/*
    This file is part of TON Blockchain Library.

    TON Blockchain Library is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 2 of the License, or
    (at your option) any later version.

    TON Blockchain Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.

    Copyright 2017-2019 Telegram Systems LLP
*/
#include "adnl-peer.h"
#include "adnl-peer.hpp"
#include "adnl-local-id.h"

#include "utils.hpp"

#include "td/actor/PromiseFuture.h"
#include "td/utils/base64.h"
#include "td/utils/Random.h"
#include "auto/tl/ton_api.h"

namespace ton {

namespace adnl {

static_assert(AdnlPeerPairImpl::get_mtu() + AdnlPeerPairImpl::packet_header_max_size() <= AdnlNetworkManager::get_mtu(),
              "wrong mtu configuration");

void AdnlPeerPairImpl::start_up() {
  auto P1 = td::PromiseCreator::lambda([SelfId = actor_id(this)](td::Result<AdnlDbItem> R) {
    td::actor::send_closure(SelfId, &AdnlPeerPairImpl::got_data_from_db, std::move(R));
  });
  td::actor::send_closure(peer_table_, &AdnlPeerTable::get_addr_list_from_db, local_id_, peer_id_short_, std::move(P1));
  auto P2 = td::PromiseCreator::lambda([SelfId = actor_id(this)](td::Result<AdnlNode> R) {
    td::actor::send_closure(SelfId, &AdnlPeerPairImpl::got_data_from_static_nodes, std::move(R));
  });
  td::actor::send_closure(peer_table_, &AdnlPeerTable::get_static_node, peer_id_short_, std::move(P2));

  if (!dht_node_.empty()) {
    discover();
  }
}

void AdnlPeerPairImpl::alarm() {
  if (next_dht_query_at_ && next_dht_query_at_.is_in_past()) {
    next_dht_query_at_ = td::Timestamp::never();
    discover();
  }
  if (next_db_update_at_ && next_db_update_at_.is_in_past()) {
    if (received_from_db_ && received_from_static_nodes_ && !peer_id_.empty()) {
      AdnlDbItem item;
      item.id = peer_id_;
      item.addr_list = addr_list_;
      item.priority_addr_list = priority_addr_list_;

      td::actor::send_closure(peer_table_, &AdnlPeerTable::write_new_addr_list_to_db, local_id_, peer_id_short_,
                              std::move(item), [](td::Unit) {});
    }
    next_db_update_at_ = td::Timestamp::in(td::Random::fast(60.0, 120.0));
  }
  if (retry_send_at_ && retry_send_at_.is_in_past()) {
    retry_send_at_ = td::Timestamp::never();
    send_messages_in(std::move(pending_messages_), false);
  }
  alarm_timestamp().relax(next_dht_query_at_);
  alarm_timestamp().relax(next_db_update_at_);
  alarm_timestamp().relax(retry_send_at_);
}

void AdnlPeerPairImpl::discover() {
  CHECK(!dht_query_active_);
  CHECK(!dht_node_.empty());
  dht_query_active_ = true;

  auto P = td::PromiseCreator::lambda([SelfId = actor_id(this), id = print_id(),
                                       peer_id = peer_id_short_](td::Result<dht::DhtValue> kv) {
    if (kv.is_error()) {
      td::actor::send_closure(SelfId, &AdnlPeerPairImpl::got_data_from_dht,
                              kv.move_as_error_prefix("failed to get from dht: "));
      return;
    }
    auto k = kv.move_as_ok();
    auto pub = AdnlNodeIdFull{k.key().public_key()};
    CHECK(pub.compute_short_id() == peer_id);

    auto addr_list = fetch_tl_object<ton_api::adnl_addressList>(k.value().clone(), true);
    if (addr_list.is_error()) {
      td::actor::send_closure(SelfId, &AdnlPeerPairImpl::got_data_from_dht,
                              addr_list.move_as_error_prefix("bad dht value: "));
      return;
    }

    auto F = AdnlAddressList::create(addr_list.move_as_ok());
    if (F.is_error()) {
      td::actor::send_closure(SelfId, &AdnlPeerPairImpl::got_data_from_dht, F.move_as_error_prefix("bad dht value: "));
      return;
    }

