#include <iostream>
#include <random>
#include <filesystem>
#include <chrono>

void random_module() {
	std::cout << std::endl << "random_module" << std::endl;
	auto seed = 12312;
	std::default_random_engine generator(seed);

	auto min = 0;
	auto max = 100;
	std::uniform_int_distribution<int> uniform(min, max);

	int random_value = uniform(generator);
	std::cout << random_value << std::endl;

	// Using capture in lambda.
	auto random_generator = [&uniform, &generator]() -> int { return uniform(generator); };

	std::cout << random_generator() << " " << random_generator() << std::endl;
}

void filesystem_module() {
	std::cout << std::endl << "filesystem_module" << std::endl;
	std::filesystem::path root("./");
	for (auto&& item : std::filesystem::recursive_directory_iterator(root)) {
		// There is also 'item.is_directory'.
		if (std::filesystem::is_directory(item.status())) {
			std::cout << "Directory: " << item.path().filename().string() << std::endl;;
		}
		else {
			auto filename = item.path().filename();
			std::cout << "  " << filename.extension().string() << " : " << filename.string() << std::endl;
		}
	}
	// There are other operations for copy/delete/...
}

void chrono_module() {
	std::cout << std::endl << "chrono_module" << std::endl;
	// system_clock
	// steady_clock - never decreasing (leaps seconds, daylight saving time)
	// high_resolution_clock

	auto start = std::chrono::high_resolution_clock::now();
	// Some busy work, just to create a delay.
	for (int x = 0; x < 10000; ++x) {
		for (int y = 0; y < 10000; ++y) {
			int z = x + y;
		}
	}
	auto end = std::chrono::high_resolution_clock::now();

	// Get internal in miliseconds.
	auto ms = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
	std::cout << "Duration: " << ms << std::endl;

	// Showcase of arithmetics.
	std::chrono::seconds seconds(55);
	std::chrono::hours hours(11);
	auto time = hours + seconds;
	std::cout << "Time: " << time << std::endl;
}

int main()
{
	random_module();
	filesystem_module();
	chrono_module();
}