/**
 * 6lowpan border router implementation
 *
 * 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    sixlowborder.c
 * @brief   constraint node implementation for a 6lowpan border router
 * @author  Martin Lenders <mlenders@inf.fu-berlin.de>
 * @author  Oliver Hahm <oliver.hahm@inria.fr>
 * @}
 */

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

#include "mutex.h"
#include "thread.h"
#include "msg.h"
#include "posix_io.h"
#include "board_uart0.h"
#include "sixlowpan/error.h"

#include "bordermultiplex.h"
#include "flowcontrol.h"
#include "border.h"
#include "ip.h"
#include "icmp.h"
#include "serialnumber.h"
#include "sys/net/ieee802154/ieee802154_frame.h"
#include "sys/net/net_help/net_help.h"

#define READER_STACK_SIZE   512

ipv6_addr_t abr_addr;

char serial_reader_stack[READER_STACK_SIZE];
uint16_t serial_reader_pid;

uint8_t serial_out_buf[BORDER_BUFFER_SIZE];
uint8_t serial_in_buf[BORDER_BUFFER_SIZE];

uint8_t *get_serial_out_buffer(int offset)
{
    if (offset > BUFFER_SIZE) {
        return NULL;
    }

    return &(serial_out_buf[offset]);
}

uint8_t *get_serial_in_buffer(int offset)
{
    if (offset > BUFFER_SIZE) {
        return NULL;
    }

    return &(serial_in_buf[offset]);
}

uint16_t border_get_serial_reader()
{
    return serial_reader_pid;
}

void serial_reader_f(void)
{
    int main_pid = 0;
    int bytes;
    msg_t m;
    border_packet_t *uart_buf;

    posix_open(uart0_handler_pid, 0);

    msg_receive(&m);
    main_pid = m.sender_pid;

    while (1) {
        posix_open(uart0_handler_pid, 0);
        bytes = readpacket(get_serial_in_buffer(0), BORDER_BUFFER_SIZE);

        if (bytes < 0) {
            switch (bytes) {
                case (-SIXLOWERROR_ARRAYFULL): {
                    printf("ERROR: Array was full\n");
                    break;
                }

                default: {
                    printf("ERROR: unknown\n");
                    break;
                }
            }

            continue;
        }

        uart_buf = (border_packet_t *)get_serial_in_buffer(0);

        if (uart_buf->empty == 0) {
            if (uart_buf->type == BORDER_PACKET_CONF_TYPE) {
                border_conf_header_t *conf_packet = (border_conf_header_t *)uart_buf;

                if (conf_packet->conftype == BORDER_CONF_SYN) {
                    m.content.ptr = (char *)conf_packet;
                    msg_send(&m, main_pid, 1);
                    continue;
                }
            }

            flowcontrol_deliver_from_uart(uart_buf, bytes);
        }
    }
}

uint8_t border_initialize(transceiver_type_t trans, ipv6_addr_t *border_router_addr)
{
    ipv6_addr_t addr;

    serial_reader_pid = thread_create(
                            serial_reader_stack, READER_STACK_SIZE,
                            PRIORITY_MAIN - 1, CREATE_STACKTEST,
                            serial_reader_f, "serial_reader");

    if (border_router_addr == NULL) {
        border_router_addr = &addr;

        addr = flowcontrol_init();
    }

    /* only allow addresses generated accoding to
     * RFC 4944 (Section 6) & RFC 2464 (Section 4) from short address
     * -- for now
     */
    if (border_router_addr->uint16[4] != HTONS(IEEE_802154_PAN_ID ^ 0x0200) ||
        border_router_addr->uint16[5] != HTONS(0x00FF) ||
        border_router_addr->uint16[6] != HTONS(0xFE00)
       ) {
        return SIXLOWERROR_ADDRESS;
    }

    /* radio-address is 8-bit so this must be tested extra */
    if (border_router_addr->uint8[14] != 0) {
        return SIXLOWERROR_ADDRESS;
    }

    memcpy(&(abr_addr.uint8[0]), &(border_router_addr->uint8[0]), 16);

    sixlowpan_init(trans, border_router_addr->uint8[15], 1);

    ipv6_init_iface_as_router();

    return SUCCESS;
}

void border_send_ipv6_over_lowpan(ipv6_hdr_t *packet, uint8_t aro_flag, uint8_t sixco_flag)
{
    uint16_t offset = IPV6_HDR_LEN + HTONS(packet->length);

    packet->flowlabel = HTONS(packet->flowlabel);
    packet->length = HTONS(packet->length);

    memset(buffer, 0, BUFFER_SIZE);
    memcpy(buffer + LL_HDR_LEN, packet, offset);

    lowpan_init((ieee_802154_long_t *) & (packet->destaddr.uint16[4]), (uint8_t *)packet);
}

void border_process_lowpan(void)
{
    msg_t m;
    ipv6_hdr_t *ipv6_buf;

    while (1) {
        msg_receive(&m);
        ipv6_buf = (ipv6_hdr_t *)m.content.ptr;

        if (ipv6_buf->nextheader == PROTO_NUM_ICMPV6) {
            struct icmpv6_hdr_t *icmp_buf = (struct icmpv6_hdr_t *)(((uint8_t *)ipv6_buf) + IPV6_HDR_LEN);

            if (icmp_buf->type == ICMP_REDIRECT) {
                continue;
            }

            if (icmpv6_demultiplex(icmp_buf) == 0) {
                continue;
            }

            /* Here, other ICMPv6 message types for ND may follow. */
        }

        /* TODO: Bei ICMPv6-Paketen entsprechende LoWPAN-Optionen verarbeiten und entfernen */
        multiplex_send_ipv6_over_uart(ipv6_buf);
    }
}