/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <stdarg.h>
#include <sys/cdefs.h>

__BEGIN_DECLS

struct syslog_data {
    char const* ident;
    int logopt;
    int facility;
    int maskpri;
};

/* The severity of the message. This is ordered. */
#define LOG_EMERG 0
#define LOG_ALERT 1
#define LOG_CRIT 2
#define LOG_ERR 3
#define LOG_WARNING 4
#define LOG_NOTICE 5
#define LOG_INFO 6
#define LOG_DEBUG 7

/* Macros for masking out the priority of a combined priority */
#define LOG_PRIMASK (7)
#define LOG_PRI(priority) ((priority) & LOG_PRIMASK)

/*
 * Many of these facilities don't really make sense anymore, but we keep them
 * for compatibility purposes.
 */
#define LOG_KERN (0 << 3)
#define LOG_USER (1 << 3)
#define LOG_MAIL (2 << 3)
#define LOG_DAEMON (3 << 3)
#define LOG_AUTH (4 << 3)
#define LOG_SYSLOG (5 << 3)
#define LOG_LPR (6 << 3)
#define LOG_NEWS (7 << 3)
#define LOG_UUCP (8 << 3)
#define LOG_CRON (9 << 3)
#define LOG_AUTHPRIV (10 << 3)
#define LOG_FTP (11 << 3)
/* glibc and OpenBSD reserve 12..15 for future system usage, we will too */
#define LOG_LOCAL0 (16 << 3)
#define LOG_LOCAL1 (17 << 3)
#define LOG_LOCAL2 (18 << 3)
#define LOG_LOCAL3 (19 << 3)
#define LOG_LOCAL4 (20 << 3)
#define LOG_LOCAL5 (21 << 3)
#define LOG_LOCAL6 (22 << 3)
#define LOG_LOCAL7 (23 << 3)

#define LOG_NFACILITIES 24

/* Macros to get the facility from a combined priority. */
#define LOG_FACMASK (~7)
#define LOG_FAC(priority) (((priority) & LOG_FACMASK) >> 3)

/* For masking logs, we use these macros with just the priority. */
#define LOG_MASK(priority) (1 << (priority))
#define LOG_UPTO(priority) (LOG_MASK(priority) + (LOG_MASK(priority) - 1))

/* Macro to make a combined priority. */
#define LOG_MAKEPRI(facility, priority) ((facility) | (priority))

/* Include a PID with the message. */
#define LOG_PID (1 << 0)
/* Log on the console. */
#define LOG_CONS (1 << 1)
/* Open the syslogd connection at the first call. (not implemented, default) */
#define LOG_ODELAY (1 << 2)
/* Open the syslogd connection immediately. (not implemented) */
#define LOG_NDELAY (1 << 3)
/* Log to stderr as well. */
#define LOG_PERROR (1 << 4)
/* Don't wait for child processes created while logging the message. */
#define LOG_NOWAIT (1 << 5)

/* This is useful to have, but has to be stored weirdly for compatibility. */
#ifdef SYSLOG_NAMES
/* Used for marking the fallback; some applications check for these defines. */
#    define INTERNAL_NOPRI 0x10
#    define INTERNAL_MARK LOG_MAKEPRI(LOG_NFACILITIES << 3, 0)

typedef struct _code {
    /*
     * Most Unices define this as char*, but in C++, we have to define it as a
     * const char* if we want to use string constants.
     */
    char const* c_name;
    int c_val;
} CODE;

/*
 * The names we use are the same as what glibc and OpenBSD use. We omit
 * deprecated values in the hope that no one uses them. Sorted, as well.
 */

CODE prioritynames[] = {
    { "alert", LOG_ALERT },
    { "crit", LOG_CRIT },
    { "debug", LOG_DEBUG },
    { "emerg", LOG_EMERG },
    { "err", LOG_ERR },
    { "info", LOG_INFO },
    /* Fallback */
    { "none", INTERNAL_NOPRI },
    { "notice", LOG_NOTICE },
    { "warning", LOG_WARNING },
    { NULL, -1 },
};

CODE facilitynames[] = {
    { "auth", LOG_AUTH },
    { "authpriv", LOG_AUTHPRIV },
    { "cron", LOG_CRON },
    { "daemon", LOG_DAEMON },
    { "ftp", LOG_FTP },
    { "kern", LOG_KERN },
    { "local0", LOG_LOCAL0 },
    { "local1", LOG_LOCAL1 },
    { "local2", LOG_LOCAL2 },
    { "local3", LOG_LOCAL3 },
    { "local4", LOG_LOCAL4 },
    { "local5", LOG_LOCAL5 },
    { "local6", LOG_LOCAL6 },
    { "local7", LOG_LOCAL7 },
    { "lpr", LOG_LPR },
    { "mail", LOG_MAIL },
    /* Fallback */
    { "mark", INTERNAL_MARK },
    { "news", LOG_NEWS },
    { "syslog", LOG_SYSLOG },
    { "user", LOG_USER },
    { "uucp", LOG_UUCP },
    { NULL, -1 },
};
#endif

/* The re-entrant versions are an OpenBSD extension we also implement. */
void syslog(int, char const*, ...);
void syslog_r(int, struct syslog_data*, char const*, ...);
void vsyslog(int, char const* message, va_list);
void vsyslog_r(int, struct syslog_data* data, char const* message, va_list);
void openlog(char const*, int, int);
void openlog_r(char const*, int, int, struct syslog_data*);
void closelog(void);
void closelog_r(struct syslog_data*);
int setlogmask(int);
int setlogmask_r(int, struct syslog_data*);

__END_DECLS