//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
// $NoKeywords: $
//=============================================================================//

#ifndef IGAMESYSTEM_H
#define IGAMESYSTEM_H
#ifdef _WIN32
#pragma once
#endif

//-----------------------------------------------------------------------------
// Game systems are singleton objects in the client + server codebase
// responsible for various tasks The order in which the server systems appear in
// this list are the order in which they are initialized and updated. They are
// shut down in reverse order from which they are initialized.
//-----------------------------------------------------------------------------

// UNDONE: Do these need GameInit/GameShutdown as well?
// UNDONE: Remove the Pre/Post entity semantics and rely on system ordering?
// FIXME: Remove all ifdef CLIENT_DLL if we can...
abstract_class IGameSystem {
   public:
    // GameSystems are expected to implement these methods.
    virtual char const *Name() = 0;

    // Init, shutdown
    // return true on success. false to abort DLL init!
    virtual bool Init() = 0;
    virtual void PostInit() = 0;
    virtual void Shutdown() = 0;

    // Level init, shutdown
    virtual void LevelInitPreEntity() = 0;
    // entities are created / spawned / precached here
    virtual void LevelInitPostEntity() = 0;

    virtual void LevelShutdownPreClearSteamAPIContext(){};
    virtual void LevelShutdownPreEntity() = 0;
    // Entities are deleted / released here...
    virtual void LevelShutdownPostEntity() = 0;
    // end of level shutdown

    // Called during game save
    virtual void OnSave() = 0;

    // Called during game restore, after the local player has connected and
    // entities have been fully restored
    virtual void OnRestore() = 0;

    // Called every frame. It's safe to remove an igamesystem from within this
    // callback.
    virtual void SafeRemoveIfDesired() = 0;

    virtual bool IsPerFrame() = 0;

    // destructor, cleans up automagically....
    virtual ~IGameSystem();

    // Client systems can use this to get at the map name
    static char const *MapName();

    // These methods are used to add and remove server systems from the
    // main server loop. The systems are invoked in the order in which
    // they are added.
    static void Add(IGameSystem * pSys);
    static void Remove(IGameSystem * pSys);
    static void RemoveAll();

    // These methods are used to initialize, shutdown, etc all systems
    static bool InitAllSystems();
    static void PostInitAllSystems();
    static void ShutdownAllSystems();
    static void LevelInitPreEntityAllSystems(char const *pMapName);
    static void LevelInitPostEntityAllSystems();
    static void
    LevelShutdownPreClearSteamAPIContextAllSystems();  // Called prior to
                                                       // steamgameserverapicontext->Clear()
    static void LevelShutdownPreEntityAllSystems();
    static void LevelShutdownPostEntityAllSystems();

    static void OnSaveAllSystems();
    static void OnRestoreAllSystems();

    static void SafeRemoveIfDesiredAllSystems();

#ifdef CLIENT_DLL
    static void PreRenderAllSystems();
    static void UpdateAllSystems(float frametime);
    static void PostRenderAllSystems();
#else
    static void FrameUpdatePreEntityThinkAllSystems();
    static void FrameUpdatePostEntityThinkAllSystems();
    static void PreClientUpdateAllSystems();

    // Accessors for the above function
    static CBasePlayer *RunCommandPlayer();
    static CUserCmd *RunCommandUserCmd();
#endif
};

class IGameSystemPerFrame : public IGameSystem {
   public:
    // destructor, cleans up automagically....
    virtual ~IGameSystemPerFrame();

#ifdef CLIENT_DLL
    // Called before rendering
    virtual void PreRender() = 0;

    // Gets called each frame
    virtual void Update(float frametime) = 0;

    // Called after rendering
    virtual void PostRender() = 0;
#else
    // Called each frame before entities think
    virtual void FrameUpdatePreEntityThink() = 0;
    // called after entities think
    virtual void FrameUpdatePostEntityThink() = 0;
    virtual void PreClientUpdate() = 0;
#endif
};

