//====== Copyright Valve Corporation, All rights reserved. ====================
//
// Internal implementation details of the steamworks SDK.
//
// You should be able to figure out how to use the SDK by reading
// steam_api_common.h, and should not need to understand anything in here.
// 
//-----------------------------------------------------------------------------

#ifdef STEAM_CALLBACK_BEGIN
#error "This file should only be included from steam_api_common.h"
#endif

#include <string.h>

// Internal functions used to locate/create interfaces
S_API HSteamPipe S_CALLTYPE SteamAPI_GetHSteamPipe();
S_API HSteamUser S_CALLTYPE SteamAPI_GetHSteamUser();
S_API HSteamPipe S_CALLTYPE SteamGameServer_GetHSteamPipe();
S_API HSteamUser S_CALLTYPE SteamGameServer_GetHSteamUser();
S_API void *S_CALLTYPE SteamInternal_ContextInit( void *pContextInitData );
S_API void *S_CALLTYPE SteamInternal_CreateInterface( const char *ver );
S_API void *S_CALLTYPE SteamInternal_FindOrCreateUserInterface( HSteamUser hSteamUser, const char *pszVersion );
S_API void *S_CALLTYPE SteamInternal_FindOrCreateGameServerInterface( HSteamUser hSteamUser, const char *pszVersion );

// Macro used to define a type-safe accessor that will always return the version
// of the interface of the *header file* you are compiling with!  We also bounce
// through a safety function that checks for interfaces being created or destroyed.
//
// SteamInternal_ContextInit takes a base pointer for the equivalent of
// struct { void (*pFn)(void* pCtx); uintptr_t counter; void *ptr; }
// Do not change layout or add non-pointer aligned data!
#define STEAM_DEFINE_INTERFACE_ACCESSOR( type, name, expr, kind, version ) \
	inline void S_CALLTYPE SteamInternal_Init_ ## name( type *p ) { *p = (type)( expr ); } \
	STEAM_CLANG_ATTR( "interface_accessor_kind:" kind ";interface_accessor_version:" version ";" ) \
	inline type name() { \
		static void* s_CallbackCounterAndContext[ 3 ] = { (void*)&SteamInternal_Init_ ## name, 0, 0 }; \
		return *(type*)SteamInternal_ContextInit( s_CallbackCounterAndContext ); \
	}

#define STEAM_DEFINE_USER_INTERFACE_ACCESSOR( type, name, version ) \
	STEAM_DEFINE_INTERFACE_ACCESSOR( type, name, SteamInternal_FindOrCreateUserInterface( SteamAPI_GetHSteamUser(), version ), "user", version )
#define STEAM_DEFINE_GAMESERVER_INTERFACE_ACCESSOR( type, name, version ) \
	STEAM_DEFINE_INTERFACE_ACCESSOR( type, name, SteamInternal_FindOrCreateGameServerInterface( SteamGameServer_GetHSteamUser(), version ), "gameserver", version )

//
// Internal stuff used for the standard, higher-level callback mechanism
//

// Internal functions used by the utility CCallback objects to receive callbacks
S_API void S_CALLTYPE SteamAPI_RegisterCallback( class CCallbackBase *pCallback, int iCallback );
S_API void S_CALLTYPE SteamAPI_UnregisterCallback( class CCallbackBase *pCallback );
// Internal functions used by the utility CCallResult objects to receive async call results
S_API void S_CALLTYPE SteamAPI_RegisterCallResult( class CCallbackBase *pCallback, SteamAPICall_t hAPICall );
S_API void S_CALLTYPE SteamAPI_UnregisterCallResult( class CCallbackBase *pCallback, SteamAPICall_t hAPICall );

