#include "util.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>

/* Portable va_copy fallback for pre-C99 or platforms without va_copy. */
#ifndef va_copy
# if defined(__va_copy)
#  define va_copy(dest, src) __va_copy(dest, src)
# else
#  define va_copy(dest, src) ((dest) = (src))
# endif
#endif

char* format_string_va(const char* fmt, va_list args) {
    /* Declarations first to satisfy -std=c89 */
    va_list args_copy;
    int needed;
    char* buf;

    if (!fmt) return NULL;

    va_copy(args_copy, args);
    needed = vsnprintf(NULL, 0, fmt, args_copy);
    va_end(args_copy);
    if (needed < 0) return NULL;

    buf = (char*)malloc((size_t)needed + 1);
    if (!buf) return NULL;
    vsnprintf(buf, (size_t)needed + 1, fmt, args);
    return buf;
}

char* format_string(const char* fmt, ...) {
    /* Declarations first to satisfy -std=c89 */
    va_list args;
    char* s;

    if (!fmt) return NULL;

    va_start(args, fmt);
    s = format_string_va(fmt, args);
    va_end(args);
    return s;
}