// Copyright Epic Games, Inc. All Rights Reserved.

#include <zenhttp/httpplugin.h>

#include "httptracer.h"

#if ZEN_WITH_PLUGINS

#	include "httpparser.h"

#	include <zencore/except.h>
#	include <zencore/filesystem.h>
#	include <zencore/fmtutils.h>
#	include <zencore/logging.h>
#	include <zencore/memory/llm.h>
#	include <zencore/scopeguard.h>
#	include <zencore/session.h>
#	include <zencore/thread.h>
#	include <zencore/trace.h>
#	include <zenhttp/httpserver.h>

#	include <memory>
#	include <string_view>

#	include <fmt/format.h>

#	if ZEN_PLATFORM_WINDOWS
#		include <conio.h>
#	endif

namespace zen {

struct HttpPluginServerImpl;
struct HttpPluginResponse;

using namespace std::literals;

const FLLMTag&
GetHttppluginTag()
{
	static FLLMTag _("httpplugin");

	return _;
}

//////////////////////////////////////////////////////////////////////////

struct HttpPluginConnectionHandler : public TransportServerConnection, public HttpRequestParserCallbacks, RefCounted
{
	HttpPluginConnectionHandler();
	~HttpPluginConnectionHandler();

	// TransportServerConnection

	virtual uint32_t AddRef() const override;
	virtual uint32_t Release() const override;
	virtual void	 OnBytesRead(const void* Buffer, size_t DataSize) override;

	// HttpRequestParserCallbacks

	virtual void HandleRequest() override;
	virtual void TerminateConnection() override;

	void Initialize(TransportConnection* Transport, HttpPluginServerImpl& Server, uint32_t ConnectionId);

private:
	enum class RequestState
	{
		kInitialState,
		kInitialRead,
		kReadingMore,
		kWriting,		// Currently writing response, connection will be re-used
		kWritingFinal,	// Writing response, connection will be closed
		kDone,
		kTerminated
	};

	RequestState	  m_RequestState = RequestState::kInitialState;
	HttpRequestParser m_RequestParser{*this};

	uint32_t				 m_ConnectionId	  = 0;
	std::atomic_uint32_t	 m_RequestCounter = 0;
	Ref<IHttpPackageHandler> m_PackageHandler;

	TransportConnection*  m_TransportConnection = nullptr;
	HttpPluginServerImpl* m_Server				= nullptr;
};

//////////////////////////////////////////////////////////////////////////

struct HttpPluginServerImpl : public HttpPluginServer, TransportServer
{
	HttpPluginServerImpl();
	~HttpPluginServerImpl();

	// HttpPluginServer

	virtual void OnRegisterService(HttpService& Service) override;
	virtual void OnSetHttpRequestFilter(IHttpRequestFilter* RequestFilter) override;
	virtual int	 OnInitialize(int BasePort, std::filesystem::path DataDir) override;
	virtual void OnRun(bool IsInteractiveSession) override;
	virtual void OnRequestExit() override;
	virtual void OnClose() override;

	virtual void AddPlugin(Ref<TransportPlugin> Plugin) override;
	virtual void RemovePlugin(Ref<TransportPlugin> Plugin) override;

	HttpService*			   RouteRequest(std::string_view Url);
	IHttpRequestFilter::Result FilterRequest(HttpServerRequest& Request);

	struct ServiceEntry
	{
		std::string	 ServiceUrlPath;
		HttpService* Service;
	};

	std::atomic<IHttpRequestFilter*>  m_HttpRequestFilter = nullptr;
	bool							  m_IsInitialized	  = false;
	RwLock							  m_Lock;
	std::vector<ServiceEntry>		  m_UriHandlers;
	std::vector<Ref<TransportPlugin>> m_Plugins;
	Event							  m_ShutdownEvent;
	bool							  m_IsRequestLoggingEnabled = false;
	LoggerRef						  m_RequestLog;
	std::atomic_uint32_t			  m_ConnectionIdCounter{0};
	int								  m_BasePort;

	HttpServerTracer m_RequestTracer;

	// TransportServer

	virtual TransportServerConnection* CreateConnectionHandler(TransportConnection* Connection) override;
	virtual int						   GetBasePort() const override;
};

