/*      $NetBSD: fmtmsg.c,v 1.6 2014/09/18 13:58:20 christos Exp $      */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Klaus Klein.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: fmtmsg.c,v 1.6 2014/09/18 13:58:20 christos Exp $");
#endif /* LIBC_SCCS and not lint */

#include <fmtmsg.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static unsigned int     msgverb(const char *);
static const char *     severity2str(int);
static int              writeit(FILE *, unsigned int, const char *,
                            const char *, const char *, const char *,
                            const char *);

#define MM_VERBLABEL            0x01U
#define MM_VERBSEVERITY         0x02U
#define MM_VERBTEXT             0x04U
#define MM_VERBACTION           0x08U
#define MM_VERBTAG              0x10U
#define MM_VERBALL      \
    (MM_VERBLABEL | MM_VERBSEVERITY | MM_VERBTEXT | MM_VERBACTION | \
     MM_VERBTAG)

static const struct keyword {
        size_t                  len;    /* strlen(keyword) */
        const char * const      keyword;
} keywords[] = {
        { 5,    "label"         },      /* log2(MM_VERBLABEL) */
        { 8,    "severity"      },      /* ... */
        { 4,    "text"          },
        { 6,    "action"        },
        { 3,    "tag"           }       /* log2(MM_VERBTAG) */
};

static const size_t nkeywords = sizeof (keywords) / sizeof (keywords[0]);

/*
 * Convert a colon-separated list of known keywords to a set of MM_VERB*
 * flags, defaulting to `all' if not set, empty, or in presence of unknown
 * keywords.
 */
static unsigned int
msgverb(const char *str)
{
        u_int i;
        unsigned int result;

        if (str == NULL)
                return (MM_VERBALL);

        result = 0;
        while (*str != '\0') {
                for (i = 0; i < nkeywords; i++) {
                        if (memcmp(str, keywords[i].keyword, keywords[i].len)
                            == 0 &&
                            (*(str + keywords[i].len) == ':' ||
                             *(str + keywords[i].len) == '\0'))
                                break;
                }
                if (i == nkeywords) {
                        result = MM_VERBALL;
                        break;
                }

                result |= (1 << i);
                if (*(str += keywords[i].len) == ':')
                        str++;  /* Advance */
        }
        if (result == 0)
                result = MM_VERBALL;

        return (result);
}

static const char severities[][8] = {
        "",             /* MM_NONE */
        "HALT",
        "ERROR",
        "WARNING",
        "INFO"
};

static const size_t nseverities = sizeof (severities) / sizeof (severities[0]);

/*
 * Returns the string representation associated with the numerical severity
 * value, defaulting to NULL for an unknown value.
 */
static const char *
severity2str(int severity)
{
        const char *result;

        if (severity >= 0 &&
            (u_int) severity < nseverities)
                result = severities[severity];
        else
                result = NULL;

        return (result);
}

/*
 * Format and write the message to the given stream, selecting those
 * components displayed from msgverb, returning the number of characters
 * written, or a negative value in case of an error.
 */
static int
writeit(FILE *stream, unsigned int which, const char *label,
        const char *sevstr, const char *text, const char *action,
        const char *tag)
{
        int nwritten;

        nwritten = fprintf(stream, "%s%s%s%s%s%s%s%s%s%s%s",
            ((which & MM_VERBLABEL) && label != MM_NULLLBL) ?
            label : "",
            ((which & MM_VERBLABEL) && label != MM_NULLLBL) ?
            ": " : "",
            (which & MM_VERBSEVERITY) ?
            sevstr : "",
            (which & MM_VERBSEVERITY) ?
            ": " : "",
            ((which & MM_VERBTEXT) && text != MM_NULLTXT) ?
            text : "",
            ((which & MM_VERBLABEL) && label != MM_NULLLBL) ||
            ((which & MM_VERBSEVERITY)) ||
            ((which & MM_VERBTEXT) && text != MM_NULLTXT) ?
            "\n" : "",
            ((which & MM_VERBACTION) && action != MM_NULLACT) ?
            "TO FIX: " : "",
            ((which & MM_VERBACTION) && action != MM_NULLACT) ?
            action : "",
            ((which & MM_VERBACTION) && label != MM_NULLACT) ?
            " " : "",
            ((which & MM_VERBTAG) && tag != MM_NULLTAG) ?
            tag : "",
            ((which & MM_VERBACTION) && action != MM_NULLACT) ||
            ((which & MM_VERBTAG) && tag != MM_NULLTAG) ?
            "\n" : "");

        return (nwritten);
}

int
fmtmsg(long classification, const char *label, int severity,
        const char *text, const char *action, const char *tag)
{
        FILE *console;
        const char *p, *sevstr;
        int result;

        /* Validate label constraints, if not null. */
        if (label != MM_NULLLBL) {
                /*
                 * Two fields, separated by a colon.  The first field is up to
                 * 10 bytes, the second is up to 14 bytes.
                 */
                p = strchr(label, ':');
                if (p ==  NULL || p - label > 10 || strlen(p + 1) > 14)
                        return (MM_NOTOK);
        }
        /* Validate severity argument. */
        if ((sevstr = severity2str(severity)) == NULL)
                return (MM_NOTOK);

        /*
         * Fact in search for a better place: XSH5 does not define any
         * functionality for `classification' bits other than the display
         * subclassification.
         */

        result = 0;

        if (classification & MM_PRINT) {
                if (writeit(stderr, msgverb(getenv("MSGVERB")),
                    label, sevstr, text, action, tag) < 0)
                        result |= MM_NOMSG;
        }
        /* Similar to MM_PRINT but ignoring $MSGVERB. */
        if (classification & MM_CONSOLE) {
                if ((console = fopen(_PATH_CONSOLE, "we")) != NULL) {
                        if (writeit(console, MM_VERBALL,
                            label, sevstr, text, action, tag) < 0)
                                result |= MM_NOCON;
                        /*
                         * Ignore result: does not constitute ``generate a
                         * console message.''
                         */
                        (void)fclose(console);
                } else {
                        result |= MM_NOCON;
                }
        }

        if (result == (MM_NOMSG | MM_NOCON))
                result = MM_NOTOK;

        return (result == 0 ? MM_OK : result);
}