/*
 * =====================================================================================
 *
 *       Filename:  status_main.cc
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年04月16日 12时17分07秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), lichao@aiotlink.com
 *   Organization:  
 *
 * =====================================================================================
 */

#include "app_arg.h"
#include "box.h"
#include "defs.h"
#include "shm.h"
#include "signalhandle.h"
#include <atomic>
#include <chrono>
#include <thread>

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

int status_main(int argc, char const *argv[])
{
	AppArg args(argc, argv);
	auto shm_name = args.Get("shm", BHomeShm().name());
	auto shm_size = std::atol(args.Get("size", "").c_str());
	if (shm_size <= 0 || shm_size > 512) {
		shm_size = 50;
	}
	auto DisplayName = [&]() -> std::string {
		return shm_name;
	};

	SharedMemory shm(shm_name, 1024 * 1024 * shm_size);
	shm_size = shm.get_size() / 1024 / 1024;
	printf("monitoring shm : %s, size : %ldM\n", DisplayName().c_str(), shm_size);
	std::atomic<bool> run(true);

	auto Now = []() { return steady_clock::now(); };
	auto ToMs = [](auto tp) { return duration_cast<milliseconds>(tp.time_since_epoch()).count(); };

	auto showStatus = [&]() {
		auto next = Now();
		const uint64_t start = ToMs(next);
		auto last = 0ul;
		while (run) {
			std::this_thread::sleep_until(next);
			auto passed = ToMs(next) - start;
			auto sec = passed / 1000;

			auto cur = shm.get_free_memory();

			auto Pretty = [](int64_t nbyte) {
				char sign = '+';
				if (nbyte < 0) {
					nbyte = -nbyte;
					sign = '-';
				}
				const int Kb = 1024;
				const int Mb = Kb * 1024;
				int nmb = nbyte / Mb;
				auto left = nbyte - nmb * Mb;
				int nkb = left / Kb;
				int nb = left - nkb * Kb;
				char buf[64] = {0};
				int n = sprintf(buf, " %4dM%4dK%4dB", nmb, nkb, nb);
				int start = (nmb > 0) ? 0 : ((nkb > 0) ? 5 : 10);
				buf[start] = sign;
				return std::string(buf + start);
			};

			char buf[200] = "\n";
			auto Print = [&](bool new_line) {
				int n = sprintf(buf, "\r%6lds avail : %12ld = %s %6lds", sec, cur, Pretty(cur).c_str() + 1, sec);
				printf("%s", buf);
				if (new_line) {
					auto diff = cur - last;
					printf(" (%+6ld = %s)\n", diff, Pretty(diff).c_str());
					printf("%s", buf);
				}
				fflush(stdout);
			};
			Print(cur != last);
			last = cur;
			next += 1000ms;
		}
	};

	std::thread t(showStatus);

	WaitForSignals({SIGINT, SIGTERM});
	run.store(false);
	t.join();

	return 0;
}

namespace
{
static bool install = BoxInstall("bhshmq_status", status_main, "bhome status program.");
}