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

    File: AuNetSocketChannel.cpp
    Date: 2022-8-16
    Author: Reece
***/
#include "Networking.hpp"
#include "AuNetSocketChannel.hpp"
#include "AuNetSocket.hpp"
#if defined(AURORA_IS_MODERNNT_DERIVED)
    #include "AuNetStream.NT.hpp"
#else
    #include "AuNetStream.Linux.hpp"
#endif
#include <Source/IO/AuIOPipeProcessor.hpp>
#include "AuNetWorker.hpp"
#include <Source/IO/Protocol/Protocol.hpp>
#include <Source/IO/Protocol/AuProtocolStack.hpp>
#include "AuNetSocketServer.hpp"

namespace Aurora::IO::Net
{
    static const bool kDefaultFuckNagle = true;

    SocketChannel::SocketChannel(SocketBase *pParent) :
        pParent_(pParent),

#if defined(AURORA_IS_MODERNNT_DERIVED)
        outputChannel(pParent, AuStaticCast<IAsyncTransaction>(AuMakeShared<NtAsyncNetworkTransaction>(pParent))),
        inputChannel(pParent, AuStaticCast<IAsyncTransaction>(AuMakeShared<NtAsyncNetworkTransaction>(pParent))),
#else

        outputChannel(pParent, AuStaticCast<IAsyncTransaction>(AuMakeShared<LinuxAsyncNetworkTransaction>(pParent))),
        inputChannel(pParent, AuStaticCast<IAsyncTransaction>(AuMakeShared<LinuxAsyncNetworkTransaction>(pParent))),
#endif

        uBytesInputBuffer(kDefaultStreamSize),
        uBytesOutputBuffer(kDefaultStreamSize),
        bTcpNoDelay(kDefaultFuckNagle)
    {
        
    }

    void                       SocketChannel::Establish()
    {
        if (this->pParent_->GetLocalEndpoint().transportProtocol == ETransportProtocol::eProtocolTCP)
        {
            this->pParent_->UpdateNagleAnyThread(true);
        }

        // Switch over to extended send/recv (its just a flag to use a different branch - fetch last addr is just a hack)
        if (this->pParent_->GetLocalEndpoint().transportProtocol == ETransportProtocol::eProtocolUDP)
        {
#if defined(AURORA_IS_MODERNNT_DERIVED)
            AuStaticCast<NtAsyncNetworkTransaction>(outputChannel.ToWriteTransaction())->bDatagramMode = true;
            AuStaticCast<NtAsyncNetworkTransaction>(inputChannel.pNetReadTransaction)->bDatagramMode = true;
#else
            AuStaticCast<LinuxAsyncNetworkTransaction>(outputChannel.ToWriteTransaction())->bDatagramMode = true;
            AuStaticCast<LinuxAsyncNetworkTransaction>(inputChannel.pNetReadTransaction)->bDatagramMode = true;
#endif
        }

        this->inputChannel.OnEstablish();
    }
  
    AuSPtr<ISocket>            SocketChannel::ToParent()
    {
        return this->pParent_->SharedFromThis();
    }

    AuSPtr<IStreamReader>      SocketChannel::AsStreamReader()
    {
        if (this->pRecvProtocol)
        {
            return this->pRecvProtocol->AsStreamReader();
        }
        else if (this->pCachedReader)
        {
            return this->pCachedReader;
        }
        else
        {
            struct A : AuIO::Buffered::BlobReader
            {
                AuWPtr<SocketChannel> swpChannel;

                A(AuSPtr<AuByteBuffer> pBuffer,
                  AuWPtr<SocketChannel> swpChannel) :
                    AuIO::Buffered::BlobReader(pBuffer),
                    swpChannel(swpChannel)
                {

                }

                virtual void Close() override
                {
                    if (auto pChannel = AuTryLockMemoryType(this->swpChannel))
                    {
                        pChannel->pParent_->Shutdown(false);
                    }
                }
            };

            return this->pCachedReader = AuMakeSharedThrow<A>(this->AsReadableByteBuffer(), AuSPtr<SocketChannel>(this->pParent_->SharedFromThis(), this));
        }
    }

