#include "GLTB/exception.h"
#include "GLTB/processinfo.h"
#include "GLTB/stringconvert.h"

#ifdef WIN32
#include <windows.h>
#include <psapi.h>
#else
#include <fstream>
#include <sstream>
#include <cstring>
#include <unistd.h>
#endif

namespace gltb {
#ifdef WIN32
	std::wstring executableFullName()
	{
		TCHAR path[MAX_PATH];
		GetModuleFileName(0,path,MAX_PATH);
		return path;
	}
	
	unsigned long long totalAllocatedMemory()
	{
		PROCESS_MEMORY_COUNTERS_EX	processMemoryCounters;
		
		processMemoryCounters.cb=sizeof(processMemoryCounters);
		GetProcessMemoryInfo(GetCurrentProcess(),(PROCESS_MEMORY_COUNTERS*)&processMemoryCounters,sizeof(processMemoryCounters));
		
		return processMemoryCounters.WorkingSetSize;
	}
#elif defined LINUX || defined ANDROID // the /proc filesystem is the same on Linux and Android
	std::wstring executableFullName()
	{
		std::ostringstream exeLink;
		exeLink << "/proc/" << getpid() << "/exe";
		char binaryPath[4096];
		memset(binaryPath,0,4096);
		ssize_t result=readlink(exeLink.str().c_str(),binaryPath,4095);
		if(result==-1 || result>=4095) {
			throw Error("failed to read link to binary from " + exeLink.str(),"gltb::executableFullName()");
		}
		
		return utf8ToUtf16WString(binaryPath);
	}
	
	unsigned long long totalAllocatedMemory()
	{
		/*
		 * Parse /proc/[pid]/statm here because it's a simple, unformatted file.
		 * The values in the file are (given in numbers of pages):
		 *
		 * total program size | resident set size | shared pages | text (code) | data/stack | library | dirty pages
		 *
		 * So here we need the total program size, that is, the first value
		 */
		std::ostringstream statmFilename;
		statmFilename << "/proc/" << getpid() << "/statm";

		std::ifstream statmFile(statmFilename.str().c_str());

		if(!statmFile) {
			throw Error("unable to read memory statistics from " + statmFilename.str(),"gltb::totalAllocatedMemory()");
		}

		unsigned long long numAllocatedPages;
		statmFile >> numAllocatedPages;

		return numAllocatedPages * (unsigned long long)sysconf(_SC_PAGESIZE);
	}
#else
#error not implemented for this platform
#endif
}