/** This is the class which request handlers interface with when
	generating responses
 */

class HttpPluginServerRequest : public HttpServerRequest
{
public:
	HttpPluginServerRequest(HttpRequestParser& Request, HttpService& Service, IoBuffer PayloadBuffer);
	~HttpPluginServerRequest();

	HttpPluginServerRequest(const HttpPluginServerRequest&) = delete;
	HttpPluginServerRequest& operator=(const HttpPluginServerRequest&) = delete;

	// As this is plugin transport connection used for specialized connections we assume it is not a machine local connection
	virtual bool			 IsLocalMachineRequest() const /* override*/ { return false; }
	virtual std::string_view GetAuthorizationHeader() const override;
	virtual Oid				 ParseSessionId() const override;
	virtual uint32_t		 ParseRequestId() const override;

	virtual IoBuffer ReadPayload() override;
	virtual void	 WriteResponse(HttpResponseCode ResponseCode) override;
	virtual void	 WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::span<IoBuffer> Blobs) override;
	virtual void	 WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::u8string_view ResponseString) override;
	virtual void	 WriteResponseAsync(std::function<void(HttpServerRequest&)>&& ContinuationHandler) override;
	virtual bool	 TryGetRanges(HttpRanges& Ranges) override;

	using HttpServerRequest::WriteResponse;

	HttpRequestParser&					m_Request;
	IoBuffer							m_PayloadBuffer;
	std::unique_ptr<HttpPluginResponse> m_Response;
};

//////////////////////////////////////////////////////////////////////////

struct HttpPluginResponse
{
public:
	HttpPluginResponse() = default;
	explicit HttpPluginResponse(HttpContentType ContentType) : m_ContentType(ContentType) {}

	HttpPluginResponse(const HttpPluginResponse&) = delete;
	HttpPluginResponse& operator=(const HttpPluginResponse&) = delete;

	void InitializeForPayload(uint16_t ResponseCode, std::span<IoBuffer> BlobList);

	inline uint16_t		   ResponseCode() const { return m_ResponseCode; }
	inline uint64_t		   ContentLength() const { return m_ContentLength; }
	inline HttpContentType ContentType() const { return m_ContentType; }

	const std::vector<IoBuffer>& ResponseBuffers() const { return m_ResponseBuffers; }
	void						 SuppressPayload() { m_ResponseBuffers.resize(1); }

	std::string_view GetHeaders();

private:
	uint16_t					 m_ResponseCode	 = 0;
	bool						 m_IsKeepAlive	 = true;
	HttpContentType				 m_ContentType	 = HttpContentType::kBinary;
	uint64_t					 m_ContentLength = 0;
	std::vector<IoBuffer>		 m_ResponseBuffers;
	ExtendableStringBuilder<160> m_Headers;
};

void
HttpPluginResponse::InitializeForPayload(uint16_t ResponseCode, std::span<IoBuffer> BlobList)
{
	ZEN_MEMSCOPE(GetHttppluginTag());
	ZEN_TRACE_CPU("http_plugin::InitializeForPayload");

	m_ResponseCode			  = ResponseCode;
	const uint32_t ChunkCount = gsl::narrow<uint32_t>(BlobList.size());

	m_ResponseBuffers.reserve(ChunkCount + 1);
	m_ResponseBuffers.push_back({});  // Placeholder for header

	uint64_t TotalDataSize = 0;

	for (IoBuffer& Buffer : BlobList)
	{
		uint64_t BufferDataSize = Buffer.Size();

		ZEN_ASSERT(BufferDataSize);

		TotalDataSize += BufferDataSize;

		IoBufferFileReference FileRef;
		if (Buffer.GetFileReference(/* out */ FileRef))
		{
			// TODO: Use direct file transfer, via TransmitFile/sendfile

			m_ResponseBuffers.emplace_back(std::move(Buffer)).MakeOwned();
		}
		else
		{
			// Send from memory

			m_ResponseBuffers.emplace_back(std::move(Buffer)).MakeOwned();
		}
	}
	m_ContentLength = TotalDataSize;

	auto Headers		 = GetHeaders();
	m_ResponseBuffers[0] = IoBufferBuilder::MakeCloneFromMemory(Headers.data(), Headers.size());
}