    AdnlNode node{pub, F.move_as_ok()};
    td::actor::send_closure(SelfId, &AdnlPeerPairImpl::got_data_from_dht, std::move(node));
  });

  td::actor::send_closure(dht_node_, &dht::Dht::get_value, dht::DhtKey{peer_id_short_.pubkey_hash(), "address", 0},
                          std::move(P));
}

void AdnlPeerPairImpl::receive_packet_checked(AdnlPacket packet) {
  auto d = Adnl::adnl_start_time();
  if (packet.dst_reinit_date() > d) {
    VLOG(ADNL_WARNING) << this << ": dropping IN message: too new our reinit date " << packet.dst_reinit_date();
    return;
  }
  if (packet.reinit_date() > td::Clocks::system() + 60) {
    VLOG(ADNL_NOTICE) << this << ": dropping IN message: too new peer reinit date " << packet.reinit_date();
    return;
  }
  if (packet.reinit_date() > reinit_date_) {
    reinit(packet.reinit_date());
  }
  if (packet.reinit_date() > 0 && packet.reinit_date() < reinit_date_) {
    VLOG(ADNL_NOTICE) << this << ": dropping IN message: old peer reinit date " << packet.reinit_date();
    return;
  }
  if (packet.dst_reinit_date() > 0 && packet.dst_reinit_date() < d) {
    if (!packet.addr_list().empty()) {
      update_addr_list(packet.addr_list());
    }
    if (!packet.priority_addr_list().empty()) {
      update_addr_list(packet.priority_addr_list());
    }
    VLOG(ADNL_NOTICE) << this << ": dropping IN message old our reinit date " << packet.reinit_date() << " date=" << d;
    auto M = AdnlMessage{adnlmessage::AdnlMessageNop{}};
    send_message(std::move(M));
    return;
  }
  if (packet.seqno() > 0) {
    if (received_packet(static_cast<td::uint32>(packet.seqno()))) {
      VLOG(ADNL_INFO) << this << ": dropping IN message: old seqno: " << packet.seqno() << " (current max " << in_seqno_
                      << ")";
      return;
    }
  }
  if (packet.confirm_seqno() > 0) {
    if (packet.confirm_seqno() > out_seqno_) {
      VLOG(ADNL_WARNING) << this << ": dropping IN message: new ack seqno: " << packet.confirm_seqno()
                         << " (current max sent " << out_seqno_ << ")";
      return;
    }
  }

  // accepted
  // delivering

  add_received_packet(static_cast<td::uint32>(packet.seqno()));

  if (packet.confirm_seqno() > ack_seqno_) {
    ack_seqno_ = packet.confirm_seqno();
  }

  if (packet.recv_addr_list_version() > peer_recv_addr_list_version_) {
    peer_recv_addr_list_version_ = packet.recv_addr_list_version();
  }

  if (packet.recv_priority_addr_list_version() > peer_recv_priority_addr_list_version_) {
    peer_recv_priority_addr_list_version_ = packet.recv_priority_addr_list_version();
  }

  if (!packet.addr_list().empty()) {
    update_addr_list(packet.addr_list());
  }
  if (!packet.priority_addr_list().empty()) {
    update_addr_list(packet.priority_addr_list());
  }

  received_messages_++;
  if (received_messages_ % 64 == 0) {
    VLOG(ADNL_INFO) << this << ": received " << received_messages_ << " messages";
  }
  for (auto &M : packet.messages().vector()) {
    deliver_message(std::move(M));
  }
}

void AdnlPeerPairImpl::receive_packet_from_channel(AdnlChannelIdShort id, AdnlPacket packet) {
  if (id != channel_in_id_) {
    VLOG(ADNL_NOTICE) << this << ": dropping IN message: outdated channel id" << id;
    return;
  }
  channel_ready_ = true;
  receive_packet_checked(std::move(packet));
}

void AdnlPeerPairImpl::receive_packet(AdnlPacket packet) {
  packet.run_basic_checks().ensure();

  if (!encryptor_) {
    VLOG(ADNL_NOTICE) << this << "dropping IN message: unitialized id";
    return;
  }

  auto S = encryptor_->check_signature(packet.to_sign().as_slice(), packet.signature().as_slice());
  if (S.is_error()) {
    VLOG(ADNL_NOTICE) << this << "dropping IN message: bad signature: " << S;
    return;
  }

  receive_packet_checked(std::move(packet));
}

void AdnlPeerPairImpl::deliver_message(AdnlMessage message) {
  message.visit([&](const auto &obj) { this->process_message(obj); });
}