    AuSPtr<Memory::ByteBuffer> SocketChannel::AsReadableByteBuffer()
    {
        if (this->pRecvProtocol)
        {
            return this->pRecvProtocol->AsReadableByteBuffer();
        }
        else
        {
            return this->inputChannel.AsReadableByteBuffer();
        }
    }

    AuSPtr<IStreamWriter>      SocketChannel::AsStreamWriter()
    {
        if (this->pCachedWriter)
        {
            return this->pCachedWriter;
        }
        else if (this->pSendProtocol)
        {
            struct C : IO::IStreamWriter
            {
                AuWPtr<IO::IStreamWriter> swpIStreamWriter;
                AuWPtr<SocketChannel> swpChannel;

                C(AuWPtr<SocketChannel> swpChannel,
                  AuWPtr<IStreamWriter> swpIStreamWriter) :
                    swpIStreamWriter(swpIStreamWriter),
                    swpChannel(swpChannel)
                {

                }

                virtual EStreamError IsOpen() override
                {
                    if (auto pStream = AuTryLockMemoryType(this->swpIStreamWriter))
                    {
                        return EStreamError::eErrorNone;
                    }
                    else
                    {
                        return EStreamError::eErrorHandleClosed;
                    }
                }

                virtual EStreamError Write(const AuMemoryViewStreamRead &read) override
                {
                    if (auto pStream = AuTryLockMemoryType(this->swpIStreamWriter))
                    {
                        return pStream->Write(read);
                    }
                    else
                    {
                        return EStreamError::eErrorHandleClosed;
                    }
                }

                virtual void Close() override
                {
                    if (auto pChannel = AuTryLockMemoryType(this->swpChannel))
                    {
                        pChannel->pParent_->Shutdown(false);
                    }
                }

                virtual void Flush() override
                {
                    if (auto pStream = AuTryLockMemoryType(this->swpIStreamWriter))
                    {
                        pStream->Flush();
                    }

                    if (auto pChannel = AuTryLockMemoryType(this->swpChannel))
                    {
                        pChannel->pParent_->ToChannel()->ScheduleOutOfFrameWrite();
                    }
                }
            };

            return this->pCachedWriter = AuMakeSharedThrow<C>(AuSPtr<SocketChannel>(this->pParent_->SharedFromThis(), this),
                                                                                    this->pSendProtocol->AsStreamWriter());
        }
        else
        {
            struct A : IO::Buffered::BlobWriter
            {
                AuWPtr<SocketChannel> swpChannel;

                A(AuSPtr<AuByteBuffer> pBuffer,
                 AuWPtr<SocketChannel> swpChannel) :
                 IO::Buffered::BlobWriter(pBuffer),
                    swpChannel(swpChannel)
                {

                }

                virtual void Close() override
                {
                    if (auto pChannel = AuTryLockMemoryType(this->swpChannel))
                    {
                        pChannel->pParent_->Shutdown(false);
                    }
                }

                virtual void Flush() override
                {
                    if (auto pChannel = AuTryLockMemoryType(this->swpChannel))
                    {
                        pChannel->pParent_->ToChannel()->ScheduleOutOfFrameWrite();
                    }
                }
            };

            return this->pCachedWriter = AuMakeSharedThrow<A>(this->AsWritableByteBuffer(), AuSPtr<SocketChannel>(this->pParent_->SharedFromThis(), this));
        }
    }

    AuSPtr<Memory::ByteBuffer> SocketChannel::AsWritableByteBuffer()
    {
        if (this->pSendProtocol)
        {
            return this->pSendProtocol->AsReadableByteBuffer();
        }
        else
        {
            return this->outputChannel.AsWritableByteBuffer();
        }
    }