std::string_view
HttpPluginResponse::GetHeaders()
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	if (m_Headers.Size() == 0)
	{
		m_Headers << "HTTP/1.1 " << ResponseCode() << " " << ReasonStringForHttpResultCode(ResponseCode()) << "\r\n"
				  << "Content-Type: " << MapContentTypeToString(m_ContentType) << "\r\n"
				  << "Content-Length: " << ContentLength() << "\r\n"sv;

		if (!m_IsKeepAlive)
		{
			m_Headers << "Connection: close\r\n"sv;
		}

		m_Headers << "\r\n"sv;
	}

	return m_Headers;
}

//////////////////////////////////////////////////////////////////////////

HttpPluginConnectionHandler::HttpPluginConnectionHandler()
{
}

HttpPluginConnectionHandler::~HttpPluginConnectionHandler()
{
	if (m_Server)
	{
		ZEN_LOG_TRACE(m_Server->m_RequestLog, "END connection #{}", m_ConnectionId);
	}
}

void
HttpPluginConnectionHandler::Initialize(TransportConnection* Transport, HttpPluginServerImpl& Server, uint32_t ConnectionId)
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	m_TransportConnection = Transport;
	m_Server			  = &Server;
	m_ConnectionId		  = ConnectionId;

	std::string_view ConnectionName;
	if (const char* Name = Transport->GetDebugName())
	{
		ConnectionName = Name;
	}
	else
	{
		ConnectionName = "anonymous";
	}

	ZEN_LOG_TRACE(m_Server->m_RequestLog, "NEW connection #{} ('')", m_ConnectionId, ConnectionName);
}

uint32_t
HttpPluginConnectionHandler::AddRef() const
{
	return RefCounted::AddRef();
}

uint32_t
HttpPluginConnectionHandler::Release() const
{
	return RefCounted::Release();
}

void
HttpPluginConnectionHandler::OnBytesRead(const void* Buffer, size_t AvailableBytes)
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	ZEN_ASSERT(m_Server);

	ZEN_LOG_TRACE(m_Server->m_RequestLog, "connection #{} OnBytesRead: {}", m_ConnectionId, AvailableBytes);

	while (AvailableBytes)
	{
		const size_t ConsumedBytes = m_RequestParser.ConsumeData((const char*)Buffer, AvailableBytes);

		if (ConsumedBytes == ~0ull)
		{
			// request parser error -- terminate connection

			ZEN_LOG_TRACE(m_Server->m_RequestLog, "connection #{} terminating due to request parsing error", m_ConnectionId);

			return TerminateConnection();
		}

		Buffer = reinterpret_cast<const uint8_t*>(Buffer) + ConsumedBytes;
		AvailableBytes -= ConsumedBytes;
	}
}

// HttpRequestParserCallbacks

void
HttpPluginConnectionHandler::HandleRequest()
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	ZEN_ASSERT(m_Server);

	const uint32_t RequestNumber = m_RequestCounter.fetch_add(1);

	ZEN_LOG_TRACE(m_Server->m_RequestLog, "connection #{} ENTER HandleRequest #{}", m_ConnectionId, RequestNumber);
	auto $Exit =
		MakeGuard([&] { ZEN_LOG_TRACE(m_Server->m_RequestLog, "connection #{} EXIT HandleRequest #{}", m_ConnectionId, RequestNumber); });

	if (!m_RequestParser.IsKeepAlive())
	{
		// Once response has been written, connection is done
		m_RequestState = RequestState::kWritingFinal;

		const bool Receive	= true;	  // We're not going to read any more data from this socket
		const bool Transmit = false;  // We will write more data however
		m_TransportConnection->Shutdown(Receive, Transmit);
	}
	else
	{
		m_RequestState = RequestState::kWriting;
	}

	auto SendBuffer = [&](const IoBuffer& InBuffer) -> int64_t {
		const char* Buffer = reinterpret_cast<const char*>(InBuffer.GetData());
		size_t		Bytes  = InBuffer.GetSize();

		return m_TransportConnection->WriteBytes(Buffer, Bytes);
	};

	// Generate response

	if (HttpService* Service = m_Server->RouteRequest(m_RequestParser.Url()))
	{
		ZEN_TRACE_CPU("http_plugin::HandleRequest");

