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

    File: AuRPCClientChannel.cpp
    Date: 2022-6-29
    Author: Reece
***/
#include <AuroraRuntime.hpp>
#include "AuRPC.hpp"
#include "AuRPCClientChannel.hpp"
#include "AuRPCRequest.hpp"
#include "AuRPCPipePacket.hpp"

AuRPCClientChannel::AuRPCClientChannel(AuSPtr<AuRPC> parent) :
    parent_(parent),
    pipe_(this)
{ }

bool AuRPCClientChannel::OnConnect()
{
    auto request = AuMakeShared<AuRPCRequest>();
    request->WriteHeaderConnect();
    AuRPCPipePacket packet;
    packet.clientRequest = request;
    packet.protPacket = true;
    packet.clientChannel = SharedFromThis();
    this->pipe_.SendPacket(packet);
    return true;
}

void AuRPCClientChannel::Disconnect()
{
    this->pipe_.Deinit();
    Finalize();
}

void AuRPCClientChannel::SendRequest(AuSPtr<AuIRPCRequest> response2)
{
    auto response = AuStaticCast<AuRPCRequest>(response2);
    if (!response)
    {
        SysPushErrorArg();
        return;
    }

    RpcLogDebug("Client sending request of bytes: {}", response->GetData().length);
    
    AuRPCPipePacket packet;
    packet.clientRequest = response;
    packet.clientChannel = SharedFromThis();
    this->pipe_.SendPacket(packet);
}

AuUInt64 AuRPCClientChannel::GetConnectTimeNS()
{
    return this->uConnectTime_;
}

bool AuRPCClientChannel::SendMessage(const AuMemoryViewRead &view, bool bLarge)
{
    if (!bLarge &&
        view.length < this->parent_->GetLargePacketLength())
    {
        auto pMessage = AuMakeShared<AuRPCRequest>();
        if (!pMessage)
        {
            return false;
        }

        pMessage->dataType = kGeneralServerMessage;
        pMessage->SetData(view);
        this->SendRequest(pMessage);
        return true;
    }
    else
    {
        auto pSharedMemory = AuIPC::NewSharedMemory(view.length);
        if (!pSharedMemory)
        {
            return false;
        }

        auto dest = pSharedMemory->GetMemory();
        AuMemcpy(dest.ptr, view.ptr, view.length);

        auto pMessage = AuMakeShared<AuRPCRequest>();
        if (!pMessage)
        {
            return false;
        }

        pMessage->dataType = kGeneralMassiveMessage;
        AuByteBuffer data;
        data.Write(pSharedMemory->ExportToString());
        if (!data)
        {
            return false;
        }

        pMessage->SetData(data);
        this->SendRequest(pMessage);
        return true;
    }
}

AuSPtr<AuRPC> AuRPCClientChannel::ToContext()
{
    return this->parent_;
}

void AuRPCClientChannel::OnDisconnect(bool error)
{
    RpcLogDebug("AuRPCClientChannel::OnDisconnect");

    if (this->bConnected_ || !this->bConnectingAlternate_)
    {
        Finalize();
    }
}

bool AuRPCClientChannel::OnDataAvailable(AuByteBuffer &view)
{
    RpcLogDebug("AuRPCClientChannel::OnDataAvailable");

    do
    {
        auto bytesAvailable = view.RemainingBytes();

        if (bytesAvailable < 4)
        {
            return true;
        }

        auto oldRead = view.readPtr;
        auto frameLength = view.Read<AuUInt32>();

        if (!frameLength)
        {
            Disconnect();
            return false;
        }

        if (frameLength > bytesAvailable)
        {
            view.readPtr = oldRead;
            return true;
        }

        auto endPtr = oldRead + frameLength;

        auto packetType = view.Read<AuUInt8>();

        if (packetType == kResponseConnectOK)
        {
            this->bConnected_ = true;
            this->ProcessConnectionOK();
        }
        else if (packetType == kResponseMulticonnect)
        {
            this->bConnectingAlternate_ = true;
            this->pipe_.Deinit();
            this->Init(view.Read<AuString>());
        }
        else if (packetType == kResponseRPC)
        {
            auto response = AuMakeShared<AuRPCResponse>();
            if (!response)
            {
                SysPushErrorMem();
                view.readPtr = oldRead;
                return true;
            }

