#include "Timer.hpp"

#include <sys/timerfd.h>

namespace nanosm {

	Timer::Timer(nanosm::EventLoop& ev)
		: nanosm::EventLoop::IoObject(ev) {
		timerFd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
		if(timerFd < 0)
			perror("timerfd_create");
	}

	Timer::~Timer() {
		Reset();
	}

	void Timer::Reset() {
		if(timerFd != -1)
			close(timerFd);
	}

	int Timer::GetFD() const {
		return timerFd;
	}

	int Timer::InterestedEvents() const {
		/// TimerFD only returns EPOLLIN.
		return EPOLLIN;
	}

	void Timer::OnReady(int eventMask) {
		u64 expiryCount {};

		// Read the amount of timer expires so it stops screaming.
		static_cast<void>(read(timerFd, &expiryCount, sizeof(expiryCount)));

		// Post the expiry callback directly into the event loop
		if(cb)
			eventLoop.Post(cb);
	}

	void Timer::SetExpiryCallback(std::function<void()> expire) {
		cb = expire;
	}

	void Timer::Arm(u32 durationSeconds) {
		itimerspec spec {};
		spec.it_value.tv_sec = durationSeconds;

		// TODO: validate.
		timerfd_settime(timerFd, 0, &spec, nullptr);
	}

} // namespace nanosm