// Copyright 2018 Proyectos y Sistemas de Mantenimiento SL (eProsima).
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/**
 * @file TimedMutex.hpp
 */

#ifndef _UTILS_TIMEDMUTEX_HPP_
#define _UTILS_TIMEDMUTEX_HPP_

#include <chrono>
#include <iostream>

#if defined(_WIN32)
#include <thread>
extern int clock_gettime(
        int,
        struct timespec* tv);
#elif _GTHREAD_USE_MUTEX_TIMEDLOCK
#include <mutex>
#else
#include <pthread.h>
#endif

namespace eprosima {
namespace fastrtps {

#if defined(_WIN32)
class TimedMutex
{
public:

    TimedMutex()
    {
        _Mtx_init(&mutex_, _Mtx_timed);
    }

    TimedMutex(
            const TimedMutex&) = delete;
    TimedMutex& operator =(
            const TimedMutex&) = delete;

    ~TimedMutex()
    {
        _Mtx_destroy(mutex_);
    }

    void lock()
    {
        _Mtx_lock(mutex_);
    }

    void unlock()
    {
        _Mtx_unlock(mutex_);
    }

    template <class Rep, class Period>
    bool try_lock_for(
            const std::chrono::duration<Rep, Period>& rel_time)
    {
        return try_lock_until(chrono::steady_clock::now() + rel_time);
    }

    template <class Clock, class Duration>
    bool try_lock_until(
            const std::chrono::time_point<Clock, Duration>& abs_time)
    {
        std::chrono::nanoseconds nsecs = abs_time - std::chrono::steady_clock::now();

        if (0 < nsecs.count())
        {
            struct timespec max_wait = { 0, 0 };
            clock_gettime(1, &max_wait);
            nsecs = nsecs + std::chrono::nanoseconds(max_wait.tv_nsec);
            auto secs = std::chrono::duration_cast<std::chrono::seconds>(nsecs);
            nsecs -= secs;
            max_wait.tv_sec += secs.count();
            max_wait.tv_nsec = (long)nsecs.count();
            return (_Thrd_success == _Mtx_timedlock(mutex_, (xtime*)&max_wait));
        }
        else
        {
            return (_Thrd_success == _Mtx_trylock(mutex_));
        }
    }

    void* native_handle() noexcept
    {
        return mutex_;
    }

private:

    _Mtx_t mutex_;
};

class RecursiveTimedMutex
{
public:

    RecursiveTimedMutex()
    {
        _Mtx_init(&mutex_, _Mtx_timed | _Mtx_recursive);
    }

    RecursiveTimedMutex(
            const TimedMutex&) = delete;
    RecursiveTimedMutex& operator =(
            const TimedMutex&) = delete;

    ~RecursiveTimedMutex()
    {
        _Mtx_destroy(mutex_);
    }

    void lock()
    {
        _Mtx_lock(mutex_);
    }

    void unlock()
    {
        _Mtx_unlock(mutex_);
    }

    template <class Rep, class Period>
    bool try_lock_for(
            const std::chrono::duration<Rep, Period>& rel_time)
    {
        return try_lock_until(chrono::steady_clock::now() + rel_time);
    }

    template <class Clock, class Duration>
    bool try_lock_until(
            const std::chrono::time_point<Clock, Duration>& abs_time)
    {
        std::chrono::nanoseconds nsecs = abs_time - std::chrono::steady_clock::now();
        if (0 < nsecs.count())
        {
            struct timespec max_wait = { 0, 0 };
            clock_gettime(1, &max_wait);
            nsecs = nsecs + std::chrono::nanoseconds(max_wait.tv_nsec);
            auto secs = std::chrono::duration_cast<std::chrono::seconds>(nsecs);
            nsecs -= secs;
            max_wait.tv_sec += secs.count();
            max_wait.tv_nsec = (long)nsecs.count();
            return (_Thrd_success == _Mtx_timedlock(mutex_, (xtime*)&max_wait));
        }
        else
        {
            return (_Thrd_success == _Mtx_trylock(mutex_));
        }
    }

    void* native_handle() noexcept
    {
        return mutex_;
    }

private:

