/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2025 Chelsio Communications, Inc.
 * Written by: John Baldwin <jhb@FreeBSD.org>
 */

#include <cstdarg>
#include <cstdio>
#include <string>

#include "libutil++.hh"

static int
stringf_write(void *cookie, const char *buf, int len)
{
        std::string *str = reinterpret_cast<std::string *>(cookie);
        try {
                str->append(buf, len);
        } catch (std::bad_alloc) {
                errno = ENOMEM;
                return (-1);
        } catch (std::length_error) {
                errno = EFBIG;
                return (-1);
        }
        return (len);
}

std::string
freebsd::stringf(const char *fmt, va_list ap)
{
        std::string str;
        freebsd::FILE_up fp(fwopen(reinterpret_cast<void *>(&str),
            stringf_write));

        vfprintf(fp.get(), fmt, ap);

        if (ferror(fp.get()))
                throw std::bad_alloc();
        fp.reset(nullptr);

        return str;
}

std::string
freebsd::stringf(const char *fmt, ...)
{
        std::va_list ap;
        std::string str;

        va_start(ap, fmt);
        str = freebsd::stringf(fmt, ap);
        va_end(ap);

        return str;
}