            auto oldLength = view.length;
            auto oldWriteHead = view.writePtr;
            view.length = (oldRead - view.base) + frameLength;
            view.writePtr = view.base + view.length;
            response->message = &view;

            response->Deserialize();
            this->ProcessResponse(response);

            view.readPtr = endPtr;
            view.writePtr = oldWriteHead;
            view.length = oldLength;
        }
        else if (packetType == kGeneralBroadcast ||
                 packetType == kGeneralClientMessage)
        {
            auto oldLength = view.length;
            auto oldWriteHead = view.writePtr;
            view.length = (oldRead - view.base) + frameLength;
            view.writePtr = view.base + view.length;

            if (auto pCallbacks = this->callbacks_)
            {
                if (packetType == kGeneralBroadcast)
                {
                    pCallbacks->OnBroadcast(view);
                }
                else
                {
                    pCallbacks->OnMessage(view);
                }
            }

            view.readPtr = endPtr;
            view.writePtr = oldWriteHead;
            view.length = oldLength;
        }
        else if (packetType == kGeneralMassiveMessage)
        {
            auto oldLength = view.length;
            auto oldWriteHead = view.writePtr;
            view.length = (oldRead - view.base) + frameLength;
            view.writePtr = view.base + view.length;

            auto str = view.Read<AuString>();
            if (view)
            {
                auto pMemory = AuIPC::ImportSharedMemory(str);
                if (!pMemory)
                {
                    SysPushErrorIO("Couldnt open shared memory for large packet");
                    this->FatalIOError();
                    return true;
                }

                AuByteBuffer buf(pMemory->GetMemory());
                if (!buf)
                {
                    SysPushErrorMemory();
                    this->FatalIOError();
                    return true;
                }

                if (auto pCallbacks = this->callbacks_)
                {
                    pCallbacks->OnMessage(buf);
                }
            }

            view.readPtr = oldRead + frameLength;
            view.writePtr = oldWriteHead;
            view.length = oldLength;
        }

    }
    while (true);

    return true;
}

bool AuRPCClientChannel::Init(const AuString &ipc)
{
    return this->pipe_.Init(ipc);
}

void AuRPCClientChannel::FatalIOError()
{
    RpcLogDebug("AuRPCClientChannel::FatalIOError");
    Disconnect();
}

void AuRPCClientChannel::ProcessConnectionOK()
{
    this->uConnectTime_ = AuTime::SteadyClockNS();

    auto re = AuExchange(this->outstandingRequests, AuList<AuSPtr<AuRPCRequest>>{});

    if (this->callbacks_)
    {
        this->callbacks_->OnConnect();
    }

    for (auto a : re)
    {
        this->SendRequest(a);
    }
}

void AuRPCClientChannel::ProcessResponse(const AuSPtr<AuRPCResponse> &response)
{
    RpcLogDebug("AuRPCClientChannel::ProcessResponse");

    for (auto itr = this->outstandingRequests.begin();
         itr != this->outstandingRequests.end();
         itr++)
    {
        if (response->cookie != AuUInt(itr->get()))
        {
            continue;
        }

        auto req = *itr;
        this->outstandingRequests.erase(itr);

        if (req->callback)
        {
            req->callback->OnResponse(*response);
        }
        break;
    }
}

bool AuRPCClientChannel::IsConnected()
{
    return this->bConnected_;
}

void AuRPCClientChannel::SetCallbacks(const AuSPtr<AuIRPCChannelCallbacks> &callbacks)
{
    if (!callbacks)
    {
        SysPushErrorArg();
        return;
    }

    if (IsConnected())
    {
        callbacks->OnConnect();
    }

    this->callbacks_ = callbacks;
}

void AuRPCClientChannel::Finalize()
{
    auto re = AuExchange(this->outstandingRequests, AuList<AuSPtr<AuRPCRequest>>{});

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

    for (auto a : re)
    {
        a->callback->OnResponse(AuRPCResponse(ERPCError::eAborted));
    }

    if (this->callbacks_)
    {
        this->callbacks_->OnDisconnect();
        this->callbacks_.reset();
    }
}