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

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

#include <Source/IPC/IPC.hpp>
#include <Source/IPC/IPCHandle.hpp>

namespace Aurora::IPC
{
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // Shared memory
    //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    
    struct IPCSharedMemoryImpl : IPCSharedMemory
    {
        IPCSharedMemoryImpl(HANDLE handle, void *ptr, const IPC::IPCHandle &ipcHandle);
        ~IPCSharedMemoryImpl();

        virtual Memory::MemoryViewWrite GetMemory() override;
        virtual AuUInt GetLength() override;

        virtual AuString ExportToString() override;

    private:
        IPC::IPCHandle ipcHandle_;
        bool owns_;
        HANDLE handle_{};
        void *base_{};
        AuUInt len_ {};
    };

    IPCSharedMemoryImpl::IPCSharedMemoryImpl(HANDLE handle, void *ptr, const IPC::IPCHandle &ipcHandle) :
        base_(ptr), len_(ipcHandle.word), handle_(handle), ipcHandle_(ipcHandle)
    {

    }

    IPCSharedMemoryImpl::~IPCSharedMemoryImpl()
    {
        if (this->base_)
        {
            ::UnmapViewOfFile(this->base_);
        }
        
        AuWin32CloseHandle(this->handle_);
    }

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

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

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

    AUKN_SYM AuSPtr<IPCSharedMemory>      NewSharedMemory(AuUInt length)
    {
        IPC::IPCHandle handle;
        handle.NewId(length);

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

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

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

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

        return object;
    }

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

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

        auto length = handle.word;
        auto path = handle.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,
                                 length);
        if (!map)
        {
            SysPushErrorIO();
            AuWin32CloseHandle(file);
            return {};
        }

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

        return object;
    }
}