/*
 * 6LoWPAN MAC - layer 2 implementations
 *
 * Copyright (C) 2013  INRIA.
 *
 * This file subject to the terms and conditions of the GNU Lesser General
 * Public License. See the file LICENSE in the top level directory for more
 * details.
 *
 * @ingroup sixlowpan
 * @{
 * @file    sixlowmac.c
 * @brief   6lowpan link layer functions
 * @author  Stephan Zeisberg <zeisberg@mi.fu-berlin.de>
 * @author  Martin Lenders <mlenders@inf.fu-berlin.de>
 * @author  Eric Engel <eric.engel@fu-berlin.de>
 * @author  Oliver Gesch <oliver.gesch@googlemail.com>
 * @author  Oliver Hahm <oliver.hahm@inria.fr>
 * @}
 */


#include <stdlib.h>
#include <stdint.h>
#include <string.h>

#include "ltc4150.h"
#include "hwtimer.h"
#include "thread.h"
#include "msg.h"
#include "radio/radio.h"
#include "transceiver.h"
#include "vtimer.h"
#include "sixlowpan/mac.h"

#include "ip.h"
#include "icmp.h"
#include "lowpan.h"
#include "sys/net/ieee802154/ieee802154_frame.h"
#include "sys/net/net_help/net_help.h"

#define ENABLE_DEBUG    (0)
#include "debug.h"

#define RADIO_STACK_SIZE            (MINIMUM_STACK_SIZE + 256)
#define RADIO_RCV_BUF_SIZE          (64)
#define RADIO_SENDING_DELAY         (1000)

char radio_stack_buffer[RADIO_STACK_SIZE];
msg_t msg_q[RADIO_RCV_BUF_SIZE];

static uint8_t r_src_addr;
uint8_t buf[PAYLOAD_SIZE];
static uint8_t macdsn;

static radio_packet_t p;
static msg_t mesg;
int transceiver_type;
static transceiver_command_t tcmd;

uint8_t sixlowpan_mac_get_radio_address(void)
{
    int16_t address;

    tcmd.transceivers = transceiver_type;
    tcmd.data = &address;
    mesg.content.ptr = (char *)&tcmd;
    mesg.type = GET_ADDRESS;
    msg_send_receive(&mesg, &mesg, transceiver_pid);

    return (uint8_t)address;
}

void sixlowpan_mac_set_radio_address(uint8_t addr)
{
    int16_t address = (int16_t)addr;

    tcmd.transceivers = transceiver_type;
    tcmd.data = &address;
    mesg.content.ptr = (char *)&tcmd;
    mesg.type = SET_ADDRESS;
    msg_send_receive(&mesg, &mesg, transceiver_pid);
}

void set_radio_channel(uint8_t channel)
{
    int16_t chan = (int16_t)channel;

    tcmd.transceivers = transceiver_type;
    tcmd.data = &chan;
    mesg.content.ptr = (char *)&tcmd;
    mesg.type = SET_CHANNEL;
    msg_send_receive(&mesg, &mesg, transceiver_pid);
}

void switch_to_rx(void)
{
    mesg.type = SWITCH_RX;
    mesg.content.ptr = (char *) &tcmd;
    tcmd.transceivers = TRANSCEIVER_CC1100;
    msg_send(&mesg, transceiver_pid, 1);
}

void sixlowpan_mac_init_802154_short_addr(ieee_802154_short_t *saddr)
{
    saddr->uint8[0] = 0;
    saddr->uint8[1] = sixlowpan_mac_get_radio_address();
}

ieee_802154_long_t *sixlowpan_mac_get_eui64(const ipv6_addr_t *ipaddr)
{
    return ((ieee_802154_long_t *) &ipaddr->uint8[8]);
}

void sixlowpan_mac_init_802154_long_addr(ieee_802154_long_t *laddr)
{
    // 16bit Pan-ID:16-zero-bits:16-bit-short-addr = 48bit
    laddr->uint16[0] = IEEE_802154_PAN_ID;

    /* RFC 4944 Section 6 / RFC 2464 Section 4 */
    laddr->uint8[0] ^= 0x02;
    laddr->uint8[2] = 0;
    laddr->uint8[3] = 0xFF;
    laddr->uint8[4] = 0xFE;
    laddr->uint8[5] = 0;
    laddr->uint8[6] = 0;
    laddr->uint8[7] = sixlowpan_mac_get_radio_address();
}

void recv_ieee802154_frame(void)
{
    msg_t m;
    radio_packet_t *p;
    uint8_t hdrlen, length;
    ieee802154_frame_t frame;

    msg_init_queue(msg_q, RADIO_RCV_BUF_SIZE);

    while (1) {
        msg_receive(&m);

        if (m.type == PKT_PENDING) {

            p = (radio_packet_t *) m.content.ptr;
            hdrlen = read_802154_frame(p->data, &frame, p->length);
            length = p->length - hdrlen;

