#ifndef COPPINO_IPV6_H
#define COPPINO_IPV6_H

#include "settings.h"
#include "Arduino.h"
#include "slip.h"

namespace ipv6
{
  /* maximum length for an IPv6 packet */
  const uint8_t LEN = 128;

  /* ICMP Types */
  const uint8_t ICMP_ECHO_REQUEST_TYPE = 128;
  const uint8_t ICMP_ECHO_REPLY_TYPE = 129;
  const uint8_t ICMP_RADV_TYPE = 134;

  /* Next-Header Types */
  const uint8_t NH_ICMP = 58;
  const uint8_t NH_UDP = 17;

  class IPv6Addr
  {
  private:
    char address[16];

  public:
    IPv6Addr();
    IPv6Addr(const char *address);
  };

  extern const IPv6Addr ALL_NODES_ADDRESS;

  class IPv6Packet
  {
  private:
    char packet[LEN];

  public:
    IPv6Packet();
    IPv6Packet(const char *buffer, int len);
    void setLen(int len);
    int getLen();
    void setSrcAddress(const IPv6Addr *address);
    const IPv6Addr *getSrcAddress();
    void setDstAddress(const IPv6Addr *address);
    const IPv6Addr *getDstAddress();
    void setNextHeader(uint8_t next_header);
    void setFlow(const char *flow);
    void setPayload(char *payload, int len);
    void send();

    void doAction();
  };

  /* incoming and outgoing packets buffer */
  extern IPv6Packet packetin;
  extern IPv6Packet packetout;

  /* Note: content of message may be changed */
  int handleICMP(char *output_buffer, const char *input_buffer, int len);

  /* Compute internet checksum. Actually it is not so straightforward: */
  uint16_t compute_checksum(
      const IPv6Addr *src_addr, /* source IPv6 address      */
      const IPv6Addr *dst_addr, /* destination IPv6 address */
      uint8_t next_header,      /* IPv6 next header number */
      int upper_len,            /* length as found in the upper layer protocol */
      const char *payload,      /* IPv6 payload */
      int len                   /* IPv6 payload length */
  );

  /* RFC 4861 -- begin */
  struct ICMPv6_RADV
  {
    uint8_t type;
    uint8_t code;
    char checksum[2];
    uint8_t cur_hop_limit;
    uint8_t mo_flags;
    uint16_t router_lifetime;
    uint32_t reachable_time;
    uint32_t retrans_time;
  };

  struct ICMPv6_RADV_Option
  {
    uint8_t type;
    uint8_t len;
  };

  struct ICMPv6_RADV_PrefixInformation
  {
    uint8_t type;
    uint8_t len;
    uint8_t prefix_length;
    uint8_t la_flags;
    uint32_t valid_lifetime;
    uint32_t preferred_lifetime;
    uint32_t reserved2;
    char prefix[16];
  };
  /* RFC 4861 -- end */

  void setEUI(const char *eui);               /* 64bit Extended Unique Identifier */
  void setGlobalAddress(const char *address); /* global IPv6 address, manually configured */
}

#endif