/*
 * =====================================================================================
 *
 *       Filename:  shm_queue.h
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年03月25日 10时35分09秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), 
 *   Organization:  
 *
 * =====================================================================================
 */

#ifndef SHM_QUEUE_JE0OEUP3
#define SHM_QUEUE_JE0OEUP3

#include "msg.h"
#include "shm.h"
#include <boost/circular_buffer.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>

namespace bhome_shm
{

template <class D>
using Circular = boost::circular_buffer<D, Allocator<D>>;

typedef boost::uuids::uuid MQId;

template <class D>
class SharedQueue : private Circular<D>
{
	typedef Circular<D> Super;
	Mutex mutex_;
	Cond cond_read_;
	Cond cond_write_;
	Mutex &mutex() { return mutex_; }

	static boost::posix_time::ptime MSFromNow(const int ms)
	{
		using namespace boost::posix_time;
		ptime cur = boost::posix_time::microsec_clock::universal_time();
		return cur + millisec(ms);
	}

public:
	SharedQueue(const uint32_t len, Allocator<D> const &alloc) :
	    Super(len, alloc) {}
	using Super::capacity;
	using Super::size;
	template <class Iter, class OnWrite>
	int Write(Iter begin, Iter end, const int timeout_ms, const OnWrite &onWrite)
	{
		int n = 0;
		if (begin != end) {
			auto endtime = MSFromNow(timeout_ms);
			Guard lock(mutex());
			while (cond_write_.timed_wait(lock, endtime, [&]() { return !this->full(); })) {
				onWrite(*begin);
				this->push_back(*begin);
				++n;
				cond_read_.notify_one();
				if (++begin == end) {
					break;
				}
			}
		}
		return n;
	}

	template <class OnWrite>
	bool Write(const D &buf, const int timeout_ms, const OnWrite &onWrite)
	{
		return Write(&buf, (&buf) + 1, timeout_ms, onWrite);
	}
	bool Write(const D &buf, const int timeout_ms)
	{
		return Write(buf, timeout_ms, [](const D &buf) {});
	}

	template <class OnData>
	bool Read(const int timeout_ms, OnData onData)
	{
		int n = 0;
		auto endtime = MSFromNow(timeout_ms);
		Guard lock(mutex());
		while (cond_read_.timed_wait(lock, endtime, [&]() { return !this->empty(); })) {
			const bool more = onData(this->front());
			this->pop_front();
			cond_write_.notify_one();
			++n;
			if (!more) {
				break;
			}
		}
		return n;
	}

	bool Read(D &buf, const int timeout_ms)
	{
		auto read1 = [&](D &d) {
			using std::swap;
			swap(buf, d);
			return false;
		};
		return Read(timeout_ms, read1) == 1;
	}
};

using namespace bhome_msg;

class ShmMsgQueue : private ShmObject<SharedQueue<MsgI>>
{
	typedef ShmObject<SharedQueue<MsgI>> Super;
	typedef Super::Data Queue;
	typedef std::function<void()> OnSend;
	bool Write(const MsgI &buf, const int timeout_ms) { return data()->Write(buf, timeout_ms); }
	bool Read(MsgI &buf, const int timeout_ms) { return data()->Read(buf, timeout_ms); }
	MQId id_;

protected:
	ShmMsgQueue(const std::string &raw_name, ShmType &segment, const int len); // internal use.
public:
	ShmMsgQueue(const MQId &id, ShmType &segment, const int len);
	ShmMsgQueue(ShmType &segment, const int len);
	~ShmMsgQueue();
	const MQId &Id() const { return id_; }

	bool Recv(BHMsg &msg, const int timeout_ms);
	bool Recv(MsgI &msg, const int timeout_ms) { return Read(msg, timeout_ms); }
	static bool Send(SharedMemory &shm, const MQId &remote_id, const MsgI &msg, const int timeout_ms, OnSend const &onsend);
	static bool Send(SharedMemory &shm, const MQId &remote_id, const MsgI &msg, const int timeout_ms);

	template <class... Extra>
	bool Send(const MQId &remote_id, const MsgI &msg, const int timeout_ms, Extra const &...extra)
	{
		return Send(shm(), remote_id, msg, timeout_ms, extra...);
	}

	template <class... Extra>
	bool Send(const MQId &remote_id, const BHMsg &data, const int timeout_ms, Extra const &...extra)
	{
		MsgI msg;
		if (msg.Make(shm(), data)) {
			if (Send(shm(), remote_id, msg, timeout_ms, extra...)) {
				return true;
			} else {
				msg.Release(shm());
			}
		}
		return false;
	}
	size_t Pending() const { return data()->size(); }
};

} // namespace bhome_shm

#endif // end of include guard: SHM_QUEUE_JE0OEUP3