//
// libtgvoip is free and unencumbered public domain software.
// For more information, see http://unlicense.org or the UNLICENSE file
// you should have received with this source code distribution.
//

#ifndef __THREADING_H
#define __THREADING_H

#include <functional>

#if defined(_POSIX_THREADS) || defined(_POSIX_VERSION) || defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))

#include <pthread.h>
#include <semaphore.h>
#include <sched.h>
#include <unistd.h>
#ifdef __APPLE__
#include "os/darwin/DarwinSpecific.h"
#endif

namespace tgvoip
{
class Mutex
{
public:
	Mutex()
	{
		pthread_mutex_init(&mtx, NULL);
	}

	~Mutex()
	{
		pthread_mutex_destroy(&mtx);
	}

	void Lock()
	{
		pthread_mutex_lock(&mtx);
	}

	void Unlock()
	{
		pthread_mutex_unlock(&mtx);
	}

	pthread_mutex_t *NativeHandle()
	{
		return &mtx;
	}

private:
	Mutex(const Mutex &other);
	pthread_mutex_t mtx;
};

class Thread
{
public:
	Thread(std::function<void()> entry) : entry(entry)
	{
		name = NULL;
		thread = 0;
	}

	virtual ~Thread()
	{
	}

	void Start()
	{
		if (pthread_create(&thread, NULL, Thread::ActualEntryPoint, this) == 0)
		{
			valid = true;
		}
	}

	void Join()
	{
		if (valid) {
			pthread_join(thread, NULL);
			valid = false;
		}
	}

	void SetName(const char *name)
	{
		this->name = name;
	}

	void SetMaxPriority()
	{
#ifdef __APPLE__
		maxPriority = true;
#endif
	}

	static void Sleep(double seconds)
	{
		usleep((useconds_t)(seconds * 1000000.0));
	}

	bool IsCurrent()
	{
		return pthread_equal(thread, pthread_self()) != 0;
	}

private:
	static void *ActualEntryPoint(void *arg)
	{
		Thread *self = reinterpret_cast<Thread *>(arg);
		if (self->name)
		{
#if !defined(__APPLE__) && !defined(__gnu_hurd__)
			pthread_setname_np(self->thread, self->name);
#elif !defined(__gnu_hurd__)
			pthread_setname_np(self->name);
			if (self->maxPriority)
			{
				DarwinSpecific::SetCurrentThreadPriority(DarwinSpecific::THREAD_PRIO_USER_INTERACTIVE);
			}
#endif
		}
		self->entry();
		return NULL;
	}
	std::function<void()> entry;
	pthread_t thread;
	const char *name;
#ifdef __APPLE__
	bool maxPriority = false;
#endif
	bool valid = false;
};
} // namespace tgvoip

#ifdef __APPLE__
#include <dispatch/dispatch.h>
namespace tgvoip
{
class Semaphore
{
public:
	Semaphore(unsigned int maxCount, unsigned int initValue)
	{
		sem = dispatch_semaphore_create(initValue);
	}

	~Semaphore()
	{
#if !__has_feature(objc_arc)
		dispatch_release(sem);
#endif
	}

	void Acquire()
	{
		dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
	}

	void Release()
	{
		dispatch_semaphore_signal(sem);
	}

	void Acquire(int count)
	{
		for (int i = 0; i < count; i++)
			Acquire();
	}

	void Release(int count)
	{
		for (int i = 0; i < count; i++)
			Release();
	}

private:
	dispatch_semaphore_t sem;
};
} // namespace tgvoip
#else
namespace tgvoip
{
class Semaphore
{
public:
	Semaphore(unsigned int maxCount, unsigned int initValue)
	{
		sem_init(&sem, 0, initValue);
	}

	~Semaphore()
	{
		sem_destroy(&sem);
	}

	void Acquire()
	{
		sem_wait(&sem);
	}

	void Release()
	{
		sem_post(&sem);
	}

	void Acquire(int count)
	{
		for (int i = 0; i < count; i++)
			Acquire();
	}

	void Release(int count)
	{
		for (int i = 0; i < count; i++)
			Release();
	}

private:
	sem_t sem;
};
} // namespace tgvoip
#endif

#elif defined(_WIN32)