void AdnlPeerPairImpl::send_messages_in(std::vector<AdnlMessage> messages, bool allow_postpone) {
  auto connR = get_conn();
  if (connR.is_error()) {
    if (!allow_postpone) {
      VLOG(ADNL_NOTICE) << this << ": dropping OUT messages: cannot get conn: " << connR.move_as_error();
      return;
    }
    VLOG(ADNL_INFO) << this << ": delaying OUT messages: cannot get conn: " << connR.move_as_error();
    if (!retry_send_at_) {
      retry_send_at_.relax(td::Timestamp::in(10.0));
      alarm_timestamp().relax(retry_send_at_);
    }
    for (auto &m : messages) {
      pending_messages_.push_back(std::move(m));
    }
    return;
  }
  auto conn = connR.move_as_ok();

  size_t ptr = 0;
  bool first = true;
  do {
    size_t s = (channel_ready_ ? channel_packet_header_max_size() : packet_header_max_size());
    if (first) {
      s += 2 * addr_list_max_size();
    }

    AdnlPacket packet;
    packet.set_seqno(++out_seqno_);
    packet.set_confirm_seqno(in_seqno_);

    if (first) {
      if (!channel_inited_) {
        auto M = adnlmessage::AdnlMessageCreateChannel{channel_pub_, channel_pk_date_};
        s += M.size();
        packet.add_message(std::move(M));
      } else if (!channel_ready_) {
        auto M = adnlmessage::AdnlMessageConfirmChannel{channel_pub_, peer_channel_pub_, channel_pk_date_};
        s += M.size();
        packet.add_message(std::move(M));
      }
    }

    if (!addr_list_.empty()) {
      packet.set_received_addr_list_version(addr_list_.version());
    }
    if (!priority_addr_list_.empty()) {
      packet.set_received_priority_addr_list_version(priority_addr_list_.version());
    }

    while (ptr < messages.size()) {
      auto &M = messages[ptr];
      CHECK(M.size() <= get_mtu());
      if (s + M.size() <= AdnlNetworkManager::get_mtu()) {
        s += M.size();
        packet.add_message(std::move(M));
        ptr++;
      } else {
        break;
      }
    }

    if (!channel_ready_) {
      packet.set_reinit_date(Adnl::adnl_start_time(), reinit_date_);
      packet.set_source(local_id_);
    }

    if (!first) {
      if (!channel_inited_) {
        auto M = adnlmessage::AdnlMessageCreateChannel{channel_pub_, channel_pk_date_};
        if (s + M.size() <= AdnlNetworkManager::get_mtu()) {
          s += M.size();
          packet.add_message(std::move(M));
        }
      } else if (!channel_ready_) {
        auto M = adnlmessage::AdnlMessageConfirmChannel{channel_pub_, peer_channel_pub_, channel_pk_date_};
        if (s + M.size() <= AdnlNetworkManager::get_mtu()) {
          s += M.size();
          packet.add_message(std::move(M));
        }
      }
    }

    packet.run_basic_checks().ensure();
    auto P = td::PromiseCreator::lambda([SelfId = actor_id(this), conn, id = print_id(),
                                         via_channel = channel_ready_](td::Result<AdnlPacket> res) {
      if (res.is_error()) {
        LOG(ERROR) << id << ": dropping OUT message: error while creating packet: " << res.move_as_error();
      } else {
        td::actor::send_closure(SelfId, &AdnlPeerPairImpl::send_packet_continue, res.move_as_ok(), conn, via_channel);
      }
    });

    td::actor::send_closure(
        local_actor_, &AdnlLocalId::update_packet, std::move(packet),
        !channel_ready_ && ack_seqno_ == 0 && in_seqno_ == 0, !channel_ready_,
        (first || s + addr_list_max_size() <= AdnlNetworkManager::get_mtu()) ? peer_recv_addr_list_version_
                                                                             : 0x7fffffff,
        (first || s + 2 * addr_list_max_size() <= AdnlNetworkManager::get_mtu()) ? peer_recv_priority_addr_list_version_
                                                                                 : 0x7fffffff,
        std::move(P));
    first = false;
  } while (ptr < messages.size());
}