    AuSPtr<Protocol::IProtocolStack> SocketChannel::NewProtocolRecvStack()
    {
        auto pProtocol = AuMakeShared<Protocol::ProtocolStack>();
        if (!pProtocol)
        {
            SysPushErrorMemory();
            return {};
        }

        pProtocol->pSourceBufer = this->inputChannel.AsReadableByteBuffer();
        pProtocol->bKillPipeOnFirstRootLevelFalse = true; // harden

        return pProtocol;
    }

    AuSPtr<Protocol::IProtocolStack> SocketChannel::NewProtocolSendStack()
    {
        auto pBaseProtocol = Protocol::NewBufferedProtocolStack(this->uBytesOutputBuffer);
        if (!pBaseProtocol)
        {
            SysPushErrorMemory();
            return {};
        }

        auto pProtocol = AuStaticCast<Protocol::ProtocolStack>(pBaseProtocol);
        if (!pProtocol)
        {
            return {};
        }

        pProtocol->pDrainBuffer = this->outputChannel.AsWritableByteBuffer();
        pProtocol->bKillPipeOnFirstRootLevelFalse = true; // harden

        return pProtocol;
    }

    void SocketChannel::SpecifyPageLength(AuUInt uPageSize)
    {
        this->uBytesPerFrame = uPageSize;
    }

    AuUInt SocketChannel::GetPageLength()
    {
        return this->uBytesPerFrame;
    }

    void SocketChannel::SpecifyRecvProtocol(const AuSPtr<Protocol::IProtocolStack> &pRecvProtocol)
    {
        this->pRecvProtocol = pRecvProtocol;
        this->pCachedReader.reset();
    }

    void SocketChannel::SpecifySendProtocol(const AuSPtr<Protocol::IProtocolStack> &pSendProtocol)
    {
        this->pSendProtocol = pSendProtocol;
        this->pCachedWriter.reset();
    }


    void SocketChannel::SetNextFrameTargetLength(AuUInt uNextFrameSize)
    {
        (void)this->inputChannel.pNetReader->SetNextFrameTargetLength(uNextFrameSize);
    }

    AuUInt SocketChannel::GetNextFrameTargetLength()
    {
        return this->inputChannel.pNetReader->GetNextFrameTargetLength();
    }

    AuSPtr<ISocketStats> SocketChannel::GetRecvStats()
    {
        return AuSPtr<ISocketStats>(this->pParent_->SharedFromThis(), &this->recvStats_);
    }

    AuSPtr<ISocketStats> SocketChannel::GetSendStats()
    {
        return AuSPtr<ISocketStats>(this->pParent_->SharedFromThis(), &this->sendStats_);
    }

    SocketStats &SocketChannel::GetSendStatsEx()
    {
        return this->sendStats_;
    }

    SocketStats &SocketChannel::GetRecvStatsEx()
    {
        return this->recvStats_;
    }

    SocketStats *SocketChannel::GetSendStatsEx2()
    {
        if (auto pTest = this->pParent_->GetSocketServer())
        {
            if (auto pWP2 = this->pParent_->wpParent2_)
            {
                return &pWP2->sendStats_;
            }
            else
            {
                return {};
            }
        }
        else
        {
            return {};
        }
    }

    SocketStats *SocketChannel::GetRecvStatsEx2()
    {
        if (auto pTest = this->pParent_->GetSocketServer())
        {
            if (auto pWP2 = this->pParent_->wpParent2_)
            {
                return &pWP2->recvStats_;
            }
            else
            {
                return {};
            }
        }
        else
        {
            return {};
        }
    }

    void SocketChannel::AddEventListener(const AuSPtr<ISocketChannelEventListener> &pListener)
    {
        AU_LOCK_GUARD(this->spinLock);

        auto pWorker = this->pParent_->ToWorkerEx();
        if (pWorker->IsOnThread() && this->AsReadableByteBuffer()->GetNextLinearRead().length)
        {
            if (!pListener->OnData())
            {
                pListener->OnComplete();
                return;
            }
        }

