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

    File: AuNetSocket.cpp
    Date: 2022-8-16
    Author: Reece
***/
#include "Networking.hpp"
#include "AuNetSocket.hpp"
#include "AuNetEndpoint.hpp"
#include "AuNetWorker.hpp"
#include "AuIPAddress.hpp"
#include "AuNetError.hpp"
#include "AuNetSocketServer.hpp"
#include "AuNetInterface.hpp"

#if defined(AURORA_IS_MODERNNT_DERIVED)
    #include "AuNetStream.NT.hpp"
#endif

namespace Aurora::IO::Net
{
    static NetError GetLastNetError()
    {
        NetError error;
        NetError_SetCurrent(error);
        return error;
    }

    SocketBase::SocketBase(struct NetInterface *pInterface,
                   struct NetWorker *pWorker,
                   const AuSPtr<ISocketDriver> &pSocketDriver,
                   AuUInt osHandle) :
        connectOperation(this),
        socketChannel_(this),
        pInterface_(pInterface),
        pWorker_(pWorker),
        pSocketDriver_(pSocketDriver),
        osHandle_(osHandle)
    {
        this->pWorker_->AddSocket(this);

        this->osHandleOwner_ = AuMakeShared<AuFS::FileHandle>();
        if (!this->osHandle_)
        {
            return;
        }


    #if defined(AURORA_IS_MODERNNT_DERIVED)
        //this->osHandleOwner_->Init((HANDLE)this->osHandle_, (HANDLE)this->osHandle_);
    #else
        this->osHandleOwner_->Init((int)this->osHandle_, (int)this->osHandle_);
    #endif
    }
    
    SocketBase::SocketBase(struct NetInterface *pInterface,
                           struct NetWorker *pWorker,
                           const AuSPtr<ISocketDriver> &pSocketDriver,
                           const NetEndpoint &endpoint) :
        connectOperation(this),
        socketChannel_(this),
        pInterface_(pInterface),
        pWorker_(pWorker),
        pSocketDriver_(pSocketDriver),
        remoteEndpoint_(endpoint)
    {
        this->osHandleOwner_ = AuMakeShared<AuFS::FileHandle>();
        if (!this->osHandle_)
        {
            return;
        }
        this->pWorker_->AddSocket(this);
    }

    SocketBase::SocketBase(struct NetInterface *pInterface,
                           struct NetWorker *pWorker,
                           const AuSPtr<ISocketDriver> &pSocketDriver,
                           const AuPair<NetHostname, AuUInt16> &endpoint,
                           AuNet::ETransportProtocol eProtocol) :
        connectOperation(this),
        socketChannel_(this),
        pInterface_(pInterface),
        pWorker_(pWorker),
        pSocketDriver_(pSocketDriver)
    {
        auto &[host, uPort] = endpoint;

        if (host.type == AuNet::EHostnameType::eHostByIp)
        {
            this->remoteEndpoint_.ip = host.address;
            this->remoteEndpoint_.uPort = uPort;
            this->remoteEndpoint_.transportProtocol = eProtocol;
            OptimizeEndpoint(this->remoteEndpoint_);
        }
        else
        {
            this->resolveLater = host.hostname;
            this->remoteEndpoint_.uPort = uPort;
            this->remoteEndpoint_.transportProtocol = eProtocol;
            this->connectMany_.uPort = uPort;
            this->connectMany_.protocol = eProtocol;
        }

        this->osHandleOwner_ = AuMakeShared<AuFS::FileHandle>();
        if (!this->osHandle_)
        {
            return;
        }

        this->pWorker_->AddSocket(this);
    }


    SocketBase::SocketBase(NetInterface *pInterface,
                   NetWorker *pWorker,
                   const AuSPtr<ISocketDriver> &pSocketDriver,
                   const NetSocketConnectMany &connectMany) :
        connectOperation(this),
        socketChannel_(this),
        pInterface_(pInterface),
        pWorker_(pWorker),
        pSocketDriver_(pSocketDriver),
        bHasRemoteMany_(true),
        connectMany_(connectMany)
    {
        this->connectMany_.pDriver.reset();

        this->osHandleOwner_ = AuMakeShared<AuFS::FileHandle>();
        if (!this->osHandle_)
        {
            return;
        }
    }

