/***
    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: AuIPCMemory.NT.cpp
    Date: 2022-4-15
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "IPC.hpp"
#include "AuIPCHandle.hpp"
#include "AuIPCMemory.NT.hpp"

namespace Aurora::IO::IPC
{
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // Shared memory
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

    IPCSharedMemoryImpl::IPCSharedMemoryImpl(HANDLE handle,
                                             void *pBase,
                                             const IPC::IPCHandle &ipcHandle) :
        pBase_(pBase),
        uLen_(ipcHandle.values[0].token.word),
        handle_(handle),
        ipcHandle_(ipcHandle)
    {

    }

    IPCSharedMemoryImpl::~IPCSharedMemoryImpl()
    {
        if (this->pBase_)
        {
            ::UnmapViewOfFile(this->pBase_);
            this->pBase_ = nullptr;
        }
        
        AuWin32CloseHandle(this->handle_);
    }

    Memory::MemoryViewWrite IPCSharedMemoryImpl::GetMemory()
    {
        return AuMemoryViewWrite(this->pBase_, this->uLen_);
    }

    AuUInt IPCSharedMemoryImpl::GetLength()
    {
        return this->uLen_;
    }

    AuString IPCSharedMemoryImpl::ExportToString()
    {
        return this->ipcHandle_.ToString();
    }

    AUKN_SYM AuSPtr<IPCSharedMemory>      NewSharedMemory(AuUInt uLength)
    {
        IPC::IPCHandle handle;
        IPC::IPCToken token;
        token.NewId();
        token.word = uLength;

        handle.PushId(EIPCHandleType::eIPCMemory, token);

        auto path = token.ToNTPath();
        auto file = CreateFileMappingA(INVALID_HANDLE_VALUE,
                                       nullptr,
                                       PAGE_READWRITE,
                                   #if defined(AURORA_IS_64BIT)
                                       AuBitsToHigher(uLength),
                                       AuBitsToLower(uLength),
                                   #else
                                       0,
                                       uLength,
                                   #endif
                                       path.c_str());

        if ((file == INVALID_HANDLE_VALUE) ||
            (!file))
        {
            return {};
        }

        auto map = ::MapViewOfFile(file,
                                   FILE_MAP_ALL_ACCESS,
                                   0,
                                   0,
                                   uLength);
        if (!map)
        {
            SysPushErrorIO();
            AuWin32CloseHandle(file);
            return {};
        }

        auto pObject = AuMakeShared<IPCSharedMemoryImpl>(file, map, handle);
        if (!pObject)
        {
            SysPushErrorMem();
            ::UnmapViewOfFile(map);
            AuWin32CloseHandle(file);
            return {};
        }

        return pObject;
    }

    AUKN_SYM AuSPtr<IPCSharedMemory>      ImportSharedMemory(const AuString &handleString)
    {
        IPC::IPCHandle handle;

        if (!handle.FromString(handleString))
        {
            SysPushErrorParseError();
            return {};
        }

        auto token = handle.GetToken(EIPCHandleType::eIPCMemory, 0);
        if (!token)
        {
            SysPushErrorParseError();
            return {};
        }

        auto uLength = token->token.word;
        auto path = token->token.ToNTPath();
        auto file = ::OpenFileMappingA(FILE_MAP_ALL_ACCESS,
                                       FALSE,
                                       path.c_str());

        if ((file == INVALID_HANDLE_VALUE) ||
            (!file))
        {
            return {};
        }

        auto map = ::MapViewOfFile(file,
                                   FILE_MAP_ALL_ACCESS,
                                   0,
                                   0,
                                   uLength);
        if (!map)
        {
            SysPushErrorIO();
            AuWin32CloseHandle(file);
            return {};
        }

        auto pObject = AuMakeShared<IPCSharedMemoryImpl>(file, map, handle);
        if (!pObject)
        {
            SysPushErrorMem();
            ::UnmapViewOfFile(map);
            AuWin32CloseHandle(file);
            return {};
        }

        return pObject;
    }
}