/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1995  Peter Wemm
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 */

/*
 * Make all the .h files for the optional entries
 */

#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include "config.h"
#include "y.tab.h"

static  struct users {
        int     u_default;
        int     u_min;
        int     u_max;
} users = { 8, 2, 512 };

static char *lower(char *);
static void read_options(void);
static void do_option(char *);
static char *tooption(char *);

void
options(void)
{
        char buf[40];
        struct cputype *cp;
        struct opt_list *ol;
        struct opt *op;

        /* Fake the cpu types as options. */
        SLIST_FOREACH(cp, &cputype, cpu_next) {
                op = (struct opt *)calloc(1, sizeof(*op));
                if (op == NULL)
                        err(EXIT_FAILURE, "calloc");
                op->op_name = ns(cp->cpu_name);
                SLIST_INSERT_HEAD(&opt, op, op_next);
        }       

        if (maxusers == 0) {
                if (verbose)
                        fprintf(stderr,
                            "maxusers not specified; will auto-size\n");
        } else if (maxusers < users.u_min) {
                fprintf(stderr, "minimum of %d maxusers assumed\n",
                    users.u_min);
                maxusers = users.u_min;
        } else if (maxusers > users.u_max)
                fprintf(stderr, "warning: maxusers > %d (%d)\n",
                    users.u_max, maxusers);

        /* Fake MAXUSERS as an option. */
        op = (struct opt *)calloc(1, sizeof(*op));
        if (op == NULL)
                err(EXIT_FAILURE, "calloc");
        op->op_name = ns("MAXUSERS");
        snprintf(buf, sizeof(buf), "%d", maxusers);
        op->op_value = ns(buf);
        SLIST_INSERT_HEAD(&opt, op, op_next);

        read_options();

        /* Fake the value of MACHINE_ARCH as an option if necessary */
        SLIST_FOREACH(ol, &otab, o_next) {
                if (strcasecmp(ol->o_name, machinearch) != 0)
                        continue;

                op = (struct opt *)calloc(1, sizeof(*op));
                if (op == NULL)
                        err(EXIT_FAILURE, "calloc");
                op->op_name = ns(ol->o_name);
                SLIST_INSERT_HEAD(&opt, op, op_next);
                break;
        }

        SLIST_FOREACH(op, &opt, op_next) {
                SLIST_FOREACH(ol, &otab, o_next) {
                        if (eq(op->op_name, ol->o_name) &&
                            (ol->o_flags & OL_ALIAS)) {
                                fprintf(stderr, "Mapping option %s to %s.\n",
                                    op->op_name, ol->o_file);
                                op->op_name = ol->o_file;
                                break;
                        }
                }
        }
        SLIST_FOREACH(ol, &otab, o_next)
                do_option(ol->o_name);
        SLIST_FOREACH(op, &opt, op_next) {
                if (!op->op_ownfile && strncmp(op->op_name, "DEV_", 4)) {
                        fprintf(stderr, "%s: unknown option \"%s\"\n",
                               PREFIX, op->op_name);
                        exit(1);
                }
        }
}

/*
 * Generate an <options>.h file
 */

static void
do_option(char *name)
{
        char *file;
        const char *basefile;
        struct opt_list *ol;
        struct opt *op;
        struct opt_head op_head;
        FILE *inf, *outf;
        char *value;
        char *oldvalue;
        int seen;
        int tidy;

        file = tooption(name);
        /*
         * Check to see if the option was specified..
         */
        value = NULL;
        SLIST_FOREACH(op, &opt, op_next) {
                if (eq(name, op->op_name)) {
                        oldvalue = value;
                        value = op->op_value;
                        if (value == NULL)
                                value = ns("1");
                        if (oldvalue != NULL && !eq(value, oldvalue))
                                fprintf(stderr,
                            "%s: option \"%s\" redefined from %s to %s\n",
                                   PREFIX, op->op_name, oldvalue,
                                   value);
                        op->op_ownfile++;
                }
        }

        remember(file);
        inf = fopen(file, "r");
        if (inf == NULL) {
                outf = fopen(file, "w");
                if (outf == NULL)
                        err(1, "%s", file);

