/*
 * =====================================================================================
 *
 *       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;
};

const int kMqLen = 700;

} // namespace

TopicNode::TopicNode(SharedMemory &shm) :
    shm_(shm), sockets_(eSockEnd), state_(eStateUnregistered)
{
	for (int i = eSockStart; i < eSockEnd; ++i) {
		sockets_[i].reset(new ShmSocket(shm_, kMqLen));
	}
	// recv msgs to avoid memory leak.
	auto default_ignore_msg = [](ShmSocket &sock, MsgI &imsg, BHMsgHead &head) { return true; };
	for (auto &p : sockets_) {
		p->Start(default_ignore_msg);
	}
}

TopicNode::~TopicNode()
{
	Stop();
	SockNode().Stop();
	if (state() == eStateUnregistered) {
		for (auto &p : sockets_) { p->Remove(); }
	}
}

void TopicNode::Start(ServerAsyncCB const &server_cb, SubDataCB const &sub_cb, RequestResultCB &client_cb, int nworker)
{
	if (nworker < 1) {
		nworker = 1;
	} else if (nworker > 16) {
		nworker = 16;
	}
	SockNode().Start();
	ServerStart(server_cb, nworker);
	SubscribeStartWorker(sub_cb, nworker);
	ClientStartWorker(client_cb, nworker);
}
void TopicNode::Stop()
{
	for (auto &p : sockets_) { p->Stop(); }
}

bool TopicNode::Register(ProcInfo &proc, MsgCommonReply &reply_body, const int timeout_ms)
{
	info_ = proc;

	auto &sock = SockNode();
	MsgRegister body;
	body.mutable_proc()->Swap(&proc);
	auto AddId = [&](const MQId &id) { body.add_addrs()->set_mq_id(&id, sizeof(id)); };
	AddId(SockNode().id());
	AddId(SockServer().id());
	AddId(SockClient().id());
	AddId(SockSub().id());
	AddId(SockPub().id());

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

	auto CheckResult = [this](MsgI &msg, BHMsgHead &head, MsgCommonReply &rbody) {
		bool ok = head.type() == kMsgTypeCommonReply &&
		          msg.ParseBody(rbody) &&
		          IsSuccess(rbody.errmsg().errcode());
		if (ok) {
			state(eStateOnline);
		} else {
			state_cas(eStateOnline, eStateOffline);
		}
	};

	if (timeout_ms == 0) {
		auto onResult = [this, CheckResult](ShmSocket &socket, MsgI &imsg, BHMsgHead &head) {
			MsgCommonReply body;
			CheckResult(imsg, head, body);
		};
		return sock.Send(&BHTopicCenterAddress(), head, body, onResult);
	} else {
		MsgI reply;
		DEFER1(reply.Release(shm_););
		BHMsgHead reply_head;
		bool r = sock.SendAndRecv(&BHTopicCenterAddress(), head, body, reply, reply_head, timeout_ms);
		if (r) {
			CheckResult(reply, reply_head, reply_body);
		}
		return IsOnline();
	}
}

bool TopicNode::Heartbeat(ProcInfo &proc, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	auto &sock = SockNode();
	MsgHeartbeat body;
	body.mutable_proc()->Swap(&proc);

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

	if (timeout_ms == 0) {
		return sock.Send(&BHTopicCenterAddress(), head, body);
	} else {
		MsgI reply;
		DEFER1(reply.Release(shm_););
		BHMsgHead reply_head;
		bool r = sock.SendAndRecv(&BHTopicCenterAddress(), head, body, reply, reply_head, timeout_ms);
		r = r && reply_head.type() == kMsgTypeCommonReply && reply.ParseBody(reply_body);
		return (r && IsSuccess(reply_body.errmsg().errcode()));
	}
}
bool TopicNode::Heartbeat(const int timeout_ms)
{
	ProcInfo proc;
	proc.set_proc_id(proc_id());
	MsgCommonReply reply_body;
	return Heartbeat(proc, reply_body, timeout_ms);
}

bool TopicNode::ServerRegisterRPC(MsgTopicList &topics, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	auto &sock = SockServer();
	MsgRegisterRPC body;
	body.mutable_topics()->Swap(&topics);

