/*
 * =====================================================================================
 *
 *       Filename:  socket.cpp
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年03月30日 15时48分58秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), 
 *   Organization:  
 *
 * =====================================================================================
 */

#include "socket.h"
#include "bh_util.h"
#include "defs.h"
#include "msg.h"

using namespace bhome_msg;
using namespace bhome_shm;

ShmSocket::ShmSocket(Shm &shm, const MQId id, const int len) :
    run_(false), mq_(id, shm, len)
{
	Start();
}
ShmSocket::ShmSocket(bhome_shm::SharedMemory &shm, const int len) :
    run_(false), mq_(shm, len)
{
	Start();
}

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

bool ShmSocket::Start(const RawRecvCB &onData, const IdleCB &onIdle, int nworker)
{
	auto ioProc = [this, onData, onIdle]() {
		auto DoSend = [this]() { return send_buffer_.TrySend(mq()); };
		auto DoRecv = [=] {
			// do not recv if no cb is set.
			if (!onData) {
				return false;
			}
			auto onMsg = [&](MsgI &imsg) {
				DEFER1(imsg.Release());
				onData(*this, imsg);
			};
			MsgI imsg;
			return mq().TryRecv(imsg) ? (onMsg(imsg), true) : false;
		};

		try {
			bool more_to_send = DoSend();
			bool more_to_recv = DoRecv();
			if (onIdle) { onIdle(*this); }
			if (!more_to_send && !more_to_recv) {
				robust::QuickSleep();
			}
		} catch (...) {
		}
	};

	std::lock_guard<std::mutex> lock(mutex_);
	StopNoLock();

	run_.store(true);
	for (int i = 0; i < nworker; ++i) {
		workers_.emplace_back([this, ioProc]() { while (run_) { ioProc(); } });
	}
	return true;
}

bool ShmSocket::Start(int nworker, const RecvCB &onData, const IdleCB &onIdle)
{
	auto ioProc = [this, onData, onIdle]() {
		auto DoSend = [this]() { return send_buffer_.TrySend(mq()); };
		auto DoRecv = [=] {
			auto onRecvWithPerMsgCB = [this, onData](ShmSocket &socket, MsgI &imsg, BHMsgHead &head) {
				RecvCB cb;
				if (per_msg_cbs_->Pick(head.msg_id(), cb)) {
					cb(socket, imsg, head);
				} else if (onData) {
					onData(socket, imsg, head);
				}
			};

			// do not recv if no cb is set.
			if (!onData && per_msg_cbs_->empty()) {
				return false;
			}
			auto onMsg = [&](MsgI &imsg) {
				DEFER1(imsg.Release());
				BHMsgHead head;
				if (imsg.ParseHead(head)) {
					onRecvWithPerMsgCB(*this, imsg, head);
				}
			};
			MsgI imsg;
			return mq().TryRecv(imsg) ? (onMsg(imsg), true) : false;
		};

		try {
			bool more_to_send = DoSend();
			bool more_to_recv = DoRecv();
			if (onIdle) { onIdle(*this); }
			if (!more_to_send && !more_to_recv) {
				robust::QuickSleep();
			}
		} catch (...) {
		}
	};

	std::lock_guard<std::mutex> lock(mutex_);
	StopNoLock();

	run_.store(true);
	for (int i = 0; i < nworker; ++i) {
		workers_.emplace_back([this, ioProc]() { while (run_) { ioProc(); } });
	}
	return true;
}

bool ShmSocket::Stop()
{
	std::lock_guard<std::mutex> lock(mutex_);
	return StopNoLock();
}

bool ShmSocket::StopNoLock()
{
	if (run_.exchange(false)) {
		for (auto &w : workers_) {
			if (w.joinable()) {
				w.join();
			}
		}
		workers_.clear();
		return true;
	}
	return false;
}

//maybe reimplment, using async cbs?
bool ShmSocket::SyncRecv(bhome_msg::MsgI &msg, bhome_msg::BHMsgHead &head, const int timeout_ms)
{
	// std::lock_guard<std::mutex> lock(mutex_); // seems no need to lock mutex_.
	bool got = (timeout_ms == 0) ? mq().TryRecv(msg) : mq().Recv(msg, timeout_ms);
	if (got) {
		if (msg.ParseHead(head)) {
			return true;
		} else {
			msg.Release();
		}
	}
	return false;
}