/*
 * =====================================================================================
 *
 *       Filename:  topic_node.cpp
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年04月07日 09时01分48秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), 
 *   Organization:  
 *
 * =====================================================================================
 */
#include "topic_node.h"
#include "bh_util.h"
#include <chrono>
#include <list>

using namespace std::chrono;
using namespace std::chrono_literals;

namespace
{
inline void AddRoute(BHMsgHead &head, const MQId &id) { head.add_route()->set_mq_id(&id, sizeof(id)); }

struct SrcInfo {
	std::vector<BHAddress> route;
	std::string msg_id;
};

class ServerFailedQ
{
	struct FailedMsg {
		steady_clock::time_point xpr;
		std::string remote_;
		BHMsgHead head_;
		MsgRequestTopicReply body_;
		FailedMsg(const std::string &addr, BHMsgHead &&head, MsgRequestTopicReply &&body) :
		    xpr(steady_clock::now() + 10s), remote_(addr), head_(std::move(head)), body_(std::move(body)) {}
		bool Expired() { return steady_clock::now() > xpr; }
	};
	typedef std::list<FailedMsg> Queue;
	Synced<Queue> queue_;

public:
	void Push(const std::string &remote, BHMsgHead &&head, MsgRequestTopicReply &&body)
	{
		queue_->emplace_back(remote, std::move(head), std::move(body));
	}
	void TrySend(ShmSocket &socket, const int timeout_ms = 0)
	{
		queue_.Apply([&](Queue &q) {
			if (!q.empty()) {
				auto it = q.begin();
				do {
					if (it->Expired()) {
						// it->msg_.Release(socket.shm());
						it = q.erase(it);
					} else if (socket.Send(it->remote_.data(), it->head_, it->body_, timeout_ms)) {
						it = q.erase(it);
					} else {
						++it;
					}
				} while (it != q.end());
			}
		});
	}
};

} // namespace
TopicNode::TopicNode(SharedMemory &shm) :
    shm_(shm), sock_node_(shm), sock_request_(shm), sock_reply_(shm), sock_sub_(shm)
{
	SockNode().Start();
}
TopicNode::~TopicNode()
{
	StopAll();
	SockNode().Stop();
}
void TopicNode::StopAll()
{
	ServerStop();
	ClientStopWorker();
}

bool TopicNode::Register(const MsgRegister &body, MsgCommonReply &reply_body, const int timeout_ms)
{
	auto head(InitMsgHead(GetType(body), body.proc().proc_id()));
	AddRoute(head, SockNode().id());

	MsgI reply;
	DEFER1(reply.Release(shm_););
	BHMsgHead reply_head;
	bool r = SockNode().SendAndRecv(&BHTopicCenterAddress(), head, body, reply, reply_head, timeout_ms);
	r = r && reply_head.type() == kMsgTypeCommonReply;
	r = r && reply.ParseBody(reply_body);
	if (r) {
		info_ = body;
	}
	return r;
}

bool TopicNode::RegisterRPC(const MsgRegisterRPC &body, MsgCommonReply &reply_body, const int timeout_ms)
{
	//TODO check registered

	auto head(InitMsgHead(GetType(body), proc_id()));
	AddRoute(head, SockReply().id());

	MsgI reply;
	DEFER1(reply.Release(shm_););
	BHMsgHead reply_head;
	bool r = SockReply().SendAndRecv(&BHTopicCenterAddress(), head, body, reply, reply_head, timeout_ms);
	r = r && reply_head.type() == kMsgTypeCommonReply;
	r = r && reply.ParseBody(reply_body);
	return r;
}

bool TopicNode::ServerStart(const OnRequest &rcb, int nworker)
{
	//TODO check registered

	auto failed_q = std::make_shared<ServerFailedQ>();

	auto onIdle = [failed_q](ShmSocket &socket) { failed_q->TrySend(socket); };

	auto onRecv = [this, rcb, failed_q, onIdle](ShmSocket &sock, MsgI &imsg, BHMsgHead &head) {
		if (head.type() == kMsgTypeRequestTopic && head.route_size() > 0) {
			MsgRequestTopic req;
			if (imsg.ParseBody(req)) {
				std::string out;
				if (rcb(req.topic(), req.data(), out)) {
					MsgRequestTopicReply reply_body;
					reply_body.set_data(std::move(out));
					BHMsgHead reply_head(InitMsgHead(GetType(reply_body), proc_id(), head.msg_id()));

					for (int i = 0; i < head.route_size() - 1; ++i) {
						reply_head.add_route()->Swap(head.mutable_route(i));
					}
					if (!sock.Send(head.route().rbegin()->mq_id().data(), reply_head, reply_body, 10)) {
						failed_q->Push(head.route().rbegin()->mq_id(), std::move(reply_head), std::move(reply_body));
					}
				}
			}
		} else {
			// ignored, or dropped
		}

		onIdle(sock);
	};

	return rcb && SockReply().Start(onRecv, onIdle, nworker);
}
bool TopicNode::ServerStop() { return SockReply().Stop(); }