#define _STEAM_CALLBACK_OFFSETOF( type, member ) ( (size_t)( (char *)&( (type *)0 )->member ) )
#define _STEAM_CALLBACK_AUTO_HOOK( thisclass, func, param )
#define _STEAM_CALLBACK_HELPER( _1, _2, SELECTED, ... )		_STEAM_CALLBACK_##SELECTED
#define _STEAM_CALLBACK_SELECT( X, Y )						_STEAM_CALLBACK_HELPER X Y
#define _STEAM_CALLBACK_3( extra_code, thisclass, func, param ) \
	struct CCallbackInternal_ ## func : private CCallbackImpl< sizeof( param ) > { \
		CCallbackInternal_ ## func () { extra_code SteamAPI_RegisterCallback( this, param::k_iCallback ); } \
		CCallbackInternal_ ## func ( const CCallbackInternal_ ## func & ) { extra_code SteamAPI_RegisterCallback( this, param::k_iCallback ); } \
		CCallbackInternal_ ## func & operator=( const CCallbackInternal_ ## func & ) { return *this; } \
		private: virtual void Run( void *pvParam ) S_OVERRIDE { _STEAM_CALLBACK_AUTO_HOOK( thisclass, func, param ) \
			thisclass *pOuter = reinterpret_cast<thisclass*>( reinterpret_cast<char*>(this) - _STEAM_CALLBACK_OFFSETOF( thisclass, m_steamcallback_ ## func ) ); \
			pOuter->func( reinterpret_cast<param*>( pvParam ) ); \
		} \
	} m_steamcallback_ ## func ; void func( param *pParam )
#define _STEAM_CALLBACK_4( _, thisclass, func, param, var ) \
	CCallback< thisclass, param > var; void func( param *pParam )
#define _STEAM_CALLBACK_GS( _, thisclass, func, param, var ) \
	CCallback< thisclass, param, true > var; void func( param *pParam )

#ifndef API_GEN

template< class T, class P >
inline CCallResult<T, P>::CCallResult()
{
	m_hAPICall = k_uAPICallInvalid;
	m_pObj = nullptr;
	m_Func = nullptr;
	m_iCallback = P::k_iCallback;
}

template< class T, class P >
inline void CCallResult<T, P>::Set( SteamAPICall_t hAPICall, T *p, func_t func )
{
	if ( m_hAPICall )
		SteamAPI_UnregisterCallResult( this, m_hAPICall );

	m_hAPICall = hAPICall;
	m_pObj = p;
	m_Func = func;

	if ( hAPICall )
		SteamAPI_RegisterCallResult( this, hAPICall );
}

template< class T, class P >
inline bool CCallResult<T, P>::IsActive() const
{
	return (m_hAPICall != k_uAPICallInvalid);
}

template< class T, class P >
inline void CCallResult<T, P>::Cancel()
{
	if ( m_hAPICall != k_uAPICallInvalid )
	{
		SteamAPI_UnregisterCallResult( this, m_hAPICall );
		m_hAPICall = k_uAPICallInvalid;
	}
}

template< class T, class P >
inline CCallResult<T, P>::~CCallResult()
{
	Cancel();
}

template< class T, class P >
inline void CCallResult<T, P>::Run( void *pvParam )
{
	m_hAPICall = k_uAPICallInvalid; // caller unregisters for us
	(m_pObj->*m_Func)((P *)pvParam, false);
}

template< class T, class P >
inline void CCallResult<T, P>::Run( void *pvParam, bool bIOFailure, SteamAPICall_t hSteamAPICall )
{
	if ( hSteamAPICall == m_hAPICall )
	{
		m_hAPICall = k_uAPICallInvalid; // caller unregisters for us
		(m_pObj->*m_Func)((P *)pvParam, bIOFailure);
	}
}

template< class T, class P, bool bGameserver >
inline CCallback< T, P, bGameserver >::CCallback( T *pObj, func_t func )
	: m_pObj( nullptr ), m_Func( nullptr )
{
	if ( bGameserver )
	{
		this->SetGameserverFlag();
	}
	Register( pObj, func );
}

template< class T, class P, bool bGameserver >
inline void CCallback< T, P, bGameserver >::Register( T *pObj, func_t func )
{
	if ( !pObj || !func )
		return;

	if ( this->m_nCallbackFlags & CCallbackBase::k_ECallbackFlagsRegistered )
		Unregister();