                /* was the option in the config file? */
                if (value) {
                        fprintf(outf, "#define %s %s\n", name, value);
                } /* else empty file */

                (void)fclose(outf);
                return;
        }
        basefile = "";
        SLIST_FOREACH(ol, &otab, o_next)
                if (eq(name, ol->o_name)) {
                        basefile = ol->o_file;
                        break;
                }
        oldvalue = NULL;
        SLIST_INIT(&op_head);
        seen = 0;
        tidy = 0;
        for (;;) {
                configword cp, inw;
                char *invalue;

                /* get the #define */
                if ((inw = get_word(inf)).eol() || inw.eof())
                        break;
                /* get the option name */
                if ((inw = get_word(inf)).eol() || inw.eof())
                        break;
                /* get the option value */
                if ((cp = get_word(inf)).eol() || cp.eof())
                        break;
                /* option value */
                invalue = ns(cp); /* malloced */
                if (eq(inw, name)) {
                        oldvalue = invalue;
                        invalue = value;
                        seen++;
                }
                SLIST_FOREACH(ol, &otab, o_next)
                        if (eq(inw, ol->o_name))
                                break;
                if (!eq(inw, name) && !ol) {
                        fprintf(stderr,
                            "WARNING: unknown option `%s' removed from %s\n",
                            inw->c_str(), file);
                        tidy++;
                } else if (ol != NULL && !eq(basefile, ol->o_file)) {
                        fprintf(stderr,
                            "WARNING: option `%s' moved from %s to %s\n",
                            inw->c_str(), basefile, ol->o_file);
                        tidy++;
                } else {
                        op = (struct opt *) calloc(1, sizeof *op);
                        if (op == NULL)
                                err(EXIT_FAILURE, "calloc");
                        op->op_name = ns(inw);
                        op->op_value = invalue;
                        SLIST_INSERT_HEAD(&op_head, op, op_next);
                }

                /* EOL? */
                cp = get_word(inf);
                if (cp.eof())
                        break;
        }
        (void)fclose(inf);
        if (!tidy && ((value == NULL && oldvalue == NULL) ||
            (value && oldvalue && eq(value, oldvalue)))) {      
                while (!SLIST_EMPTY(&op_head)) {
                        op = SLIST_FIRST(&op_head);
                        SLIST_REMOVE_HEAD(&op_head, op_next);
                        free(op->op_name);
                        free(op->op_value);
                        free(op);
                }
                return;
        }

        if (value && !seen) {
                /* New option appears */
                op = (struct opt *) calloc(1, sizeof *op);
                if (op == NULL)
                        err(EXIT_FAILURE, "calloc");
                op->op_name = ns(name);
                op->op_value = ns(value);
                SLIST_INSERT_HEAD(&op_head, op, op_next);
        }

        outf = fopen(file, "w");
        if (outf == NULL)
                err(1, "%s", file);
        while (!SLIST_EMPTY(&op_head)) {
                op = SLIST_FIRST(&op_head);
                /* was the option in the config file? */
                if (op->op_value) {
                        fprintf(outf, "#define %s %s\n",
                                op->op_name, op->op_value);
                }
                SLIST_REMOVE_HEAD(&op_head, op_next);
                free(op->op_name);
                free(op->op_value);
                free(op);
        }
        (void)fclose(outf);
}

/*
 * Find the filename to store the option spec into.
 */
static char *
tooption(char *name)
{
        static char hbuf[MAXPATHLEN];
        char nbuf[MAXPATHLEN];
        struct opt_list *po;
        char *fpath;

        /* "cannot happen"?  the otab list should be complete.. */
        (void)strlcpy(nbuf, "options.h", sizeof(nbuf));

