#pragma once

#include <net/sock_addr.hpp>

#include <optional>
#include <string_view>
#include <string>

namespace llarp
{
  /// A struct that can represent either an IPv4 or IPv6 address. It is meant for representation
  /// purposes only (e.g. serialization/deserialization). In addition, it also optionally stores
  /// a port.
  ///
  /// As a convenience, it can produce a SockAddr for dealing with network libraries which depend
  /// sockaddr structs. However, it does not keep this as a member variable and isn't responsible
  /// for its lifetime/memory/etc.
  ///
  /// TODO: IPv6 is not currently supported.
  struct IpAddress
  {
    /// Empty constructor.
    IpAddress() = default;

    /// Constructor. Takes a string which can be an IPv4 or IPv6 address optionally followed by
    /// a colon and a port.
    ///
    /// Examples:
    ///
    /// 127.0.0.1
    /// 1.2.3.4:53
    ///
    /// Note that an IPv6 + port representation must be done in an unambiguous way, e.g. wrap the
    /// IP portion of the string in brackets: [IPv6Addr]:port
    ///
    /// @param str is a string representing an IP address and optionally a port
    /// @throws std::invalid_argument if str cannot be parsed
    IpAddress(std::string_view str);

    /// Constructor. Takes an IP address (as above) and a port. The string may not contain a port.
    ///
    /// @param str is a string representing an IP address and optionally a port
    /// @throws std::invalid_argument if str cannot be parsed
    IpAddress(std::string_view str, std::optional<uint16_t> port);

    /// Construct from a SockAddr.
    ///
    /// @param addr is an SockAddr to initialize from.
    IpAddress(const SockAddr& addr);

    IpAddress&
    operator=(const sockaddr& other);

    /// Return the port. Returns -1 if no port has been provided.
    ///
    /// @return the port, if present
    std::optional<uint16_t>
    getPort() const;

    /// Set the port.
    ///
    /// @param port
    void
    setPort(std::optional<uint16_t> port);

    /// Set the IP address. Follows the same logic as the constructor with the same signature, but
    /// doesn't overwrite the port if the port isn't present in the string.
    void
    setAddress(std::string_view str);
    void
    setAddress(std::string_view str, std::optional<uint16_t> port);

    /// Returns true if this is an IPv4 address (or an IPv6 address representing an IPv4 address)
    ///
    /// TODO: could return an int (e.g. 4 or 6) or an enum
    ///
    /// @return true if this is an IPv4 address, false otherwise
    bool
    isIPv4();

    /// Returns true if this represents a valid IpAddress, false otherwise.
    ///
    /// @return whether or not this IpAddress is empty
    bool
    isEmpty() const;

    /// Creates an instance of SockAddr representing this IpAddress.
    ///
    /// @return an instance of a SockAddr created from this IpAddress
    SockAddr
    createSockAddr() const;

    /// Returns true if this IpAddress is a bogon, false otherwise
    ///
    /// @return whether or not this IpAddress is a bogon
    bool
    isBogon() const;

    /// Returns a string representing this IpAddress
    ///
    /// @return string representation of this IpAddress
    std::string
    toString() const;

    // TODO: other utility functions left over from Addr which may be useful
    // IsBogon() const;
    // isPrivate() const;
    // struct Hash
    // to string / stream / etc

    bool
    operator<(const IpAddress& other) const;

    bool
    operator==(const IpAddress& other) const;

    struct Hash
    {
      std::size_t
      operator()(const IpAddress& address) const noexcept
      {
        (void)address;
        // throw std::runtime_error("FIXME: IpAddress::Hash"); // can't do this in operator(),
        // apparently, so hopefully it's me that stumbles upon this (if not, sorry!)
        return 0;

        /*
        if(a.af() == AF_INET)
        {
          return a.port() ^ a.addr4()->s_addr;
        }
        static const uint8_t empty[16] = {0};
        return (a.af() + memcmp(a.addr6(), empty, 16)) ^ a.port();
        */
      }
    };

   private:
    bool m_empty = true;
    std::string m_ipAddress;
    std::optional<uint16_t> m_port = std::nullopt;
  };

  std::ostream&
  operator<<(std::ostream& out, const IpAddress& address);

}  // namespace llarp