#include <unistd.h>
#include <iostream>
#include <pthread.h>
#include <sched.h>
#include <boost/asio.hpp>
#include <mind.h>
#include <componentThread.h>
#include <marionette/marionette.h>

namespace smo {

thread_local std::shared_ptr<ComponentThread> thisComponentThread;

namespace mrntt {
extern std::shared_ptr<ComponentThread> mrntt;
}

// Implementation of static method
std::shared_ptr<ComponentThread> ComponentThread::getMrntt()
{
	return mrntt::mrntt;
}

void ComponentThread::initializeTls(void)
{
	thisComponentThread = shared_from_this();
}

const std::shared_ptr<ComponentThread> ComponentThread::getSelf(void)
{
	if (!thisComponentThread)
	{
		throw std::runtime_error(std::string(__func__)
			+ ": TLS not initialized");
	}

	return thisComponentThread;
}

void ComponentThread::main(ComponentThread& self)
{
	std::cout << self.name << ":" << __func__ << ": Waiting for JOLT" <<"\n";
	self.getIoService().run();
	self.initializeTls();

	std::cout << self.name << ":" << __func__ << ": Entering event loop" <<"\n";

	/* We loop here because when an exception is caught, we need to first catch
	 * it in the catch blocks. We bubble the exception to mrntt in the catch
	 * blocks, and then we loop here to await control messages from mrntt.
	 *
	 * We can't just exit on our own. Rather, we must wait for mrntt to tell us
	 * to exit. When we wish to finally exit, we set keepLooping to false.
	 */
	for (self.keepLooping = true; self.keepLooping;)
	{
		bool sendExceptionInd = false;

		try {
			/**		EXPLANATION:
			 * This reset() call is crucial for async bridging patterns
			 * to work.
			 * When the outermost thread's io_service is stop()ped (e.g.,
			 * from JOLT sequence), it won't process any new work until
			 * reset() is called, even if nested async operations try to
			 * post work to it. This means async bridges invoked from
			 * the outermost thread main sequence won't work until this
			 * reset() call.
			 */
			self.getIoService().reset();
			self.getIoService().run();
		}
		catch (const std::exception& e)
		{
			sendExceptionInd = true;
			std::cerr << self.name << ":" << __func__
				<< ": Exception occurred: " << e.what() << "\n";
		}
		catch (...)
		{
			sendExceptionInd = true;
			std::cerr << self.name << ":" << __func__
				<< ": Unknown exception occurred" << "\n";
		}

		if (sendExceptionInd) { mrntt::mrntt->exceptionInd(self); }
	}

	std::cout << self.name << ":" << __func__ << ": Exited event loop" << "\n";
}

// Thread management method implementations
void ComponentThread::startThreadReq(std::function<void()> callback)
{
	this->getIoService().post([this, caller = getSelf(), callback]()
	{
		std::cout << "Thread '" << name << "': handling startThread." << "\n";

		// Execute private setup sequence here
		// This is where each thread would implement its specific initialization

		if (callback) {
			caller->getIoService().post(callback);
		}
	});
}

void ComponentThread::cleanup(void)
{
	this->keepLooping = false;
}

void ComponentThread::exitThreadReq(std::function<void()> callback)
{
	// Post to the main io_service
	this->getIoService().post([this, caller = getSelf(), callback]()
	{
		std::cout << "Thread '" << name << "': handling exitThread "
			"(main queue)." << std::endl;

		cleanup();

		// Stop the main io_service to exit the thread
		io_service.stop();
		if (callback) { caller->getIoService().post(callback); }
	});

	// Also post to the pause io_service
	this->pause_io_service.post([this, caller = getSelf(), callback]()
	{
		std::cout << "Thread '" << name << "': handling exitThread "
			"(pause queue)." << std::endl;

		cleanup();

		// Stop both io_services to exit the thread
		pause_io_service.stop();
		io_service.stop();
		if (callback) { caller->getIoService().post(callback); }
	});
}

void ComponentThread::pauseThreadReq(std::function<void()> callback)
{
	this->getIoService().post([this, caller = getSelf(), callback]()
	{
		std::cout << "Thread '" << name << "': handling pauseThread."
			<< std::endl;

		if (callback) {
			caller->getIoService().post(callback);
		}

		// Reset the pause io_service before running to ensure it can run again
		pause_io_service.reset();
		// Run the pause io_service to block this thread
		pause_io_service.run();
	});
}

void ComponentThread::resumeThreadReq(std::function<void()> callback)
{
	// Post to the pause_io_service to unblock the paused thread
	pause_io_service.post([this, caller = getSelf(), callback]()
	{
		std::cout << "Thread '" << name << "': handling resumeThread."
			<< std::endl;

		if (callback) {
			caller->getIoService().post(callback);
		}

		// Stop the pause_io_service to unblock the thread
		pause_io_service.stop();
	});
}

void ComponentThread::joltThreadReq(std::function<void()> callback)
{
	this->getIoService().post([this, caller = getSelf(), callback]()
	{
		std::cout << "Thread '" << name << "': handling JOLT request." << "\n";

