#pragma once

#include "config.h"
#include "posts.h"
#include "state.h"
#include "td/tl/TlObject.h"
#include "tg.h"
#include "vk.h"
#include <functional>
#include <queue>
#include <vector>

namespace manager {
  namespace td_api = td::td_api;

  using posts::AbstractPost;

  class RepostManager;

  struct NewPostFetcher {
    struct fetcher_state {
      int sourceIndex;
      bool ready = false;
      bool needRequest = true;
      long offset = 0, count = 3;
      std::vector<AbstractPost> posts;
    };

    bool working = false;
    RepostManager *mgr;
    std::vector<fetcher_state> vkState, tgState;
    std::function<void(std::vector<AbstractPost>&&)> onDone;
    std::function<void()> onError;

    inline NewPostFetcher(RepostManager *m) : mgr(m) {};
    void fetch(bool fetchVk, bool fetchTg, decltype(onDone) onDone, decltype(onError) onError);
  private:
    void reset_state();
    void continue_fetch();
    void check_vk_posts(int index, std::vector<vk::Post> posts);
    void check_tg_posts(int index, std::vector<td::tl::unique_ptr<td_api::message>> posts);
  };

  class RepostManager {
    friend struct NewPostFetcher;
  public:
    RepostManager(uv_loop_t *eventLoop, tg::AuthCodeProvider tgCodeProvider, tg::PasswordProvider tgPasswordProvider, state::AppState *appState, config::AppConfig *config);
    RepostManager(RepostManager&) = delete;
    ~RepostManager();
    void start();
  private:
    void on_clients_ready();
    void load_more_telegram_chats();
    void on_new_posts(std::vector<AbstractPost> posts);
    void on_tg_message(td_api::updateNewMessage &update);
    bool recheck_vk_posts(std::function<void()> onDone);

    void collect_all_vk_posts(const std::variant<long, std::string> wall, std::function<void(std::vector<vk::Post>)> callback);
    void collect_all_tg_posts(long channel, std::function<void(std::vector<td::tl::unique_ptr<td_api::message>>)> callback);
    void collect_last_vk_posts(const std::variant<long, std::string> wall, int count, std::function<void(std::vector<vk::Post>)> callback);
    void collect_last_tg_posts(long channel, int count, std::function<void(std::vector<td::tl::unique_ptr<td_api::message>>)> callback);
    void collect_vk_posts_from(const std::variant<long, std::string> wall, int offset, int count, std::function<void(std::vector<vk::Post>)> callback);
    void collect_tg_posts_from(long channel, long from, int count, std::function<void(std::vector<td::tl::unique_ptr<td_api::message>>)> callback);

    void collect_vk_posts_from__intermediate(const std::variant<long, std::string> wall, int offset, int count, std::shared_ptr<std::vector<vk::Post>> intermediateResult, std::function<void(std::vector<vk::Post>)> callback);
    void collect_tg_posts_from__intermediate(long channel, long from, int count, std::shared_ptr<std::vector<td::tl::unique_ptr<td_api::message>>> intermediateResult, std::function<void(std::vector<td::tl::unique_ptr<td_api::message>>)> callback);

    bool drop_posts_older_than(std::vector<AbstractPost> &posts, long lastPostId);
    
    std::optional<AbstractPost> to_abstract_post(const vk::Post &post, int sourceIndex);
    std::optional<AbstractPost> to_abstract_post(const td_api::message &post, int sourceIndex);
    std::vector<AbstractPost> to_abstract_posts(std::vector<vk::Post> &posts, int sourceIndex);
    std::vector<AbstractPost> to_abstract_posts(std::vector<td::tl::unique_ptr<td_api::message>> &posts, int sourceIndex);

    void enqueue_for_repost(std::vector<AbstractPost> posts);
    static void repost_timer_callback(uv_timer_t *h);
    static void check_timer_callback(uv_timer_t *h);
    void repost(AbstractPost &post);

    state::AppState *m_appState;
    config::AppConfig *m_appConfig;
    vk::VKClient m_vk;
    tg::TelegramClient m_tg;
    NewPostFetcher m_fetcher;
    std::queue<AbstractPost> m_repostQueue;
    std::queue<AbstractPost> m_unprocessedTgPosts;
    uv_timer_t *m_repostTimer = nullptr;
    bool m_checkTimerStarted = false;
    uv_timer_t *m_checkTimer = nullptr;
    int m_nRequiredChats;
    int m_nLoadedRequiredChats = 0;
  };
}