#ifndef COPPINO_IPV6_H
#define COPPINO_IPV6_H

namespace ipv6 {

  const uint8_t LEN = 128;
  const uint8_t ICMP_ECHO_REQUEST_TYPE = 128;
  const uint8_t ICMP_ECHO_REPLY_TYPE   = 129;

  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;

  struct ipv6_packet_header {
    char field[4];
    char len[2];
    char next_header;
    char hop_limit;
    IPv6Addr src_addr;
    IPv6Addr dst_addr;
  }__attribute__((packed));

  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();
  };

  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 */
   );
}

#endif