/*
 * Copyright (c) 2010-2013 BitTorrent, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef __UTP_INTERNAL_H__
#define __UTP_INTERNAL_H__

#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>

#include "utp.h"
#include "utp_callbacks.h"
#include "utp_templates.h"
#include "utp_hash.h"
#include "utp_hash.h"
#include "utp_packedsockaddr.h"

/* These originally lived in utp_config.h */
#define CCONTROL_TARGET (100 * 1000)  // us

enum bandwidth_type_t
{
  payload_bandwidth,
  connect_overhead,
  close_overhead,
  ack_overhead,
  header_overhead,
  retransmit_overhead
};

#ifdef WIN32
#ifdef _MSC_VER
#include "libutp_inet_ntop.h"
#endif

// newer versions of MSVC define these in errno.h
#ifndef ECONNRESET
#define ECONNRESET WSAECONNRESET
#define EMSGSIZE WSAEMSGSIZE
#define ECONNREFUSED WSAECONNREFUSED
#define ETIMEDOUT WSAETIMEDOUT
#endif
#endif

struct PACKED_ATTRIBUTE RST_Info
{
  PackedSockAddr addr;
  uint32 connid;
  uint16 ack_nr;
  uint64 timestamp;
};

// It's really important that we don't have duplicate keys in the hash table.
// If we do, we'll eventually crash. if we try to remove the second instance
// of the key, we'll accidentally remove the first instead. then later,
// checkTimeouts will try to access the second one's already freed memory.
void
UTP_FreeAll(struct UTPSocketHT *utp_sockets);

struct UTPSocketKey
{
  PackedSockAddr addr;
  uint32 recv_id;  // "conn_seed", "conn_id"

  UTPSocketKey(const PackedSockAddr &_addr, uint32 _recv_id)
  {
    memset(this, 0, sizeof(*this));
    addr    = _addr;
    recv_id = _recv_id;
  }

  bool
  operator==(const UTPSocketKey &other) const
  {
    return recv_id == other.recv_id && addr == other.addr;
  }

  uint32
  compute_hash() const
  {
    return recv_id ^ addr.compute_hash();
  }
};

struct UTPSocketKeyData
{
  UTPSocketKey key;
  UTPSocket *socket;
  utp_link_t link;
};

#define UTP_SOCKET_BUCKETS 79
#define UTP_SOCKET_INIT 15

struct UTPSocketHT : utpHashTable< UTPSocketKey, UTPSocketKeyData >
{
  UTPSocketHT()
  {
    const int buckets = UTP_SOCKET_BUCKETS;
    const int initial = UTP_SOCKET_INIT;
    this->Create(buckets, initial);
  }
  ~UTPSocketHT()
  {
    UTP_FreeAll(this);
    this->Free();
  }
};

struct struct_utp_context
{
  void *userdata;
  utp_callback_t *callbacks[UTP_ARRAY_SIZE];

  uint64 current_ms;
  utp_context_stats context_stats;
  UTPSocket *last_utp_socket;
  Array< UTPSocket * > ack_sockets;
  Array< RST_Info > rst_info;
  UTPSocketHT *utp_sockets;
  size_t target_delay;
  size_t opt_sndbuf;
  size_t opt_rcvbuf;
  uint64 last_check;

  struct_utp_context();
  ~struct_utp_context();

  void
  log(int level, utp_socket *socket, char const *fmt, ...);
  void
  log_unchecked(utp_socket *socket, char const *fmt, ...);
  bool
  would_log(int level);

  bool log_normal : 1;  // log normal events?
  bool log_mtu : 1;     // log MTU related events?
  bool log_debug : 1;   // log debugging events? (Must also compile with
                        // UTP_DEBUG_LOGGING defined)
};

#endif  //__UTP_INTERNAL_H__