void AdnlPeerPairImpl::send_messages(std::vector<AdnlMessage> messages) {
  std::vector<AdnlMessage> new_vec;
  for (auto &M : messages) {
    if (M.size() <= get_mtu()) {
      new_vec.push_back(std::move(M));
    } else {
      auto B = serialize_tl_object(M.tl(), true);
      CHECK(B.size() <= huge_packet_max_size());

      auto hash = sha256_bits256(B.as_slice());

      auto size = static_cast<td::uint32>(B.size());
      td::uint32 offset = 0;
      td::uint32 part_size = Adnl::get_mtu();
      while (offset < size) {
        auto data = B.clone();
        if (data.size() > part_size) {
          data.truncate(part_size);
        }
        B.confirm_read(data.size());

        new_vec.push_back(AdnlMessage{adnlmessage::AdnlMessagePart{hash, size, offset, std::move(data)}});
        offset += part_size;
      }
    }
  }
  send_messages_in(std::move(new_vec), true);
}

void AdnlPeerPairImpl::send_packet_continue(AdnlPacket packet, td::actor::ActorId<AdnlNetworkConnection> conn,
                                            bool via_channel) {
  packet.run_basic_checks().ensure();
  auto B = serialize_tl_object(packet.tl(), true);
  if (via_channel) {
    if (channel_ready_) {
      td::actor::send_closure(channel_, &AdnlChannel::send_message, priority_, conn, std::move(B));
    } else {
      VLOG(ADNL_WARNING) << this << ": dropping OUT message [" << local_id_ << "->" << peer_id_short_
                         << "]: channel destroyed in process";
    }
    return;
  }

  if (!encryptor_) {
    VLOG(ADNL_INFO) << this << ": dropping OUT message [" << local_id_ << "->" << peer_id_short_
                    << "]: empty encryptor";
    return;
  }

  auto res = encryptor_->encrypt(B.as_slice());
  if (res.is_error()) {
    VLOG(ADNL_WARNING) << this << ": dropping OUT message [" << local_id_ << "->" << peer_id_short_
                       << "]: failed to encrypt: " << res.move_as_error();
    return;
  }
  auto X = res.move_as_ok();
  auto enc = td::BufferSlice(X.size() + 32);
  td::MutableSlice S = enc.as_slice();
  S.copy_from(peer_id_short_.as_slice());
  S.remove_prefix(32);
  S.copy_from(X.as_slice());

  td::actor::send_closure(conn, &AdnlNetworkConnection::send, local_id_, peer_id_short_, priority_, std::move(enc));
}

void AdnlPeerPairImpl::send_query(std::string name, td::Promise<td::BufferSlice> promise, td::Timestamp timeout,
                                  td::BufferSlice data) {
  AdnlQueryId id = AdnlQuery::random_query_id();
  CHECK(out_queries_.count(id) == 0);

  auto P = [SelfId = actor_id(this)](AdnlQueryId id) {
    td::actor::send_closure(SelfId, &AdnlPeerPairImpl::delete_query, id);
  };

  out_queries_[id] = AdnlQuery::create(std::move(promise), std::move(P), name, timeout, id);

  send_message(adnlmessage::AdnlMessageQuery{id, std::move(data)});
}

void AdnlPeerPairImpl::alarm_query(AdnlQueryId id) {
  out_queries_.erase(id);
}

AdnlPeerPairImpl::AdnlPeerPairImpl(td::actor::ActorId<AdnlNetworkManager> network_manager,
                                   td::actor::ActorId<AdnlPeerTable> peer_table,
                                   td::actor::ActorId<AdnlLocalId> local_actor, td::actor::ActorId<AdnlPeer> peer,
                                   td::actor::ActorId<dht::Dht> dht_node, AdnlNodeIdShort local_id,
                                   AdnlNodeIdShort peer_id) {
  network_manager_ = network_manager;
  peer_table_ = peer_table;
  local_actor_ = local_actor;
  peer_ = peer;
  dht_node_ = dht_node;

  local_id_ = local_id;
  peer_id_short_ = peer_id;

  channel_pk_ = privkeys::Ed25519::random();
  channel_pub_ = channel_pk_.pub();
  channel_pk_date_ = static_cast<td::int32>(td::Clocks::system());
}

