//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2022
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/telegram/MessageReaction.h"

#include "td/telegram/ContactsManager.h"
#include "td/telegram/MessageSender.h"
#include "td/telegram/MessagesManager.h"
#include "td/telegram/Td.h"
#include "td/telegram/UpdatesManager.h"

#include "td/utils/algorithm.h"
#include "td/utils/buffer.h"
#include "td/utils/logging.h"

#include <unordered_set>

namespace td {

class SendReactionQuery final : public Td::ResultHandler {
  Promise<Unit> promise_;
  DialogId dialog_id_;
  MessageId message_id_;

 public:
  explicit SendReactionQuery(Promise<Unit> &&promise) : promise_(std::move(promise)) {
  }

  void send(FullMessageId full_message_id, string reaction) {
    dialog_id_ = full_message_id.get_dialog_id();
    message_id_ = full_message_id.get_message_id();

    auto input_peer = td_->messages_manager_->get_input_peer(dialog_id_, AccessRights::Read);
    if (input_peer == nullptr) {
      return on_error(Status::Error(400, "Can't access the chat"));
    }

    int32 flags = 0;
    if (!reaction.empty()) {
      flags |= telegram_api::messages_sendReaction::REACTION_MASK;
    }

    send_query(G()->net_query_creator().create(telegram_api::messages_sendReaction(
        flags, false /*ignored*/, std::move(input_peer), message_id_.get_server_message_id().get(), reaction)));
  }

  void on_result(BufferSlice packet) final {
    auto result_ptr = fetch_result<telegram_api::messages_sendReaction>(packet);
    if (result_ptr.is_error()) {
      return on_error(result_ptr.move_as_error());
    }

    auto ptr = result_ptr.move_as_ok();
    LOG(INFO) << "Receive result for SendReactionQuery: " << to_string(ptr);
    td_->updates_manager_->on_get_updates(std::move(ptr), std::move(promise_));
  }

  void on_error(Status status) final {
    td_->messages_manager_->on_get_dialog_error(dialog_id_, status, "SendReactionQuery");
    promise_.set_error(std::move(status));
  }
};

class GetMessageReactionsListQuery final : public Td::ResultHandler {
  Promise<td_api::object_ptr<td_api::chosenReactions>> promise_;
  DialogId dialog_id_;
  MessageId message_id_;
  string reaction_;
  string offset_;

 public:
  explicit GetMessageReactionsListQuery(Promise<td_api::object_ptr<td_api::chosenReactions>> &&promise)
      : promise_(std::move(promise)) {
  }

  void send(FullMessageId full_message_id, string reaction, string offset, int32 limit) {
    dialog_id_ = full_message_id.get_dialog_id();
    message_id_ = full_message_id.get_message_id();
    reaction_ = std::move(reaction);
    offset_ = std::move(offset);

    auto input_peer = td_->messages_manager_->get_input_peer(dialog_id_, AccessRights::Read);
    if (input_peer == nullptr) {
      return on_error(Status::Error(400, "Can't access the chat"));
    }

    int32 flags = 0;
    if (!reaction_.empty()) {
      flags |= telegram_api::messages_getMessageReactionsList::REACTION_MASK;
    }
    if (!offset_.empty()) {
      flags |= telegram_api::messages_getMessageReactionsList::OFFSET_MASK;
    }

    send_query(G()->net_query_creator().create(telegram_api::messages_getMessageReactionsList(
        flags, std::move(input_peer), message_id_.get_server_message_id().get(), reaction_, offset_, limit)));
  }

  void on_result(BufferSlice packet) final {
    auto result_ptr = fetch_result<telegram_api::messages_getMessageReactionsList>(packet);
    if (result_ptr.is_error()) {
      return on_error(result_ptr.move_as_error());
    }

    auto ptr = result_ptr.move_as_ok();
    LOG(INFO) << "Receive result for GetMessageReactionsListQuery: " << to_string(ptr);

    td_->contacts_manager_->on_get_users(std::move(ptr->users_), "GetMessageReactionsListQuery");
    td_->contacts_manager_->on_get_chats(std::move(ptr->chats_), "GetMessageReactionsListQuery");

    int32 total_count = ptr->count_;
    if (total_count < static_cast<int32>(ptr->reactions_.size())) {
      LOG(ERROR) << "Receive invalid total_count in " << to_string(ptr);
      total_count = static_cast<int32>(ptr->reactions_.size());
    }

    vector<td_api::object_ptr<td_api::chosenReaction>> reactions;
    for (auto &reaction : ptr->reactions_) {
      DialogId dialog_id(reaction->peer_id_);
      if (!dialog_id.is_valid() || (!reaction_.empty() && reaction_ != reaction->reaction_)) {
        LOG(ERROR) << "Receive unexpected " << to_string(reaction);
        continue;
      }

