/*
 *
 * Copyright 2023 Oleg Borodin  <borodin@unix7.org>
 *
 */

#include <stdio.h>
#include <string.h>
#include <time.h>
#include <stdarg.h>
#include <pthread.h>


#define CLOCK_SOURCE CLOCK_MONOTONIC
#define MAX_TS_LEN 256


static pthread_mutex_t logmutex = NULL;
static pthread_mutexattr_t logmutex_attrs;

void log_init(void) {
    pthread_mutexattr_init(&logmutex_attrs);
    pthread_mutexattr_setpshared(&logmutex_attrs, PTHREAD_PROCESS_SHARED);
    pthread_mutex_init(&logmutex, &logmutex_attrs);
}

void log_destroy(void) {
    pthread_mutex_destroy(&logmutex);
    pthread_mutexattr_destroy(&logmutex_attrs);
}

void static set_timestamp(char* buffer) {
    time_t now = time(NULL);
    if (now < 0) {
        return;
    }
    struct tm* ptm = localtime(&now);
    if (ptm == NULL) {
        return;
    }
    struct timespec tv;

    clock_gettime(CLOCK_SOURCE, &tv);
    memset(buffer, '\0', MAX_TS_LEN);
    sprintf(buffer, "%04d-%02d-%02dT%02d:%02d:%02d.%ld+%s",
            ptm->tm_year + 1900, ptm->tm_mon + 1, ptm->tm_mday, ptm->tm_hour,
            ptm->tm_min, ptm->tm_sec, tv.tv_nsec, ptm->tm_zone);
}

void log_error(const char* format, ...) {

    char timestamp[MAX_TS_LEN];
    set_timestamp(timestamp);

    pthread_mutex_lock(&logmutex);
    va_list args;
    fprintf(stderr, "%s error: ", timestamp);
    va_start(args, format);
    vfprintf(stderr, format, args);
    va_end(args);
    fprintf(stderr, "\n");
    pthread_mutex_unlock(&logmutex);
}

void log_warning(const char* format, ...) {

    char timestamp[MAX_TS_LEN];
    set_timestamp(timestamp);

    pthread_mutex_lock(&logmutex);
    va_list args;
    fprintf(stderr, "%s warning: ", timestamp);
    va_start(args, format);
    vfprintf(stderr, format, args);
    va_end(args);
    fprintf(stderr, "\n");
    pthread_mutex_unlock(&logmutex);
}


void log_debug(const char* format, ...) {

    char timestamp[MAX_TS_LEN];
    set_timestamp(timestamp);

    pthread_mutex_lock(&logmutex);
    va_list args;
    fprintf(stderr, "%s debug: ", timestamp);
    va_start(args, format);
    vfprintf(stderr, format, args);
    va_end(args);
    fprintf(stderr, "\n");
    pthread_mutex_unlock(&logmutex);
}