void AdnlPeerPairImpl::create_channel(pubkeys::Ed25519 pub, td::uint32 date) {
  if (channel_inited_ && peer_channel_pub_ == pub) {
    return;
  }
  if (channel_inited_ && date <= peer_channel_date_) {
    return;
  }
  if (channel_inited_) {
    td::actor::send_closure(peer_table_, &AdnlPeerTable::unregister_channel, channel_in_id_);
    channel_.reset();
    channel_inited_ = false;
    channel_ready_ = false;
  }
  CHECK(!channel_ready_);

  peer_channel_pub_ = pub;
  peer_channel_date_ = date;

  auto R = AdnlChannel::create(channel_pk_, peer_channel_pub_, local_id_, peer_id_short_, channel_out_id_,
                               channel_in_id_, actor_id(this));
  if (R.is_ok()) {
    channel_ = R.move_as_ok();
    channel_inited_ = true;

    td::actor::send_closure_later(peer_table_, &AdnlPeerTable::register_channel, channel_in_id_, channel_.get());
  } else {
    VLOG(ADNL_WARNING) << this << ": failed to create channel: " << R.move_as_error();
  }
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessageCreateChannel &message) {
  create_channel(message.key(), message.date());
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessageConfirmChannel &message) {
  if (message.peer_key() != channel_pub_) {
    VLOG(ADNL_NOTICE) << this << ": received adnl.message.confirmChannel with bad peer_key";
    return;
  }
  create_channel(message.key(), message.date());
  if (!channel_inited_ || peer_channel_pub_ != message.key()) {
    VLOG(ADNL_NOTICE) << this << ": received adnl.message.confirmChannel with old key";
    return;
  }
  channel_ready_ = true;
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessageCustom &message) {
  td::actor::send_closure(local_actor_, &AdnlLocalId::deliver, peer_id_short_, message.data());
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessageNop &message) {
  // nop
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessageReinit &message) {
  reinit(message.date());
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessageQuery &message) {
  auto P = td::PromiseCreator::lambda(
      [SelfId = actor_id(this), query_id = message.query_id()](td::Result<td::BufferSlice> R) {
        if (R.is_error()) {
          LOG(WARNING) << "failed to answer query: " << R.move_as_error();
        } else {
          auto data = R.move_as_ok();
          if (data.size() > Adnl::huge_packet_max_size()) {
            LOG(WARNING) << "dropping too big answer query: size=" << data.size();
          } else {
            td::actor::send_closure(SelfId, &AdnlPeerPairImpl::send_message,
                                    AdnlMessage{adnlmessage::AdnlMessageAnswer{query_id, std::move(data)}});
          }
        }
      });
  td::actor::send_closure(local_actor_, &AdnlLocalId::deliver_query, peer_id_short_, message.data(), std::move(P));
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessageAnswer &message) {
  auto Q = out_queries_.find(message.query_id());

  if (Q == out_queries_.end()) {
    VLOG(ADNL_NOTICE) << this << ": dropping IN answer: unknown query id " << message.query_id();
    return;
  }

  if (message.data().size() > Adnl::huge_packet_max_size()) {
    VLOG(ADNL_NOTICE) << this << ": dropping IN answer: too big answer size";
    return;
  }

  td::actor::send_closure_later(Q->second, &AdnlQuery::result, message.data());
  out_queries_.erase(Q);
}

void AdnlPeerPairImpl::process_message(const adnlmessage::AdnlMessagePart &message) {
  auto size = message.total_size();
  if (size > huge_packet_max_size()) {
    VLOG(ADNL_WARNING) << this << ": dropping too big huge message: size=" << size;
    return;
  }
  if (message.hash().is_zero()) {
    VLOG(ADNL_WARNING) << this << ": dropping huge message with zero hash";
    return;
  }
  if (message.hash() != huge_message_hash_) {
    huge_message_hash_.set_zero();
    huge_message_.clear();
    huge_message_offset_ = 0;
    if (message.offset() == 0) {
      huge_message_hash_ = message.hash();
      huge_message_ = td::BufferSlice{size};
    } else {
      return;
    }
  }
  auto data = message.data();
  if (data.size() + message.offset() > size) {
    VLOG(ADNL_WARNING) << this << ": dropping huge message with bad part";
    return;
  }
  if (size != huge_message_.size()) {
    VLOG(ADNL_WARNING) << this << ": dropping huge message part with inconsistent size";
    return;
  }
  if (message.offset() == huge_message_offset_) {
    auto S = huge_message_.as_slice();
    S.remove_prefix(huge_message_offset_);
    S.copy_from(data.as_slice());
    huge_message_offset_ += static_cast<td::uint32>(data.size());

