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

Description	:	Basic system info.
Author		:	J.M.P. van Waveren
Date		:	12/10/2016
Language	:	C99
Format		:	Real tabs with the tab size equal to 4 spaces.
Copyright	:	Copyright (c) 2016 Oculus VR, LLC. All Rights reserved.


LICENSE
=======

Copyright (c) 2016 Oculus VR, LLC.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

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

#if !defined( KSSYSINFO_H )
#define KSSYSINFO_H

#if defined( WIN32 ) || defined( _WIN32 ) || defined( WIN64 ) || defined( _WIN64 )
	#if !defined( OS_WINDOWS )
		#define OS_WINDOWS
	#endif
#elif defined( __ANDROID__ )
	#if !defined( OS_ANDROID )
		#define OS_ANDROID
	#endif
#elif defined( __hexagon__ ) || defined( __qdsp6__ )
	#if !defined( OS_HEXAGON )
		#define OS_HEXAGON
	#endif
#elif defined( __APPLE__ )
	#if !defined( OS_APPLE )
		#define OS_APPLE
	#endif
	#include <Availability.h>
	#if __IPHONE_OS_VERSION_MAX_ALLOWED && !defined( OS_APPLE_IOS )
		#define OS_APPLE_IOS
	#elif __MAC_OS_X_VERSION_MAX_ALLOWED && !defined( OS_APPLE_MACOS )
		#define OS_APPLE_MACOS
	#endif
#elif defined( __linux__ )
	#if !defined( OS_LINUX )
		#define OS_LINUX
	#endif
#else
	#error "unknown platform"
#endif

#if defined( OS_WINDOWS )
	#include <windows.h>
#elif defined( OS_APPLE )
	#include <Foundation/NSString.h>
	#include <Foundation/NSProcessInfo.h>
#elif defined( OS_ANDROID )
	#include <dlfcn.h>							// for dlopen
#endif

#include <stdio.h>

static const char * GetOSVersion()
{
#if defined( OS_WINDOWS )
	HKEY hKey = 0;
	if ( RegOpenKeyA( HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", &hKey ) == ERROR_SUCCESS )
	{
		static char version[1024];
		DWORD version_length = sizeof( version );
		DWORD dwType = REG_SZ;
		DWORD dwRet = RegQueryValueExA( hKey, "ProductName", NULL, &dwType, (LPBYTE)&version, &version_length );
		RegCloseKey( hKey );
		if ( dwRet == ERROR_SUCCESS )
		{
			return version;
		}
	}
	return "Microsoft Windows";
#elif defined( OS_LINUX )
	static char buffer[1024];

	FILE * os_release = fopen( "/etc/os-release", "r" );
	if ( os_release != NULL )
	{
		while ( fgets( buffer, sizeof( buffer ), os_release ) )
		{
			if ( strncmp( buffer, "PRETTY_NAME=", 12 ) == 0 )
			{
				char * pretty_name = buffer + 12;

				// remove newline and enclosing quotes
				while(	pretty_name[0] == ' ' ||
						pretty_name[0] == '\t' ||
						pretty_name[0] == ':' ||
						pretty_name[0] == '\'' ||
						pretty_name[0] == '\"' )
				{
					pretty_name++;
				}
				int last = strlen( pretty_name ) - 1;
				while(	last >= 0 && (
						pretty_name[last] == '\n' ||
						pretty_name[last] == '\'' ||
						pretty_name[last] == '\"' ) )
				{
					pretty_name[last--] = '\0';
				}
				return pretty_name;
			}
		}

		fclose( os_release );
	}

	return "Linux";
#elif defined( OS_APPLE_MACOS )
	return [NSString stringWithFormat: @"Apple macOS %@", NSProcessInfo.processInfo.operatingSystemVersionString].UTF8String;
#elif defined( OS_APPLE_IOS )
	return [NSString stringWithFormat: @"Apple iOS %@", NSProcessInfo.processInfo.operatingSystemVersionString].UTF8String;
#elif defined( OS_ANDROID )
	static char version[1024];

	#define PROP_NAME_MAX   32
	#define PROP_VALUE_MAX  92

	char release[PROP_VALUE_MAX] = { 0 };
	char build[PROP_VALUE_MAX] = { 0 };

	void * handle = dlopen( "libc.so", RTLD_NOLOAD );
	if ( handle != NULL )
	{
		typedef int (*PFN_SYSTEM_PROP_GET)(const char *, char *);
		PFN_SYSTEM_PROP_GET __my_system_property_get = (PFN_SYSTEM_PROP_GET)dlsym( handle, "__system_property_get" );
		if ( __my_system_property_get != NULL )
		{
			__my_system_property_get( "ro.build.version.release", release );
			__my_system_property_get( "ro.build.version.incremental", build );
		}
	}

	snprintf( version, sizeof( version ), "Android %s (%s)", release, build );

	return version;
#endif
}

static const char * GetCPUVersion()
{
#if defined( OS_WINDOWS )
	HKEY hKey = 0;
	if ( RegOpenKeyA( HKEY_LOCAL_MACHINE, "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", &hKey ) == ERROR_SUCCESS )
	{
		static char processor[1024];
		DWORD processor_length = sizeof( processor );
		DWORD dwType = REG_SZ;
		DWORD dwRet = RegQueryValueExA( hKey, "ProcessorNameString", NULL, &dwType, (LPBYTE)&processor, &processor_length );
		RegCloseKey( hKey );
		if ( dwRet == ERROR_SUCCESS )
		{
			return processor;
		}
	}
	return "unknown";
#elif defined( OS_APPLE )
	static char processor[1024];
	size_t processor_length = sizeof( processor );
	sysctlbyname( "machdep.cpu.brand_string", &processor, &processor_length, NULL, 0 );
	return processor;
#elif defined( OS_LINUX ) || defined( OS_ANDROID )
	struct
	{
		const char * key;
		char value[1024];
	} keyValues[] =
	{
		{ "model name", "" },
		{ "Processor", "" },
		{ "Hardware", "" }
	};
	static char name[1024];

	FILE * cpuinfo = fopen( "/proc/cpuinfo", "r" );
	if ( cpuinfo != NULL )
	{
		char buffer[1024];
		while ( fgets( buffer, sizeof( buffer ), cpuinfo ) )
		{
			for ( int i = 0; i < (int)( sizeof( keyValues ) / sizeof( keyValues[0] ) ); i++ )
			{
				const size_t length = strlen( keyValues[i].key );
				if ( strncmp( buffer, keyValues[i].key, length ) == 0 )
				{
					char * pretty_name = buffer + length;

					// remove newline and enclosing quotes
					while(	pretty_name[0] == ' ' ||
							pretty_name[0] == '\t' ||
							pretty_name[0] == ':' ||
							pretty_name[0] == '\'' ||
							pretty_name[0] == '\"' )
					{
						pretty_name++;
					}
					int last = strlen( pretty_name ) - 1;
					while(	last >= 0 && (
							pretty_name[last] == '\n' ||
							pretty_name[last] == '\'' ||
							pretty_name[last] == '\"' ) )
					{
						pretty_name[last--] = '\0';
					}

					strcpy( keyValues[i].value, pretty_name );
					break;
				}
			}
		}

		fclose( cpuinfo );

		sprintf( name, "%s%s%s", keyValues[2].value,
				( keyValues[2].value[0] != '\0' ) ? " - " : "",
				( keyValues[0].value[0] != '\0' ) ? keyValues[0].value : keyValues[1].value );
		return name;
	}
	return "unknown";
#endif
}

#endif // !KSSYSINFO_H
