//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2023
//
// 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/MessageImportManager.h"

#include "td/telegram/AccessRights.h"
#include "td/telegram/ContactsManager.h"
#include "td/telegram/DialogManager.h"
#include "td/telegram/FileReferenceManager.h"
#include "td/telegram/files/FileManager.h"
#include "td/telegram/files/FileType.h"
#include "td/telegram/Global.h"
#include "td/telegram/MessageContent.h"
#include "td/telegram/Td.h"
#include "td/telegram/telegram_api.h"

#include "td/utils/buffer.h"
#include "td/utils/logging.h"
#include "td/utils/misc.h"
#include "td/utils/PathView.h"
#include "td/utils/Random.h"

namespace td {

class CheckHistoryImportQuery final : public Td::ResultHandler {
  Promise<td_api::object_ptr<td_api::MessageFileType>> promise_;

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

  void send(const string &message_file_head) {
    send_query(G()->net_query_creator().create(telegram_api::messages_checkHistoryImport(message_file_head)));
  }

  void on_result(BufferSlice packet) final {
    auto result_ptr = fetch_result<telegram_api::messages_checkHistoryImport>(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 CheckHistoryImportQuery: " << to_string(ptr);
    auto file_type = [&]() -> td_api::object_ptr<td_api::MessageFileType> {
      if (ptr->pm_) {
        return td_api::make_object<td_api::messageFileTypePrivate>(ptr->title_);
      } else if (ptr->group_) {
        return td_api::make_object<td_api::messageFileTypeGroup>(ptr->title_);
      } else {
        return td_api::make_object<td_api::messageFileTypeUnknown>();
      }
    }();
    promise_.set_value(std::move(file_type));
  }

  void on_error(Status status) final {
    promise_.set_error(std::move(status));
  }
};

class CheckHistoryImportPeerQuery final : public Td::ResultHandler {
  Promise<string> promise_;
  DialogId dialog_id_;

 public:
  explicit CheckHistoryImportPeerQuery(Promise<string> &&promise) : promise_(std::move(promise)) {
  }

  void send(DialogId dialog_id) {
    dialog_id_ = dialog_id;
    auto input_peer = td_->dialog_manager_->get_input_peer(dialog_id, AccessRights::Write);
    CHECK(input_peer != nullptr);
    send_query(G()->net_query_creator().create(telegram_api::messages_checkHistoryImportPeer(std::move(input_peer))));
  }

  void on_result(BufferSlice packet) final {
    auto result_ptr = fetch_result<telegram_api::messages_checkHistoryImportPeer>(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 CheckHistoryImportPeerQuery: " << to_string(ptr);
    promise_.set_value(std::move(ptr->confirm_text_));
  }

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

class InitHistoryImportQuery final : public Td::ResultHandler {
  Promise<Unit> promise_;
  FileId file_id_;
  DialogId dialog_id_;
  vector<FileId> attached_file_ids_;

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

  void send(DialogId dialog_id, FileId file_id, tl_object_ptr<telegram_api::InputFile> &&input_file,
            vector<FileId> attached_file_ids) {
    CHECK(input_file != nullptr);
    file_id_ = file_id;
    dialog_id_ = dialog_id;
    attached_file_ids_ = std::move(attached_file_ids);

    auto input_peer = td_->dialog_manager_->get_input_peer(dialog_id, AccessRights::Write);
    CHECK(input_peer != nullptr);
    send_query(G()->net_query_creator().create(telegram_api::messages_initHistoryImport(
        std::move(input_peer), std::move(input_file), narrow_cast<int32>(attached_file_ids_.size()))));
  }

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

    auto ptr = result_ptr.move_as_ok();
    td_->message_import_manager_->start_import_messages(dialog_id_, ptr->id_, std::move(attached_file_ids_),
                                                        std::move(promise_));

    td_->file_manager_->delete_partial_remote_location(file_id_);
  }

  void on_error(Status status) final {
    if (FileReferenceManager::is_file_reference_error(status)) {
      LOG(ERROR) << "Receive file reference error " << status;
    }
    auto bad_parts = FileManager::get_missing_file_parts(status);
    if (!bad_parts.empty()) {
      // TODO reupload the file
    }

    td_->file_manager_->delete_partial_remote_location(file_id_);
    td_->dialog_manager_->on_get_dialog_error(dialog_id_, status, "InitHistoryImportQuery");
    promise_.set_error(std::move(status));
  }
};

class UploadImportedMediaQuery final : public Td::ResultHandler {
  Promise<Unit> promise_;
  DialogId dialog_id_;
  int64 import_id_;
  FileId file_id_;

