// Copyright 2010 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#pragma once

#include <SFML/Network/Packet.hpp>
#include <array>
#include <chrono>
#include <map>
#include <memory>
#include <mutex>
#include <span>
#include <string>
#include <thread>
#include <unordered_map>
#include <utility>
#include <vector>

#include "Common/CommonTypes.h"
#include "Common/Event.h"
#include "Common/SPSCQueue.h"
#include "Common/TraversalClient.h"
#include "Core/NetPlayProto.h"
#include "Core/SyncIdentifier.h"
#include "InputCommon/GCPadStatus.h"

class BootSessionData;

namespace IOS::HLE::FS
{
class FileSystem;
}

namespace UICommon
{
class GameFile;
}

namespace WiimoteEmu
{
struct SerializedWiimoteState;
}

namespace NetPlay
{
class NetPlayUI
{
public:
  virtual ~NetPlayUI() {}
  virtual void BootGame(const std::string& filename,
                        std::unique_ptr<BootSessionData> boot_session_data) = 0;
  virtual void StopGame() = 0;
  virtual bool IsHosting() const = 0;

  virtual void Update() = 0;
  virtual void AppendChat(const std::string& msg) = 0;

  virtual void OnMsgChangeGame(const SyncIdentifier& sync_identifier,
                               const std::string& netplay_name) = 0;
  virtual void OnMsgChangeGBARom(int pad, const NetPlay::GBAConfig& config) = 0;
  virtual void OnMsgStartGame() = 0;
  virtual void OnMsgStopGame() = 0;
  virtual void OnMsgPowerButton() = 0;
  virtual void OnPlayerConnect(const std::string& player) = 0;
  virtual void OnPlayerDisconnect(const std::string& player) = 0;
  virtual void OnPadBufferChanged(u32 buffer) = 0;
  virtual void OnHostInputAuthorityChanged(bool enabled) = 0;
  virtual void OnDesync(u32 frame, const std::string& player) = 0;
  virtual void OnConnectionLost() = 0;
  virtual void OnConnectionError(const std::string& message) = 0;
  virtual void OnTraversalError(Common::TraversalClient::FailureReason error) = 0;
  virtual void OnTraversalStateChanged(Common::TraversalClient::State state) = 0;
  virtual void OnGameStartAborted() = 0;
  virtual void OnGolferChanged(bool is_golfer, const std::string& golfer_name) = 0;
  virtual void OnTtlDetermined(u8 ttl) = 0;

  virtual bool IsRecording() = 0;
  virtual std::shared_ptr<const UICommon::GameFile>
  FindGameFile(const SyncIdentifier& sync_identifier,
               SyncIdentifierComparison* found = nullptr) = 0;
  virtual std::string FindGBARomPath(const std::array<u8, 20>& hash, std::string_view title,
                                     int device_number) = 0;
  virtual void ShowGameDigestDialog(const std::string& title) = 0;
  virtual void SetGameDigestProgress(int pid, int progress) = 0;
  virtual void SetGameDigestResult(int pid, const std::string& result) = 0;
  virtual void AbortGameDigest() = 0;

  virtual void OnIndexAdded(bool success, std::string error) = 0;
  virtual void OnIndexRefreshFailed(std::string error) = 0;

  virtual void ShowChunkedProgressDialog(const std::string& title, u64 data_size,
                                         const std::vector<int>& players) = 0;
  virtual void HideChunkedProgressDialog() = 0;
  virtual void SetChunkedProgress(int pid, u64 progress) = 0;

  virtual void SetHostWiiSyncData(std::vector<u64> titles, std::string redirect_folder) = 0;
};

class Player
{
public:
  PlayerId pid{};
  std::string name;
  std::string revision;
  u32 ping = 0;
  SyncIdentifierComparison game_status = SyncIdentifierComparison::Unknown;

  bool IsHost() const { return pid == 1; }
};

class NetPlayClient : public Common::TraversalClientClient
{
public:
  void ThreadFunc();
  void SendAsync(sf::Packet&& packet, u8 channel_id = DEFAULT_CHANNEL);

  NetPlayClient(const std::string& address, const u16 port, NetPlayUI* dialog,
                const std::string& name, const NetTraversalConfig& traversal_config);
  ~NetPlayClient();

  std::vector<const Player*> GetPlayers();
  const NetSettings& GetNetSettings() const;

  // Called from the GUI thread.
  bool IsConnected() const { return m_is_connected; }
  bool StartGame(const std::string& path);
  void InvokeStop();
  bool StopGame();
  void Stop();
  bool ChangeGame(const std::string& game);
  void SendChatMessage(const std::string& msg);
  void RequestStopGame();
  void SendPowerButtonEvent();
  void RequestGolfControl(PlayerId pid);
  void RequestGolfControl();
  std::string GetCurrentGolfer();

