////////////////////////////////////////////////////////////
//~ Command buff types

Struct(NET_W32_Cmd)
{
  NET_W32_Cmd *next;

  NET_Key key;
  String data;
  NET_SendFlag send_flags;
};

Struct(NET_W32_CmdList)
{
  i64 count;
  NET_W32_Cmd *first;
  NET_W32_Cmd *last;
};

Struct(NET_W32_CmdBuff)
{
  Arena *arena;
  NET_W32_CmdList cmds;
};

////////////////////////////////////////////////////////////
//~ Message buff types

Struct(NET_W32_MsgBuff)
{
  Arena *arena;
  NET_MsgList msgs;
};

////////////////////////////////////////////////////////////
//~ Packet types

#define NET_W32_ProtocolMagic 0xde8c590b

Enum(NET_W32_PacketFlag)
{
  NET_W32_PacketFlag_None = 0,

  NET_W32_PacketFlag_EndMsg       = (1 << 0),
  NET_W32_PacketFlag_Heartbeat    = (1 << 2),
  NET_W32_PacketFlag_Raw          = (1 << 3),
};

Struct(NET_W32_PacketHeader)
{
  u32 checksum;
  NET_W32_PacketFlag flags;
  i64 seq;
  i64 msg_seq;
  i64 bottom_ack;
  u64 ack_bits;
};

Struct(NET_W32_Packet)
{
  NET_W32_Packet *next;
  NET_W32_Packet *prev;

  NET_W32_PacketFlag flags;
  i64 seq;
  i64 msg_seq;
  String data;

  i64 last_sent_ns;
};

////////////////////////////////////////////////////////////
//~ Peer types

Struct(NET_W32_Peer)
{
  NET_W32_Peer *next;
  NET_W32_Peer *prev;
  NET_W32_Peer *next_in_bin;
  NET_W32_Peer *prev_in_bin;

  u64 hash;
  NET_Key key;

  i64 remote_bottom_ack;
  u64 remote_ack_bits;
  i64 bottom_ack;
  u64 ack_bits;

  // Outgoing packets awaiting acknowledgement
  NET_W32_Packet *first_remote_packet;
  NET_W32_Packet *last_remote_packet;

  // Fragmented msg packets awaiting holes to be filled
  NET_W32_Packet *first_frag_packet;
  NET_W32_Packet *last_frag_packet;

  // Contiguous msg packets awaiting assembly
  NET_W32_Packet *first_cont_packet;
  NET_W32_Packet *last_cont_packet;

  i64 seq;
  i64 msg_seq;
  String msg_fragment;

  i64 last_ack_received_ns;
  i64 last_ack_sent_ns;
  i64 num_msg_packets_received_this_frame;
};

Struct(NET_W32_PeerBin)
{
  NET_W32_Peer *first;
  NET_W32_Peer *last;
};

////////////////////////////////////////////////////////////
//~ Pipe types

Struct(NET_W32_Pipe)
{
  //- IOCP data

  OVERLAPPED ovl; // First field must be OVERLAPPED for cast from IOCP returns

  i32 iocp_count; // How many overlapped operations are currently queued.

  WSABUF recv_wsabuff;
  struct sockaddr_in6 recv_addr;
  i32 recv_addr_sz;

  SOCKET udp;

  //- Shared data

  NET_W32_Pipe *next;
  NET_W32_Pipe *prev;

  Atomic64 desired_port;  // ports >64k become ephemeral
  Atomic64 seen_desired_port;

  Atomic64 total_bytes_sent;
  Atomic64 total_bytes_received;

  TicketMutex back_cmd_buff_seq_tm;
  i64 back_cmd_buff_seq;
  NET_W32_CmdBuff cmd_buffs[2];

  TicketMutex back_msg_buff_seq_tm;
  i64 back_msg_buff_seq;
  NET_W32_MsgBuff msg_buffs[2];

  //- Worker data

  i64 last_attempted_bind_ns;

  NET_W32_Peer *first_peer;
  NET_W32_Peer *last_peer;
  i64 num_msg_packets_received_this_frame;

  i64 peer_bins_count;
  NET_W32_PeerBin *peer_bins;

  u64 bound_port;
};

////////////////////////////////////////////////////////////
//~ State types

Struct(NET_W32_DummySocket)
{
  SOCKET sock;
  i32 addr_size;
  struct sockaddr_storage addr;
};

Struct(NET_W32_Ctx)
{
  TicketMutex pipes_tm;
  i64 pipes_count;
  NET_W32_Pipe *first_pipe;
  NET_W32_Pipe *last_pipe;

  NET_W32_Peer *first_free_peer;
  NET_W32_Packet *first_free_packet;

  HANDLE iocp;

  Atomic64 signal;
  Atomic64 seen_signal;
};

extern NET_W32_Ctx NET_W32;

////////////////////////////////////////////////////////////
//~ Helpers

NET_W32_DummySocket NET_W32_CreateDummySocket(void);
NET_W32_Pipe *NET_W32_PipeFromHandle(NET_PipeHandle pipe_handle);
NET_Key NET_W32_KeyFromAddress(struct sockaddr_in6 addr);
struct sockaddr_in6 NET_W32_AddressFromKey(NET_Key key);
void NET_W32_SignalWorker(void);
NET_W32_Peer *NET_W32_TouchPeerFromKey(NET_W32_Pipe *pipe, NET_Key key);
u32 NET_W32_ChecksumFromPacketString(String str);
void NET_W32_PostRecv(NET_W32_Pipe *pipe);
void NET_W32_SendTo(NET_W32_Pipe *pipe, NET_W32_Peer *peer, NET_W32_PacketHeader header, String data);

////////////////////////////////////////////////////////////
//~ Worker

void NET_W32_TickForever(WaveLaneCtx *lane);