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

  void send(DialogId dialog_id, int64 import_id, const string &file_name, FileId file_id,
            tl_object_ptr<telegram_api::InputMedia> &&input_media) {
    CHECK(input_media != nullptr);
    dialog_id_ = dialog_id;
    import_id_ = import_id;
    file_id_ = file_id;

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

    send_query(G()->net_query_creator().create(telegram_api::messages_uploadImportedMedia(
        std::move(input_peer), import_id, file_name, std::move(input_media))));
  }

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

    // ignore response

    promise_.set_value(Unit());

    td_->file_manager_->delete_partial_remote_location(file_id_);
  }

  void on_error(Status status) final {
    if (FileReferenceManager::is_file_reference_error(status)) {
      LOG(ERROR) << "Receive file reference error " << status;
    }
    auto bad_parts = FileManager::get_missing_file_parts(status);
    if (!bad_parts.empty()) {
      // TODO reupload the file
    }

    td_->file_manager_->delete_partial_remote_location(file_id_);
    td_->dialog_manager_->on_get_dialog_error(dialog_id_, status, "UploadImportedMediaQuery");
    promise_.set_error(std::move(status));
  }
};

class StartImportHistoryQuery final : public Td::ResultHandler {
  Promise<Unit> promise_;
  DialogId dialog_id_;

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

  void send(DialogId dialog_id, int64 import_id) {
    dialog_id_ = dialog_id;

    auto input_peer = td_->dialog_manager_->get_input_peer(dialog_id, AccessRights::Write);
    CHECK(input_peer != nullptr);

    send_query(
        G()->net_query_creator().create(telegram_api::messages_startHistoryImport(std::move(input_peer), import_id)));
  }

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

    if (!result_ptr.ok()) {
      return on_error(Status::Error(500, "Import history returned false"));
    }
    promise_.set_value(Unit());
  }

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

class MessageImportManager::UploadImportedMessagesCallback final : public FileManager::UploadCallback {
 public:
  void on_upload_ok(FileId file_id, tl_object_ptr<telegram_api::InputFile> input_file) final {
    send_closure_later(G()->message_import_manager(), &MessageImportManager::on_upload_imported_messages, file_id,
                       std::move(input_file));
  }
  void on_upload_encrypted_ok(FileId file_id, tl_object_ptr<telegram_api::InputEncryptedFile> input_file) final {
    UNREACHABLE();
  }
  void on_upload_secure_ok(FileId file_id, tl_object_ptr<telegram_api::InputSecureFile> input_file) final {
    UNREACHABLE();
  }
  void on_upload_error(FileId file_id, Status error) final {
    send_closure_later(G()->message_import_manager(), &MessageImportManager::on_upload_imported_messages_error, file_id,
                       std::move(error));
  }
};

class MessageImportManager::UploadImportedMessageAttachmentCallback final : public FileManager::UploadCallback {
 public:
  void on_upload_ok(FileId file_id, tl_object_ptr<telegram_api::InputFile> input_file) final {
    send_closure_later(G()->message_import_manager(), &MessageImportManager::on_upload_imported_message_attachment,
                       file_id, std::move(input_file));
  }
  void on_upload_encrypted_ok(FileId file_id, tl_object_ptr<telegram_api::InputEncryptedFile> input_file) final {
    UNREACHABLE();
  }
  void on_upload_secure_ok(FileId file_id, tl_object_ptr<telegram_api::InputSecureFile> input_file) final {
    UNREACHABLE();
  }
  void on_upload_error(FileId file_id, Status error) final {
    send_closure_later(G()->message_import_manager(),
                       &MessageImportManager::on_upload_imported_message_attachment_error, file_id, std::move(error));
  }
};

MessageImportManager::MessageImportManager(Td *td, ActorShared<> parent) : td_(td), parent_(std::move(parent)) {
  upload_imported_messages_callback_ = std::make_shared<UploadImportedMessagesCallback>();
  upload_imported_message_attachment_callback_ = std::make_shared<UploadImportedMessageAttachmentCallback>();
}

void MessageImportManager::tear_down() {
  parent_.reset();
}

void MessageImportManager::get_message_file_type(const string &message_file_head,
                                                 Promise<td_api::object_ptr<td_api::MessageFileType>> &&promise) {
  td_->create_handler<CheckHistoryImportQuery>(std::move(promise))->send(message_file_head);
}