      auto message_sender = get_min_message_sender_object(td_, dialog_id, "GetMessageReactionsListQuery");
      if (message_sender != nullptr) {
        reactions.push_back(
            td_api::make_object<td_api::chosenReaction>(reaction->reaction_, std::move(message_sender)));
      }
    }

    promise_.set_value(
        td_api::make_object<td_api::chosenReactions>(total_count, std::move(reactions), ptr->next_offset_));
  }

  void on_error(Status status) final {
    td_->messages_manager_->on_get_dialog_error(dialog_id_, status, "GetMessageReactionsListQuery");
    promise_.set_error(std::move(status));
  }
};

void MessageReaction::set_is_chosen(bool is_chosen, DialogId chooser_dialog_id, bool can_see_all_choosers) {
  if (is_chosen_ == is_chosen) {
    return;
  }

  is_chosen_ = is_chosen;

  if (chooser_dialog_id.is_valid()) {
    choose_count_ += is_chosen_ ? 1 : -1;
    if (can_see_all_choosers) {
      td::remove(recent_chooser_dialog_ids_, chooser_dialog_id);
      if (is_chosen_) {
        recent_chooser_dialog_ids_.insert(recent_chooser_dialog_ids_.begin(), chooser_dialog_id);
        if (recent_chooser_dialog_ids_.size() > MAX_RECENT_CHOOSERS) {
          recent_chooser_dialog_ids_.resize(MAX_RECENT_CHOOSERS);
        }
      }
    }
  }
}

td_api::object_ptr<td_api::messageReaction> MessageReaction::get_message_reaction_object(Td *td) const {
  CHECK(!is_empty());

  vector<td_api::object_ptr<td_api::MessageSender>> recent_choosers;
  for (auto dialog_id : recent_chooser_dialog_ids_) {
    auto recent_chooser = get_min_message_sender_object(td, dialog_id, "get_message_reaction_object");
    if (recent_chooser != nullptr) {
      recent_choosers.push_back(std::move(recent_chooser));
    }
  }
  return td_api::make_object<td_api::messageReaction>(reaction_, choose_count_, is_chosen_, std::move(recent_choosers));
}

bool operator==(const MessageReaction &lhs, const MessageReaction &rhs) {
  return lhs.reaction_ == rhs.reaction_ && lhs.choose_count_ == rhs.choose_count_ && lhs.is_chosen_ == rhs.is_chosen_ &&
         lhs.recent_chooser_dialog_ids_ == rhs.recent_chooser_dialog_ids_;
}

StringBuilder &operator<<(StringBuilder &string_builder, const MessageReaction &reaction) {
  string_builder << '[' << reaction.reaction_ << (reaction.is_chosen_ ? " X " : " x ") << reaction.choose_count_;
  if (!reaction.recent_chooser_dialog_ids_.empty()) {
    string_builder << " by " << reaction.recent_chooser_dialog_ids_;
  }
  return string_builder << ']';
}

unique_ptr<MessageReactions> MessageReactions::get_message_reactions(
    Td *td, tl_object_ptr<telegram_api::messageReactions> &&reactions, bool is_bot) {
  if (reactions == nullptr || is_bot) {
    return nullptr;
  }

  auto result = make_unique<MessageReactions>();
  result->can_see_all_choosers_ = reactions->can_see_list_;
  result->is_min_ = reactions->min_;

  std::unordered_set<string> reaction_strings;
  std::unordered_set<DialogId, DialogIdHash> recent_choosers;
  for (auto &reaction_count : reactions->results_) {
    if (reaction_count->count_ <= 0 || reaction_count->count_ >= MessageReaction::MAX_CHOOSE_COUNT) {
      LOG(ERROR) << "Receive reaction " << reaction_count->reaction_ << " with invalid count "
                 << reaction_count->count_;
      continue;
    }

    if (!reaction_strings.insert(reaction_count->reaction_).second) {
      LOG(ERROR) << "Receive duplicate reaction " << reaction_count->reaction_;
      continue;
    }

    vector<DialogId> recent_chooser_dialog_ids;
    vector<std::pair<ChannelId, MinChannel>> recent_chooser_min_channels;
    for (auto &peer_reaction : reactions->recent_reactions_) {
      if (peer_reaction->reaction_ == reaction_count->reaction_) {
        DialogId dialog_id(peer_reaction->peer_id_);
        if (!dialog_id.is_valid()) {
          LOG(ERROR) << "Receive invalid " << dialog_id << " as a recent chooser";
          continue;
        }
        if (!recent_choosers.insert(dialog_id).second) {
          LOG(ERROR) << "Receive duplicate " << dialog_id << " as a recent chooser";
          continue;
        }
        if (!td->messages_manager_->have_dialog_info(dialog_id)) {
          auto dialog_type = dialog_id.get_type();
          if (dialog_type == DialogType::User) {
            auto user_id = dialog_id.get_user_id();
            if (!td->contacts_manager_->have_min_user(user_id)) {
              LOG(ERROR) << "Have no info about " << user_id;
              continue;
            }
          } else if (dialog_type == DialogType::Channel) {
            auto channel_id = dialog_id.get_channel_id();
            auto min_channel = td->contacts_manager_->get_min_channel(channel_id);
            if (min_channel == nullptr) {
              LOG(ERROR) << "Have no info about reacted " << channel_id;
              continue;
            }
            recent_chooser_min_channels.emplace_back(channel_id, *min_channel);
          } else {
            LOG(ERROR) << "Have no info about reacted " << dialog_id;
            continue;
          }
        }