            /* deliver packet to network(6lowpan)-layer */
            lowpan_read(frame.payload, length, (ieee_802154_long_t *)&frame.src_addr,
                        (ieee_802154_long_t *)&frame.dest_addr);

            p->processing--;
        }
        else if (m.type == ENOBUFFER) {
            puts("Transceiver buffer full");
        }
        else {
            puts("Unknown packet received");
        }
    }
}

void set_ieee802154_fcf_values(ieee802154_frame_t *frame, uint8_t dest_mode,
                               uint8_t src_mode)
{
    frame->fcf.frame_type = IEEE_802154_DATA_FRAME;
    frame->fcf.sec_enb = 0;
    frame->fcf.frame_pend = 0;
    frame->fcf.ack_req = 0;
    frame->fcf.panid_comp = 0;
    frame->fcf.frame_ver = 0;
    frame->fcf.src_addr_m = src_mode;
    frame->fcf.dest_addr_m = dest_mode;
#if ENABLE_DEBUG
    print_802154_fcf_frame(frame);
#endif
}

void set_ieee802154_frame_values(ieee802154_frame_t *frame)
{
    // TODO: addresse aus ip paket auslesen und in frame einfuegen
    frame->dest_pan_id = IEEE_802154_PAN_ID;
    frame->src_pan_id = IEEE_802154_PAN_ID;
    frame->seq_nr = macdsn;
    macdsn++;
}

void sixlowpan_mac_send_ieee802154_frame(const ieee_802154_long_t *addr,
        const uint8_t *payload,
        uint8_t length, uint8_t mcast)
{
    uint16_t daddr;
    /* TODO: check if dedicated response struct is necessary */
    msg_t transceiver_rsp;
    r_src_addr = local_address;
    mesg.type = SND_PKT;
    mesg.content.ptr = (char *) &tcmd;

    tcmd.transceivers = transceiver_type;
    tcmd.data = &p;

    ieee802154_frame_t frame;

    memset(&frame, 0, sizeof(frame));
    set_ieee802154_fcf_values(&frame, IEEE_802154_LONG_ADDR_M,
                              IEEE_802154_LONG_ADDR_M);
    set_ieee802154_frame_values(&frame);

    memcpy(&(frame.dest_addr[0]), &(addr->uint8[0]), 8);
    memcpy(&(frame.src_addr[0]), &(iface.laddr.uint8[0]), 8);

    daddr = HTONS(addr->uint16[3]);
    frame.payload = (uint8_t *)payload; // payload won't be changed so cast is legal.
    frame.payload_len = length;
    uint8_t hdrlen = get_802154_hdr_len(&frame);

    memset(&buf, 0, PAYLOAD_SIZE);
    init_802154_frame(&frame, (uint8_t *)&buf);
    memcpy(&buf[hdrlen], frame.payload, frame.payload_len);
    /* set FCS */
    /* RSSI = 0 */
    buf[frame.payload_len+hdrlen] = 0;
    /* FCS Valid = 1 / LQI Correlation Value = 0 */
    buf[frame.payload_len+hdrlen+1] = 0x80;
    DEBUG("IEEE802.15.4 frame - FCF: %02X %02X DPID: %02X SPID: %02X DSN: %02X\n", buf[0], buf[1], frame->dest_pan_id, frame->src_pan_id, frame->seq_nr);

    p.length = hdrlen + frame.payload_len + IEEE_802154_FCS_LEN;

    if (mcast == 0) {
        p.dst = daddr;
    }
    else {
        p.dst = 0;
    }

    p.data = buf;
    msg_send_receive(&mesg, &transceiver_rsp, transceiver_pid);

    hwtimer_wait(5000);
}

void sixlowpan_mac_init(transceiver_type_t type)
{
    int recv_pid = thread_create(radio_stack_buffer, RADIO_STACK_SIZE,
                                 PRIORITY_MAIN - 2, CREATE_STACKTEST, recv_ieee802154_frame , "radio");
    transceiver_type = type;
    transceiver_init(transceiver_type);
    transceiver_start();
    transceiver_register(type, recv_pid);

    macdsn = rand() % 256;
}