#include "Utils/ThreadPool.hpp"
#include "precomp.hpp"

namespace Chattr {

ThreadPool::ThreadPool() {
}

ThreadPool::ThreadPool(std::uint32_t numThreads) {
	init(numThreads);
}

ThreadPool::~ThreadPool() {
	terminate_ = true;
	jobQueueCV_.notify_all();

	for (auto& t : workers_)
		t.join();
}

void ThreadPool::init(std::uint32_t numThreads) {
	int numCPU = numThreads;
	if (numThreads == 0) {
#ifdef _WIN32
		SYSTEM_INFO sysinfo;
		GetSystemInfo(&sysinfo);
		numCPU = sysinfo.dwNumberOfProcessors;
#elif __linux__
		numCPU = sysconf(_SC_NPROCESSORS_ONLN);
#endif
		spdlog::info("Auto-detected cpu count: {}", numCPU);
		spdlog::info("Set ThreadPool Worker count to: {}", numCPU);
	}
	workers_.reserve(numCPU);

	while (numCPU--)
		workers_.push_back([this]() { this->Worker(); });
}

void* ThreadPool::Worker() {
#ifdef _WIN32
	DWORD pid = GetCurrentThreadId();
#elif __linux__
	pthread_t pid = pthread_self();
#endif
	spdlog::info("ThreadPool Worker : {} up.", pid);
	while (!terminate_) {
		std::unique_lock<std::mutex> lock(jobQueueMutex);
		jobQueueCV_.wait(lock, [this]() { return !this->jobs_.empty() || terminate_; });
		if (this->jobs_.empty())
			return nullptr;

		auto job = std::move(jobs_.front());
		jobs_.pop();
		lock.unlock();

		spdlog::info("ThreadPool Worker : {} Executing a job", pid);
		job();
	}

	return nullptr;
}

}