    if (huge_message_offset_ == huge_message_.size()) {
      //td::actor::send_closure(local_actor_, &AdnlLocalId::deliver, peer_id_short_, std::move(huge_message_));
      if (sha256_bits256(huge_message_.as_slice()) != huge_message_hash_) {
        VLOG(ADNL_WARNING) << this << ": dropping huge message: hash mismatch";
        return;
      }
      huge_message_hash_.set_zero();
      huge_message_offset_ = 0;
      auto MR = fetch_tl_object<ton_api::adnl_Message>(std::move(huge_message_), true);
      if (MR.is_error()) {
        VLOG(ADNL_WARNING) << this << ": dropping huge message part with bad data";
        return;
      }
      auto M = AdnlMessage{MR.move_as_ok()};
      deliver_message(std::move(M));
    }
  }
}

void AdnlPeerPairImpl::delete_query(AdnlQueryId id) {
  auto Q = out_queries_.find(id);

  if (Q != out_queries_.end()) {
    out_queries_.erase(Q);
  }
}

void AdnlPeerPairImpl::reinit(td::int32 date) {
  if (reinit_date_ == 0) {
    reinit_date_ = date;
  }
  if (reinit_date_ < date) {
    if (channel_inited_) {
      td::actor::send_closure(peer_table_, &AdnlPeerTable::unregister_channel, channel_in_id_);
    }

    in_seqno_ = 0;
    out_seqno_ = 0;
    ack_seqno_ = 0;
    recv_seqno_mask_ = 0;

    channel_ready_ = false;
    channel_inited_ = false;

    peer_recv_addr_list_version_ = 0;

    huge_message_offset_ = 0;
    huge_message_hash_.set_zero();
    huge_message_.clear();

    channel_.release();

    reinit_date_ = date;
  }
}

td::Result<td::actor::ActorId<AdnlNetworkConnection>> AdnlPeerPairImpl::get_conn() {
  if (!priority_addr_list_.empty() && priority_addr_list_.expire_at() < td::Clocks::system()) {
    priority_addr_list_ = AdnlAddressList{};
    priority_conns_.clear();
  }

  if (conns_.size() == 0 && priority_conns_.size() == 0) {
    return td::Status::Error(ErrorCode::notready, PSTRING()
                                                      << "empty network information: version=" << addr_list_.version()
                                                      << " reinit_date=" << addr_list_.reinit_date()
                                                      << " real_reinit_date=" << reinit_date_);
  }

  for (auto &conn : priority_conns_) {
    if (conn.ready()) {
      return conn.conn.get();
    }
  }
  for (auto &conn : conns_) {
    if (conn.ready()) {
      return conn.conn.get();
    }
  }
  return td::Status::Error(ErrorCode::notready, "no active connections");
}

void AdnlPeerPairImpl::update_addr_list(AdnlAddressList addr_list) {
  if (addr_list.empty()) {
    return;
  }
  CHECK(addr_list.size() > 0);

  if (addr_list.reinit_date() > td::Clocks::system() + 60) {
    VLOG(ADNL_WARNING) << "dropping addr list with too new reinit date";
    return;
  }

  if (addr_list.reinit_date() > reinit_date_) {
    reinit(addr_list.reinit_date());
  } else if (addr_list.reinit_date() < reinit_date_) {
    return;
  }

  bool priority = addr_list.priority() > 0;

  if ((priority ? priority_addr_list_ : addr_list_).version() >= addr_list.version()) {
    if (priority && priority_addr_list_.version() == addr_list.version()) {
      auto expire_at = addr_list.expire_at();
      if (expire_at > priority_addr_list_.expire_at()) {
        priority_addr_list_.set_expire_at(expire_at);
      }
    }
    return;
  }

