/*
 * =====================================================================================
 *
 *       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 "sleeper.h"
#include <chrono>
#include <list>

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

const char *const kErrMsgNotInit = "BHome node NOT initialized.";
const char *const kErrMsgNotRegistered = "BHome node NOT registered.";

namespace
{
bool ValidUserSymbol(const std::string &s)
{
	return !s.empty() && s[0] != '#' && s[0] != '@';
}

inline void AddRoute(BHMsgHead &head, const ShmSocket &sock)
{
	auto route = head.add_route();
	route->set_mq_id(sock.id());
	route->set_abs_addr(sock.AbsAddr());
}

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

const int kMqLen = 700;

} // namespace

TopicNode::TopicNode(SharedMemory &shm, MQId ssn_id) :
    shm_(shm), state_(eStateUninited), ssn_id_(ssn_id)
{
}

TopicNode::~TopicNode()
{
	Stop();
}

bool TopicNode::Init()
{
	std::lock_guard<std::mutex> lk(mutex_);

	if (Valid()) {
		return true;
	} else if (info_.proc_id().empty()) {
		return false;
	}

	if (ssn_id_ == 0) {
		ssn_id_ = NewSession();
	}
	LOG_DEBUG() << "Node Init, id " << ssn_id_;
	auto NodeInit = [&]() {
		int64_t init_request = ssn_id_ << 4 | EncodeCmd(eCmdNodeInit);
		int64_t reply = 0;
		if (BHNodeInit(shm(), init_request, reply) && DecodeCmd(reply) == eCmdNodeInitReply) {
			int64_t abs_addr = reply >> 4;
			sockets_.emplace_back(new ShmSocket(abs_addr, shm_, ssn_id_));
			LOG_DEBUG() << "node init ok";
		} else {
			LOG_ERROR() << "Node Init Error";
		}
	};
	if (sockets_.empty()) {
		NodeInit();
	}
	if (!sockets_.empty()) {
		auto onMsg = [this](ShmSocket &socket, MsgI &imsg, BHMsgHead &head) {
			LOG_DEBUG() << "node recv type: " << head.type();
			switch (head.type()) {
			case kMsgTypeProcInit: {
				// reuse msg to send proc init.
				MsgProcInit body;
				body.set_extra_mq_num(eSockEnd - eSockStart - 1);
				auto head = InitMsgHead(GetType(body), info_.proc_id(), ssn_id_);
				AddRoute(head, socket);
				if (imsg.Fill(head, body)) {
					socket.Send(CenterAddr(), imsg);
				}
			} break;
			case kMsgTypeProcInitReply: {
				LOG_DEBUG() << "got proc init reply";
				MsgProcInitReply reply;
				if (imsg.ParseBody(reply) && IsSuccess(reply.errmsg().errcode())) {
					for (auto &addr : reply.extra_mqs()) {
						LOG_DEBUG() << "add socket " << addr.abs_addr() << ", id:" << addr.mq_id();
						sockets_.emplace_back(new ShmSocket(addr.abs_addr(), shm(), addr.mq_id()));
					}
					SetProcIndex(reply.proc_index());
					this->state_ = eStateUnregistered;

					ServerStart(ServerAsyncCB(), 1);
					SubscribeStartWorker(SubDataCB(), 1);
				}
			} break;
			default: break;
			}
			return true;
		};
		SockNode().Start(1, onMsg);
		return true;
	}
	return false;
}

void TopicNode::Start(ServerAsyncCB const &server_cb, SubDataCB const &sub_cb, RequestResultCB &client_cb, int nworker)
{
	if (!Init()) {
		SetLastError(eError, kErrMsgNotInit);
		return;
	}
	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::DoRegister(const bool internal, ProcInfo &proc, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!internal && !ValidUserSymbol(proc.proc_id())) {
		SetLastError(eInvalidInput, "invalid proc id :'" + proc.proc_id() + "'");
		return false;
	}

