/**
 * Jingga
 *
 * @copyright Jingga
 * @license   OMS License 2.0
 * @version   1.0.0
 * @link      https://jingga.app
 */
#ifndef TOS_THREADS_OS_WRAPPER_H
#define TOS_THREADS_OS_WRAPPER_H

#include "../stdlib/Types.h"

#ifdef _WIN32
    #include <stdbool.h>
    #include <windows.h>
    #include <time.h>
#else
    #include <pthread.h>
    #include <unistd.h>
#endif

#include "ThreadJob.h"

void ms_to_timespec(timespec *ts, uint32 ms)
{
    if (ts == 0) {
        return;
    }

    ts->tv_sec  = (ms / 1000) + time(0);
    ts->tv_nsec = (ms % 1000) * 1000000;
}

#ifdef _WIN32
    typedef CRITICAL_SECTION pthread_mutex_t;
    typedef void pthread_mutexattr_t;
    typedef void pthread_condattr_t;
    typedef void pthread_rwlockattr_t;
    typedef HANDLE pthread_t;
    typedef CONDITION_VARIABLE pthread_cond_t;

    struct pthread_rwlock_t {
        SRWLOCK lock;
        bool exclusive;
    };

    int pthread_create(pthread_t* thread, void*, ThreadJobFunc start_routine, void* arg)
    {
        if (thread == NULL || start_routine == NULL) {
            return 1;
        }

        *thread = CreateThread(NULL, 0, start_routine, arg, 0, NULL);
        if (*thread == NULL) {
            return 1;
        }

        return 0;
    }

    int pthread_join(pthread_t thread, void** value_ptr)
    {
        WaitForSingleObject(thread, INFINITE);
        CloseHandle(thread);

        return 0;
    }

    int pthread_detach(pthread_t thread)
    {
        CloseHandle(thread);

        return 0;
    }

    int pthread_mutex_init(pthread_mutex_t* mutex, pthread_mutexattr_t*)
    {
        if (mutex == NULL) {
            return 1;
        }

        InitializeCriticalSection(mutex);

        return 0;
    }

    int pthread_mutex_destroy(pthread_mutex_t* mutex)
    {
        if (mutex == NULL) {
            return 1;
        }

        DeleteCriticalSection(mutex);

        return 0;
    }

    int pthread_mutex_lock(pthread_mutex_t* mutex)
    {
        if (mutex == NULL) {
            return 1;
        }

        EnterCriticalSection(mutex);

        return 0;
    }

    int pthread_mutex_unlock(pthread_mutex_t* mutex)
    {
        if (mutex == NULL) {
            return 1;
        }

        LeaveCriticalSection(mutex);

        return 0;
    }

    int pthread_cond_init(pthread_cond_t* cond, pthread_condattr_t*)
    {
        if (cond == NULL) {
            return 1;
        }

        InitializeConditionVariable(cond);

        return 0;
    }

    int pthread_cond_destroy(pthread_cond_t*)
    {
        /* Windows does not have a destroy for conditionals */
        return 0;
    }

    static DWORD timespec_to_ms(const timespec* abstime)
    {
        if (abstime == NULL) {
            return INFINITE;
        }

        DWORD t = (DWORD) (((abstime->tv_sec - time(0)) * 1000) + (abstime->tv_nsec / 1000000));

        return t < 0 ? 1 : t;
    }

    int pthread_cond_timedwait(pthread_cond_t* cond, pthread_mutex_t* mutex, const timespec* abstime)
    {
        if (cond == NULL || mutex == NULL) {
            return 1;
        }

        if (!SleepConditionVariableCS(cond, mutex, timespec_to_ms(abstime))) {
            return 1;
        }

        return 0;
    }

    int pthread_cond_wait(pthread_cond_t* cond, pthread_mutex_t* mutex)
    {
        if (cond == NULL || mutex == NULL) {
            return 1;
        }

        return pthread_cond_timedwait(cond, mutex, NULL);
    }

    int pthread_cond_signal(pthread_cond_t* cond)
    {
        if (cond == NULL) {
            return 1;
        }

        WakeConditionVariable(cond);

        return 0;
    }

    int pthread_cond_broadcast(pthread_cond_t* cond)
    {
        if (cond == NULL) {
            return 1;
        }

        WakeAllConditionVariable(cond);

        return 0;
    }

    int pthread_rwlock_init(pthread_rwlock_t* rwlock, const pthread_rwlockattr_t*)
    {
        if (rwlock == NULL) {
            return 1;
        }

        InitializeSRWLock(&rwlock->lock);
        rwlock->exclusive = false;

        return 0;
    }

    int pthread_rwlock_destroy(pthread_rwlock_t* rwlock)
    {
        return 0;
    }

    int pthread_rwlock_rdlock(pthread_rwlock_t* rwlock)
    {
        if (rwlock == NULL) {
            return 1;
        }

        AcquireSRWLockShared(&rwlock->lock);

        return 0;
    }

    int pthread_rwlock_tryrdlock(pthread_rwlock_t* rwlock)
    {
        if (rwlock == NULL) {
            return 1;
        }

        return !TryAcquireSRWLockShared(&rwlock->lock);
    }

    int pthread_rwlock_wrlock(pthread_rwlock_t* rwlock)
    {
        if (rwlock == NULL) {
            return 1;
        }

        AcquireSRWLockExclusive(&rwlock->lock);
        rwlock->exclusive = true;

        return 0;
    }

    int pthread_rwlock_trywrlock(pthread_rwlock_t  *rwlock)
    {
        if (rwlock == NULL) {
            return 1;
        }

        BOOLEAN ret = TryAcquireSRWLockExclusive(&rwlock->lock);
        if (ret) {
            rwlock->exclusive = true;
        }

        return ret;
    }

    int pthread_rwlock_unlock(pthread_rwlock_t* rwlock)
    {
        if (rwlock == NULL) {
            return 1;
        }

        if (rwlock->exclusive) {
            rwlock->exclusive = false;
            ReleaseSRWLockExclusive(&rwlock->lock);
        } else {
            ReleaseSRWLockShared(&rwlock->lock);
        }

        return 0;
    }

    unsigned int pcthread_get_num_procs()
    {
        SYSTEM_INFO sysinfo;
        GetSystemInfo(&sysinfo);

        return sysinfo.dwNumberOfProcessors;
    }
#else
    unsigned int pcthread_get_num_procs()
    {
        return (unsigned int) sysconf(_SC_NPROCESSORS_ONLN);
    }
#endif

#endif