  VLOG(ADNL_INFO) << this << ": updating addr list to version " << addr_list.version() << " size=" << addr_list.size();

  const auto addrs = addr_list.addrs();
  std::vector<Conn> conns;
  conns.resize(std::min(addr_list.size(), 3u));
  auto &old_conns = priority ? priority_conns_ : conns_;

  for (size_t i = 0; i < conns.size(); i++) {
    auto &addr = addrs[i];
    auto hash = addr->get_hash();
    if (i < old_conns.size() && old_conns[i].addr->get_hash() == hash) {
      conns[i] = std::move(old_conns[i]);
    } else {
      conns[i] = Conn{addr, actor_id(this), network_manager_};
    }
  }

  old_conns = std::move(conns);
  (priority ? priority_addr_list_ : addr_list_) = addr_list;
}

void AdnlPeerImpl::update_id(AdnlNodeIdFull id) {
  CHECK(id.compute_short_id() == peer_id_short_);
  if (!peer_id_.empty()) {
    return;
  }

  peer_id_ = std::move(id);

  for (auto &it : peer_pairs_) {
    td::actor::send_closure(it.second.get(), &AdnlPeerPair::update_peer_id, peer_id_);
  }
}

void AdnlPeerPairImpl::Conn::create_conn(td::actor::ActorId<AdnlPeerPairImpl> peer,
                                         td::actor::ActorId<AdnlNetworkManager> network_manager) {
  auto id = addr->get_hash();

  conn = addr->create_connection(network_manager, std::make_unique<ConnCallback>(peer, id));
}

void AdnlPeerPairImpl::conn_change_state(AdnlConnectionIdShort id, bool ready) {
  if (ready) {
    if (pending_messages_.size() > 0) {
      send_messages_in(std::move(pending_messages_), true);
    }
  }
}

td::actor::ActorOwn<AdnlPeerPair> AdnlPeerPair::create(td::actor::ActorId<AdnlNetworkManager> network_manager,
                                                       td::actor::ActorId<AdnlPeerTable> peer_table,
                                                       td::actor::ActorId<AdnlLocalId> local_actor,
                                                       td::actor::ActorId<AdnlPeer> peer_actor,
                                                       td::actor::ActorId<dht::Dht> dht_node, AdnlNodeIdShort local_id,
                                                       AdnlNodeIdShort peer_id) {
  auto X = td::actor::create_actor<AdnlPeerPairImpl>("peerpair", network_manager, peer_table, local_actor, peer_actor,
                                                     dht_node, local_id, peer_id);
  return td::actor::ActorOwn<AdnlPeerPair>(std::move(X));
}

td::actor::ActorOwn<AdnlPeer> AdnlPeer::create(td::actor::ActorId<AdnlNetworkManager> network_manager,
                                               td::actor::ActorId<AdnlPeerTable> peer_table,
                                               td::actor::ActorId<dht::Dht> dht_node, AdnlNodeIdShort peer_id) {
  auto X = td::actor::create_actor<AdnlPeerImpl>("peer", network_manager, peer_table, dht_node, peer_id);
  return td::actor::ActorOwn<AdnlPeer>(std::move(X));
}

void AdnlPeerImpl::receive_packet(AdnlNodeIdShort dst, td::actor::ActorId<AdnlLocalId> dst_actor, AdnlPacket packet) {
  if (packet.inited_from()) {
    update_id(packet.from());
  }

  auto it = peer_pairs_.find(dst);
  if (it == peer_pairs_.end()) {
    auto X =
        AdnlPeerPair::create(network_manager_, peer_table_, dst_actor, actor_id(this), dht_node_, dst, peer_id_short_);
    peer_pairs_.emplace(dst, std::move(X));
    it = peer_pairs_.find(dst);
    CHECK(it != peer_pairs_.end());

    if (!peer_id_.empty()) {
      td::actor::send_closure(it->second.get(), &AdnlPeerPair::update_peer_id, peer_id_);
    }
  }

  td::actor::send_closure(it->second.get(), &AdnlPeerPair::receive_packet_checked, std::move(packet));
}

void AdnlPeerImpl::send_messages(AdnlNodeIdShort src, td::actor::ActorId<AdnlLocalId> src_actor,
                                 std::vector<AdnlMessage> messages) {
  auto it = peer_pairs_.find(src);
  if (it == peer_pairs_.end()) {
    auto X =
        AdnlPeerPair::create(network_manager_, peer_table_, src_actor, actor_id(this), dht_node_, src, peer_id_short_);
    peer_pairs_.emplace(src, std::move(X));
    it = peer_pairs_.find(src);
    CHECK(it != peer_pairs_.end());

    if (!peer_id_.empty()) {
      td::actor::send_closure(it->second.get(), &AdnlPeerPair::update_peer_id, peer_id_);
    }
  }

