#ifndef COMPONENT_THREAD_H
#define COMPONENT_THREAD_H

#include <atomic>
#include <thread>
#include <unordered_map>
#include <boost/asio.hpp>
#include <stdexcept>
#include <queue>
#include <functional>
#include <pthread.h>
#include <sched.h>
#include <unistd.h>
#include <memory>

namespace smo {

class Mind; // Forward declaration

class ComponentThread
:   public std::enable_shared_from_this<ComponentThread>
{
public:
	enum ThreadId
	{
		MRNTT = 0,
		DIRECTOR,
		SIMULATOR,
		SUBCONSCIOUS,
		BODY,
		WORLD,
		N_ITEMS
	};

	ComponentThread(ThreadId _id, Mind& parent)
    :   id(_id), name(getThreadName(_id)), parent(parent),
        work(io_service), pause_work(pause_io_service),
        pinnedCpuId(-1),
        thread(
			((id == MRNTT) ? marionetteMain : main),
			std::ref(*this))
	{}

	void cleanup(void);

	boost::asio::io_service& getIoService(void) { return io_service; }

	void initializeTls(void);
	static const std::shared_ptr<ComponentThread> getSelf(void);

	static std::shared_ptr<ComponentThread> getMrntt();
	Mind& getParent() const { return parent; }

	typedef void (mainFn)(ComponentThread &self);
	static mainFn main, marionetteMain;

	typedef std::function<void()> threadLifetimeMgmtOpCbFn;
	// Thread management methods
	void startThreadReq(threadLifetimeMgmtOpCbFn callback);
	void exitThreadReq(threadLifetimeMgmtOpCbFn callback);
	void pauseThreadReq(threadLifetimeMgmtOpCbFn callback);
	void resumeThreadReq(threadLifetimeMgmtOpCbFn callback);

	/**
	 * JOLTs this thread to begin processing after global initialization.
	 *
	 * JOLTing is the mechanism that allows threads to enter their main
	 * event loops and set up TLS vars after all global constructors have
	 * completed. This prevents race conditions during system startup.
	 */
	void joltThreadReq(threadLifetimeMgmtOpCbFn callback);

	// CPU management methods
	static int getAvailableCpuCount();
	void pinToCpu(int cpuId);

	enum class ThreadOp
	{
		START,
		PAUSE,
		RESUME,
		EXIT,
		JOLT,
		N_ITEMS
	};

	typedef std::function<void()> mindShutdownIndOpCbFn;
	// Intentionally doesn't take a callback.
	void exceptionInd(const std::shared_ptr<ComponentThread> &faultyThread);
	// Intentionally doesn't take a callback.
	void userShutdownInd();

public:
	ThreadId id;
	std::string name;
	Mind &parent;
	boost::asio::io_service io_service;
	boost::asio::io_service::work work;
	boost::asio::io_service pause_io_service;
	boost::asio::io_service::work pause_work;
	std::atomic<bool> keepLooping;
	int pinnedCpuId;


    /* Always ensure that this is last so that the thread is spawned after
     * everything else is constructed.
     */
	std::thread thread;

	static const std::string getThreadName(ThreadId id)
	{
		if (id < 0 || id >= ComponentThread::N_ITEMS)
		{
			throw std::runtime_error(std::string(__func__)
				+ ": Invalid thread ID");
		}

		// Use function-local static to ensure proper initialization order
		static const std::string threadNames[N_ITEMS] = {
			"mrntt",
			"director",
			"simulator",
			"subconscious",
			"body",
			"world"
		};

		return threadNames[id];
	}

private:
	class ThreadLifetimeMgmtOp;
	class MindShutdownIndOp;
};

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

} // namespace smo

#endif // COMPONENT_THREAD_H