    SocketBase::~SocketBase()
    {
        this->Destroy();
    }

    bool SocketBase::IsValid()
    {
        return (this->resolveLater.size()) ||
               bool(this->osHandleOwner_) &&
               bool(this->connectOperation.IsValid()) && 
               bool(this->osHandle_ != 0) &&
               bool(this->osHandle_ != -1) &&
               bool(!this->bForceFailConstruct_);
    }

    bool SocketBase::TryStartResolve()
    {
        auto pThat = this->SharedFromThis();

        if (this->bResolving_)
        {
            return true;
        }

        this->bResolving_ = true;
        auto address = this->resolveLater;
        this->resolveLater.clear();

        auto pResolver = this->pInterface_->GetResolveService()->SimpleAllResolve(address,
                                                                                  AuMakeSharedThrow<AuAsync::PromiseCallbackFunctional<AuList<AuNet::IPAddress>,
                                                                                                         AuNet::NetError>>(
                                                                 [=](const AuSPtr<AuList<AuNet::IPAddress>> &ips)
        {

            pThat->bResolving_ = false;
            pThat->connectMany_.uPort = pThat->remoteEndpoint_.uPort;
            pThat->connectMany_.ips.insert(pThat->connectMany_.ips.end(), ips->begin(), ips->end());
            pThat->bHasRemoteMany_ = true;
            pThat->RenewSocket();
            pThat->ConnectNext();
        },
        [=](const AuSPtr<AuNet::NetError> &error)
        {
            pThat->SendErrorNoStream(error ? *error.get() : AuNet::NetError {});
        }));
        
        return bool(pResolver);
    }

    bool SocketBase::ConnectNext()
    {
        if (this->connectMany_.ips.empty())
        {
            return false;
        }

        auto topLevelEntry = this->connectMany_.ips[0];
        this->connectMany_.ips.erase(this->connectMany_.ips.begin());

        NetEndpoint endpoint;
        endpoint.uPort = this->connectMany_.uPort;
        endpoint.ip = topLevelEntry;
        endpoint.transportProtocol = this->connectMany_.protocol;
        return this->Connect(endpoint);
    }

    bool SocketBase::Connect(const NetEndpoint &endpoint)
    {
        if (!this->IsValid())
        {
            this->SendErrorNoStream({});
            return false;
        }

        this->remoteEndpoint_ = endpoint;
        this->endpointSize_ = OptimizeEndpoint(this->remoteEndpoint_);
        this->localEndpoint_.transportProtocol = this->remoteEndpoint_.transportProtocol;

        if (!this->endpointSize_)
        {
            SysPushErrorIO("Invalid remote endpoint");
            return false;
        }

        bool bStatus = this->ConnectOverlapped() ||
                       this->ConnectNonblocking() ||
                       this->ConnectBlocking();

        if (!bStatus)
        {
            this->connectOperation.OnIOFailure();
        }

        return bStatus;
    }

    AuUInt SocketBase::ToPlatformHandle()
    {
        return this->osHandle_;
    }

    AuSPtr<ISocketDriver> SocketBase::GetUserDriver()
    {
        return this->pSocketDriver_;
    }

    const NetEndpoint &SocketBase::GetRemoteEndpoint()
    {
        return this->remoteEndpoint_;
    }

    const NetEndpoint &SocketBase::GetLocalEndpoint()
    {
        return this->localEndpoint_;
    }

    void SocketBase::ConnectFinished()
    {
        this->UpdateLocalEndpoint();
        this->UpdateRemoteEndpoint();
        DoMain();
    }

    void SocketBase::DoMain()
    {
        this->socketChannel_.Establish();

        if (AuExchange(this->bHasConnected_, true))
        {
            return;
        }

        if (this->bHasErrored_)
        {
            return;
        }

        if (this->bHasEnded)
        {
            return;
        }

        auto pDriver = this->pSocketDriver_;
        if (bool(pDriver))
        {
            try
            {
                pDriver->OnEstablish();
            }
            catch (...)
            {
                SysPushErrorCatch();
                this->SendErrorBeginShutdown({});
            }
        }