  td::actor::send_closure(it->second, &AdnlPeerPair::send_messages, std::move(messages));
}

void AdnlPeerImpl::send_query(AdnlNodeIdShort src, td::actor::ActorId<AdnlLocalId> src_actor, std::string name,
                              td::Promise<td::BufferSlice> promise, td::Timestamp timeout, td::BufferSlice data) {
  auto it = peer_pairs_.find(src);
  if (it == peer_pairs_.end()) {
    auto X =
        AdnlPeerPair::create(network_manager_, peer_table_, src_actor, actor_id(this), dht_node_, src, peer_id_short_);
    peer_pairs_.emplace(src, std::move(X));
    it = peer_pairs_.find(src);
    CHECK(it != peer_pairs_.end());

    if (!peer_id_.empty()) {
      td::actor::send_closure(it->second.get(), &AdnlPeerPair::update_peer_id, peer_id_);
    }
  }

  td::actor::send_closure(it->second, &AdnlPeerPair::send_query, name, std::move(promise), timeout, std::move(data));
}

void AdnlPeerImpl::del_local_id(AdnlNodeIdShort local_id) {
  peer_pairs_.erase(local_id);
}

void AdnlPeerImpl::update_dht_node(td::actor::ActorId<dht::Dht> dht_node) {
  dht_node_ = dht_node;
  for (auto it = peer_pairs_.begin(); it != peer_pairs_.end(); it++) {
    td::actor::send_closure(it->second, &AdnlPeerPair::update_dht_node, dht_node_);
  }
}

void AdnlPeerImpl::update_addr_list(AdnlNodeIdShort local_id, td::actor::ActorId<AdnlLocalId> local_actor,
                                    AdnlAddressList addr_list) {
  auto it = peer_pairs_.find(local_id);
  if (it == peer_pairs_.end()) {
    auto X = AdnlPeerPair::create(network_manager_, peer_table_, local_actor, actor_id(this), dht_node_, local_id,
                                  peer_id_short_);
    peer_pairs_.emplace(local_id, std::move(X));
    it = peer_pairs_.find(local_id);
    CHECK(it != peer_pairs_.end());

    if (!peer_id_.empty()) {
      td::actor::send_closure(it->second.get(), &AdnlPeerPair::update_peer_id, peer_id_);
    }
  }

  td::actor::send_closure(it->second, &AdnlPeerPair::update_addr_list, std::move(addr_list));
}

void AdnlPeerPairImpl::got_data_from_db(td::Result<AdnlDbItem> R) {
  received_from_db_ = false;
  if (R.is_error()) {
    return;
  }
  auto value = R.move_as_ok();
  if (!value.id.empty()) {
    update_peer_id(value.id);
  }
  update_addr_list(value.addr_list);
  update_addr_list(value.priority_addr_list);
}

void AdnlPeerPairImpl::got_data_from_static_nodes(td::Result<AdnlNode> R) {
  received_from_static_nodes_ = false;
  if (R.is_error()) {
    return;
  }
  auto value = R.move_as_ok();
  if (!value.pub_id().empty()) {
    update_peer_id(value.pub_id());
  }
  update_addr_list(value.addr_list());
}

void AdnlPeerPairImpl::got_data_from_dht(td::Result<AdnlNode> R) {
  CHECK(dht_query_active_);
  dht_query_active_ = false;
  next_dht_query_at_ = td::Timestamp::in(td::Random::fast(60.0, 120.0));
  if (R.is_error()) {
    VLOG(ADNL_INFO) << this << ": dht query failed: " << R.move_as_error();
    return;
  }
  auto value = R.move_as_ok();
  if (!value.pub_id().empty()) {
    update_peer_id(value.pub_id());
  }
  update_addr_list(value.addr_list());
}

void AdnlPeerPairImpl::update_peer_id(AdnlNodeIdFull id) {
  if (peer_id_.empty()) {
    peer_id_ = std::move(id);
    auto R = peer_id_.pubkey().create_encryptor();
    if (R.is_ok()) {
      encryptor_ = R.move_as_ok();
    } else {
      VLOG(ADNL_WARNING) << this << ": failed to create encryptor: " << R.move_as_error();
    }
  }
  CHECK(!peer_id_.empty());
}

}  // namespace adnl

}  // namespace ton