/* This work is licensed under a Creative Commons CCZero 1.0 Universal License.

 * See http://creativecommons.org/publicdomain/zero/1.0/ for more information.

 *

 *    Copyright 2020 (c) Fraunhofer IOSB (Author: Julius Pfrommer)

 */

#include <open62541/plugin/log_syslog.h>

#include <open62541/types.h>

#if defined(__linux__) || defined(__unix__)

#include <syslog.h>

#include "mp_printf.h"

static const char *syslogLevelNames[6] = {"trace", "debug", "info",

                                   "warn", "error", "fatal"};

static const char *syslogCategoryNames[UA_LOGCATEGORIES] =

    {"network", "channel", "session", "server", "client",

     "application", "security", "eventloop", "pubsub", "discovery"};

static const char *

syslogCategoryName(UA_LogCategory category) {

    if((UA_UInt32)category >= UA_LOGCATEGORIES)

        return "unknown";

    return syslogCategoryNames[category];

}

#ifdef __clang__

__attribute__((__format__(__printf__, 4 , 0)))

#endif

static void

UA_Log_Syslog_log(void *context, UA_LogLevel level, UA_LogCategory category,

                  const char *msg, va_list args) {

    /* Assume that context is casted to UA_LogLevel */

    if(context != NULL && (UA_LogLevel)(uintptr_t)context > level)

        return;

    int priority = LOG_INFO;

    switch(level) {

    case UA_LOGLEVEL_DEBUG:

        priority = LOG_DEBUG;

        break;

    case UA_LOGLEVEL_INFO:

        priority = LOG_INFO;

        break;

    case UA_LOGLEVEL_WARNING:

        priority = LOG_WARNING;

        break;

    case UA_LOGLEVEL_ERROR:

        priority = LOG_ERR;

        break;

    case UA_LOGLEVEL_FATAL:

        priority = LOG_CRIT;

        break;

    case UA_LOGLEVEL_TRACE:

    default:

        return;

    }

    int logLevelSlot = ((int)level / 100) - 1;

#define LOGBUFSIZE 512

    char logbuf[LOGBUFSIZE];

    int pos = mp_snprintf(logbuf, LOGBUFSIZE, "[%s/%s] ",

                          syslogLevelNames[logLevelSlot],

                          syslogCategoryName(category));

    if(pos < 0) {

        syslog(LOG_WARNING, "Log message too long for syslog");

        return;

    }

    pos = mp_vsnprintf(&logbuf[pos], LOGBUFSIZE - (size_t)pos, msg, args);

    if(pos < 0) {

        syslog(LOG_WARNING, "Log message too long for syslog");

        return;

    }

    syslog(priority, "%s", logbuf);

}

static void

UA_Log_Syslog_clear(UA_Logger *logger) {

    /* closelog is optional. We don't use it as several loggers might be

     * instantiated in parallel. */

    /* closelog(); */

    UA_free(logger);

}

UA_Logger

UA_Log_Syslog(void) {

    return UA_Log_Syslog_withLevel(UA_LOGLEVEL_TRACE);

}

UA_Logger

UA_Log_Syslog_withLevel(UA_LogLevel minlevel) {

    UA_Logger logger = {UA_Log_Syslog_log, (void*)(uintptr_t)minlevel, NULL};

    return logger;

}

UA_Logger *

UA_Log_Syslog_new(UA_LogLevel minlevel) {

    UA_Logger *logger = (UA_Logger*)UA_malloc(sizeof(UA_Logger));

    if(!logger)

        return NULL;

    *logger = UA_Log_Syslog_withLevel(minlevel);

    logger->clear = UA_Log_Syslog_clear;

    return logger;

}

#endif