/*
 * wip, a small TCP/IP stack.
 * Copyright (C) 2025  Xavier Del Campo Romero
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include <wip/wip.h>
#include <wip/prv/io.h>

enum wip_state wip_io_read_c(struct wip_cfg *const cfg, struct wip_sm_io *const io)
{
    void *const buf = (unsigned char *)io->buf + io->read;
    const size_t rem = io->n - io->read;
    const int n = cfg->read(buf, rem, cfg->user);

    if (n < 0)
        return WIP_FATAL;
    else if ((io->read += n) >= io->n)
    {
        io->read = 0;
        return WIP_OK;
    }

    return WIP_AGAIN;
}