/*
 * Copyright (C) 2015 Freie Universität Berlin
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @{
 * @ingroup     net_gnrc_netapi
 * @file
 * @brief       This file contains a number of helper functions that provide
 *              some shortcuts for some always repeating code snippets when
 *              servicing the netapi interface
 *
 * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
 * @}
 */

#include "kernel.h"
#include "msg.h"
#include "net/gnrc/netreg.h"
#include "net/gnrc/pktbuf.h"
#include "net/gnrc/netapi.h"

/**
 * @brief   Unified function for getting and setting netapi options
 *
 * @param[in] pid       PID of the targeted thread
 * @param[in] type      specify if option is to be set or get
 * @param[in] opt       option to set or get
 * @param[in] data      data to set or pointer to buffer for reading options
 * @param[in] data_len  size of the given buffer
 *
 * @return              the value from the received ACK message
 */
static inline int _get_set(kernel_pid_t pid, uint16_t type,
                           netopt_t opt, uint16_t context,
                           void *data, size_t data_len)
{
    msg_t cmd;
    msg_t ack;
    gnrc_netapi_opt_t o;
    /* set ńetapi's option struct */
    o.opt = opt;
    o.context = context;
    o.data = data;
    o.data_len = data_len;
    /* set outgoing message's fields */
    cmd.type = type;
    cmd.content.ptr = (void *)&o;
    /* trigger the netapi */
    msg_send_receive(&cmd, &ack, pid);
    /* return the ACK message's value */
    return (int)ack.content.value;
}

static inline int _snd_rcv(kernel_pid_t pid, uint16_t type, gnrc_pktsnip_t *pkt)
{
    msg_t msg;
    /* set the outgoing message's fields */
    msg.type = type;
    msg.content.ptr = (void *)pkt;
    /* send message */
    return msg_send(&msg, pid);
}

int gnrc_netapi_dispatch(gnrc_nettype_t type, uint32_t demux_ctx,
                         uint16_t cmd, gnrc_pktsnip_t *pkt)
{
    int numof = gnrc_netreg_num(type, demux_ctx);

    if (numof != 0) {
        gnrc_netreg_entry_t *sendto = gnrc_netreg_lookup(type, demux_ctx);

        gnrc_pktbuf_hold(pkt, numof - 1);

        while (sendto) {
            if (_snd_rcv(sendto->pid, cmd, pkt) < 1) {
                /* unable to dispatch packet */
                gnrc_pktbuf_release(pkt);
            }
            sendto = gnrc_netreg_getnext(sendto);
        }
    }

    return numof;
}

int gnrc_netapi_send(kernel_pid_t pid, gnrc_pktsnip_t *pkt)
{
    return _snd_rcv(pid, GNRC_NETAPI_MSG_TYPE_SND, pkt);
}

int gnrc_netapi_receive(kernel_pid_t pid, gnrc_pktsnip_t *pkt)
{
    return _snd_rcv(pid, GNRC_NETAPI_MSG_TYPE_RCV, pkt);
}

int gnrc_netapi_get(kernel_pid_t pid, netopt_t opt, uint16_t context,
                    void *data, size_t data_len)
{
    return _get_set(pid, GNRC_NETAPI_MSG_TYPE_GET, opt, context,
                    data, data_len);
}

int gnrc_netapi_set(kernel_pid_t pid, netopt_t opt, uint16_t context,
                    void *data, size_t data_len)
{
    return _get_set(pid, GNRC_NETAPI_MSG_TYPE_SET, opt, context,
                    data, data_len);
}