/*! @file pithread.h
 * @brief Thread
 * 
 * This file declare thread class and some wait functions
*/
/*
	PIP - Platform Independent Primitives
	Thread
	Ivan Pelipenko peri4ko@yandex.ru, Andrey Bychkov work.a.b@yandex.ru

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PITHREAD_H
#define PITHREAD_H

#include "piinit.h"
#include "pimutex.h"
#include "piobject.h"

class PIThread;

#ifndef MICRO_PIP
class PIIntrospectionThreads;

class PIP_EXPORT __PIThreadCollection: public PIObject {
	PIOBJECT(__PIThreadCollection)
public:
	static __PIThreadCollection * instance();
	void registerThread(PIThread * t);
	void unregisterThread(PIThread * t);
	PIVector<PIThread * > threads() const;
	void lock() {mutex.lock();}
	void unlock() {mutex.unlock();}
	void startedAuto(PIThread * t);
	EVENT_HANDLER(void, stoppedAuto);
private:
	PIVector<PIThread * > threads_, auto_threads_;
	mutable PIMutex mutex, auto_mutex;
};


class PIP_EXPORT __PIThreadCollection_Initializer__ {
public:
	__PIThreadCollection_Initializer__();
	~__PIThreadCollection_Initializer__();
	static int count_;
	static __PIThreadCollection * __instance__;
};

static __PIThreadCollection_Initializer__ __PIThreadCollection_initializer__;
#endif // MICRO_PIP

typedef std::function<void(void *)> ThreadFunc;

class PIP_EXPORT PIThread: public PIObject
{
	PIOBJECT_SUBCLASS(PIThread, PIObject)
#ifndef MICRO_PIP
	friend class PIIntrospectionThreads;
#endif
public:
	NO_COPY_CLASS(PIThread)

	//! Contructs thread with custom data "data", external function "func" and main loop delay "loop_delay".
	PIThread(void * data, ThreadFunc func, bool startNow = false, int loop_delay = -1);

	//! Contructs thread with external function "func" and main loop delay "loop_delay".
	PIThread(std::function<void()> func, bool startNow = false, int loop_delay = -1);

	//! Contructs thread with main loop delay "loop_delay".
	PIThread(bool startNow = false, int loop_delay = -1);
	
	virtual ~PIThread();

	//! Priority of thread
	enum Priority {
		piLowerst /** Lowest */,
		piLow /** Low */,
		piNormal /** Normal, this is default priority of threads and timers */,
		piHigh /** High */,
		piHighest /** Highest */
	};

	EVENT_HANDLER0(bool, start) {return start(-1);}
	EVENT_HANDLER1(bool, start, int, timer_delay);
	bool start(ThreadFunc func) {return start(func, -1);}
	bool start(ThreadFunc func, int timer_delay) {ret_func = func; return start(timer_delay);}
	bool start(std::function<void()> func) {return start(func, -1);}
	bool start(std::function<void()> func, int timer_delay) {ret_func = [func](void*){func();}; return start(timer_delay);}
	EVENT_HANDLER0(bool, startOnce);
	EVENT_HANDLER1(bool, startOnce, ThreadFunc, func) {ret_func = func; return startOnce();}
	EVENT_HANDLER0(void, stop) {stop(false);}
	EVENT_HANDLER1(void, stop, bool, wait);
	EVENT_HANDLER0(void, terminate);
	
	//! @brief Set common data passed to external function
	void setData(void * d) {data_ = d;}

	//! @brief Set external function that will be executed after every \a run()
	void setSlot(ThreadFunc func) {ret_func = func;}

	//! @brief Set external function that will be executed after every \a run()
	void setSlot(std::function<void()> func) {ret_func = [func](void*){func();};}

	//! @brief Set priority of thread
	void setPriority(PIThread::Priority prior);
	
	//! @brief Returns common data passed to external function
	void * data() const {return data_;}

	//! @brief Return priority of thread
	PIThread::Priority priority() const {return priority_;}

	//! @brief Return \c true if thread is running
	bool isRunning() const {return running_;}
	
	bool isStopping() const {return running_ && terminating;}
	
	EVENT_HANDLER0(bool, waitForStart) {return waitForStart(-1);}
	EVENT_HANDLER1(bool, waitForStart, int, timeout_msecs);
	EVENT_HANDLER0(bool, waitForFinish) {return waitForFinish(-1);}
	EVENT_HANDLER1(bool, waitForFinish, int, timeout_msecs);