		HttpPluginServerRequest Request(m_RequestParser, *Service, m_RequestParser.Body());

		const HttpVerb		   RequestVerb = Request.RequestVerb();
		const std::string_view Uri		   = Request.RelativeUri();

		if (m_Server->m_RequestLog.ShouldLog(logging::level::Trace))
		{
			ZEN_LOG_TRACE(m_Server->m_RequestLog,
						  "connection #{} Handling Request: {} {} ({} bytes ({}), accept: {})",
						  m_ConnectionId,
						  ToString(RequestVerb),
						  Uri,
						  Request.ContentLength(),
						  ToString(Request.RequestContentType()),
						  ToString(Request.AcceptContentType()));

			m_Server->m_RequestTracer.WriteDebugPayload(fmt::format("request_{}_{}.bin", m_ConnectionId, RequestNumber),
														std::vector<IoBuffer>{Request.ReadPayload()});
		}

		IHttpRequestFilter::Result FilterResult = m_Server->FilterRequest(Request);
		if (FilterResult == IHttpRequestFilter::Result::Accepted)
		{
			if (!HandlePackageOffers(*Service, Request, m_PackageHandler))
			{
				try
				{
					Service->HandleRequest(Request);
				}
				catch (const AssertException& AssertEx)
				{
					// Drop any partially formatted response
					Request.m_Response.reset();

					ZEN_ERROR("Caught assert exception while handling request: {}", AssertEx.FullDescription());
					Request.WriteResponse(HttpResponseCode::InternalServerError, HttpContentType::kText, AssertEx.FullDescription());
				}
				catch (const std::system_error& SystemError)
				{
					// Drop any partially formatted response
					Request.m_Response.reset();

					if (IsOOM(SystemError.code()) || IsOOD(SystemError.code()))
					{
						Request.WriteResponse(HttpResponseCode::InsufficientStorage, HttpContentType::kText, SystemError.what());
					}
					else
					{
						ZEN_WARN("Caught system error exception while handling request: {}. ({})",
								 SystemError.what(),
								 SystemError.code().value());
						Request.WriteResponse(HttpResponseCode::InternalServerError, HttpContentType::kText, SystemError.what());
					}
				}
				catch (const std::bad_alloc& BadAlloc)
				{
					// Drop any partially formatted response
					Request.m_Response.reset();

					Request.WriteResponse(HttpResponseCode::InsufficientStorage, HttpContentType::kText, BadAlloc.what());
				}
				catch (const std::exception& ex)
				{
					// Drop any partially formatted response
					Request.m_Response.reset();

					ZEN_WARN("Caught exception while handling request: {}", ex.what());
					Request.WriteResponse(HttpResponseCode::InternalServerError, HttpContentType::kText, ex.what());
				}
			}
		}
		else if (FilterResult == IHttpRequestFilter::Result::Forbidden)
		{
			Request.WriteResponse(HttpResponseCode::Forbidden);
		}
		else
		{
			ZEN_ASSERT(FilterResult == IHttpRequestFilter::Result::ResponseSent);
		}

		if (std::unique_ptr<HttpPluginResponse> Response = std::move(Request.m_Response))
		{
			{
				const uint16_t ResponseCode = Response->ResponseCode();
				ZEN_LOG_TRACE(m_Server->m_RequestLog,
							  "connection #{} Response: {} {} ({} bytes, {})",
							  m_ConnectionId,
							  ResponseCode,
							  ToString(HttpResponseCode(ResponseCode)),
							  Response->ContentLength(),
							  ToString(Response->ContentType()));
			}

			// Transmit the response

			if (m_RequestParser.RequestVerb() == HttpVerb::kHead)
			{
				Response->SuppressPayload();
			}

			const std::vector<IoBuffer>& ResponseBuffers = Response->ResponseBuffers();

			if (m_Server->m_RequestLog.ShouldLog(logging::level::Trace))
			{
				m_Server->m_RequestTracer.WriteDebugPayload(fmt::format("response_{}_{}.bin", m_ConnectionId, RequestNumber),
															ResponseBuffers);
			}

			for (const IoBuffer& Buffer : ResponseBuffers)
			{
				ZEN_LOG_TRACE(m_Server->m_RequestLog,
							  "connection #{} SEND: {} bytes, {}",
							  m_ConnectionId,
							  Buffer.GetSize(),
							  ToString(Buffer.GetContentType()));

