#include "Internal.h"
#include "Timespec.h"
#include "Codemap.h"
#include <stdlib.h>

#if (_POSIX_SEMAPHORES >= 200112L)
CgeSemaphore *CgeSemaphoreNew(int value, int *result) {
    CgeSemaphore *semaphore;
    int code = CGE_THREAD_EOK;

    semaphore = malloc(sizeof(CgeSemaphore));
    if (semaphore && sem_init(&semaphore->handle, 0, value)) {
        code = errorToErrorCode(errno);
        free(semaphore);
        semaphore = NULL;
    } else if (!semaphore) {
        code = CGE_THREAD_EOOM;
    }

    if (result)
        *result = code;

    return semaphore;
}

void CgeSemaphoreFree(CgeSemaphore *semaphore) {
    if (!semaphore)
        return;

    sem_destroy(&semaphore->handle);
    free(semaphore);
}


int CgeSemaphorePost(CgeSemaphore *semaphore, int *result) {
    int code = CGE_THREAD_EOK;

    if (sem_post(&semaphore->handle))
        code = errorToErrorCode(errno);

    if (result)
        *result = code;

    return code == CGE_THREAD_EOK;
}


int CgeSemaphoreWait(CgeSemaphore *semaphore, int *result) {
    int code = CGE_THREAD_EOK;

    if (sem_wait(&semaphore->handle))
        code = errorToErrorCode(errno);

    if (result)
        *result = code;

    return code == CGE_THREAD_EOK;
}


int CgeSemaphoreTryWait(CgeSemaphore *semaphore, int *result) {
    int code = CGE_THREAD_EOK;

    if (sem_trywait(&semaphore->handle))
        code = errorToErrorCode(errno);

    if (result)
        *result = code;

    return code == CGE_THREAD_EOK;
}


int CgeSemaphoreWaitFor(CgeSemaphore *semaphore, uint32_t timeout, int *result) {
    struct timespec ts;
    int code = CGE_THREAD_EOK;

    if (!convertToTimespec(&ts, timeout)) {
        if (result)
            *result = CGE_THREAD_EINVAL;
        return 0;
    }

    if (sem_timedwait(&semaphore->handle, &ts))
        code = errorToErrorCode(errno);

    if (result)
        *result = code;

    return code == CGE_THREAD_EOK;
}
#else
CgeSemaphore *CgeSemaphoreNew(int value, int *result) {
    CgeSemaphore *semaphore;
    int code = CGE_THREAD_EOOM;

    if (semaphore = malloc(sizeof(*semaphore))) {
        semaphore->count = value;
        semaphore->waiters = 0;

        if ((code = errorToErrorCode(pthread_mutex_init(&semaphore->mutex, NULL)))) {
            free(semaphore);
            if (result)
                *result = code;
            return NULL;
        }

        if ((code = errorToErrorCode(pthread_cond_init(&semaphore->condition, NULL)))) {
            pthread_mutex_destroy(&semaphore->mutex);
            free(semaphore);
            if (result)
                *result = code;
            return NULL;
        }
    }

    if (result)
        *result = code;

    return semaphore;
}

void CgeSemaphoreFree(CgeSemaphore *semaphore) {
    if (!semaphore)
        return;
    pthread_cond_destroy(&semaphore->condition);
    pthread_mutex_destroy(&semaphore->mutex);
    free(semaphore);
}

int CgeSemaphorePost(CgeSemaphore *semaphore, int *result) {
    int code;

    if ((code = errorToErrorCode(pthread_mutex_lock(&semaphore->mutex)))) {
        if (result)
            *result = code;
        return 0;
    }

    semaphore->count++;
    if (semaphore->waiters && (code = errorToErrorCode(pthread_cond_signal(&semaphore->condition)))) {
        if (result)
            *result = code;
    }

    pthread_mutex_unlock(&semaphore->mutex);
    return code == CGE_THREAD_EOK;
}

int CgeSemaphoreWait(CgeSemaphore *semaphore, int *result) {
    int code;

    if ((code = pthread_mutex_lock(&semaphore->mutex))) {
        if (result)
            *result = code;
        return 0;
    }

    semaphore->waiters++;
    while (!semaphore->count) {
        if ((code = errorToErrorCode(pthread_cond_wait(&semaphore->condition, &semaphore->mutex))))
            break;
    }
    semaphore->waiters--;
    semaphore->count--;
    pthread_mutex_unlock(&semaphore->mutex);

    return code == CGE_THREAD_EOK;
}


int CgeSemaphoreTryWait(CgeSemaphore *semaphore, int *result) {
    int code;

    if ((code = errorToErrorCode(pthread_mutex_lock(&semaphore->mutex)))) {
        if (result)
            *result = code;
        return 0;
    }

    if (!semaphore->count)
        code = CGE_THREAD_EBUSY;
    else
        semaphore->count--;

    pthread_mutex_unlock(&semaphore->mutex);
    return code == CGE_THREAD_EOK;
}


int CgeSemaphoreWaitFor(CgeSemaphore *semaphore,
                        uint32_t timeout, int *result) {
    struct timespec ts;
    int code;

    if (!convertToTimespec(&ts, timeout)) {
        if (result)
            *result = CGE_THREAD_EINVAL;
        return 0;
    }

    if ((code = errorToErrorCode(pthread_mutex_lock(&semaphore->mutex)))) {
        if (result)
            *result = code;
        return 0;
    }

    semaphore->waiters++;
    while (!semaphore->count && code == CGE_THREAD_EOK) {
        code = errorToErrorCode(pthread_cond_timedwait(&semaphore->condition, &semaphore->mutex, &ts));
    }
    semaphore->waiters--;

    if (code == CGE_THREAD_EOK)
        semaphore->count--;
    pthread_mutex_unlock(&semaphore->mutex);

    if (result)
        *result = code;

    return code == CGE_THREAD_EOK;
}
#endif