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

	if (timeout_ms == 0) {
		return sock.Send(&BHTopicCenterAddress(), head, body);
	} else {
		MsgI reply;
		DEFER1(reply.Release(shm_););
		BHMsgHead reply_head;
		bool r = sock.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 ServerSyncCB &rcb, int nworker)
{
	auto onRecv = [this, rcb](ShmSocket &sock, MsgI &imsg, BHMsgHead &head) {
		if (head.type() != kMsgTypeRequestTopic || head.route_size() == 0) { return; }
		MsgRequestTopic req;
		if (!imsg.ParseBody(req)) { return; }

		MsgRequestTopicReply reply_body;
		if (rcb(head.proc_id(), req, reply_body)) {
			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));
			}
			auto &remote = head.route().rbegin()->mq_id();
			sock.Send(remote.data(), reply_head, reply_body);
		}
	};

	auto &sock = SockServer();
	return rcb && sock.Start(onRecv, nworker);
}

bool TopicNode::ServerStart(const ServerAsyncCB &acb, int nworker)
{
	auto onRecv = [this, acb](ShmSocket &sock, MsgI &imsg, BHMsgHead &head) {
		if (head.type() != kMsgTypeRequestTopic || head.route_size() == 0) { return; }
		MsgRequestTopic req;
		if (!imsg.ParseBody(req)) { return; }

		SrcInfo *p = new SrcInfo;
		p->route.assign(head.route().begin(), head.route().end());
		p->msg_id = head.msg_id();
		acb(p, *head.mutable_proc_id(), req);
	};

	auto &sock = SockServer();
	return acb && sock.Start(onRecv, nworker);
}

bool TopicNode::ServerRecvRequest(void *&src_info, std::string &proc_id, MsgRequestTopic &request, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	auto &sock = SockServer();

	MsgI imsg;
	BHMsgHead head;
	if (sock.SyncRecv(imsg, head, timeout_ms) && head.type() == kMsgTypeRequestTopic) {
		if (imsg.ParseBody(request)) {
			head.mutable_proc_id()->swap(proc_id);
			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 MsgRequestTopicReply &body)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	auto &sock = SockServer();

	SrcInfo *p = static_cast<SrcInfo *>(src_info);
	DEFER1(delete p);
	if (!p || p->route.empty()) {
		return false;
	}
	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 sock.Send(p->route.back().mq_id().data(), head, body);
}

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(head, reply);
			}
		}
	};

	return SockClient().Start(onData, nworker);
}

bool TopicNode::ClientAsyncRequest(const MsgRequestTopic &req, std::string &out_msg_id, const RequestResultCB &cb)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	const std::string &msg_id(NewMsgId());

	out_msg_id = msg_id;

	auto SendTo = [this, msg_id](const BHAddress &addr, const MsgRequestTopic &req, const RequestResultCB &cb) {
		auto &sock = SockClient();
		BHMsgHead head(InitMsgHead(GetType(req), proc_id(), msg_id));
		AddRoute(head, sock.id());
		head.set_topic(req.topic());

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

	try {
		BHAddress addr;
#if 1
		return (ClientQueryRPCTopic(req.topic(), addr, 3000)) && SendTo(addr, req, cb);
#else
		if (topic_query_cache_.Pick(req.topic(), addr)) {
			return SendTo(addr, req, cb);
		}

		auto &sock = SockClient();
		MsgQueryTopic query;
		query.set_topic(req.topic());
		BHMsgHead head(InitMsgHead(GetType(query), proc_id()));
		AddRoute(head, sock.id());

		auto onQueryResult = [this, SendTo, req, cb](ShmSocket &sock, MsgI &imsg, BHMsgHead &head) {
			MsgQueryTopicReply rep;
			if (head.type() == kMsgTypeQueryTopicReply && imsg.ParseBody(rep)) {
				auto &addr = rep.address();
				if (!addr.mq_id().empty()) {
					topic_query_cache_.Store(req.topic(), addr);
					SendTo(addr, req, cb);
				}
			}
		};
		return sock.Send(&BHTopicCenterAddress(), head, query, std::move(onQueryResult));
#endif