				int64_t SentBytes = SendBuffer(Buffer);

				if (SentBytes < 0)
				{
					TerminateConnection();

					return;
				}
			}

			return;
		}
	}

	// No route found for request

	std::string_view Response;

	if (m_RequestParser.RequestVerb() == HttpVerb::kHead)
	{
		if (m_RequestParser.IsKeepAlive())
		{
			Response =
				"HTTP/1.1 404 NOT FOUND\r\n"
				"\r\n"sv;
		}
		else
		{
			Response =
				"HTTP/1.1 404 NOT FOUND\r\n"
				"Connection: close\r\n"
				"\r\n"sv;
		}
	}
	else
	{
		if (m_RequestParser.IsKeepAlive())
		{
			Response =
				"HTTP/1.1 404 NOT FOUND\r\n"
				"Content-Length: 23\r\n"
				"Content-Type: text/plain\r\n"
				"\r\n"
				"No suitable route found"sv;
		}
		else
		{
			Response =
				"HTTP/1.1 404 NOT FOUND\r\n"
				"Content-Length: 23\r\n"
				"Content-Type: text/plain\r\n"
				"Connection: close\r\n"
				"\r\n"
				"No suitable route found"sv;
		}
	}

	const int64_t SentBytes = SendBuffer(IoBufferBuilder::MakeFromMemory(MakeMemoryView(Response)));

	if (SentBytes < 0)
	{
		TerminateConnection();

		return;
	}
}

void
HttpPluginConnectionHandler::TerminateConnection()
{
	ZEN_MEMSCOPE(GetHttppluginTag());
	ZEN_ASSERT(m_TransportConnection);
	m_TransportConnection->CloseConnection();
}

//////////////////////////////////////////////////////////////////////////

HttpPluginServerRequest::HttpPluginServerRequest(HttpRequestParser& Request, HttpService& Service, IoBuffer PayloadBuffer)
: HttpServerRequest(Service)
, m_Request(Request)
, m_PayloadBuffer(std::move(PayloadBuffer))
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	const int PrefixLength = Service.UriPrefixLength();

	std::string_view Uri = Request.Url();
	Uri.remove_prefix(std::min(PrefixLength, static_cast<int>(Uri.size())));
	m_Uri			   = Uri;
	m_UriWithExtension = Uri;
	m_QueryString	   = Request.QueryString();

	m_Verb			= Request.RequestVerb();
	m_ContentLength = Request.Body().Size();
	m_ContentType	= Request.ContentType();

	HttpContentType AcceptContentType = HttpContentType::kUnknownContentType;

	// Parse any extension, to allow requesting a particular response encoding via the URL

	{
		std::string_view UriSuffix8{m_Uri};

		const size_t LastComponentIndex = UriSuffix8.find_last_of('/');

		if (LastComponentIndex != std::string_view::npos)
		{
			UriSuffix8.remove_prefix(LastComponentIndex);
		}

		const size_t LastDotIndex = UriSuffix8.find_last_of('.');

		if (LastDotIndex != std::string_view::npos)
		{
			UriSuffix8.remove_prefix(LastDotIndex + 1);

			AcceptContentType = ParseContentType(UriSuffix8);

			if (AcceptContentType != HttpContentType::kUnknownContentType)
			{
				m_Uri.remove_suffix(uint32_t(UriSuffix8.size() + 1));
			}
		}
	}

	// It an explicit content type extension was specified then we'll use that over any
	// Accept: header value that may be present

	if (AcceptContentType != HttpContentType::kUnknownContentType)
	{
		m_AcceptType = AcceptContentType;
	}
	else
	{
		m_AcceptType = Request.AcceptType();
	}
}

HttpPluginServerRequest::~HttpPluginServerRequest()
{
}

std::string_view
HttpPluginServerRequest::GetAuthorizationHeader() const
{
	return m_Request.AuthorizationHeader();
}

Oid
HttpPluginServerRequest::ParseSessionId() const
{
	return m_Request.SessionId();
}

uint32_t
HttpPluginServerRequest::ParseRequestId() const
{
	return m_Request.RequestId();
}