// Quick and dirty server system for users who don't care about precise ordering
// and usually only want to implement a few of the callbacks
class CBaseGameSystem : public IGameSystem {
   public:
    virtual char const *Name() { return "unnamed"; }

    // Init, shutdown
    // return true on success. false to abort DLL init!
    virtual bool Init() { return true; }
    virtual void PostInit() {}
    virtual void Shutdown() {}

    // Level init, shutdown
    virtual void LevelInitPreEntity() {}
    virtual void LevelInitPostEntity() {}
    virtual void LevelShutdownPreClearSteamAPIContext() {}
    virtual void LevelShutdownPreEntity() {}
    virtual void LevelShutdownPostEntity() {}

    virtual void OnSave() {}
    virtual void OnRestore() {}
    virtual void SafeRemoveIfDesired() {}

    virtual bool IsPerFrame() { return false; }

   private:
    // Prevent anyone derived from CBaseGameSystem from implementing these, they
    // need
    //  to derive from CBaseGameSystemPerFrame below!!!
#ifdef CLIENT_DLL
    // Called before rendering
    virtual void PreRender() {}

    // Gets called each frame
    virtual void Update(float frametime) {}

    // Called after rendering
    virtual void PostRender() {}
#else
    // Called each frame before entities think
    virtual void FrameUpdatePreEntityThink() {}
    // called after entities think
    virtual void FrameUpdatePostEntityThink() {}
    virtual void PreClientUpdate() {}
#endif
};

// Quick and dirty server system for users who don't care about precise ordering
// and usually only want to implement a few of the callbacks
class CBaseGameSystemPerFrame : public IGameSystemPerFrame {
   public:
    virtual char const *Name() { return "unnamed"; }

    // Init, shutdown
    // return true on success. false to abort DLL init!
    virtual bool Init() { return true; }
    virtual void PostInit() {}
    virtual void Shutdown() {}

    // Level init, shutdown
    virtual void LevelInitPreEntity() {}
    virtual void LevelInitPostEntity() {}
    virtual void LevelShutdownPreClearSteamAPIContext() {}
    virtual void LevelShutdownPreEntity() {}
    virtual void LevelShutdownPostEntity() {}

    virtual void OnSave() {}
    virtual void OnRestore() {}
    virtual void SafeRemoveIfDesired() {}

    virtual bool IsPerFrame() { return true; }

#ifdef CLIENT_DLL
    // Called before rendering
    virtual void PreRender() {}

    // Gets called each frame
    virtual void Update(float frametime) {}

    // Called after rendering
    virtual void PostRender() {}
#else
    // Called each frame before entities think
    virtual void FrameUpdatePreEntityThink() {}
    // called after entities think
    virtual void FrameUpdatePostEntityThink() {}
    virtual void PreClientUpdate() {}
#endif
};

// Quick and dirty server system for users who don't care about precise ordering
// and usually only want to implement a few of the callbacks
class CAutoGameSystem : public CBaseGameSystem {
   public:
    CAutoGameSystem(char const *name = NULL);  // hooks in at startup, no need
                                               // to explicitly add
    CAutoGameSystem *m_pNext;

    virtual char const *Name() { return m_pszName ? m_pszName : "unnamed"; }

   private:
    char const *m_pszName;
};

//-----------------------------------------------------------------------------
// Purpose: This is a CAutoGameSystem which also cares about the "per frame"
// hooks
//-----------------------------------------------------------------------------
class CAutoGameSystemPerFrame : public CBaseGameSystemPerFrame {
   public:
    CAutoGameSystemPerFrame(char const *name = NULL);
    CAutoGameSystemPerFrame *m_pNext;

    virtual char const *Name() { return m_pszName ? m_pszName : "unnamed"; }

   private:
    char const *m_pszName;
};

//-----------------------------------------------------------------------------
// Purpose: This interface is here to add more hooks than IGameSystemPerFrame
// exposes, so we don't pollute it with hooks that only the tool cares about
//-----------------------------------------------------------------------------
class IToolFrameworkServer {
   public:
    virtual void PreSetupVisibility() = 0;
};

#endif  // IGAMESYSTEM_H