        this->ToChannel()->ScheduleOutOfFrameWrite();
    }
    
    void SocketBase::ConnectFailed(const NetError &error)
    {
        if (this->ConnectNext())
        {
            return;
        }

        this->SendErrorNoStream(error);
    }

    void SocketBase::SendErrorNoStream(const NetError &error)
    {
        if (AuExchange(this->bHasErrored_, true))
        {
            return;
        }

        this->error_ = error;

        this->RejectAllListeners();

        if (this->pSocketDriver_)
        {
            try
            {
                this->pSocketDriver_->OnFatalErrorReported(error);
            }
            catch (...)
            {
                SysPushErrorCatch();
            }
        }

        this->SendFinalize();
    }

    void SocketBase::SendErrorBeginShutdown(const NetError &error)
    {
        if (AuExchange(this->bHasErrored_, true))
        {
            return;
        }

        this->error_ = error;

        if (this->pSocketDriver_)
        {
            try
            {
                this->pSocketDriver_->OnFatalErrorReported(error);
            }
            catch (...)
            {
                SysPushErrorCatch();
            }
        }

        RejectAllListeners();

        this->Shutdown();
    }

    void SocketBase::RejectAllListeners()
    {
        AU_LOCK_GUARD(this->socketChannel_.spinLock);

        for (const auto &pListener : this->socketChannel_.eventListeners)
        {
            pListener->OnRejected();
        }

        this->socketChannel_.eventListeners.clear();
    }

    void SocketBase::CompleteAllListeners()
    {
        AU_LOCK_GUARD(this->socketChannel_.spinLock);

        for (const auto &pListener : this->socketChannel_.eventListeners)
        {
            pListener->OnComplete();
        }

        this->socketChannel_.eventListeners.clear();
    }

    void SocketBase::SendOnData()
    {
        auto pReadableBuffer = this->socketChannel_.AsReadableByteBuffer();
        auto pStartOffset = pReadableBuffer ? pReadableBuffer->readPtr : nullptr;

        if (this->bHasFinalized_)
        {
            if (this->socketChannel_.pRecvProtocol)
            {
                this->socketChannel_.pRecvProtocol->DoTick();
            }

            this->socketChannel_.ScheduleOutOfFrameWrite();
            return;
        }

        if (this->socketChannel_.pRecvProtocol)
        {
            this->socketChannel_.pRecvProtocol->DoTick();
        }

        if (this->pSocketDriver_)
        {
            try
            {
                this->pSocketDriver_->OnStreamUpdated();
            }
            catch (...)
            {
                SysPushErrorCatch();
                this->SendErrorBeginShutdown({});
            }
        }

        {
            AuList<AuSPtr<ISocketChannelEventListener>> listeners;
            AuList<AuSPtr<ISocketChannelEventListener>> listenersToEvict;
            {
                AU_LOCK_GUARD(this->socketChannel_.spinLock);
                listeners = this->socketChannel_.eventListeners;
            }

            if (AuTryReserve(listenersToEvict, listeners.size()))
            {
                for (const auto &pListener : listeners)
                {
                    if (!pListener->OnData())
                    {
                        pListener->OnComplete();
                        listenersToEvict.push_back(pListener);
                    }
                }

                {
                    AU_LOCK_GUARD(this->socketChannel_.spinLock);
                    for (const auto &pListener : listenersToEvict)
                    {
                        AuTryRemove(this->socketChannel_.eventListeners, pListener);
                    }
                }
            }
        }

        this->ToChannel()->ScheduleOutOfFrameWrite();

        auto uHeadDelta = pReadableBuffer ? (pReadableBuffer->readPtr - pStartOffset) : 0;
        this->socketChannel_.GetRecvStatsEx().AddBytes(uHeadDelta);
    }
    