IoBuffer
HttpPluginServerRequest::ReadPayload()
{
	return m_PayloadBuffer;
}

void
HttpPluginServerRequest::WriteResponse(HttpResponseCode ResponseCode)
{
	ZEN_ASSERT(!m_Response);
	ZEN_MEMSCOPE(GetHttppluginTag());

	m_Response.reset(new HttpPluginResponse(HttpContentType::kBinary));
	std::array<IoBuffer, 0> Empty;

	m_Response->InitializeForPayload((uint16_t)ResponseCode, Empty);
}

void
HttpPluginServerRequest::WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::span<IoBuffer> Blobs)
{
	ZEN_ASSERT(!m_Response);
	ZEN_MEMSCOPE(GetHttppluginTag());

	m_Response.reset(new HttpPluginResponse(ContentType));
	m_Response->InitializeForPayload((uint16_t)ResponseCode, Blobs);
}

void
HttpPluginServerRequest::WriteResponse(HttpResponseCode ResponseCode, HttpContentType ContentType, std::u8string_view ResponseString)
{
	ZEN_ASSERT(!m_Response);
	ZEN_MEMSCOPE(GetHttppluginTag());

	m_Response.reset(new HttpPluginResponse(ContentType));

	IoBuffer				MessageBuffer(IoBuffer::Wrap, ResponseString.data(), ResponseString.size());
	std::array<IoBuffer, 1> SingleBufferList({MessageBuffer});

	m_Response->InitializeForPayload((uint16_t)ResponseCode, SingleBufferList);
}

void
HttpPluginServerRequest::WriteResponseAsync(std::function<void(HttpServerRequest&)>&& ContinuationHandler)
{
	ZEN_ASSERT(!m_Response);
	ZEN_MEMSCOPE(GetHttppluginTag());

	// Not one bit async, innit
	ContinuationHandler(*this);
}

bool
HttpPluginServerRequest::TryGetRanges(HttpRanges& Ranges)
{
	return TryParseHttpRangeHeader(m_Request.RangeHeader(), Ranges);
}

//////////////////////////////////////////////////////////////////////////

HttpPluginServerImpl::HttpPluginServerImpl() : m_RequestLog(logging::Get("http_requests"))
{
}

HttpPluginServerImpl::~HttpPluginServerImpl()
{
}

TransportServerConnection*
HttpPluginServerImpl::CreateConnectionHandler(TransportConnection* Connection)
{
	ZEN_MEMSCOPE(GetHttppluginTag());
	HttpPluginConnectionHandler* Handler{new HttpPluginConnectionHandler()};
	const uint32_t				 ConnectionId = m_ConnectionIdCounter.fetch_add(1);
	Handler->Initialize(Connection, *this, ConnectionId);
	return Handler;
}

int
HttpPluginServerImpl::GetBasePort() const
{
	return m_BasePort;
}

int
HttpPluginServerImpl::OnInitialize(int InBasePort, std::filesystem::path DataDir)
{
	ZEN_TRACE_CPU("HttpPluginServerImpl::Initialize");

	ZEN_MEMSCOPE(GetHttppluginTag());
	m_RequestTracer.Initialize(DataDir);
	m_BasePort = InBasePort;

	try
	{
		RwLock::ExclusiveLockScope _(m_Lock);

		for (auto& Plugin : m_Plugins)
		{
			try
			{
				Plugin->Initialize(this);
			}
			catch (const std::exception& Ex)
			{
				ZEN_WARN("exception caught during plugin initialization: {}", Ex.what());
			}
		}
	}
	catch (const std::exception& ex)
	{
		ZEN_WARN("Caught exception starting http plugin server: {}", ex.what());
	}

	m_IsInitialized = true;

	return m_BasePort;
}

void
HttpPluginServerImpl::OnSetHttpRequestFilter(IHttpRequestFilter* RequestFilter)
{
	RwLock::ExclusiveLockScope _(m_Lock);
	m_HttpRequestFilter.store(RequestFilter);
}

void
HttpPluginServerImpl::OnClose()
{
	if (!m_IsInitialized)
		return;

	ZEN_MEMSCOPE(GetHttppluginTag());

	try
	{
		RwLock::ExclusiveLockScope _(m_Lock);

		for (auto& Plugin : m_Plugins)
		{
			try
			{
				Plugin->Shutdown();
			}
			catch (const std::exception& Ex)
			{
				ZEN_WARN("exception caught during plugin shutdown: {}", Ex.what());
			}

