/*
    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
*/
#pragma once

#include "adnl/adnl.h"
#include "dht/dht.h"

#include "td/actor/actor.h"

#include <map>

namespace ton {

namespace overlay {

class OverlayIdShort {
 public:
  OverlayIdShort() {
  }
  explicit OverlayIdShort(td::Bits256 id) : id_(id) {
  }
  auto bits256_value() const {
    return id_;
  }
  auto pubkey_hash() const {
    return PublicKeyHash{id_};
  }

  auto tl() const {
    return id_;
  }
  bool operator<(const OverlayIdShort &with) const {
    return id_ < with.id_;
  }
  bool operator==(const OverlayIdShort &with) const {
    return id_ == with.id_;
  }
  bool operator!=(const OverlayIdShort &with) const {
    return id_ != with.id_;
  }

 private:
  td::Bits256 id_;
};

class OverlayIdFull {
 public:
  OverlayIdFull() {
  }
  OverlayIdFull clone() const {
    return OverlayIdFull{name_.clone()};
  }
  explicit OverlayIdFull(td::BufferSlice name) : name_(std::move(name)) {
  }
  auto pubkey() const {
    return PublicKey{pubkeys::Overlay{name_.clone()}};
  }

  OverlayIdShort compute_short_id() const {
    return OverlayIdShort{pubkey().compute_short_id().bits256_value()};
  }

 private:
  td::BufferSlice name_;
};

class OverlayPrivacyRules {
 public:
  OverlayPrivacyRules() {
  }
  OverlayPrivacyRules(td::uint32 size) : max_unath_size_(size) {
  }
  OverlayPrivacyRules(td::uint32 max_size, std::map<PublicKeyHash, td::uint32> authorized_keys)
      : max_unath_size_(max_size), authorized_keys_(std::move(authorized_keys)) {
  }

  td::uint32 max_size(PublicKeyHash hash) {
    auto it = authorized_keys_.find(hash);
    if (it == authorized_keys_.end()) {
      return max_unath_size_;
    } else {
      return it->second;
    }
  }

 private:
  td::uint32 max_unath_size_{0};
  std::map<PublicKeyHash, td::uint32> authorized_keys_;
};

class Certificate {
 public:
  Certificate(PublicKeyHash issued_by, td::int32 expire_at, td::uint32 max_size, td::BufferSlice signature);
  Certificate(PublicKey issued_by, td::int32 expire_at, td::uint32 max_size, td::BufferSlice signature);
  Certificate() {
  }
  void set_signature(td::BufferSlice signature);
  void set_issuer(PublicKey issuer);
  td::BufferSlice to_sign(OverlayIdShort overlay_id, PublicKeyHash issued_to) const;

  td::Status check(PublicKeyHash node, OverlayIdShort overlay_id, td::int32 unix_time, td::uint32 size) const;
  tl_object_ptr<ton_api::overlay_Certificate> tl() const;
  const PublicKey &issuer() const;
  const PublicKeyHash issuer_hash() const;

  static td::Result<std::shared_ptr<Certificate>> create(tl_object_ptr<ton_api::overlay_Certificate> cert);
  static tl_object_ptr<ton_api::overlay_Certificate> empty_tl();

 private:
  td::Variant<PublicKey, PublicKeyHash> issued_by_;
  td::int32 expire_at_;
  td::uint32 max_size_;
  td::SharedSlice signature_;
};

class Overlays : public td::actor::Actor {
 public:
  class Callback {
   public:
    virtual void receive_message(adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id, td::BufferSlice data) = 0;
    virtual void receive_query(adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id, td::BufferSlice data,
                               td::Promise<td::BufferSlice> promise) = 0;
    virtual void receive_broadcast(PublicKeyHash src, OverlayIdShort overlay_id, td::BufferSlice data) = 0;
    virtual ~Callback() = default;
  };