        this->eventListeners.push_back(pListener);
    }

    void SocketChannel::RemoveEventListener(const AuSPtr<ISocketChannelEventListener> &pListener)
    {
        AU_LOCK_GUARD(this->spinLock);
         
        bool bSuccess = AuTryRemove(this->eventListeners, pListener);

        auto pWorker = this->pParent_->ToWorkerEx();
        if (pWorker->IsOnThread() && bSuccess)
        {
            pListener->OnRejected();
        }
    }

    bool SocketChannel::IsValid()
    {
        return bool(this->outputChannel.IsValid()) &&
               bool(this->inputChannel.IsValid());
    }

    AuSPtr<ISocketChannelLimits> SocketChannel::GetChannelLimits()
    {
        return AuSPtr<ISocketChannelLimits>(this->pParent_->SharedFromThis(), &this->channelSecurity_);
    }

    bool SocketChannel::SpecifyBufferSize(AuUInt uBytes,
                                          const AuSPtr<AuAsync::PromiseCallback<AuNullS, AuNullS>> &pCallbackOptional)
    {
        auto pWorker = this->pParent_->ToWorkerEx();
        if (!pWorker)
        {
            return false;
        }

        if (pWorker->IsOnThread())
        {
            this->DoBufferResizeOnThread(true,
                                         true,
                                         uBytes,
                                         pCallbackOptional);
            return true;
        }

        auto that = AuSPtr<SocketChannel>(this->pParent_->SharedFromThis(), this);
        
        if (!pWorker->TryScheduleInternalTemplate<AuNullS>([=](const AuSPtr<AuAsync::PromiseCallback<AuNullS>> &info)
        {
            that->DoBufferResizeOnThread(true,
                                         true,
                                         uBytes,
                                         pCallbackOptional);
        }, AuSPtr<AuAsync::PromiseCallback<AuNullS, AuNullS>>{}))
        {
            return false;
        }

        return true;
    }
    
    bool SocketChannel::SpecifyOutputBufferSize(AuUInt uBytes,
                                                const AuSPtr<AuAsync::PromiseCallback<AuNullS, AuNullS>> &pCallbackOptional)
    {
        auto pWorker = this->pParent_->ToWorkerEx();
        if (!pWorker)
        {
            return false;
        }

        if (pWorker->IsOnThread())
        {
            this->DoBufferResizeOnThread(false,
                                         true,
                                         uBytes,
                                         pCallbackOptional);
            return true;
        }

        auto that = AuSPtr<SocketChannel>(this->pParent_->SharedFromThis(), this);

        if (!pWorker->TryScheduleInternalTemplate<AuNullS>([=](const AuSPtr<AuAsync::PromiseCallback<AuNullS>> &info)
        {
            that->DoBufferResizeOnThread(false,
                                         true,
                                         uBytes,
                                         pCallbackOptional);
        }, AuSPtr<AuAsync::PromiseCallback<AuNullS, AuNullS>>{}))
        {
            return false;
        }

        return true;
    }

    bool SocketChannel::SpecifyInputBufferSize(AuUInt uBytes,
                                               const AuSPtr<AuAsync::PromiseCallback<AuNullS, AuNullS>> &pCallbackOptional)
    {
        auto pWorker = this->pParent_->ToWorkerEx();
        if (!pWorker)
        {
            return false;
        }

        if (pWorker->IsOnThread())
        {
            this->DoBufferResizeOnThread(true,
                                         false,
                                         uBytes,
                                         pCallbackOptional);
            return true;
        }

        auto that = AuSPtr<SocketChannel>(this->pParent_->SharedFromThis(), this);

        if (!pWorker->TryScheduleInternalTemplate<AuNullS>([=](const AuSPtr<AuAsync::PromiseCallback<AuNullS>> &info)
        {
            that->DoBufferResizeOnThread(true,
                                         false,
                                         uBytes,
                                         pCallbackOptional);
        }, AuSPtr<AuAsync::PromiseCallback<AuNullS, AuNullS>>{}))
        {
            return false;
        }

        return true;
    }

    void SocketChannel::ScheduleOutOfFrameWrite()
    {
        if (this->pSendProtocol)
        {
            this->pSendProtocol->DoTick();
        }

        this->outputChannel.ScheduleOutOfFrameWrite();
    }

    AuSPtr<IAsyncTransaction> SocketChannel::ToReadTransaction()
    {
        return this->bIsManualRead ?
                   this->inputChannel.pNetReadTransaction :
                   AuSPtr<IAsyncTransaction> {};
    }