	{
		std::lock_guard<std::mutex> lk(mutex_);
		info_ = proc;
	}

	if (!Init()) {
		SetLastError(eError, kErrMsgNotInit);
		return false;
	}
	auto end_time = steady_clock::now() + milliseconds(timeout_ms);

	while (!Valid() && steady_clock::now() < end_time) {
		std::this_thread::yield();
	}
	if (!Valid()) {
		SetLastError(eError, kErrMsgNotInit);
		return false;
	}

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

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

	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(CenterAddr(), head, body, onResult);
	} else {
		MsgI reply(shm());
		DEFER1(reply.Release(););
		BHMsgHead reply_head;
		bool r = sock.SendAndRecv(CenterAddr(), head, body, reply, reply_head, timeout_ms);
		if (r) {
			CheckResult(reply, reply_head, reply_body);
		}
		return IsOnline();
	}
}
bool TopicNode::Unregister(ProcInfo &proc, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

	info_.Clear();
	state_cas(eStateOnline, eStateOffline);

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

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

	auto CheckResult = [this](MsgI &msg, BHMsgHead &head, MsgCommonReply &rbody) {
		bool r = head.type() == kMsgTypeCommonReply &&
		         msg.ParseBody(rbody) &&
		         IsSuccess(rbody.errmsg().errcode());
		return r;
	};

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

bool TopicNode::Heartbeat(ProcInfo &proc, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

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

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

	if (timeout_ms == 0) {
		return sock.Send(CenterAddr(), head, body);
	} else {
		MsgI reply(shm());
		DEFER1(reply.Release(););
		BHMsgHead reply_head;
		bool r = sock.SendAndRecv(CenterAddr(), 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::QueryTopicAddress(BHAddress &dest, MsgQueryTopic &query, MsgQueryTopicReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}
	auto &sock = SockNode();

	BHMsgHead head(InitMsgHead(GetType(query), proc_id(), ssn()));
	AddRoute(head, sock);

	MsgI reply(shm());
	DEFER1(reply.Release());
	BHMsgHead reply_head;
	return (sock.SendAndRecv(CenterAddr(), head, query, reply, reply_head, timeout_ms) &&
	        reply_head.type() == kMsgTypeQueryTopicReply &&
	        reply.ParseBody(reply_body));
}

bool TopicNode::QueryProcs(BHAddress &dest, MsgQueryProc &query, MsgQueryProcReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}
	auto &sock = SockNode();

	BHMsgHead head(InitMsgHead(GetType(query), proc_id(), ssn()));
	AddRoute(head, sock);

	MsgI reply(shm());
	DEFER1(reply.Release());
	BHMsgHead reply_head;
	return (sock.SendAndRecv(CenterAddr(), head, query, reply, reply_head, timeout_ms) &&
	        reply_head.type() == kMsgTypeQueryProcReply &&
	        reply.ParseBody(reply_body));
}

bool TopicNode::DoServerRegisterRPC(const bool internal, MsgTopicList &topics, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!internal) {
		for (auto &&topic : topics.topic_list()) {
			if (!ValidUserSymbol(topic)) {
				SetLastError(eInvalidInput, "invalid user topic :'" + topic + "'");
				return false;
			}
		}
	}

	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

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

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

	if (timeout_ms == 0) {
		return sock.Send(CenterAddr(), head, body);
	} else {
		MsgI reply(shm());
		DEFER1(reply.Release(););
		BHMsgHead reply_head;
		bool r = sock.SendAndRecv(CenterAddr(), 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(), ssn(), head.msg_id()));

			for (int i = 0; i < head.route_size() - 1; ++i) {
				reply_head.add_route()->Swap(head.mutable_route(i));
			}
			MQInfo remote = {head.route().rbegin()->mq_id(), head.route().rbegin()->abs_addr()};
			sock.Send(remote, reply_head, reply_body);
		}
	};

