename[1]==':')
	/* string only containing slashes and a drive */
	return str_dup(GC_DIR_SEPARATOR_S);
#endif
    base=last_nonslash;
    while (base>=0 && !GC_IS_DIR_SEPARATOR(filename[base]))
	base--;
#ifdef WIN32
    if (base==-1 && is_valid_drive(filename[0]) && filename[1] == ':')
	  base=1;
#endif
    len=last_nonslash-base;
    retval=mem_alloc(len+1,1);
    memcpy(retval,filename+base+1,len);
    retval[len]='\0';
    return retval;
}