/*
 * =====================================================================================
 *
 *       Filename:  socket.h
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年03月30日 15时49分19秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), 
 *   Organization:  
 *
 * =====================================================================================
 */

#ifndef SOCKET_GWTJHBPO
#define SOCKET_GWTJHBPO

#include "defs.h"
#include "shm_queue.h"
#include <atomic>
#include <boost/noncopyable.hpp>
#include <condition_variable>
#include <functional>
#include <memory>
#include <mutex>
#include <thread>
#include <vector>

using namespace bhome_msg;

class ShmSocket : private boost::noncopyable
{
protected:
	typedef bhome_shm::ShmMsgQueue Queue;

public:
	typedef bhome_shm::SharedMemory Shm;
	typedef std::function<void(ShmSocket &sock, MsgI &imsg, BHMsgHead &head)> RecvCB;
	typedef std::function<bool(ShmSocket &sock, MsgI &imsg, BHMsgHead &head)> PartialRecvCB;
	typedef std::function<void(ShmSocket &sock)> IdleCB;

	ShmSocket(Shm &shm, const MQId &id, const int len);
	ShmSocket(Shm &shm, const int len = 12);
	~ShmSocket();
	const MQId &id() const { return mq().Id(); }
	Shm &shm() { return shm_; }
	// start recv.
	bool Start(int nworker = 1, const RecvCB &onData = RecvCB(), const IdleCB &onIdle = IdleCB());
	bool Start(const RecvCB &onData, const IdleCB &onIdle, int nworker = 1) { return Start(nworker, onData, onIdle); }
	bool Start(const RecvCB &onData, int nworker = 1) { return Start(nworker, onData); }
	bool Stop();
	size_t Pending() const { return mq().Pending(); }

	bool Send(const void *id, const MsgI &imsg, const int timeout_ms)
	{
		return mq().Send(*static_cast<const MQId *>(id), imsg, timeout_ms);
	}
	//TODO reimplment, using async.
	bool SyncRecv(MsgI &msg, bhome::msg::BHMsgHead &head, const int timeout_ms);

	template <class Body>
	bool Send(const void *valid_remote, const BHMsgHead &head, const Body &body, const int timeout_ms, const RecvCB &cb = RecvCB())
	{
		assert(valid_remote);
		try {
			if (cb) {
				auto RegisterCB = [&]() {
					std::lock_guard<std::mutex> lock(mutex());
					async_cbs_.emplace(head.msg_id(), cb);
				};
				return mq().Send(*static_cast<const MQId *>(valid_remote), head, body, timeout_ms, RegisterCB);
			} else {
				return mq().Send(*static_cast<const MQId *>(valid_remote), head, body, timeout_ms);
			}
		} catch (...) {
			return false;
		}
	}

	template <class Body>
	bool SendAndRecv(const void *remote, const BHMsgHead &head, const Body &body, MsgI &reply, BHMsgHead &reply_head, const int timeout_ms)
	{
		struct State {
			std::mutex mutex;
			std::condition_variable cv;
			bool canceled = false;
		};

		try {
			std::shared_ptr<State> st(new State);
			auto endtime = std::chrono::steady_clock::now() + std::chrono::milliseconds(timeout_ms);

			auto OnRecv = [st, &reply, &reply_head](ShmSocket &sock, MsgI &msg, BHMsgHead &head) {
				std::unique_lock<std::mutex> lk(st->mutex);
				if (!st->canceled) {
					reply.swap(msg);
					reply_head.Swap(&head);
					st->cv.notify_one();
				} else {
				}
			};

			std::unique_lock<std::mutex> lk(st->mutex);
			bool sendok = Send(remote, head, body, timeout_ms, OnRecv);
			if (sendok && st->cv.wait_until(lk, endtime) == std::cv_status::no_timeout) {
				return true;
			} else {
				st->canceled = true;
				return false;
			}
		} catch (...) {
			return false;
		}
	}

protected:
	const Shm &shm() const { return shm_; }
	Queue &mq() { return mq_; } // programmer should make sure that mq_ is valid.
	const Queue &mq() const { return mq_; }
	std::mutex &mutex() { return mutex_; }

private:
	bool StopNoLock();
	bool RunningNoLock() { return !workers_.empty(); }

	Shm &shm_;
	std::vector<std::thread> workers_;
	std::mutex mutex_;
	std::atomic<bool> run_;

	Queue mq_;
	std::unordered_map<std::string, RecvCB> async_cbs_;
};

#endif // end of include guard: SOCKET_GWTJHBPO