	} catch (...) {
		SetLastError(eError, "internal error.");
		return false;
	}
}

bool TopicNode::ClientSyncRequest(const MsgRequestTopic &request, std::string &out_proc_id, MsgRequestTopicReply &out_reply, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	try {
		auto &sock = SockClient();

		BHAddress addr;
		if (ClientQueryRPCTopic(request.topic(), addr, timeout_ms)) {
			BHMsgHead head(InitMsgHead(GetType(request), proc_id()));
			AddRoute(head, sock.id());
			head.set_topic(request.topic());

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

			if (sock.SendAndRecv(addr.mq_id().data(), head, request, reply_msg, reply_head, timeout_ms) &&
			    reply_head.type() == kMsgTypeRequestTopicReply &&
			    reply_msg.ParseBody(out_reply)) {
				reply_head.mutable_proc_id()->swap(out_proc_id);
				return true;
			}
		} else {
			SetLastError(eNotFound, "remote not found.");
		}
	} catch (...) {
		SetLastError(eError, __func__ + std::string(" internal errer."));
	}
	return false;
}

bool TopicNode::ClientQueryRPCTopic(const Topic &topic, BHAddress &addr, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	auto &sock = SockClient();

	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_.Store(topic, addr);
					return true;
				}
			}
		}
	} else {
	}
	return false;
}

// publish

bool TopicNode::Publish(const MsgPublish &pub, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	try {
		auto &sock = SockPub();
		BHMsgHead head(InitMsgHead(GetType(pub), proc_id()));
		AddRoute(head, sock.id());

		if (timeout_ms == 0) {
			return sock.Send(&BHTopicBusAddress(), head, pub);
		} else {
			MsgI reply;
			DEFER1(reply.Release(shm()););
			BHMsgHead reply_head;
			MsgCommonReply reply_body;
			return sock.SendAndRecv(&BHTopicBusAddress(), head, pub, reply, reply_head, timeout_ms) &&
			       reply_head.type() == kMsgTypeCommonReply &&
			       reply.ParseBody(reply_body) &&
			       IsSuccess(reply_body.errmsg().errcode());
		}
	} catch (...) {
	}
	return false;
}

// subscribe

bool TopicNode::Subscribe(MsgTopicList &topics, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	try {
		auto &sock = SockSub();
		MsgSubscribe sub;
		sub.mutable_topics()->Swap(&topics);

		BHMsgHead head(InitMsgHead(GetType(sub), proc_id()));
		AddRoute(head, sock.id());
		if (timeout_ms == 0) {
			return sock.Send(&BHTopicBusAddress(), head, sub);
		} else {
			MsgI reply;
			DEFER1(reply.Release(shm()););
			BHMsgHead reply_head;
			return sock.SendAndRecv(&BHTopicBusAddress(), head, sub, reply, reply_head, timeout_ms) &&
			       reply_head.type() == kMsgTypeCommonReply &&
			       reply.ParseBody(reply_body) &&
			       IsSuccess(reply_body.errmsg().errcode());
		}
		// TODO wait for result?
	} catch (...) {
		return false;
	}
}

bool TopicNode::SubscribeStartWorker(const SubDataCB &tdcb, int nworker)
{
	auto &sock = SockSub();

	auto AsyncRecvProc = [this, tdcb](ShmSocket &, MsgI &imsg, BHMsgHead &head) {
		if (head.type() == kMsgTypePublish) {
			MsgPublish pub;
			if (imsg.ParseBody(pub)) {
				tdcb(head.proc_id(), pub);
			}
		} else {
			// ignored, or dropped
		}
	};

	return tdcb && sock.Start(AsyncRecvProc, nworker);
}

bool TopicNode::RecvSub(std::string &proc_id, MsgPublish &pub, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, "Not Registered.");
		return false;
	}

	auto &sock = SockSub();
	MsgI msg;
	DEFER1(msg.Release(shm()););
	BHMsgHead head;
	//TODO error msg.
	if (sock.SyncRecv(msg, head, timeout_ms) && head.type() == kMsgTypePublish) {
		if (msg.ParseBody(pub)) {
			head.mutable_proc_id()->swap(proc_id);
			return true;
		}
	}
	return false;
}