#include <Windows.h>
#include <assert.h>

namespace tgvoip
{
class Mutex
{
public:
	Mutex()
	{
#if !defined(WINAPI_FAMILY) || WINAPI_FAMILY != WINAPI_FAMILY_PHONE_APP
		InitializeCriticalSection(&section);
#else
		InitializeCriticalSectionEx(&section, 0, 0);
#endif
	}

	~Mutex()
	{
		DeleteCriticalSection(&section);
	}

	void Lock()
	{
		EnterCriticalSection(&section);
	}

	void Unlock()
	{
		LeaveCriticalSection(&section);
	}

private:
	Mutex(const Mutex &other);
	CRITICAL_SECTION section;
};

class Thread
{
public:
	Thread(std::function<void()> entry) : entry(entry)
	{
		name = NULL;
		thread = NULL;
	}

	~Thread()
	{
	}

	void Start()
	{
		thread = CreateThread(NULL, 0, Thread::ActualEntryPoint, this, 0, &id);
	}

	void Join()
	{
		if (!thread)
			return;
#if !defined(WINAPI_FAMILY) || WINAPI_FAMILY != WINAPI_FAMILY_PHONE_APP
		WaitForSingleObject(thread, INFINITE);
#else
		WaitForSingleObjectEx(thread, INFINITE, false);
#endif
		CloseHandle(thread);
		thread = nullptr;
	}

	void SetName(const char *name)
	{
		this->name = name;
	}

	void SetMaxPriority()
	{
		SetThreadPriority(thread, THREAD_PRIORITY_HIGHEST);
	}

	static void Sleep(double seconds)
	{
		::Sleep((DWORD)(seconds * 1000));
	}

	bool IsCurrent()
	{
		return id == GetCurrentThreadId();
	}

private:
	static const DWORD MS_VC_EXCEPTION = 0x406D1388;

#pragma pack(push, 8)
	typedef struct tagTHREADNAME_INFO
	{
		DWORD dwType;	 // Must be 0x1000.
		LPCSTR szName;	// Pointer to name (in user addr space).
		DWORD dwThreadID; // Thread ID (-1=caller thread).
		DWORD dwFlags;	// Reserved for future use, must be zero.
	} THREADNAME_INFO;
#pragma pack(pop)

	static DWORD WINAPI ActualEntryPoint(void *arg)
	{
		Thread *self = reinterpret_cast<Thread *>(arg);
		if (self->name)
		{
			THREADNAME_INFO info;
			info.dwType = 0x1000;
			info.szName = self->name;
			info.dwThreadID = -1;
			info.dwFlags = 0;
			__try
			{
				RaiseException(MS_VC_EXCEPTION, 0, sizeof(info) / sizeof(ULONG_PTR), (ULONG_PTR *)&info);
			}
			__except (EXCEPTION_EXECUTE_HANDLER)
			{
			}
		}
		self->entry();
		return 0;
	}
	std::function<void()> entry;
	HANDLE thread;
	DWORD id;
	const char *name;
};

class Semaphore
{
public:
	Semaphore(unsigned int maxCount, unsigned int initValue)
	{
#if !defined(WINAPI_FAMILY) || WINAPI_FAMILY != WINAPI_FAMILY_PHONE_APP
		h = CreateSemaphore(NULL, initValue, maxCount, NULL);
#else
		h = CreateSemaphoreEx(NULL, initValue, maxCount, NULL, 0, SEMAPHORE_ALL_ACCESS);
		assert(h);
#endif
	}

	~Semaphore()
	{
		CloseHandle(h);
	}

	void Acquire()
	{
#if !defined(WINAPI_FAMILY) || WINAPI_FAMILY != WINAPI_FAMILY_PHONE_APP
		WaitForSingleObject(h, INFINITE);
#else
		WaitForSingleObjectEx(h, INFINITE, false);
#endif
	}

	void Release()
	{
		ReleaseSemaphore(h, 1, NULL);
	}

	void Acquire(int count)
	{
		for (int i = 0; i < count; i++)
			Acquire();
	}

	void Release(int count)
	{
		ReleaseSemaphore(h, count, NULL);
	}

private:
	HANDLE h;
};
} // namespace tgvoip
#else
#error "No threading implementation for your operating system"
#endif

namespace tgvoip
{
class MutexGuard
{
public:
	MutexGuard(Mutex &mutex) : mutex(mutex)
	{
		mutex.Lock();
	}
	~MutexGuard()
	{
		mutex.Unlock();
	}

private:
	Mutex &mutex;
};
} // namespace tgvoip

#endif //__THREADING_H