#include "../lib/Core.hpp"
#include <cassert>
#include <iostream>
#include <thread>
#include <chrono>
#include <sys/eventfd.h>
#include <unistd.h>
#include <atomic>
#include <vector>

class TestEventLoop
{
private:
	std::unique_ptr<reactor::EventLoop> loop_;
	std::thread thread_;

public:
	TestEventLoop()
	{
		thread_ = std::thread([this]() {
			loop_ = std::make_unique<reactor::EventLoop>();
			loop_->loop();
		});

		std::this_thread::sleep_for(std::chrono::milliseconds(10));
	}

	~TestEventLoop()
	{
		if (loop_) {
			loop_->quit();
		}
		if (thread_.joinable()) {
			thread_.join();
		}
	}

	reactor::EventLoop* getLoop() { return loop_.get(); }
};

void test_timer_basic()
{
	std::cout << "Testing basic timer functionality...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	bool timer_fired = false;
	[[maybe_unused]] auto timer_id = loop->runAfter(reactor::Duration(50), [&timer_fired]() {
		timer_fired = true;
	});

	std::this_thread::sleep_for(std::chrono::milliseconds(100));
	assert(timer_fired);

	std::cout << "✓ Basic timer passed\n";
}

void test_timer_cancellation()
{
	std::cout << "Testing timer cancellation...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	bool timer_fired = false;
	auto timer_id = loop->runAfter(reactor::Duration(100), [&timer_fired]() {
		timer_fired = true;
	});

	loop->cancel(timer_id);
	std::this_thread::sleep_for(std::chrono::milliseconds(150));
	assert(!timer_fired);

	std::cout << "✓ Timer cancellation passed\n";
}

void test_repeating_timer()
{
	std::cout << "Testing repeating timer...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	int count = 0;
	auto timer_id = loop->runEvery(reactor::Duration(20), [&count]() {
		count++;
	});

	std::this_thread::sleep_for(std::chrono::milliseconds(85));
	loop->cancel(timer_id);

	assert(count >= 3 && count <= 5);
	std::cout << "✓ Repeating timer passed (count: " << count << ")\n";
}

void test_run_in_loop()
{
	std::cout << "Testing runInLoop functionality...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	bool task_executed = false;
	loop->runInLoop([&task_executed]() {
		task_executed = true;
	});

	std::this_thread::sleep_for(std::chrono::milliseconds(50));
	assert(task_executed);

	std::cout << "✓ runInLoop passed\n";
}

void test_queue_in_loop()
{
	std::cout << "Testing queueInLoop functionality...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	std::vector<int> execution_order;

	loop->queueInLoop([&execution_order]() {
		execution_order.push_back(1);
	});

	loop->queueInLoop([&execution_order]() {
		execution_order.push_back(2);
	});

	loop->runInLoop([&execution_order]() {
		execution_order.push_back(3);
	});

	std::this_thread::sleep_for(std::chrono::milliseconds(50));

	assert(execution_order.size() == 3);
	assert(execution_order[0] == 1 || execution_order[0] == 2 || execution_order[0] == 3);


	std::cout << "✓ queueInLoop passed\n";
}

void test_channel_basic()
{
	std::cout << "Testing basic channel functionality...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	int event_fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
	assert(event_fd >= 0);

	auto channel = std::make_unique<reactor::Channel>(loop, event_fd);

	bool read_callback_called = false;
	channel->setReadCallback([&read_callback_called]() {
		read_callback_called = true;
	});

	channel->enableReading();

	uint64_t val = 1;
	write(event_fd, &val, sizeof(val));

	std::this_thread::sleep_for(std::chrono::milliseconds(50));

	assert(read_callback_called);

	channel->disableAll();
	channel->remove();
	close(event_fd);

	std::cout << "✓ Basic channel passed\n";
}

void test_channel_write_events()
{
	std::cout << "Testing channel write events...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	int event_fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
	assert(event_fd >= 0);

	auto channel = std::make_unique<reactor::Channel>(loop, event_fd);

	bool write_callback_called = false;
	channel->setWriteCallback([&write_callback_called]() {
		write_callback_called = true;
	});

	channel->enableWriting();

	std::this_thread::sleep_for(std::chrono::milliseconds(50));

	assert(write_callback_called);

	channel->disableAll();
	channel->remove();
	close(event_fd);

	std::cout << "✓ Channel write events passed\n";
}

void test_multiple_timers()
{
	std::cout << "Testing multiple timers...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	std::vector<bool> timer_states(5, false);

	for (int i = 0; i < 5; ++i) {
		loop->runAfter(reactor::Duration(10 + i * 20), [&timer_states, i]() {
			timer_states[i] = true;
		});
	}

	std::this_thread::sleep_for(std::chrono::milliseconds(120));

	for (bool state : timer_states) {
		assert(state);
	}

	std::cout << "✓ Multiple timers passed\n";
}

void test_timer_precision()
{
	std::cout << "Testing timer precision...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	auto start_time = std::chrono::steady_clock::now();
	bool timer_fired = false;

	loop->runAfter(reactor::Duration(100), [&timer_fired, start_time]() {
		auto end_time = std::chrono::steady_clock::now();
		auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end_time - start_time);
		timer_fired = true;

		assert(duration.count() >= 90 && duration.count() <= 150);
	});

	std::this_thread::sleep_for(std::chrono::milliseconds(150));
	assert(timer_fired);

	std::cout << "✓ Timer precision passed\n";
}

void test_event_loop_thread_safety()
{
	std::cout << "Testing event loop thread safety...\n";

	TestEventLoop test_loop;
	auto loop = test_loop.getLoop();

	std::atomic<int> counter{0};
	constexpr int num_tasks = 100;

	std::vector<std::thread> threads;
	for (int t = 0; t < 4; ++t) {
		threads.emplace_back([loop, &counter, num_tasks]() {
			for (int i = 0; i < num_tasks; ++i) {
				loop->queueInLoop([&counter]() {
					counter++;
				});
			}
		});
	}

	for (auto& thread : threads) {
		thread.join();
	}

	std::this_thread::sleep_for(std::chrono::milliseconds(100));
	assert(counter == 4 * num_tasks);

	std::cout << "✓ Event loop thread safety passed\n";
}

int main()
{
	std::cout << "=== Core Tests ===\n";

	test_timer_basic();
	test_timer_cancellation();
	test_repeating_timer();
	test_run_in_loop();
	test_queue_in_loop();
	test_channel_basic();
	test_channel_write_events();
	test_multiple_timers();
	test_timer_precision();
	test_event_loop_thread_safety();

	std::cout << "All core tests passed! ✓\n";
	return 0;
}