		// Stop the main io_service to jolt the thread
		io_service.stop();

		if (callback) {
			caller->getIoService().post(callback);
		}
	});
}

/* This shouldn't take a callback because the caller shouldn't expect to
 * Mrntt to send a reply signal to it. Sending this Indication means that
 * Mrntt will send the calling thread an exitThreadReq. When the caller
 * processes that exitThreadReq(), the caller will exit its event loop and then
 * terminate.
 *
 * Even if Mrntt sent a RDY response, the caller shouldn't actually be executing
 * any longer to receive it anyway.
 */
void ComponentThread::exceptionInd(ComponentThread& thread)
{
	if (this->id != ComponentThread::MRNTT)
	{
		throw std::runtime_error(std::string(__func__)
			+ ": invoked on non-mrntt thread " + thread.name);
	}

	// Post the exception to the mrntt thread.
	this->getIoService().post(
	[&thread]()
	{
		std::cerr << "Mrntt: Exception occurred: in thread "
			<< thread.name << ". Killing Salmanoff." << "\n";

		/**		EXPLANATION:
		 * An exception has occurred in one of a mind's threads. We need to
		 * shut down all of that particular mind's threads.
		 */
        thread.parent.finalizeReq([]() {
            /**		FIXME:
             * When we eventually support multiple minds, we should remove this
			 * since it causes marionette to exit, even if there are other minds
			 * that are still running.
             */
            smo::mrntt::exitMarionetteLoop();
        });
	});
}

void ComponentThread::userShutdownInd()
{
    if (this->id != ComponentThread::MRNTT)
    {
        throw std::runtime_error(std::string(__func__)
            + ": invoked on non-mrntt thread " + this->name);
    }

    // Post the user shutdown to the mrntt thread.
    this->getIoService().post(
    [this]()
    {
        std::cerr << "Mrntt: User requested shutdown (SIGINT)."
                  << " Killing Salmanoff." << "\n";

		/**		EXPLANATION:
		 * A user has requested a shutdown. We need to shut down all of the
		 * threads in all running Minds.
		 */
        parent.finalizeReq([]() {
            /**		FIXME:
             * When we eventually support multiple minds, we should remove this
			 * since it causes marionette to exit, even if there are other minds
			 * that are still running.
             */
            smo::mrntt::exitMarionetteLoop();
        });
	});
}

// CPU management method implementations
int ComponentThread::getAvailableCpuCount()
{
	int cpuCount = sysconf(_SC_NPROCESSORS_ONLN);
	if (cpuCount <= 0)
	{
		throw std::runtime_error(std::string(__func__)
			+ ": Failed to determine CPU count");
	}

	// Check if std::thread::hardware_concurrency() matches sysconf result
	unsigned int hwConcurrency = std::thread::hardware_concurrency();
	if (hwConcurrency != static_cast<unsigned int>(cpuCount))
	{
		std::cerr << "Warning: CPU count mismatch - "
			"std::thread::hardware_concurrency() = "
			<< hwConcurrency << ", sysconf(_SC_NPROCESSORS_ONLN) = "
			<< cpuCount << "\n";
	}

	return cpuCount;
}

void ComponentThread::pinToCpu(int cpuId)
{
	if (cpuId < 0)
	{
		throw std::runtime_error(std::string(__func__)
			+ ": Invalid CPU ID: " + std::to_string(cpuId));
	}

	cpu_set_t cpuset;
	CPU_ZERO(&cpuset);
	CPU_SET(cpuId, &cpuset);

	int result = pthread_setaffinity_np(
		thread.native_handle(), sizeof(cpu_set_t), &cpuset);
	if (result != 0)
	{
		throw std::runtime_error(std::string(__func__)
			+ ": Failed to pin thread to CPU " + std::to_string(cpuId)
			+ ": " + std::strerror(result));
	}

	pinnedCpuId = cpuId;
	std::cout << name << ": Pinned to CPU " << cpuId << "\n";
}

} // namespace smo