    _Mtx_t mutex_;
};
#elif _GTHREAD_USE_MUTEX_TIMEDLOCK || !defined(__linux__)
using TimedMutex = std::timed_mutex;
using RecursiveTimedMutex = std::recursive_timed_mutex;
#else
class TimedMutex
{
public:

    TimedMutex()
    {
        pthread_mutex_init(&mutex_, nullptr);
    }

    TimedMutex(
            const TimedMutex&) = delete;
    TimedMutex& operator =(
            const TimedMutex&) = delete;

    ~TimedMutex()
    {
        pthread_mutex_destroy(&mutex_);
    }

    void lock()
    {
        pthread_mutex_lock(&mutex_);
    }

    void unlock()
    {
        pthread_mutex_unlock(&mutex_);
    }

    template <class Rep, class Period>
    bool try_lock_for(
            const std::chrono::duration<Rep, Period>& rel_time)
    {
        return try_lock_until(std::chrono::steady_clock::now() + rel_time);
    }

    template <class Clock, class Duration>
    bool try_lock_until(
            const std::chrono::time_point<Clock, Duration>& abs_time)
    {
        std::chrono::nanoseconds nsecs = abs_time - std::chrono::steady_clock::now();
        struct timespec max_wait = { 0, 0 };
        clock_gettime(CLOCK_REALTIME, &max_wait);
        nsecs = nsecs + std::chrono::nanoseconds(max_wait.tv_nsec);
        auto secs = std::chrono::duration_cast<std::chrono::seconds>(nsecs);
        nsecs -= secs;
        max_wait.tv_sec += secs.count();
        max_wait.tv_nsec = (long)nsecs.count();
        return (0 == pthread_mutex_timedlock(&mutex_, &max_wait));
    }

    pthread_mutex_t* native_handle() noexcept
    {
        return &mutex_;
    }

private:

    pthread_mutex_t mutex_;
};

class RecursiveTimedMutex
{
public:

    RecursiveTimedMutex()
    {
        pthread_mutexattr_init(&mutex_attr_);
        pthread_mutexattr_settype(&mutex_attr_, PTHREAD_MUTEX_RECURSIVE);
        pthread_mutex_init(&mutex_, &mutex_attr_);
    }

    RecursiveTimedMutex(
            const RecursiveTimedMutex&) = delete;
    RecursiveTimedMutex& operator =(
            const RecursiveTimedMutex&) = delete;

    ~RecursiveTimedMutex()
    {
        pthread_mutex_destroy(&mutex_);
        pthread_mutexattr_destroy(&mutex_attr_);
    }

    void lock()
    {
        pthread_mutex_lock(&mutex_);
    }

    void unlock()
    {
        pthread_mutex_unlock(&mutex_);
    }

    template <class Rep, class Period>
    bool try_lock_for(
            const std::chrono::duration<Rep, Period>& rel_time)
    {
        return try_lock_until(std::chrono::steady_clock::now() + rel_time);
    }

    template <class Clock, class Duration>
    bool try_lock_until(
            const std::chrono::time_point<Clock, Duration>& abs_time)
    {
        std::chrono::nanoseconds nsecs = abs_time - std::chrono::steady_clock::now();
        struct timespec max_wait = { 0, 0 };
        clock_gettime(CLOCK_REALTIME, &max_wait);
        nsecs = nsecs + std::chrono::nanoseconds(max_wait.tv_nsec);
        auto secs = std::chrono::duration_cast<std::chrono::seconds>(nsecs);
        nsecs -= secs;
        max_wait.tv_sec += secs.count();
        max_wait.tv_nsec = (long)nsecs.count();
        return (0 == pthread_mutex_timedlock(&mutex_, &max_wait));
    }

    pthread_mutex_t* native_handle() noexcept
    {
        return &mutex_;
    }

private:

    pthread_mutexattr_t mutex_attr_;

    pthread_mutex_t mutex_;
};

#endif //_WIN32

} //namespace fastrtps
} //namespace eprosima

#endif // _UTILS_TIMEDMUTEX_HPP_
