/*
lib_common.c - common dynamic library code
Copyright (C) 2018 Flying With Gauss

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
*/

#include "common.h"
#include "library.h"
#include "filesystem.h"
#include "server.h"

static char s_szLastError[1024] = "";

const char *COM_GetLibraryError( void )
{
	return s_szLastError;
}

void COM_ResetLibraryError( void )
{
	s_szLastError[0] = 0;
}

void COM_PushLibraryError( const char *error )
{
	Q_strncat( s_szLastError, error, sizeof( s_szLastError ) );
	Q_strncat( s_szLastError, "\n", sizeof( s_szLastError ) );
}

void *COM_FunctionFromName_SR( void *hInstance, const char *pName )
{
#ifdef XASH_ALLOW_SAVERESTORE_OFFSETS
	if( !Q_memcmp( pName, "ofs:",4 ) )
		return svgame.dllFuncs.pfnGameInit + Q_atoi(pName + 4);
#endif
	return COM_FunctionFromName( hInstance, pName );
}

const char *COM_OffsetNameForFunction( void *function )
{
	static string sname;
	Q_snprintf( sname, MAX_STRING, "ofs:%lu", (size_t)((byte*)function - (byte*)svgame.dllFuncs.pfnGameInit) );
	Con_Reportf( "COM_OffsetNameForFunction %s\n", sname );
	return sname;
}

/*
=============================================================================

	LIBRARY NAMING(see Documentation/library-naming.md for more info)

=============================================================================
*/

static void COM_GenerateCommonLibraryName( const char *name, const char *ext, char *out, size_t size )
{
#if ( XASH_WIN32 || XASH_LINUX || XASH_APPLE ) && XASH_X86
	Q_snprintf( out, size, "%s.%s", name, ext );
#elif ( XASH_WIN32 || XASH_LINUX || XASH_APPLE )
	Q_snprintf( out, size, "%s_%s.%s", name, Q_buildarch(), ext );
#else
	Q_snprintf( out, size, "%s_%s_%s.%s", name, Q_buildos(), Q_buildarch(), ext );
#endif
}

/*
==============
COM_GenerateClientLibraryPath

Generates platform-unique and compatible name for client libraries
==============
*/
static void COM_GenerateClientLibraryPath( const char *name, char *out, size_t size )
{
#ifdef XASH_INTERNAL_GAMELIBS // assuming library loader knows where to get libraries
	Q_strncpy( out, name, size );
#else
	string dllpath;

	// we don't have any library prefixes, so we can safely append dll_path here
	Q_snprintf( dllpath, sizeof( dllpath ), "%s/%s", GI->dll_path, name );

	COM_GenerateCommonLibraryName( dllpath, OS_LIB_EXT, out, size );
#endif
}

/*
==============
COM_GenerateServerLibraryPath

Generates platform-unique and compatible name for server library
==============
*/
static void COM_GenerateServerLibraryPath( char *out, size_t size )
{
#ifdef XASH_INTERNAL_GAMELIBS // assuming library loader knows where to get libraries
	Q_strncpy( out, "server", size );
#elif ( XASH_WIN32 || XASH_LINUX || XASH_APPLE ) && XASH_X86

#if XASH_WIN32
	Q_strncpy( out, GI->game_dll, size );
#elif XASH_APPLE
	Q_strncpy( out, GI->game_dll_osx, size );
#else // XASH_LINUX
	Q_strncpy( out, GI->game_dll_linux, size );
#endif

#else
	string dllpath;
	const char *ext;

#if XASH_WIN32
	Q_strncpy( dllpath, GI->game_dll, sizeof( dllpath ) );
#elif XASH_APPLE
	Q_strncpy( dllpath, GI->game_dll_osx, sizeof( dllpath ) );
#else // XASH_APPLE
	Q_strncpy( dllpath, GI->game_dll_linux, sizeof( dllpath ) );
#endif

	ext = COM_FileExtension( dllpath );
	COM_StripExtension( dllpath );

	COM_GenerateCommonLibraryName( dllpath, ext, out, size );
#endif
}


/*
==============
COM_GetCommonLibraryPath

Generates platform-unique and compatible name for server library
==============
*/
void COM_GetCommonLibraryPath( ECommonLibraryType eLibType, char *out, size_t size )
{
	switch( eLibType )
	{
	case LIBRARY_GAMEUI:
		COM_GenerateClientLibraryPath( "menu", out, size );
		break;
	case LIBRARY_CLIENT:
		if( SI.clientlib[0] )
		{
			Q_strncpy( out, SI.clientlib, size );
		}
		else
		{
			COM_GenerateClientLibraryPath( "client", out, size );
		}
		break;
	case LIBRARY_SERVER:
		if( SI.gamedll[0] )
		{
			Q_strncpy( out, SI.gamedll, size );
		}
		else
		{
			COM_GenerateServerLibraryPath( out, size );
		}
		break;
	default:
		ASSERT( true );
		out[0] = 0;
		break;
	}
}