#include "SharedMemory.hpp"

void* pData = NULL;
HANDLE hMapFile = NULL;
std::string SharedMemoryName = "Local\\GLHookMap";

GL_EXTERN bool __stdcall CreateSharedMemory()
{
    if ((hMapFile = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, MapSize, SharedMemoryName.c_str())) == NULL)
    {
        return false;
    }

    if ((pData = MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, MapSize)) == NULL)
    {
        CloseHandle(hMapFile);
        return false;
    }
    return true;
}

GL_EXTERN bool __stdcall OpenSharedMemory()
{
    if ((hMapFile = OpenFileMappingA(FILE_MAP_ALL_ACCESS, false, SharedMemoryName.c_str())) == NULL)
    {
        std::cout<<"\nCould Not Open Shared Memory Map.\n";
        return false;
    }

    if ((pData = MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, MapSize)) == NULL)
    {
        CloseHandle(hMapFile);
        std::cout<<"\nCould Not Map View Of File.\n";
        return false;
    }
    std::cout<<"\nInter-Process Communication Successful.\n";
    return true;
}

GL_EXTERN bool __stdcall UnMapSharedMemory()
{
    if (hMapFile != NULL)
    {
        UnmapViewOfFile(pData);
        CloseHandle(hMapFile);
        return true;
    }
    return false;
}

GL_EXTERN bool __stdcall SharedMemoryBusy()
{
    int* Data = static_cast<int*>(pData);
    return Data[1] > 0 ? true : false;
}

GL_EXTERN void* __stdcall RequestSharedMemory()
{
    for (int Success = 0; Success < 50; ++Success)
    {
        if (SharedMemoryBusy())
            Sleep(10);
        else
            break;
    }
    return pData;
}

GL_EXTERN bool __stdcall SharedMemoryReturned()
{
    int* Data = static_cast<int*>(pData);
    return Data[1] == 2 ? true : false;
}

GL_EXTERN bool __stdcall SharedDataFetched()
{
    for (int Success = 0; Success < 50; ++Success)
    {
        if (SharedMemoryReturned())
            return true;

        if (!SharedMemoryBusy())
            return false;

        Sleep(10);
    }
    return false;
}