Status MessageImportManager::can_import_messages(DialogId dialog_id) {
  if (!td_->dialog_manager_->have_dialog_force(dialog_id, "can_import_messages")) {
    return Status::Error(400, "Chat not found");
  }
  if (!td_->dialog_manager_->have_input_peer(dialog_id, AccessRights::Write)) {
    return Status::Error(400, "Have no write access to the chat");
  }

  switch (dialog_id.get_type()) {
    case DialogType::User:
      if (!td_->contacts_manager_->is_user_contact(dialog_id.get_user_id(), true)) {
        return Status::Error(400, "User must be a mutual contact");
      }
      break;
    case DialogType::Chat:
      return Status::Error(400, "Basic groups must be upgraded to supergroups first");
    case DialogType::Channel:
      if (td_->dialog_manager_->is_broadcast_channel(dialog_id)) {
        return Status::Error(400, "Can't import messages to channels");
      }
      if (!td_->contacts_manager_->get_channel_permissions(dialog_id.get_channel_id()).can_change_info_and_settings()) {
        return Status::Error(400, "Not enough rights to import messages");
      }
      break;
    case DialogType::SecretChat:
      return Status::Error(400, "Can't import messages to secret chats");
    case DialogType::None:
    default:
      UNREACHABLE();
  }

  return Status::OK();
}

void MessageImportManager::get_message_import_confirmation_text(DialogId dialog_id, Promise<string> &&promise) {
  TRY_STATUS_PROMISE(promise, can_import_messages(dialog_id));

  td_->create_handler<CheckHistoryImportPeerQuery>(std::move(promise))->send(dialog_id);
}

void MessageImportManager::import_messages(DialogId dialog_id,
                                           const td_api::object_ptr<td_api::InputFile> &message_file,
                                           const vector<td_api::object_ptr<td_api::InputFile>> &attached_files,
                                           Promise<Unit> &&promise) {
  TRY_STATUS_PROMISE(promise, can_import_messages(dialog_id));

  TRY_RESULT_PROMISE(promise, file_id,
                     td_->file_manager_->get_input_file_id(FileType::Document, message_file, dialog_id, false, false));

  vector<FileId> attached_file_ids;
  attached_file_ids.reserve(attached_files.size());
  for (auto &attached_file : attached_files) {
    auto file_type = td_->file_manager_->guess_file_type(attached_file);
    if (file_type != FileType::Animation && file_type != FileType::Audio && file_type != FileType::Document &&
        file_type != FileType::Photo && file_type != FileType::Sticker && file_type != FileType::Video &&
        file_type != FileType::VoiceNote) {
      LOG(INFO) << "Skip attached file of type " << file_type;
      continue;
    }
    TRY_RESULT_PROMISE(promise, attached_file_id,
                       td_->file_manager_->get_input_file_id(file_type, attached_file, dialog_id, false, false));
    attached_file_ids.push_back(attached_file_id);
  }

  upload_imported_messages(dialog_id, td_->file_manager_->dup_file_id(file_id, "import_messages"),
                           std::move(attached_file_ids), false, std::move(promise));
}

void MessageImportManager::upload_imported_messages(DialogId dialog_id, FileId file_id,
                                                    vector<FileId> attached_file_ids, bool is_reupload,
                                                    Promise<Unit> &&promise, vector<int> bad_parts) {
  CHECK(file_id.is_valid());
  LOG(INFO) << "Ask to upload imported messages file " << file_id;
  auto info = td::make_unique<UploadedImportedMessagesInfo>(dialog_id, std::move(attached_file_ids), is_reupload,
                                                            std::move(promise));
  bool is_inserted = being_uploaded_imported_messages_.emplace(file_id, std::move(info)).second;
  CHECK(is_inserted);
  // TODO use force_reupload if is_reupload
  td_->file_manager_->resume_upload(file_id, std::move(bad_parts), upload_imported_messages_callback_, 1, 0, false,
                                    true);
}

void MessageImportManager::on_upload_imported_messages(FileId file_id,
                                                       tl_object_ptr<telegram_api::InputFile> input_file) {
  LOG(INFO) << "File " << file_id << " has been uploaded";

  auto it = being_uploaded_imported_messages_.find(file_id);
  if (it == being_uploaded_imported_messages_.end()) {
    // just in case, as in on_upload_media
    return;
  }