  // Send and receive pads values
  struct WiimoteDataBatchEntry
  {
    int wiimote;
    WiimoteEmu::SerializedWiimoteState* state;
  };
  bool WiimoteUpdate(const std::span<WiimoteDataBatchEntry>& entries);
  bool GetNetPads(int pad_nb, bool from_vi, GCPadStatus* pad_status);

  u64 GetInitialRTCValue() const;

  void OnTraversalStateChanged() override;
  void OnConnectReady(ENetAddress addr) override;
  void OnConnectFailed(Common::TraversalConnectFailedReason reason) override;
  void OnTtlDetermined(u8 ttl) override {}

  bool IsFirstInGamePad(int ingame_pad) const;
  int NumLocalPads() const;
  int NumLocalWiimotes() const;

  int InGamePadToLocalPad(int ingame_pad) const;
  int LocalPadToInGamePad(int local_pad) const;
  int InGameWiimoteToLocalWiimote(int ingame_wiimote) const;
  int LocalWiimoteToInGameWiimote(int local_wiimote) const;

  bool PlayerHasControllerMapped(PlayerId pid) const;
  bool LocalPlayerHasControllerMapped() const;
  bool IsLocalPlayer(PlayerId pid) const;
  const PlayerId& GetLocalPlayerId() const;

  static void SendTimeBase();
  bool DoAllPlayersHaveGame();

  const PadMappingArray& GetPadMapping() const;
  const GBAConfigArray& GetGBAConfig() const;
  const PadMappingArray& GetWiimoteMapping() const;

  void AdjustPadBufferSize(unsigned int size);

  void SetWiiSyncData(std::unique_ptr<IOS::HLE::FS::FileSystem> fs, std::vector<u64> titles,
                      std::string redirect_folder);

  static SyncIdentifier GetSDCardIdentifier();

protected:
  struct AsyncQueueEntry
  {
    sf::Packet packet;
    u8 channel_id = 0;
  };

  void ClearBuffers();

  struct
  {
    std::recursive_mutex game;
    // lock order
    std::recursive_mutex players;
    std::recursive_mutex async_queue_write;
  } m_crit;

  Common::SPSCQueue<AsyncQueueEntry, false> m_async_queue;

  std::array<Common::SPSCQueue<GCPadStatus>, 4> m_pad_buffer;
  std::array<Common::SPSCQueue<WiimoteEmu::SerializedWiimoteState>, 4> m_wiimote_buffer;

  std::array<GCPadStatus, 4> m_last_pad_status{};
  std::array<bool, 4> m_first_pad_status_received{};

  std::chrono::time_point<std::chrono::steady_clock> m_buffer_under_target_last;

  NetPlayUI* m_dialog = nullptr;

  ENetHost* m_client = nullptr;
  ENetPeer* m_server = nullptr;
  std::thread m_thread;

  SyncIdentifier m_selected_game;
  Common::Flag m_is_running{false};
  Common::Flag m_do_loop{true};

  // In non-host input authority mode, this is how many packets each client should
  // try to keep in-flight to the other clients. In host input authority mode, this is how
  // many incoming input packets need to be queued up before the client starts
  // speeding up the game to drain the buffer.
  unsigned int m_target_buffer_size = 20;
  bool m_host_input_authority = false;
  PlayerId m_current_golfer = 1;

  // This bool will stall the client at the start of GetNetPads, used for switching input control
  // without deadlocking. Use the correspondingly named Event to wake it up.
  bool m_wait_on_input;
  bool m_wait_on_input_received;

  Player* m_local_player = nullptr;

  u32 m_current_game = 0;

  PadMappingArray m_pad_map{};
  GBAConfigArray m_gba_config{};
  PadMappingArray m_wiimote_map{};

  bool m_is_recording = false;

private:
  enum class ConnectionState
  {
    WaitingForTraversalClientConnection,
    WaitingForTraversalClientConnectReady,
    Connecting,
    WaitingForHelloResponse,
    Connected,
    Failure
  };

  void SendStartGamePacket();
  void SendStopGamePacket();

  void SyncSaveDataResponse(bool success);
  void SyncCodeResponse(bool success);

  bool PollLocalPad(int local_pad, sf::Packet& packet);
  void SendPadHostPoll(PadIndex pad_num);

  bool AddLocalWiimoteToBuffer(int local_wiimote, const WiimoteEmu::SerializedWiimoteState& state,
                               sf::Packet& packet);