			Plugin = nullptr;
		}

		m_Plugins.clear();
	}
	catch (const std::exception& ex)
	{
		ZEN_WARN("Caught exception stopping http plugin server: {}", ex.what());
	}

	m_IsInitialized = false;
}

void
HttpPluginServerImpl::OnRun(bool IsInteractive)
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	const int WaitTimeout = 1000;

#	if ZEN_PLATFORM_WINDOWS
	if (IsInteractive)
	{
		ZEN_CONSOLE("Zen Server running (plugin HTTP). Press ESC or Q to quit");
	}

	do
	{
		if (IsInteractive && _kbhit() != 0)
		{
			char c = (char)_getch();

			if (c == 27 || c == 'Q' || c == 'q')
			{
				m_ShutdownEvent.Set();
				RequestApplicationExit(0);
			}
		}

		m_ShutdownEvent.Wait(WaitTimeout);
	} while (!IsApplicationExitRequested());
#	else
	if (IsInteractive)
	{
		ZEN_CONSOLE("Zen Server running (plugin HTTP). Ctrl-C to quit");
	}

	do
	{
		m_ShutdownEvent.Wait(WaitTimeout);
	} while (!IsApplicationExitRequested());
#	endif
}

void
HttpPluginServerImpl::OnRequestExit()
{
	m_ShutdownEvent.Set();
}

void
HttpPluginServerImpl::AddPlugin(Ref<TransportPlugin> Plugin)
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	RwLock::ExclusiveLockScope _(m_Lock);
	m_Plugins.emplace_back(std::move(Plugin));
}

void
HttpPluginServerImpl::RemovePlugin(Ref<TransportPlugin> Plugin)
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	RwLock::ExclusiveLockScope _(m_Lock);
	auto					   It = std::find(begin(m_Plugins), end(m_Plugins), Plugin);
	if (It != m_Plugins.end())
	{
		m_Plugins.erase(It);
	}
}

void
HttpPluginServerImpl::OnRegisterService(HttpService& Service)
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	std::string_view UrlPath(Service.BaseUri());
	Service.SetUriPrefixLength(UrlPath.size());

	if (!UrlPath.empty() && UrlPath.back() == '/')
	{
		UrlPath.remove_suffix(1);
	}

	RwLock::ExclusiveLockScope _(m_Lock);
	m_UriHandlers.push_back({std::string(UrlPath), &Service});
}

HttpService*
HttpPluginServerImpl::RouteRequest(std::string_view Url)
{
	ZEN_MEMSCOPE(GetHttppluginTag());

	RwLock::SharedLockScope _(m_Lock);

	HttpService*		   CandidateService	  = nullptr;
	std::string::size_type CandidateMatchSize = 0;
	for (const ServiceEntry& SvcEntry : m_UriHandlers)
	{
		const std::string&			 SvcUrl		= SvcEntry.ServiceUrlPath;
		const std::string::size_type SvcUrlSize = SvcUrl.size();
		if ((SvcUrlSize >= CandidateMatchSize) && Url.compare(0, SvcUrlSize, SvcUrl) == 0 &&
			((SvcUrlSize == Url.size()) || (Url[SvcUrlSize] == '/')))
		{
			CandidateMatchSize = SvcUrl.size();
			CandidateService   = SvcEntry.Service;
		}
	}

	return CandidateService;
}

IHttpRequestFilter::Result
HttpPluginServerImpl::FilterRequest(HttpServerRequest& Request)
{
	if (!m_HttpRequestFilter.load())
	{
		return IHttpRequestFilter::Result::Accepted;
	}
	RwLock::SharedLockScope _(m_Lock);
	IHttpRequestFilter*		RequestFilter = m_HttpRequestFilter.load();
	if (!RequestFilter)
	{
		return IHttpRequestFilter::Result::Accepted;
	}
	return RequestFilter->FilterRequest(Request);
}

//////////////////////////////////////////////////////////////////////////

struct HttpPluginServerImpl;

Ref<HttpPluginServer>
CreateHttpPluginServer()
{
	ZEN_MEMSCOPE(GetHttppluginTag());
	return Ref<HttpPluginServer>(new HttpPluginServerImpl);
}

}  // namespace zen
#endif