//
// 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)
//
#pragma once

#include "td/telegram/files/FileId.h"
#include "td/telegram/files/FileSourceId.h"
#include "td/telegram/td_api.h"

#include "td/actor/actor.h"
#include "td/actor/PromiseFuture.h"

#include "td/utils/common.h"
#include "td/utils/Status.h"

namespace td {

class DownloadManager : public Actor {
 public:
  // creates, but do not starts the actor
  static unique_ptr<DownloadManager> create();

  struct Counters {
    int64 total_size{};
    int32 total_count{};
    int64 downloaded_size{};

    bool operator==(const Counters &other) const {
      return total_size == other.total_size && total_count == other.total_count &&
             downloaded_size == other.downloaded_size;
    }

    td_api::object_ptr<td_api::updateFileDownloads> get_update_file_downloads_object() const;

    template <class StorerT>
    void store(StorerT &storer) const;

    template <class ParserT>
    void parse(ParserT &parser);
  };

  // trying to make DownloadManager testable, so all interactions with G() will be hidden is this probably monstrous interface
  class Callback {
   public:
    virtual ~Callback() = default;
    virtual void update_counters(Counters counters) = 0;
    virtual void start_file(FileId file_id, int8 priority) = 0;
    virtual void pause_file(FileId file_id) = 0;
    virtual void delete_file(FileId file_id) = 0;
    virtual FileId dup_file_id(FileId file_id) = 0;

    virtual string get_unique_file_id(FileId file_id) = 0;
    virtual td_api::object_ptr<td_api::fileDownload> get_file_download_object(FileId file_id,
                                                                              FileSourceId file_source_id,
                                                                              int32 add_date, int32 complete_date,
                                                                              bool is_paused) = 0;
  };

  //
  // public interface for user
  //

  // sets callback to handle all updates
  virtual void set_callback(unique_ptr<Callback> callback) = 0;

  // files are always added in is_paused = false state
  virtual Status add_file(FileId file_id, FileSourceId file_source_id, string search_by, int8 priority) = 0;
  virtual Status change_search_text(FileId file_id, FileSourceId file_source_id, string search_by) = 0;
  virtual Status toggle_is_paused(FileId file_id, bool is_paused) = 0;
  virtual Status toggle_all_is_paused(bool is_paused) = 0;
  virtual void search(string query, bool only_active, bool only_completed, string offset, int32 limit,
                      Promise<td_api::object_ptr<td_api::foundFileDownloads>> promise) = 0;
  virtual Status remove_file(FileId file_id, FileSourceId file_source_id, bool delete_from_cache) = 0;
  virtual Status remove_all_files(bool only_active, bool only_completed, bool delete_from_cache) = 0;

  //
  // private interface to handle all kinds of updates
  //
  virtual void update_file_download_state(FileId internal_file_id, int64 download_size, int64 size, bool is_paused) = 0;
  virtual void update_file_deleted(FileId internal_file_id) = 0;
};

}  // namespace td