	m_pObj = pObj;
	m_Func = func;
	// SteamAPI_RegisterCallback sets k_ECallbackFlagsRegistered
	SteamAPI_RegisterCallback( this, P::k_iCallback );
}

template< class T, class P, bool bGameserver >
inline void CCallback< T, P, bGameserver >::Unregister()
{
	// SteamAPI_UnregisterCallback removes k_ECallbackFlagsRegistered
	SteamAPI_UnregisterCallback( this );
}

template< class T, class P, bool bGameserver >
inline void CCallback< T, P, bGameserver >::Run( void *pvParam )
{
	(m_pObj->*m_Func)((P *)pvParam);
}

#endif // #ifndef API_GEN

// structure that contains client callback data
// see callbacks documentation for more details
#if defined( VALVE_CALLBACK_PACK_SMALL )
#pragma pack( push, 4 )
#elif defined( VALVE_CALLBACK_PACK_LARGE )
#pragma pack( push, 8 )
#else
#error steam_api_common.h should define VALVE_CALLBACK_PACK_xxx
#endif 

/// Internal structure used in manual callback dispatch
struct CallbackMsg_t
{
	HSteamUser m_hSteamUser; // Specific user to whom this callback applies.
	int m_iCallback; // Callback identifier.  (Corresponds to the k_iCallback enum in the callback structure.)
	uint8 *m_pubParam; // Points to the callback structure
	int m_cubParam; // Size of the data pointed to by m_pubParam
};
#pragma pack( pop )

// Macros to define steam callback structures.  Used internally for debugging
#ifdef STEAM_CALLBACK_INSPECTION_ENABLED
	#include "../../clientdll/steam_api_callback_inspection.h"
#else
	#define STEAM_CALLBACK_BEGIN( callbackname, callbackid )	struct callbackname { enum { k_iCallback = callbackid };
	#define STEAM_CALLBACK_MEMBER( varidx, vartype, varname )	vartype varname ; 
	#define STEAM_CALLBACK_MEMBER_ARRAY( varidx, vartype, varname, varcount ) vartype varname [ varcount ];
	#define STEAM_CALLBACK_END(nArgs) };
#endif

// Forward declare all of the Steam interfaces.  (Do we really need to do this?)
class ISteamClient;
class ISteamUser;
class ISteamGameServer;
class ISteamFriends;
class ISteamUtils;
class ISteamMatchmaking;
class ISteamContentServer;
class ISteamMatchmakingServers;
class ISteamUserStats;
class ISteamApps;
class ISteamNetworking;
class ISteamRemoteStorage;
class ISteamScreenshots;
class ISteamMusic;
class ISteamMusicRemote;
class ISteamGameServerStats;
class ISteamHTTP;
class ISteamController;
class ISteamUGC;
class ISteamHTMLSurface;
class ISteamInventory;
class ISteamVideo;
class ISteamParentalSettings;
class ISteamGameSearch;
class ISteamInput;
class ISteamParties;
class ISteamRemotePlay;

// Forward declare types
struct SteamNetworkingIdentity;