bool TopicNode::ServerRecvRequest(void *&src_info, std::string &topic, std::string &data, const int timeout_ms)
{
	MsgI imsg;
	BHMsgHead head;
	if (SockReply().SyncRecv(imsg, head, timeout_ms) && head.type() == kMsgTypeRequestTopic) {
		MsgRequestTopic request;
		if (imsg.ParseBody(request)) {
			request.mutable_topic()->swap(topic);
			request.mutable_data()->swap(data);
			SrcInfo *p = new SrcInfo;
			p->route.assign(head.route().begin(), head.route().end());
			p->msg_id = head.msg_id();
			src_info = p;
			return true;
		}
	}
	return false;
}

bool TopicNode::ServerSendReply(void *src_info, const std::string &data, const int timeout_ms)
{
	SrcInfo *p = static_cast<SrcInfo *>(src_info);
	DEFER1(delete p);
	if (!p || p->route.empty()) {
		return false;
	}
	MsgRequestTopicReply body;
	body.set_data(data);
	BHMsgHead head(InitMsgHead(GetType(body), proc_id(), p->msg_id));

	for (unsigned i = 0; i < p->route.size() - 1; ++i) {
		head.add_route()->Swap(&p->route[i]);
	}

	return SockReply().Send(p->route.back().mq_id().data(), head, body, timeout_ms);
}

bool TopicNode::ClientStartWorker(RequestResultCB const &cb, const int nworker)
{
	if (!cb) {
		return false;
	}
	auto onData = [this, cb](ShmSocket &socket, MsgI &imsg, BHMsgHead &head) {
		if (head.type() == kMsgTypeRequestTopicReply) {
			MsgRequestTopicReply reply;
			if (imsg.ParseBody(reply)) {
				cb(reply.data());
			}
		}
	};

	return SockRequest().Start(onData, nworker);
}
bool TopicNode::ClientStopWorker() { return SockRequest().Stop(); }

bool TopicNode::ClientAsyncRequest(const Topic &topic, const void *data, const size_t size, const int timeout_ms, const RequestResultCB &cb)
{
	auto Call = [&](const void *remote) {
		auto &sock = SockRequest();
		MsgRequestTopic req;
		req.set_topic(topic);
		req.set_data(data, size);
		BHMsgHead head(InitMsgHead(GetType(req), proc_id()));
		AddRoute(head, sock.id());

		if (cb) {
			auto onRecv = [cb](ShmSocket &sock, MsgI &imsg, BHMsgHead &head) {
				if (head.type() == kMsgTypeRequestTopicReply) {
					MsgRequestTopicReply reply;
					if (imsg.ParseBody(reply)) {
						cb(reply.data());
					}
				}
			};
			return sock.Send(remote, head, req, timeout_ms, onRecv);
		} else {
			return sock.Send(remote, head, req, timeout_ms);
		}
	};

	try {
		BHAddress addr;
		if (ClientQueryRPCTopic(topic, addr, timeout_ms)) {
			return Call(addr.mq_id().data());
		} else {
			return false;
		}
	} catch (...) {
		return false;
	}
}

bool TopicNode::ClientSyncRequest(const Topic &topic, const void *data, const size_t size, std::string &out, const int timeout_ms)
{
	try {
		auto &sock = SockRequest();
		BHAddress addr;
		if (ClientQueryRPCTopic(topic, addr, timeout_ms)) {

			MsgRequestTopic req;
			req.set_topic(topic);
			req.set_data(data, size);
			BHMsgHead head(InitMsgHead(GetType(req), proc_id()));
			AddRoute(head, sock.id());

			MsgI reply;
			DEFER1(reply.Release(shm_););
			BHMsgHead reply_head;

			if (sock.SendAndRecv(addr.mq_id().data(), head, req, reply, reply_head, timeout_ms) && reply_head.type() == kMsgTypeRequestTopicReply) {
				MsgRequestTopicReply dr;
				if (reply.ParseBody(dr)) {
					dr.mutable_data()->swap(out);
					return true;
				} else {
					printf("error parse reply.\n");
				}
			} else {
				printf("error recv data. line: %d\n", __LINE__);
			}
		} else {
			printf("error recv data. line: %d\n", __LINE__);
		}
	} catch (...) {
		printf("error recv data. line: %d\n", __LINE__);
	}
	return false;
}

bool TopicNode::ClientQueryRPCTopic(const Topic &topic, bhome::msg::BHAddress &addr, const int timeout_ms)
{
	auto &sock = SockRequest();
	if (topic_query_cache_.Find(topic, addr)) {
		return true;
	}

	MsgQueryTopic query;
	query.set_topic(topic);
	BHMsgHead head(InitMsgHead(GetType(query), proc_id()));
	AddRoute(head, sock.id());

	MsgI reply;
	DEFER1(reply.Release(shm_));
	BHMsgHead reply_head;

	if (sock.SendAndRecv(&BHTopicCenterAddress(), head, query, reply, reply_head, timeout_ms)) {
		if (reply_head.type() == kMsgTypeQueryTopicReply) {
			MsgQueryTopicReply rep;
			if (reply.ParseBody(rep)) {
				addr = rep.address();
				if (addr.mq_id().empty()) {
					return false;
				} else {
					topic_query_cache_.Update(topic, addr);
					return true;
				}
			}
		}
	} else {
	}
	return false;
}