    AuSPtr<IAsyncTransaction> SocketChannel::ToWriteTransaction()
    {
        return this->bIsManualWrite ?
                   this->outputChannel.ToWriteTransaction() :
                   AuSPtr<IAsyncTransaction> {};
    }

    bool SocketChannel::SpecifyTCPNoDelay(bool bFuckNagle)
    {
        if (!this->bIsManualWrite)
        {
            return false;
        }

        this->bTcpNoDelay = bFuckNagle;
        this->pParent_->UpdateNagleAnyThread(this->bTcpNoDelay);
        return true;
    }

    bool SocketChannel::SpecifyTransactionsHaveIOFence(bool bAllocateFence)
    {
        return false;
    }

    bool SocketChannel::SpecifyManualWrite(bool bEnableDirectAIOWrite)
    {
        if (this->bIsEstablished)
        {
            return false;
        }

        this->bIsManualWrite = true;
        return true;
    }

    bool SocketChannel::SpecifyManualRead(bool bEnableDirectAIORead)
    {
        if (this->bIsEstablished)
        {
            return false;
        }

        this->bIsManualRead = true;
        return true;
    }

    bool SocketChannel::SpecifyPerTickAsyncReadLimit(AuUInt uBytes)
    {
        if (this->bIsEstablished)
        {
            return false;
        }

        this->uBytesToFlip = true;
        return true;
    }

    void SocketChannel::StopTime()
    {
        this->sendStats_.End();
        this->recvStats_.End();
    }

    void SocketChannel::StartTime()
    {
        this->sendStats_.Start();
        this->recvStats_.Start();
    }

    void SocketChannel::Release()
    {
        this->StopTime();

        if (this->inputChannel.pNetReader)
        {
           this->inputChannel.pNetReader->End();
        }

        this->PrivateUserDataClear();

        this->pCachedReader.reset();
        this->pCachedWriter.reset();

        this->pRecvProtocol.reset();
        this->pSendProtocol.reset();

        this->inputChannel.pNetReader.reset();
    }
    
    static bool ForceResize(AuByteBuffer &buffer, AuUInt uLength)
    {
        auto old = buffer.flagNoRealloc;
        buffer.flagNoRealloc = false;
        bool bRet = buffer.Resize(uLength);
        buffer.flagNoRealloc = old;
        return bRet;
    }

    void SocketChannel::DoBufferResizeOnThread(bool bInput,
                                               bool bOutput,
                                               AuUInt uBytes,
                                               const AuSPtr<AuAsync::PromiseCallback<AuNullS, AuNullS>> &pCallbackOptional)
    {
        if (!this->bIsEstablished)
        {
            if (bInput)
            {
                this->uBytesInputBuffer = uBytes;
            }

            if (bOutput)
            {
                this->uBytesOutputBuffer = uBytes;
            }

            if (pCallbackOptional)
            {
                try
                {
                    pCallbackOptional->OnSuccess((void *)nullptr);
                }
                catch (...)
                {
                    SysPushErrorCatch();
                }
            }

            return;
        }

        bool bHasCurrentSuccess {};

        if (bOutput)
        {
            if (this->outputChannel.CanResize())
            {
                if (ForceResize(this->outputChannel.GetByteBuffer(), uBytes))
                {
                    bOutput = false;
                    bHasCurrentSuccess = !bInput;
                }
            }
        }