    const NetError &SocketBase::GetError()
    {
        if (this->error_.netError == ENetworkError::kEnumInvalid)
        {
            // Note: some interfaces will now have a `HasErrorCode` that reports non-fatal errors
            // This should be useful for reporting the disconnect reason when otherwise filtered as not-an-error
            if (this->socketChannel_.inputChannel.pNetReadTransaction &&
    #if defined(AURORA_IS_MODERNNT_DERIVED)
                AuStaticCast<NtAsyncNetworkTransaction>(this->socketChannel_.inputChannel.pNetReadTransaction)->HasErrorCode()
    #else
                this->socketChannel_.inputChannel.pNetReadTransaction->Failed()
    #endif
                )
            {
                NetError_SetOsError(this->error_, this->socketChannel_.inputChannel.pNetReadTransaction->GetOSErrorCode());
            }
            else if (this->socketChannel_.outputChannel.pNetWriteTransaction_ &&
    #if defined(AURORA_IS_MODERNNT_DERIVED)
                     AuStaticCast<NtAsyncNetworkTransaction>(this->socketChannel_.outputChannel.pNetWriteTransaction_)->HasErrorCode()
    #else
                     this->socketChannel_.outputChannel.pNetWriteTransaction_->Failed()
    #endif
                     )
            {
                NetError_SetOsError(this->error_, this->socketChannel_.outputChannel.pNetWriteTransaction_->GetOSErrorCode());
            }
        }

        return this->error_;
    }
 
    AuSPtr<ISocketChannel> SocketBase::ToChannel()
    {
        return AuSPtr<ISocketChannel>(AuSharedFromThis(), &this->socketChannel_);
    }

    void SocketBase::ShutdownLite()
    {
        if (this->osHandleOwner_)
        {
            this->osHandleOwner_->bWriteLock = true;
        }
    }

    void SocketBase::Destroy()
    {
        this->SendFinalize();
    }

    INetWorker *SocketBase::ToWorker()
    {
        return this->pWorker_;
    }

    NetWorker *SocketBase::ToWorkerEx()
    {
        return this->pWorker_;
    }

    bool SocketBase::SendPreestablish(SocketServer *pServer)
    {
        if (this->bHasPreestablished_)
        {
            return true;
        }

        if (pServer && pServer->uDefaultInputStreamSize)
        {
            this->socketChannel_.uBytesInputBuffer = pServer->uDefaultInputStreamSize;
        }

        this->socketChannel_.inputChannel.WarmOnEstablish(); // Allocate stream resources, in case we need to start working with the source buffer
                                                             // think: setting up protocol stacks, accessing the base bytebuffer, without the pipe being
                                                             // allocated already

        if (this->pSocketDriver_)
        {
            try
            {
                return this->pSocketDriver_->OnPreestablish(AuSharedFromThis());
            }
            catch (...)
            {
                SysPushErrorCatch();
            }
        }

        return this->bHasPreestablished_ = true;
    }

    void SocketBase::SendEnd()
    {
        if (AuExchange(this->bHasEnded, true))
        {
            return;
        }

        if (this->pSocketDriver_)
        {
            try
            {
                this->pSocketDriver_->OnEnd();
            }
            catch (...)
            {
                SysPushErrorCatch();
            }
        }

        this->SendFinalize();
    }

    void SocketBase::SendFinalize()
    {
        if (AuExchange(this->bHasFinalized_, true))
        {
            return;
        }

        this->pWorker_->RemoveSocket(this);

        if (this->bHasErrored_)
        {
            this->RejectAllListeners();
        }
        else
        {
            this->CompleteAllListeners();
        }

        if (this->pSocketDriver_)
        {
            try
            {
                this->pSocketDriver_->OnFinalize();
            }
            catch (...)
            {
                SysPushErrorCatch();
            }

            this->pSocketDriver_.reset();
        }
        
        auto pWriteTransaction = this->socketChannel_.outputChannel.ToWriteTransaction();

        #if defined(AURORA_IS_MODERNNT_DERIVED)
            AuStaticCast<NtAsyncNetworkTransaction>(pWriteTransaction)->MakeSyncable();
            AuStaticCast<NtAsyncNetworkTransaction>(pWriteTransaction)->ForceNextWriteWait();
        #endif

        this->SendOnData();

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

        this->socketChannel_.inputChannel.pNetReader.reset();
        this->socketChannel_.inputChannel.pNetReadTransaction->Reset();

        this->CloseSocket();
    }
}