        SLIST_FOREACH(po, &otab, o_next) {
                if (eq(po->o_name, name)) {
                        strlcpy(nbuf, po->o_file, sizeof(nbuf));
                        break;
                }
        }

        fpath = path(nbuf);
        (void)strlcpy(hbuf, fpath, sizeof(hbuf));
        free(fpath);
        return (hbuf);
}

        
static void
check_duplicate(const char *fname, const char *chkopt)
{
        struct opt_list *po;

        SLIST_FOREACH(po, &otab, o_next) {
                if (eq(po->o_name, chkopt)) {
                        fprintf(stderr, "%s: Duplicate option %s.\n",
                            fname, chkopt);
                        exit(1);
                }
        }
}

static void
insert_option(const char *fname, char *optname, char *val)
{
        struct opt_list *po;

        check_duplicate(fname, optname);
        po = (struct opt_list *) calloc(1, sizeof *po);
        if (po == NULL)
                err(EXIT_FAILURE, "calloc");
        po->o_name = optname;
        po->o_file = val;
        po->o_flags = 0;
        SLIST_INSERT_HEAD(&otab, po, o_next);
}

static void
update_option(const char *optname, char *val, int flags)
{
        struct opt_list *po;

        SLIST_FOREACH(po, &otab, o_next) {
                if (eq(po->o_name, optname)) {
                        free(po->o_file);
                        po->o_file = val;
                        po->o_flags = flags;
                        return;
                }
        }
        /*
         * Option not found, but that's OK, we just ignore it since it
         * may be for another arch.
         */
        return;
}

static int
read_option_file(const char *fname, int flags)
{
        FILE *fp;
        configword wd;
        char *optname, *val;
        char genopt[MAXPATHLEN];

        fp = fopen(fname, "r");
        if (fp == NULL) {
                if (verbose) {
                        getcwd(genopt, sizeof(genopt));
                        fprintf(stderr, "Unable to open options file: %s\n",
                            fname);
                        fprintf(stderr, "CWD: %s\n", genopt);
                }
                return (0);
        }
        while (!(wd = get_word(fp)).eof()) {
                if (wd.eol())
                        continue;
                if (wd[0] == '#') {
                        while (!(wd = get_word(fp)).eof() && !wd.eol())
                                continue;
                        continue;
                }
                optname = ns(wd);
                wd = get_word(fp);
                if (wd.eof()) {
                        free(optname);
                        break;
                }
                if (wd.eol()) {
                        if (flags) {
                                fprintf(stderr, "%s: compat file requires two"
                                    " words per line at %s\n", fname, optname);
                                exit(1);
                        }
                        char *s = ns(optname);
                        (void)snprintf(genopt, sizeof(genopt), "opt_%s.h",
                            lower(s));
                        val = ns(genopt);
                        free(s);
                } else {
                        val = ns(wd);
                }

                if (flags == 0) {
                        /*
                         * insert_option takes possession of `optname` in the
                         * new option instead of making yet another copy.
                         */
                        insert_option(fname, optname, val);
                } else {
                        update_option(optname, val, flags);
                        free(optname);
                        optname = NULL;
                }
        }
        (void)fclose(fp);
        return (1);
}

/*
 * read the options and options.<machine> files
 */
static void
read_options(void)
{
        char fname[MAXPATHLEN];
        struct files_name *nl, *tnl;

        SLIST_INIT(&otab);
        read_option_file("../../conf/options", 0);
        (void)snprintf(fname, sizeof fname, "../../conf/options.%s",
            machinename);
        if (!read_option_file(fname, 0)) {
                (void)snprintf(fname, sizeof fname, "options.%s", machinename);
                read_option_file(fname, 0);
        }
        for (nl = STAILQ_FIRST(&optfntab); nl != NULL; nl = tnl) {
                read_option_file(nl->f_name, 0);
                tnl = STAILQ_NEXT(nl, f_next);
                free(nl->f_name);
                free(nl);
        }
        read_option_file("../../conf/options-compat", OL_ALIAS);
}

static char *
lower(char *str)
{
        char *cp = str;

        while (*str) {
                if (isupper(*str))
                        *str = tolower(*str);
                str++;
        }
        return (cp);
}