  CHECK(it->second != nullptr);
  DialogId dialog_id = it->second->dialog_id;
  vector<FileId> attached_file_ids = std::move(it->second->attached_file_ids);
  bool is_reupload = it->second->is_reupload;
  Promise<Unit> promise = std::move(it->second->promise);

  being_uploaded_imported_messages_.erase(it);

  if (!td_->dialog_manager_->have_input_peer(dialog_id, AccessRights::Write)) {
    return promise.set_error(Status::Error(400, "Have no write access to the chat"));
  }

  FileView file_view = td_->file_manager_->get_file_view(file_id);
  CHECK(!file_view.is_encrypted());
  if (input_file == nullptr && file_view.has_remote_location()) {
    if (file_view.main_remote_location().is_web()) {
      return promise.set_error(Status::Error(400, "Can't use web file"));
    }
    if (is_reupload) {
      return promise.set_error(Status::Error(400, "Failed to reupload the file"));
    }

    CHECK(file_view.get_type() == FileType::Document);
    // delete file reference and forcely reupload the file
    auto file_reference = FileManager::extract_file_reference(file_view.main_remote_location().as_input_document());
    td_->file_manager_->delete_file_reference(file_id, file_reference);
    upload_imported_messages(dialog_id, file_id, std::move(attached_file_ids), true, std::move(promise), {-1});
    return;
  }
  CHECK(input_file != nullptr);

  td_->create_handler<InitHistoryImportQuery>(std::move(promise))
      ->send(dialog_id, file_id, std::move(input_file), std::move(attached_file_ids));
}

void MessageImportManager::on_upload_imported_messages_error(FileId file_id, Status status) {
  if (G()->close_flag()) {
    // do not fail upload if closing
    return;
  }

  LOG(INFO) << "File " << file_id << " has upload error " << status;
  CHECK(status.is_error());

  auto it = being_uploaded_imported_messages_.find(file_id);
  if (it == being_uploaded_imported_messages_.end()) {
    // just in case, as in on_upload_media_error
    return;
  }

  Promise<Unit> promise = std::move(it->second->promise);

  being_uploaded_imported_messages_.erase(it);

  promise.set_error(std::move(status));
}

void MessageImportManager::start_import_messages(DialogId dialog_id, int64 import_id,
                                                 vector<FileId> &&attached_file_ids, Promise<Unit> &&promise) {
  TRY_STATUS_PROMISE(promise, G()->close_status());
  if (!td_->dialog_manager_->have_input_peer(dialog_id, AccessRights::Write)) {
    return promise.set_error(Status::Error(400, "Have no write access to the chat"));
  }

  auto pending_message_import = make_unique<PendingMessageImport>();
  pending_message_import->dialog_id = dialog_id;
  pending_message_import->import_id = import_id;
  pending_message_import->promise = std::move(promise);

  auto &multipromise = pending_message_import->upload_files_multipromise;

  int64 random_id;
  do {
    random_id = Random::secure_int64();
  } while (random_id == 0 || pending_message_imports_.count(random_id) > 0);
  pending_message_imports_[random_id] = std::move(pending_message_import);

  multipromise.add_promise(PromiseCreator::lambda([actor_id = actor_id(this), random_id](Result<Unit> result) {
    send_closure_later(actor_id, &MessageImportManager::on_imported_message_attachments_uploaded, random_id,
                       std::move(result));
  }));
  auto lock_promise = multipromise.get_promise();

  for (auto attached_file_id : attached_file_ids) {
    upload_imported_message_attachment(dialog_id, import_id,
                                       td_->file_manager_->dup_file_id(attached_file_id, "start_import_messages"),
                                       false, multipromise.get_promise());
  }

  lock_promise.set_value(Unit());
}

void MessageImportManager::upload_imported_message_attachment(DialogId dialog_id, int64 import_id, FileId file_id,
                                                              bool is_reupload, Promise<Unit> &&promise,
                                                              vector<int> bad_parts) {
  CHECK(file_id.is_valid());
  LOG(INFO) << "Ask to upload imported message attached file " << file_id;
  auto info =
      td::make_unique<UploadedImportedMessageAttachmentInfo>(dialog_id, import_id, is_reupload, std::move(promise));
  bool is_inserted = being_uploaded_imported_message_attachments_.emplace(file_id, std::move(info)).second;
  CHECK(is_inserted);
  // TODO use force_reupload if is_reupload
  td_->file_manager_->resume_upload(file_id, std::move(bad_parts), upload_imported_message_attachment_callback_, 1, 0,
                                    false, true);
}

void MessageImportManager::on_upload_imported_message_attachment(FileId file_id,
                                                                 tl_object_ptr<telegram_api::InputFile> input_file) {
  LOG(INFO) << "File " << file_id << " has been uploaded";

  auto it = being_uploaded_imported_message_attachments_.find(file_id);
  if (it == being_uploaded_imported_message_attachments_.end()) {
    // just in case, as in on_upload_media
    return;
  }