	//! @brief Set necessity of lock every \a run with internal mutex
	void needLockRun(bool need) {lockRun = need;}

	//! @brief Lock internal mutex
	EVENT_HANDLER0(void, lock) const {thread_mutex.lock();}

	//! @brief Unlock internal mutex
	EVENT_HANDLER0(void, unlock) const {thread_mutex.unlock();}

	//! @brief Returns internal mutex
	PIMutex & mutex() const {return thread_mutex;}

	//! @brief Returns thread ID
	llong tid() const {return tid_;}
	
	void __thread_func__();
	void __thread_func_once__();

	EVENT(started)
	EVENT(stopped)

	//! @brief Start event handler with name \"handler\" of object \"object\"
	//! in separate thread with name \"name\"
	//! and automatically delete it on function finish
	static void runOnce(PIObject * object, const char * handler, const PIString & name = PIString());

	//! @brief Start function \"func\" in separate thread with name \"name\"
	//! and automatically delete it on function finish
	static void runOnce(std::function<void()> func, const PIString & name = PIString());

//! \handlers
//! \{
	
	/** \fn bool start(int timer_delay = -1)
	 * @brief Start thread
	 * \details Start execution of \a run() in internal loop with
	 * "timer_delay" delay in milliseconds. If "timer_delay" <= 0
	 * there is no delay in loop. Thread also exec external function
	 * set by \a setSlot() if it`s not null
	 * 
	 * \return \c false if thread already started or can`t start thread */
	
	/** \fn bool startOnce()
	 * @brief Start thread without internal loop
	 * \details Start execution of \a run() once. Thread also exec
	 * external function set by \a setSlot() if it`s not null
	 * 
	 * \return \c false if thread already started or can`t start thread */
	
	/** \fn bool startOnce(ThreadFunc func)
	 * @brief Start thread without internal loop
	 * \details Overloaded function. Set external function "func" before start
	 * 
	 * \return \c false if thread already started or can`t start thread */
	
	/** \fn void stop(bool wait = false)
	 * @brief Stop thread
	 * \details Stop execution of thread and wait for it finish
	 * if "wait" is \c true. This function can block for infinite
	 * time if "wait" is \c true and any of thread function is
	 * busy forever */
	
	/** \fn void terminate()
	 * @brief Strongly stop thread
	 * \details Stop execution of thread immediately */
	
	/** \fn bool waitForStart(int timeout_msecs = -1)
	 * @brief Wait for thread start
	 * \details This function block until thread start for "timeout_msecs"
	 * or forever if "timeout_msecs" < 0
	 * 
	 * \return \c false if timeout is exceeded */
	
	/** \fn bool waitForFinish(int timeout_msecs = -1)
	 * @brief Wait for thread finish
	 * \details This function block until thread finish for "timeout_msecs"
	 * or forever if "timeout_msecs" < 0
	 * 
	 * \return \c false if timeout is exceeded */
	
	//! \fn void lock()
	//! @brief Lock internal mutex
	
	//! \fn void unlock()
	//! @brief Unlock internal mutex
	
//! \}
//! \events
//! \{
	
	//! \fn void started()
	//! @brief Raise on thread start
	
	//! \fn void stopped()
	//! @brief Raise on thread stop
	
//! \}

protected:
	static int priority2System(PIThread::Priority p);
	
	//! Function executed once at the start of thread.
	virtual void begin() {;}
	
	//! Function executed at every "timer_delay" msecs until thread was stopped.
	virtual void run() {;}
	
	//! Function executed once at the end of thread.
	virtual void end() {;}

	std::atomic_bool terminating, running_, lockRun;
	int delay_, policy_;
	llong tid_;
	void * data_;
	mutable PIMutex thread_mutex;
	PITimeMeasurer tmf_, tms_, tmr_;
	PIThread::Priority priority_;
	ThreadFunc ret_func;
	PRIVATE_DECLARATION(PIP_EXPORT)

private:
	bool _startThread(void * func);
	void _beginThread();
	void _runThread();
	void _endThread();

};


#endif // PITHREAD_H