        if (bHasCurrentSuccess)
        {
            try
            {
                pCallbackOptional->OnSuccess((void *)nullptr);
            }
            catch (...)
            {
                SysPushErrorCatch();
            }

            return;
        }

        {
            AU_LOCK_GUARD(this->spinLock);

            if (bOutput)
            {
                if (this->uBytesOutputBufferRetarget)
                {
                    if (auto pOutput = AuExchange(this->pRetargetOutput, {}))
                    {
                        try
                        {
                            pOutput->OnFailure((void *)nullptr);
                        }
                        catch (...)
                        {
                            SysPushErrorCatch();
                        }
                        if (this->pRetargetInput == pOutput)
                        {
                            AuResetMember(this->pRetargetInput);
                        }
                    }
                }

                this->uBytesOutputBufferRetarget = uBytes;
                this->pRetargetOutput = pCallbackOptional;
            }

            if (bInput)
            {
                if (this->uBytesInputBufferRetarget)
                {
                    if (auto pInput = AuExchange(this->pRetargetInput, {}))
                    {
                        try
                        {
                            pInput->OnFailure((void *)nullptr);
                        }
                        catch (...)
                        {
                            SysPushErrorCatch();
                        }
                        if (this->pRetargetOutput == pInput)
                        {
                            AuResetMember(this->pRetargetOutput);
                        }
                    }
                }

                this->uBytesInputBufferRetarget = uBytes;
                this->pRetargetInput  = pCallbackOptional;
            }
        }
    }

    void SocketChannel::DoReallocWriteTick()
    {
        AU_LOCK_GUARD(this->spinLock);

        if (!this->uBytesOutputBufferRetarget)
        {
            return;
        }

        if (!ForceResize(this->outputChannel.GetByteBuffer(), uBytesOutputBufferRetarget))
        {
            SysPushErrorMemory();

            if (auto pOutput = AuExchange(this->pRetargetOutput, {}))
            {
                try
                {
                    pOutput->OnFailure((void *)nullptr);
                }
                catch (...)
                {
                    SysPushErrorCatch();
                }
                if (this->pRetargetInput == pOutput)
                {
                    AuResetMember(this->pRetargetInput);
                }
            }
            return;
        }

        this->uBytesOutputBufferRetarget = 0;

        if (auto pOutput = AuExchange(this->pRetargetOutput, {}))
        {
            if (this->pRetargetInput != pOutput)
            {
                try
                {
                    pOutput->OnSuccess((void *)nullptr);
                }
                catch (...)
                {
                    SysPushErrorCatch();
                }
            }
        }
    }

    void SocketChannel::DoReallocReadTick()
    {
        AU_LOCK_GUARD(this->spinLock);

        if (!this->uBytesInputBufferRetarget)
        {
            return;
        }

        if (!ForceResize(*this->inputChannel.AsReadableByteBuffer(), uBytesOutputBufferRetarget))
        {
            SysPushErrorMemory();

            if (auto pInput = AuExchange(this->pRetargetInput, {}))
            {
                try
                {
                    pInput->OnFailure((void *)nullptr);
                }
                catch (...)
                {
                    SysPushErrorCatch();
                }

                if (this->pRetargetOutput == pInput)
                {
                    AuResetMember(this->pRetargetOutput);
                }
            }

            return;
        }

        this->uBytesInputBufferRetarget = 0;

        if (auto pInput = AuExchange(this->pRetargetInput, {}))
        {
            if (this->pRetargetOutput != pInput)
            {
                try
                {
                    pInput->OnSuccess((void *)nullptr);
                }
                catch (...)
                {
                    SysPushErrorCatch();
                }
            }
        }
    }

    bool SocketChannel::GetCurrentTCPNoDelay()
    {
        return this->bTcpNoDelay;
    }

    AuUInt SocketChannel::GetInputBufferSize()
    {
        return this->uBytesInputBuffer;
    }

    AuUInt SocketChannel::GetOutputBufferSize()
    {
        return this->uBytesOutputBuffer;
    }
}