  CHECK(it->second != nullptr);
  DialogId dialog_id = it->second->dialog_id;
  int64 import_id = it->second->import_id;
  bool is_reupload = it->second->is_reupload;
  Promise<Unit> promise = std::move(it->second->promise);

  being_uploaded_imported_message_attachments_.erase(it);

  FileView file_view = td_->file_manager_->get_file_view(file_id);
  CHECK(!file_view.is_encrypted());
  if (input_file == nullptr && file_view.has_remote_location()) {
    if (file_view.main_remote_location().is_web()) {
      return promise.set_error(Status::Error(400, "Can't use web file"));
    }
    if (is_reupload) {
      return promise.set_error(Status::Error(400, "Failed to reupload the file"));
    }

    // delete file reference and forcely reupload the file
    auto file_reference =
        file_view.get_type() == FileType::Photo
            ? FileManager::extract_file_reference(file_view.main_remote_location().as_input_photo())
            : FileManager::extract_file_reference(file_view.main_remote_location().as_input_document());
    td_->file_manager_->delete_file_reference(file_id, file_reference);
    upload_imported_message_attachment(dialog_id, import_id, file_id, true, std::move(promise), {-1});
    return;
  }
  CHECK(input_file != nullptr);

  auto suggested_path = file_view.suggested_path();
  const PathView path_view(suggested_path);
  td_->create_handler<UploadImportedMediaQuery>(std::move(promise))
      ->send(dialog_id, import_id, path_view.file_name().str(), file_id,
             get_fake_input_media(td_, std::move(input_file), file_id));
}

void MessageImportManager::on_upload_imported_message_attachment_error(FileId file_id, Status status) {
  if (G()->close_flag()) {
    // do not fail upload if closing
    return;
  }

  LOG(INFO) << "File " << file_id << " has upload error " << status;
  CHECK(status.is_error());

  auto it = being_uploaded_imported_message_attachments_.find(file_id);
  if (it == being_uploaded_imported_message_attachments_.end()) {
    // just in case, as in on_upload_media_error
    return;
  }

  Promise<Unit> promise = std::move(it->second->promise);

  being_uploaded_imported_message_attachments_.erase(it);

  promise.set_error(std::move(status));
}

void MessageImportManager::on_imported_message_attachments_uploaded(int64 random_id, Result<Unit> &&result) {
  G()->ignore_result_if_closing(result);

  auto it = pending_message_imports_.find(random_id);
  CHECK(it != pending_message_imports_.end());

  auto pending_message_import = std::move(it->second);
  CHECK(pending_message_import != nullptr);

  pending_message_imports_.erase(it);

  if (result.is_error()) {
    pending_message_import->promise.set_error(result.move_as_error());
    return;
  }

  CHECK(pending_message_import->upload_files_multipromise.promise_count() == 0);

  auto promise = std::move(pending_message_import->promise);
  auto dialog_id = pending_message_import->dialog_id;

  if (!td_->dialog_manager_->have_input_peer(dialog_id, AccessRights::Write)) {
    return promise.set_error(Status::Error(400, "Have no write access to the chat"));
  }

  td_->create_handler<StartImportHistoryQuery>(std::move(promise))->send(dialog_id, pending_message_import->import_id);
}

void MessageImportManager::memory_stats(vector<string> &output) {
  output.emplace_back("\"being_uploaded_imported_messages_\":"); output.emplace_back(std::to_string(this->being_uploaded_imported_messages_.size()));
  output.emplace_back(",");
  output.emplace_back("\"being_uploaded_imported_message_attachments_\":"); output.emplace_back(std::to_string(this->being_uploaded_imported_message_attachments_.size()));
  output.emplace_back(",");
  output.emplace_back("\"pending_message_imports_\":"); output.emplace_back(std::to_string(this->pending_message_imports_.size()));
}

}  // namespace td