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

bool TopicNode::ServerStart(const ServerAsyncCB &acb, int nworker)
{
	if (acb) {
		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; }

			try {
				SrcInfo *p = new SrcInfo;
				if (!p) {
					throw std::runtime_error("no memory.");
				}
				p->route.assign(head.route().begin(), head.route().end());
				p->msg_id = head.msg_id();
				acb(p, *head.mutable_proc_id(), req);
			} catch (std::exception &e) {
				LOG_ERROR() << "error server handle msg:" << e.what();
			}
		};

		return SockServer().Start(onRecv, nworker);
	} else {
		auto onRequest = [this](ShmSocket &socket, MsgI &msg, BHMsgHead &head) {
			server_buffer_->Write(std::move(head), msg.body());
		};
		return SockServer().Start(onRequest, nworker);
	}
}

bool TopicNode::ServerRecvRequest(void *&src_info, std::string &proc_id, MsgRequestTopic &request, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}
	BHMsgHead head;
	std::string body;
	FibUSleeper sleeper(1000 * 10);
	auto end_time = steady_clock::now() + milliseconds(timeout_ms);
	while (!server_buffer_->Read(head, body)) {
		if (steady_clock::now() < end_time) {
			sleeper.Sleep();
		} else {
			return false;
		}
	}

	if (head.type() == kMsgTypeRequestTopic) {
		if (request.ParseFromString(body)) {
			head.mutable_proc_id()->swap(proc_id);
			try {
				SrcInfo *p = new SrcInfo;
				if (!p) {
					throw std::runtime_error("no memory.");
				}
				p->route.assign(head.route().begin(), head.route().end());
				p->msg_id = head.msg_id();
				src_info = p;
				return true;
			} catch (std::exception &e) {
				LOG_ERROR() << "error recv request: " << e.what();
				return false;
			}
		}
	}
	return false;
}

bool TopicNode::ServerSendReply(void *src_info, const MsgRequestTopicReply &body)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		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(), ssn(), p->msg_id));
	for (unsigned i = 0; i < p->route.size() - 1; ++i) {
		head.add_route()->Swap(&p->route[i]);
	}
	MQInfo dest = {p->route.back().mq_id(), p->route.back().abs_addr()};
	return sock.Send(dest, 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 BHAddress &remote_addr, const MsgRequestTopic &req, std::string &out_msg_id, const RequestResultCB &cb)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

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

	out_msg_id = msg_id;

	auto SendTo = [this, remote_addr, msg_id](const MQInfo &remote, const MsgRequestTopic &req, const RequestResultCB &cb) {
		auto &sock = SockClient();
		BHMsgHead head(InitMsgHead(GetType(req), proc_id(), ssn(), msg_id));
		*head.mutable_dest() = remote_addr;
		AddRoute(head, sock);
		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(remote, head, req, onRecv);
		} else {
			return sock.Send(remote, head, req);
		}
	};

	try {
		if (remote_addr.ip().empty()) {
			BHAddress addr;
			return (ClientQueryRPCTopic(req.topic(), addr, 3000)) && SendTo(MQInfo{addr.mq_id(), addr.abs_addr()}, req, cb);
		} else {
			return SendTo(CenterAddr(), req, cb);
		}
	} catch (...) {
		SetLastError(eError, "internal error.");
		return false;
	}
}

bool TopicNode::ClientSyncRequest(const BHAddress &remote_addr, const MsgRequestTopic &request, std::string &out_proc_id, MsgRequestTopicReply &out_reply, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

	try {
		auto &sock = SockClient();
		MQInfo dest;
		if (!remote_addr.ip().empty()) {
			dest = CenterAddr();
		} else {
			BHAddress addr;
			if (ClientQueryRPCTopic(request.topic(), addr, timeout_ms)) {
				dest.offset_ = addr.abs_addr();
				dest.id_ = addr.mq_id();
			} else {
				return false;
			}
		}