  void UpdateDevices();
  void AddPadStateToPacket(int in_game_pad, const GCPadStatus& np, sf::Packet& packet);
  void AddWiimoteStateToPacket(int in_game_pad, const WiimoteEmu::SerializedWiimoteState& np,
                               sf::Packet& packet);
  void Send(const sf::Packet& packet, u8 channel_id = DEFAULT_CHANNEL);
  void Disconnect();
  bool Connect();
  void SendGameStatus();
  void ComputeGameDigest(const SyncIdentifier& sync_identifier);
  void DisplayPlayersPing();
  u32 GetPlayersMaxPing() const;

  void OnData(sf::Packet& packet);
  void OnPlayerJoin(sf::Packet& packet);
  void OnPlayerLeave(sf::Packet& packet);
  void OnChatMessage(sf::Packet& packet);
  void OnChunkedDataStart(sf::Packet& packet);
  void OnChunkedDataEnd(sf::Packet& packet);
  void OnChunkedDataPayload(sf::Packet& packet);
  void OnChunkedDataAbort(sf::Packet& packet);
  void OnPadMapping(sf::Packet& packet);
  void OnWiimoteMapping(sf::Packet& packet);
  void OnGBAConfig(sf::Packet& packet);
  void OnPadData(sf::Packet& packet);
  void OnPadHostData(sf::Packet& packet);
  void OnWiimoteData(sf::Packet& packet);
  void OnPadBuffer(sf::Packet& packet);
  void OnHostInputAuthority(sf::Packet& packet);
  void OnGolfSwitch(sf::Packet& packet);
  void OnGolfPrepare(sf::Packet& packet);
  void OnChangeGame(sf::Packet& packet);
  void OnGameStatus(sf::Packet& packet);
  void OnStartGame(sf::Packet& packet);
  void OnStopGame(sf::Packet& packet);
  void OnPowerButton();
  void OnPing(sf::Packet& packet);
  void OnPlayerPingData(sf::Packet& packet);
  void OnDesyncDetected(sf::Packet& packet);
  void OnSyncSaveData(sf::Packet& packet);
  void OnSyncSaveDataNotify(sf::Packet& packet);
  void OnSyncSaveDataRaw(sf::Packet& packet);
  void OnSyncSaveDataGCI(sf::Packet& packet);
  void OnSyncSaveDataWii(sf::Packet& packet);
  void OnSyncSaveDataGBA(sf::Packet& packet);
  void OnSyncCodes(sf::Packet& packet);
  void OnSyncCodesNotify();
  void OnSyncCodesNotifyGecko(sf::Packet& packet);
  void OnSyncCodesDataGecko(sf::Packet& packet);
  void OnSyncCodesNotifyAR(sf::Packet& packet);
  void OnSyncCodesDataAR(sf::Packet& packet);
  void OnComputeGameDigest(sf::Packet& packet);
  void OnGameDigestProgress(sf::Packet& packet);
  void OnGameDigestResult(sf::Packet& packet);
  void OnGameDigestError(sf::Packet& packet);
  void OnGameDigestAbort();

  bool m_is_connected = false;
  ConnectionState m_connection_state = ConnectionState::Failure;

  PlayerId m_pid = 0;
  NetSettings m_net_settings{};
  std::map<PlayerId, Player> m_players;
  std::string m_host_spec;
  std::string m_player_name;
  bool m_connecting = false;
  Common::TraversalClient* m_traversal_client = nullptr;
  std::thread m_game_digest_thread;
  bool m_should_compute_game_digest = false;
  Common::Event m_gc_pad_event;
  Common::Event m_wii_pad_event;
  Common::Event m_first_pad_status_received_event;
  Common::Event m_wait_on_input_event;
  u8 m_sync_save_data_count = 0;
  u8 m_sync_save_data_success_count = 0;
  u16 m_sync_gecko_codes_count = 0;
  u16 m_sync_gecko_codes_success_count = 0;
  bool m_sync_gecko_codes_complete = false;
  u16 m_sync_ar_codes_count = 0;
  u16 m_sync_ar_codes_success_count = 0;
  bool m_sync_ar_codes_complete = false;
  std::unordered_map<u32, sf::Packet> m_chunked_data_receive_queue;

  u64 m_initial_rtc = 0;
  u32 m_timebase_frame = 0;

  std::unique_ptr<IOS::HLE::FS::FileSystem> m_wii_sync_fs;
  std::vector<u64> m_wii_sync_titles;
  std::string m_wii_sync_redirect_folder;
};

void NetPlay_Enable(NetPlayClient* const np);
void NetPlay_Disable();
bool NetPlay_GetWiimoteData(const std::span<NetPlayClient::WiimoteDataBatchEntry>& entries);
unsigned int NetPlay_GetLocalWiimoteForSlot(unsigned int slot);
}  // namespace NetPlay