//-----------------------------------------------------------------------------
// Purpose: Base values for callback identifiers, each callback must
//			have a unique ID.
//-----------------------------------------------------------------------------
enum { k_iSteamUserCallbacks = 100 };
enum { k_iSteamGameServerCallbacks = 200 };
enum { k_iSteamFriendsCallbacks = 300 };
enum { k_iSteamBillingCallbacks = 400 };
enum { k_iSteamMatchmakingCallbacks = 500 };
enum { k_iSteamContentServerCallbacks = 600 };
enum { k_iSteamUtilsCallbacks = 700 };
enum { k_iSteamAppsCallbacks = 1000 };
enum { k_iSteamUserStatsCallbacks = 1100 };
enum { k_iSteamNetworkingCallbacks = 1200 };
enum { k_iSteamNetworkingSocketsCallbacks = 1220 };
enum { k_iSteamNetworkingMessagesCallbacks = 1250 };
enum { k_iSteamNetworkingUtilsCallbacks = 1280 };
enum { k_iSteamRemoteStorageCallbacks = 1300 };
enum { k_iSteamGameServerItemsCallbacks = 1500 };
enum { k_iSteamGameCoordinatorCallbacks = 1700 };
enum { k_iSteamGameServerStatsCallbacks = 1800 };
enum { k_iSteam2AsyncCallbacks = 1900 };
enum { k_iSteamGameStatsCallbacks = 2000 };
enum { k_iSteamHTTPCallbacks = 2100 };
enum { k_iSteamScreenshotsCallbacks = 2300 };
// NOTE: 2500-2599 are reserved
enum { k_iSteamStreamLauncherCallbacks = 2600 };
enum { k_iSteamControllerCallbacks = 2800 };
enum { k_iSteamUGCCallbacks = 3400 };
enum { k_iSteamStreamClientCallbacks = 3500 };
enum { k_iSteamMusicCallbacks = 4000 };
enum { k_iSteamMusicRemoteCallbacks = 4100 };
enum { k_iSteamGameNotificationCallbacks = 4400 }; 
enum { k_iSteamHTMLSurfaceCallbacks = 4500 };
enum { k_iSteamVideoCallbacks = 4600 };
enum { k_iSteamInventoryCallbacks = 4700 };
enum { k_ISteamParentalSettingsCallbacks = 5000 };
enum { k_iSteamGameSearchCallbacks = 5200 };
enum { k_iSteamPartiesCallbacks = 5300 };
enum { k_iSteamSTARCallbacks = 5500 };
enum { k_iSteamRemotePlayCallbacks = 5700 };
enum { k_iSteamChatCallbacks = 5900 };
enum { k_iSteamTimelineCallbacks = 6000 };
// NOTE: Internal "IClientXxx" callback IDs go in clientenums.h

// Macros used to annotate various Steamworks interfaces to generate the
// flat API
#ifdef API_GEN
# define STEAM_CLANG_ATTR(ATTR) __attribute__((annotate( ATTR )))
#else
# define STEAM_CLANG_ATTR(ATTR)
#endif

#define STEAM_OUT_STRUCT() STEAM_CLANG_ATTR( "out_struct: ;" )
#define STEAM_OUT_STRING() STEAM_CLANG_ATTR( "out_string: ;" )
#define STEAM_OUT_ARRAY_CALL(COUNTER,FUNCTION,PARAMS) STEAM_CLANG_ATTR( "out_array_call:" #COUNTER "," #FUNCTION "," #PARAMS ";" )
#define STEAM_OUT_ARRAY_COUNT(COUNTER, DESC) STEAM_CLANG_ATTR( "out_array_count:" #COUNTER  ";desc:" #DESC )
#define STEAM_ARRAY_COUNT(COUNTER) STEAM_CLANG_ATTR( "array_count:" #COUNTER ";" )
#define STEAM_ARRAY_COUNT_D(COUNTER, DESC) STEAM_CLANG_ATTR( "array_count:" #COUNTER ";desc:" #DESC )
#define STEAM_BUFFER_COUNT(COUNTER) STEAM_CLANG_ATTR( "buffer_count:" #COUNTER ";" )
#define STEAM_OUT_BUFFER_COUNT(COUNTER) STEAM_CLANG_ATTR( "out_buffer_count:" #COUNTER ";" )
#define STEAM_OUT_STRING_COUNT(COUNTER) STEAM_CLANG_ATTR( "out_string_count:" #COUNTER ";" )
#define STEAM_DESC(DESC) STEAM_CLANG_ATTR("desc:" #DESC ";")
#define STEAM_CALL_RESULT(RESULT_TYPE) STEAM_CLANG_ATTR("callresult:" #RESULT_TYPE ";")
#define STEAM_CALL_BACK(RESULT_TYPE) STEAM_CLANG_ATTR("callback:" #RESULT_TYPE ";")
#define STEAM_FLAT_NAME(NAME) STEAM_CLANG_ATTR("flat_name:" #NAME ";")
