#ifndef FORTUNA_FORTUNA_CPP
#define FORTUNA_FORTUNA_CPP

#include "fortuna.h"
#include "seed_file_management.h"
#include "util.h"

#include <cryptopp/cryptlib.h>
#include <fmt/chrono.h>

#include <chrono>
#include <exception>
#include <memory>
#include <mutex>

namespace fortuna {
static constexpr const unsigned int min_pool_size{64};
auto now{std::chrono::steady_clock::now()};


Fortuna::Fortuna() {
	try {
		initialize_prng();
	}
	catch (CryptoPP::Exception& e) {
		fmt::print(stderr, "{}\n", e.what());
	}
	th_gen = std::thread(&Fortuna::generator_service,
						 this,
						 std::make_shared<fortuna::generator::Generator>());
	th_accu = std::thread(&Fortuna::accumulator_service, this);
	th_sfm = std::thread(&Fortuna::seed_file_manager_service, this);
}
Fortuna::~Fortuna() noexcept {
	if (th_gen.joinable()) {
		th_gen.join();
	}
	if (th_gen.joinable()) {
		th_accu.join();
	}
	if (th_sfm.joinable()) {
		th_sfm.join();
	}
}


auto Fortuna::random_data(unsigned int n_bytes) -> void {
	const auto start{std::chrono::system_clock::now()};
	fmt::print("random_data starting - {}\n", start);
	auto elapsed{std::chrono::duration_cast<std::chrono::milliseconds>(
		std::chrono::steady_clock::now().time_since_epoch() -
		now.time_since_epoch())};
	fmt::print("[i] fortuna: last_reseed: {} ago\n", elapsed);
	now = std::chrono::steady_clock::now();
	std::string s;
	// synchronise reads and writes to the between
	// {generator,accumulator,fortuna} service threads -> in member functions
	const int pools_to_use{ffsll(static_cast<int>(get_reseed_ctr()))};

	fmt::print("[*] fortuna: current p0 length: {}\n",
			   R.pools[0].get_s_length());
	if (R.pools[0].get_s_length() >= min_pool_size &&
		elapsed > R.Gen.reseed_interval) {
		for (int i = 0; i < static_cast<int>(pools_to_use); ++i) {
			if (R.reseed_ctr % static_cast<int>(pow(2, i)) == 0) {
				try {
					s.append(fortuna::Util::do_sha(R.pools[i].get_s()));
					R.pools[i].clear_pool();
				}
				catch (std::exception& e) {
					fmt::print("{}\n", e.what());
				}
			}
		}
		incr_reseed_ctr();
		R.Gen.reseed(s);
		R.last_reseed = std::chrono::steady_clock::now();
		s.clear();
	}

	fmt::print("[i] fortuna: reseed ctr {}\n", R.reseed_ctr);
	if (R.reseed_ctr == 0) {
		fmt::print("[!] ERROR: reseed ctr is 0, PRNG not seeded!\n");
		throw std::runtime_error("illegal state, PRNG not seeded");
	}
	else {
		std::string n{R.Gen.generate_random_data(n_bytes)};
		fmt::print("got you {} proper bytes from generate_random_data -> {}\n",
				   n_bytes,
				   n);
		n.clear();
	}

	const auto end{std::chrono::system_clock::now()};
	std::chrono::duration<float> diff = end - start;
	fmt::print("random_data done - {}\n", end);
	fmt::print("getting random data took {:.{}f}s\n", diff.count(), 12);
} // random_data

auto Fortuna::generator_service(
	std::shared_ptr<fortuna::generator::Generator> Gen) -> void {
	int i{0};
	std::chrono::milliseconds sleep_time{1000};
	std::chrono::system_clock::time_point time_point;
	std::unique_lock<std::mutex> p_ul(print_mtx);
	fmt::print("[i] fortuna: starting generator service\n");
	p_ul.unlock();

	while (true) {
		p_ul.lock();
		fmt::print("[*] g: sleeping [{}]\n", i);
		p_ul.unlock();
		++i;
		time_point = fortuna::Util::current_time();
		p_ul.lock();
		fmt::print("[*] g: @{}\n", time_point);
		p_ul.unlock();
		std::this_thread::sleep_until(time_point +
									  std::chrono::milliseconds(sleep_time));
	}
}

auto Fortuna::accumulator_service() -> void {
	std::chrono::seconds sleep_time{10};
	std::chrono::system_clock::time_point time_point;
	std::unique_lock<std::mutex> p_ul(print_mtx);
	fmt::print("[i] fortuna: starting accumulator service\n");
	p_ul.unlock();

	while (true) {
		time_point = fortuna::Util::current_time();
		p_ul.lock();
		fmt::print("[*] accu: @{}\n", time_point);
		p_ul.unlock();
		std::this_thread::sleep_until(time_point +
									  std::chrono::seconds(sleep_time));
	}
}

auto Fortuna::seed_file_manager_service() -> void {
	static constexpr const std::chrono::seconds checkup_interval{10};
	std::unique_lock<std::mutex> p_ul(print_mtx);
	fmt::print("[i] fortuna: starting seed file manager service\n");
	fmt::print("[*] sfm: checkup interval {}\n", checkup_interval);
	p_ul.unlock();
	auto right_now{fortuna::Util::current_time()};
	std::unique_lock<std::mutex> mtx_l(mtx);
	std::unique_lock<std::mutex> a_ul(accu_mtx);
	SeedFileManager sfm(this->accumulator);
	a_ul.unlock();
	mtx_l.unlock();

	while (true) {
		right_now = fortuna::Util::current_time();
		p_ul.lock();
		fmt::print("[*] sfm: checkup time @{}\n", right_now);
		if (!sfm.is_job_running()) {
			fmt::print("[*] sfm: job not running, starting\n");
			try {
				sfm.do_stuff();
			}
			catch (std::exception& e) {
				fmt::print(stderr, "[!] sfm: exception caught: {}\n", e.what());
			}
		}
		else {
			fmt::print("[*] sfm: job running\n");
		}
		p_ul.unlock();
		std::this_thread::sleep_until(right_now +
									  std::chrono::seconds(checkup_interval));
	}
}

} // namespace fortuna

#endif // FORTUNA_FORTUNA_CPP