		BHMsgHead head(InitMsgHead(GetType(request), proc_id(), ssn()));
		*head.mutable_dest() = remote_addr;
		AddRoute(head, sock);
		head.set_topic(request.topic());

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

		if (sock.SendAndRecv(dest, 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;
		}
	} catch (std::exception &e) {
		LOG_ERROR() << __func__ << " exception: " << e.what();
		SetLastError(eError, __func__ + std::string(" internal errer."));
	}
	return false;
}

int TopicNode::QueryTopicServers(const Topic &topic, std::vector<NodeAddress> &addr, const int timeout_ms)
{
	int n = 0;
	MsgQueryTopic query;
	query.set_topic(topic);
	MsgQueryTopicReply rep;
	BHAddress dest; // empty means local.
	if (QueryTopicAddress(dest, query, rep, timeout_ms)) {
		auto &ls = rep.node_address();
		n = ls.size();
		for (auto &na : ls) {
			addr.push_back(na);
		}
	}
	return n;
}

bool TopicNode::ClientQueryRPCTopic(const Topic &topic, BHAddress &addr, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

	if (topic_query_cache_.Find(topic, addr)) {
		return true;
	}
	std::vector<NodeAddress> lst;
	if (QueryTopicServers(topic, lst, timeout_ms)) {
		addr = lst.front().addr();
		if (addr.mq_id() != 0) {
			topic_query_cache_.Store(topic, addr);
			return true;
		}
	}
	SetLastError(eNotFound, "remote not found.");
	return false;
}

// publish

bool TopicNode::Publish(const MsgPublish &pub, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

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

		if (timeout_ms == 0) {
			return sock.Send(BusAddr(), head, pub);
		} else {
			MsgI reply(shm());
			DEFER1(reply.Release(););
			BHMsgHead reply_head;
			MsgCommonReply reply_body;
			return sock.SendAndRecv(BusAddr(), 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::DoSubscribe(MsgTopicList &topics, const bool net, MsgCommonReply &reply_body, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

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

		BHMsgHead head(InitMsgHead(GetType(sub), proc_id(), ssn()));
		AddRoute(head, sock);
		if (timeout_ms == 0) {
			return sock.Send(BusAddr(), head, sub);
		} else {
			MsgI reply(shm());
			DEFER1(reply.Release(););
			BHMsgHead reply_head;
			return sock.SendAndRecv(BusAddr(), head, sub, reply, reply_head, timeout_ms) &&
			       reply_head.type() == kMsgTypeCommonReply &&
			       reply.ParseBody(reply_body) &&
			       IsSuccess(reply_body.errmsg().errcode());
		}
	} catch (...) {
		return false;
	}
}

bool TopicNode::SubscribeStartWorker(const SubDataCB &tdcb, int nworker)
{
	if (tdcb) {
		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 SockSub().Start(AsyncRecvProc, nworker);
	} else {
		auto onSub = [this](ShmSocket &socket, MsgI &msg, BHMsgHead &head) {
			sub_buffer_->Write(std::move(head), msg.body());
		};
		return SockSub().Start(onSub, nworker);
	}
}

bool TopicNode::RecvSub(std::string &proc_id, MsgPublish &pub, const int timeout_ms)
{
	if (!IsOnline()) {
		SetLastError(eNotRegistered, kErrMsgNotRegistered);
		return false;
	}

	BHMsgHead head;
	std::string body;
	FibUSleeper sleeper(1000 * 10);
	auto end_time = steady_clock::now() + milliseconds(timeout_ms);
	while (!sub_buffer_->Read(head, body)) {
		if (steady_clock::now() < end_time) {
			sleeper.Sleep();
		} else {
			return false;
		}
	}
	if (head.type() == kMsgTypePublish) {
		if (pub.ParseFromString(body)) {
			head.mutable_proc_id()->swap(proc_id);
			return true;
		}
	}
	SetLastError(eError, "invalid subcribe msg received.");
	return false;
}