/*
 * =====================================================================================
 *
 *       Filename:  center_main.cc
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年04月13日 16时16分26秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), lichao@aiotlink.com
 *   Organization:  
 *
 * =====================================================================================
 */
#include "app_arg.h"
#include "box.h"
#include "center.h"
#include "defs.h"
#include "signalhandle.h"
#include <boost/interprocess/sync/named_mutex.hpp>
#include <chrono>
#include <thread>
using namespace std::chrono_literals;
using namespace bhome_shm;

namespace
{
const std::string kCenterRunningFlag = "bh_center_single_flag_0";

class InstanceFlag
{

public:
	InstanceFlag(SharedMemory &shm, const std::string &name) :
	    shm_(shm), name_(name), run_(false) {}
	~InstanceFlag() { Stop(); }

	bool TryStartAsFirstInstance()
	{
		if (run_) {
			return true;
		}

		auto mtx(shm_.find_or_construct<Mutex>((name_ + "_mutex_0").c_str())());
		auto time_stamp(shm_.find_or_construct<int64_t>((name_ + "_timestamp_0").c_str())(0));

		if (mtx && time_stamp) {
			Guard lock(*mtx);
			auto now = NowSec();
			// printf("old: %ld, now: %ld\n", *time_stamp, now);
			if (now > *time_stamp + 10) {
				*time_stamp = now;
				auto UpdateTime = [this, time_stamp]() {
					while (run_) {
						std::this_thread::sleep_for(1s);
						*time_stamp = NowSec();
					}
				};
				run_.store(true);
				std::thread(UpdateTime).swap(worker_);
				return true;
			}
		}
		return false;
	}

private:
	void Stop()
	{
		run_.store(false);
		if (worker_.joinable()) {
			worker_.join();
		}
	}

	std::thread worker_;
	SharedMemory &shm_;
	std::string name_;
	std::atomic<bool> run_;
};

} // namespace
int center_main(int argc, const char *argv[])
{
	auto &shm = BHomeShm();

	AppArg args(argc, argv);
	if (args.Has("remove")) {
		shm.Remove();
		return 0;
	}

	InstanceFlag inst(shm, kCenterRunningFlag);
	if (!inst.TryStartAsFirstInstance()) {
		printf("another instance is running, exit.\n");
		return 0;
	}

	if (args.Has("daemon") || args.Has("d")) {
		int r = daemon(0, 0); // TODO center control msg to close itself.
	}

	BHCenter center(shm);
	center.Start();

	printf("center started ...\n");
	WaitForSignals({SIGINT, SIGTERM});
	return 0;
}

namespace
{
static bool install = BoxInstall("bhshmq_center", center_main, "bhome center program.");
}