        recent_chooser_dialog_ids.push_back(dialog_id);
        if (recent_chooser_dialog_ids.size() == MessageReaction::MAX_RECENT_CHOOSERS) {
          break;
        }
      }
    }

    result->reactions_.emplace_back(std::move(reaction_count->reaction_), reaction_count->count_,
                                    reaction_count->chosen_, std::move(recent_chooser_dialog_ids),
                                    std::move(recent_chooser_min_channels));
  }
  return result;
}

void MessageReactions::update_from(const MessageReactions &old_reactions) {
  if (old_reactions.has_pending_reaction_) {
    // we will ignore all updates, received while there is a pending reaction, so there are no reasons to update
    return;
  }
  CHECK(!has_pending_reaction_);

  if (is_min_ && !old_reactions.is_min_) {
    // chosen reaction was known, keep it
    is_min_ = false;
    for (const auto &old_reaction : old_reactions.reactions_) {
      if (old_reaction.is_chosen()) {
        for (auto &reaction : reactions_) {
          if (reaction.get_reaction() == old_reaction.get_reaction()) {
            reaction.set_is_chosen(true, DialogId(), false);
          }
        }
      }
    }
  }
}

void MessageReactions::sort(const std::unordered_map<string, size_t> &active_reaction_pos) {
  std::sort(reactions_.begin(), reactions_.end(),
            [&active_reaction_pos](const MessageReaction &lhs, const MessageReaction &rhs) {
              if (lhs.get_choose_count() != rhs.get_choose_count()) {
                return lhs.get_choose_count() > rhs.get_choose_count();
              }
              auto lhs_it = active_reaction_pos.find(lhs.get_reaction());
              auto lhs_pos = lhs_it != active_reaction_pos.end() ? lhs_it->second : active_reaction_pos.size();
              auto rhs_it = active_reaction_pos.find(rhs.get_reaction());
              auto rhs_pos = rhs_it != active_reaction_pos.end() ? rhs_it->second : active_reaction_pos.size();
              if (lhs_pos != rhs_pos) {
                return lhs_pos < rhs_pos;
              }

              return lhs.get_reaction() < rhs.get_reaction();
            });
}

bool MessageReactions::need_update_message_reactions(const MessageReactions *old_reactions,
                                                     const MessageReactions *new_reactions) {
  if (old_reactions == nullptr) {
    // add reactions
    return new_reactions != nullptr;
  }
  if (old_reactions->has_pending_reaction_) {
    // ignore all updates, received while there is a pending reaction
    return false;
  }
  if (new_reactions == nullptr) {
    // remove reactions when they are disabled
    return true;
  }

  // has_pending_reaction_ doesn't affect visible state
  // compare all other fields
  return old_reactions->reactions_ != new_reactions->reactions_ || old_reactions->is_min_ != new_reactions->is_min_ ||
         old_reactions->can_see_all_choosers_ != new_reactions->can_see_all_choosers_ ||
         old_reactions->need_polling_ != new_reactions->need_polling_;
}

void set_message_reaction(Td *td, FullMessageId full_message_id, string reaction, Promise<Unit> &&promise) {
  td->create_handler<SendReactionQuery>(std::move(promise))->send(full_message_id, std::move(reaction));
}

void get_message_chosen_reactions(Td *td, FullMessageId full_message_id, string reaction, string offset, int32 limit,
                                  Promise<td_api::object_ptr<td_api::chosenReactions>> &&promise) {
  if (!td->messages_manager_->have_message_force(full_message_id, "get_message_chosen_reactions")) {
    return promise.set_error(Status::Error(400, "Message not found"));
  }

  auto message_id = full_message_id.get_message_id();
  if (full_message_id.get_dialog_id().get_type() == DialogType::SecretChat || !message_id.is_valid() ||
      !message_id.is_server()) {
    return promise.set_value(td_api::make_object<td_api::chosenReactions>(0, Auto(), string()));
  }

  if (limit <= 0) {
    return promise.set_error(Status::Error(400, "Parameter limit must be positive"));
  }
  static constexpr int32 MAX_GET_CHOSEN_REACTIONS = 100;  // server side limit
  if (limit > MAX_GET_CHOSEN_REACTIONS) {
    limit = MAX_GET_CHOSEN_REACTIONS;
  }

  td->create_handler<GetMessageReactionsListQuery>(std::move(promise))
      ->send(full_message_id, std::move(reaction), std::move(offset), limit);
}

}  // namespace td