/*-------------------------------------------------------------------------
 * Vulkan CTS Framework
 * --------------------
 *
 * Copyright (c) 2021 The Khronos Group Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 *-------------------------------------------------------------------------*/

#include "vksIPC.hpp"
#include "vksStore.hpp"
#include "vksClient.hpp"

#include <future>

namespace vksc_server
{

namespace ipc
{

constexpr int DefaultPortIPC = 57323;

struct ChildConnection
{
	int id;
	std::unique_ptr<de::Socket> socket;
	std::atomic<bool>& appactive;
	vector<u8> recvb;
};

struct PacketsLoop
{
	ChildConnection client;
	Store& fileStore;

	template <typename T>
	static void SendResponse (ChildConnection& c, T& data)
	{
		SendPayloadWithHeader(c.socket.get(), T::Type(), Serialize(data));
	}

	void ProcessPacketsOnServer (ChildConnection& c, u32 type, vector<u8> packet)
	{
		switch (type)
		{
			case StoreContentRequest::Type():
			{
				auto req = Deserialize<StoreContentRequest>(packet);
				bool ok = fileStore.Set(req.name, req.data);

				StoreContentResponse res;
				res.status = ok;
				SendResponse(c, res);
			}
			break;
			case GetContentRequest::Type():
			{
				auto req = Deserialize<GetContentRequest>(packet);

				vector<u8> content;
				bool ok = fileStore.Get(req.path, content, req.removeAfter);

				GetContentResponse res;
				res.status = ok;
				res.data = std::move(content);
				SendResponse(c, res);
			}
			break;

			default:
				throw std::runtime_error("ipc communication error");
		}
	}

	void Loop ()
	{
		while (client.socket->isConnected() && client.appactive)
		{
			RecvSome(client.socket.get(), client.recvb);
			auto interpret = [this](u32 type, vector<u8> packet) { ProcessPacketsOnServer(client, type, std::move(packet)); };
			while (ProccessNetworkData(client.recvb, interpret)) {}
		}
	}

	void operator() ()
	{
		try { Loop(); }
		catch (const std::exception& ) { client.socket->close(); }
	}
};

struct ParentImpl
{
	Store				fileStore;
	int					m_portOffset;
	std::thread			listenerLoop;
	std::atomic<bool>	appActive{true};

	void ParentLoop ()
	{
		vector<std::future<void>> clients;
		int id{};

		try
		{
			de::SocketAddress addr;
			addr.setHost("localhost");
			addr.setPort(DefaultPortIPC+m_portOffset);
			de::Socket listener;
			listener.listen(addr);

			while (appActive)
			{
				remove_erase_if(clients, [](const std::future<void>& c) { return is_ready(c); });
				ChildConnection client{ ++id, std::unique_ptr<de::Socket>(listener.accept()), appActive, vector<u8>{} };
				clients.push_back(CreateClientThread(std::move(client)));
			}
		}
		catch (const std::exception&) { appActive = false; }
	}

	ParentImpl (const int portOffset)
		: m_portOffset { portOffset }
		, listenerLoop {[this](){ParentLoop();}}
	{
	}

	~ParentImpl ()
	{
		appActive = false;

		// Dummy connection to trigger accept()
		de::SocketAddress addr;
		addr.setHost("localhost");
		addr.setPort(DefaultPortIPC + m_portOffset);
		de::Socket socket;

		try
		{
			socket.connect(addr);
		}
		catch (const de::SocketError&)
		{
		}

		try
		{
			socket.close();
		}
		catch (const de::SocketError&)
		{
		}

		listenerLoop.join();
	}

	std::future<void> CreateClientThread (ChildConnection client)
	{
		return std::async( PacketsLoop{ std::move(client), fileStore } );
	}
};

Parent::Parent (const int portOffset)
{
	impl.reset( new ParentImpl(portOffset) );
}

Parent::~Parent ()
{
}


bool Parent::SetFile (const string& name, const std::vector<u8>& content)
{
	return impl->fileStore.Set(name, content);
}

vector<u8> Parent::GetFile (const string& name)
{
	vector<u8> content;
	bool result = impl->fileStore.Get(name, content, false);
	if (result) return content;
	else return {};
}

struct ChildImpl
{
	ChildImpl(const int portOffset)
		: m_portOffset(portOffset)
	{
		connection.reset(new Server{ "localhost:" + std::to_string(DefaultPortIPC + m_portOffset) });
	}

	int m_portOffset;
	std::unique_ptr<Server> connection;
};

Child::Child (const int portOffset)
{
	impl.reset( new ChildImpl(portOffset) );
}

Child::~Child ()
{
}

bool Child::SetFile (const string& name, const std::vector<u8>& content)
{
	StoreContentRequest request;
	request.name = name;
	request.data = content;
	StoreContentResponse response;
	impl->connection->SendRequest(request, response);
	return response.status;
}

std::vector<u8> Child::GetFile (const string& name)
{
	GetContentRequest request;
	request.path = name;
	request.physicalFile = false;
	request.removeAfter = false;
	GetContentResponse response;
	impl->connection->SendRequest(request, response);
	if (response.status == true) return response.data;
	else return {};
}

} // ipc

} // vksc_server