  static constexpr td::uint32 max_simple_broadcast_size() {
    return 768;
  }
  static constexpr td::uint32 max_message_size() {
    return adnl::Adnl::get_mtu() - 36;
  }
  static constexpr td::uint32 max_fec_broadcast_size() {
    return 16 << 20;
  }

  static constexpr td::uint32 BroadcastFlagAnySender() {
    return 1;
  }

  static td::actor::ActorOwn<Overlays> create(std::string db_root, td::actor::ActorId<keyring::Keyring> keyring,
                                              td::actor::ActorId<adnl::Adnl> adnl, td::actor::ActorId<dht::Dht> dht);

  virtual void update_dht_node(td::actor::ActorId<dht::Dht> dht) = 0;

  virtual void create_public_overlay(adnl::AdnlNodeIdShort local_id, OverlayIdFull overlay_id,
                                     std::unique_ptr<Callback> callback, OverlayPrivacyRules rules) = 0;
  virtual void create_private_overlay(adnl::AdnlNodeIdShort local_id, OverlayIdFull overlay_id,
                                      std::vector<adnl::AdnlNodeIdShort> nodes, std::unique_ptr<Callback> callback,
                                      OverlayPrivacyRules rules) = 0;
  virtual void delete_overlay(adnl::AdnlNodeIdShort local_id, OverlayIdShort overlay_id) = 0;

  virtual void send_query(adnl::AdnlNodeIdShort dst, adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id,
                          std::string name, td::Promise<td::BufferSlice> promise, td::Timestamp timeout,
                          td::BufferSlice query) = 0;
  virtual void send_query_via(adnl::AdnlNodeIdShort dst, adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id,
                              std::string name, td::Promise<td::BufferSlice> promise, td::Timestamp timeout,
                              td::BufferSlice query, td::uint64 max_answer_size,
                              td::actor::ActorId<adnl::AdnlSenderInterface> via) = 0;
  void send_multiple_messages(std::vector<adnl::AdnlNodeIdShort> dst, adnl::AdnlNodeIdShort src,
                              OverlayIdShort overlay_id, td::BufferSlice object) {
    for (auto &n : dst) {
      send_message(n, src, overlay_id, object.clone());
    }
  }

  virtual void send_message(adnl::AdnlNodeIdShort dst, adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id,
                            td::BufferSlice object) = 0;
  virtual void send_message_via(adnl::AdnlNodeIdShort dst, adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id,
                                td::BufferSlice object, td::actor::ActorId<adnl::AdnlSenderInterface> via) = 0;

  virtual void send_broadcast(adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id, td::BufferSlice object) = 0;
  virtual void send_broadcast_ex(adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id, PublicKeyHash send_as,
                                 td::uint32 flags, td::BufferSlice object) = 0;
  virtual void send_broadcast_fec(adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id, td::BufferSlice object) = 0;
  virtual void send_broadcast_fec_ex(adnl::AdnlNodeIdShort src, OverlayIdShort overlay_id, PublicKeyHash send_as,
                                     td::uint32 flags, td::BufferSlice object) = 0;

  virtual void set_privacy_rules(adnl::AdnlNodeIdShort local_id, OverlayIdShort overlay_id,
                                 OverlayPrivacyRules rules) = 0;
  virtual void update_certificate(adnl::AdnlNodeIdShort local_id, OverlayIdShort overlay_id, PublicKeyHash key,
                                  std::shared_ptr<Certificate> cert) = 0;

  virtual void get_overlay_random_peers(adnl::AdnlNodeIdShort local_id, OverlayIdShort overlay, td::uint32 max_peers,
                                        td::Promise<std::vector<adnl::AdnlNodeIdShort>> promise) = 0;
};

}  // namespace overlay

}  // namespace ton

namespace td {

inline StringBuilder &operator<<(StringBuilder &stream, const ton::overlay::OverlayIdShort &value) {
  return stream << value.bits256_value();
}

}  // namespace td