/*-
 * Copyright (c) 2016 The DragonFly Project
 * Copyright (c) 2014 The FreeBSD Foundation
 * All rights reserved.
 *
 * This software was developed by Edward Tomasz Napierala under sponsorship
 * from the FreeBSD Foundation.
 *
 * 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 AUTHOR 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 AUTHOR 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/param.h>
#include <sys/diskslice.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <iconv.h>
#include <locale.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vis.h>

#include "fstyp.h"

#define LABEL_LEN       512

bool show_label = false;

typedef int (*fstyp_function)(FILE *, char *, size_t, const char *);
typedef int (*fsvtyp_function)(const char *, char *, size_t);

static struct {
        const char      *name;
        fstyp_function  function;
        bool            unmountable;
        const char      *precache_encoding;
} fstypes[] = {
        { "apfs", &fstyp_apfs, true, NULL },
        { "befs", &fstyp_befs, false, NULL },
        { "cd9660", &fstyp_cd9660, false, NULL },
        { "exfat", &fstyp_exfat, false, EXFAT_ENC },
        { "ext2fs", &fstyp_ext2fs, false, NULL },
        { "hfs+", &fstyp_hfsp, false, NULL },
        { "msdosfs", &fstyp_msdosfs, false, NULL },
        { "ntfs", &fstyp_ntfs, false, NTFS_ENC },
        { "ufs", &fstyp_ufs, false, NULL },
        { "hammer", &fstyp_hammer, false, NULL },
        { "hammer2", &fstyp_hammer2, false, NULL },
        { NULL, NULL, NULL, NULL }
};

static struct {
        const char      *name;
        fsvtyp_function function;
        bool            unmountable;
        const char      *precache_encoding;
} fsvtypes[] = {
        { "hammer", &fsvtyp_hammer, false, NULL }, /* Must be before partial */
        { "hammer(partial)", &fsvtyp_hammer_partial, true, NULL },
        { "hammer2", &fsvtyp_hammer2, false, NULL }, /* Must be before partial */
        { "hammer2(partial)", &fsvtyp_hammer2_partial, true, NULL },
        { NULL, NULL, NULL, NULL }
};

void *
read_buf(FILE *fp, off_t off, size_t len)
{
        int error;
        size_t nread;
        void *buf;

        error = fseek(fp, off, SEEK_SET);
        if (error != 0) {
                warn("cannot seek to %jd", (uintmax_t)off);
                return (NULL);
        }

        buf = malloc(len);
        if (buf == NULL) {
                warn("cannot malloc %zd bytes of memory", len);
                return (NULL);
        }

        nread = fread(buf, len, 1, fp);
        if (nread != 1) {
                free(buf);
                if (feof(fp) == 0)
                        warn("fread");
                return (NULL);
        }

        return (buf);
}

char *
checked_strdup(const char *s)
{
        char *c;

        c = strdup(s);
        if (c == NULL)
                err(1, "strdup");
        return (c);
}

void
rtrim(char *label, size_t size)
{
        ptrdiff_t i;

        for (i = size - 1; i >= 0; i--) {
                if (label[i] == '\0')
                        continue;
                else if (label[i] == ' ')
                        label[i] = '\0';
                else
                        break;
        }
}

static void
usage(void)
{

        fprintf(stderr, "usage: fstyp [-l] [-s] [-u] special\n");
        exit(1);
}

static void
type_check(const char *path, FILE *fp)
{
        int error, fd;
        struct stat sb;
        struct partinfo pinfo;

        fd = fileno(fp);

        error = fstat(fd, &sb);
        if (error != 0)
                err(1, "%s: fstat", path);

        if (S_ISREG(sb.st_mode))
                return;

        error = ioctl(fd, DIOCGPART, &pinfo);
        if (error != 0)
                errx(1, "%s: not a disk", path);
}

int
main(int argc, char **argv)
{
        int ch, error, i, nbytes;
        bool ignore_type = false, show_unmountable = false;
        char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
        char fdpath[MAXPATHLEN];
        char *p;
        const char *path;
        const char *name = NULL;
        FILE *fp;
        fstyp_function fstyp_f;
        fsvtyp_function fsvtyp_f;

        while ((ch = getopt(argc, argv, "lsu")) != -1) {
                switch (ch) {
                case 'l':
                        show_label = true;
                        break;
                case 's':
                        ignore_type = true;
                        break;
                case 'u':
                        show_unmountable = true;
                        break;
                default:
                        usage();
                }
        }

        argc -= optind;
        argv += optind;
        if (argc != 1)
                usage();

        path = argv[0];

        if (setlocale(LC_CTYPE, "") == NULL)
                err(1, "setlocale");

        /*
         * DragonFly: Filesystems may have syntax to decorate path.
         * Make a wild guess.
         */
        strlcpy(fdpath, path, sizeof(fdpath));
        p = strchr(fdpath, '@');
        if (p)
                *p = '\0';

        fp = fopen(fdpath, "r");
        if (fp == NULL) {
                if (strcmp(path, fdpath))
                        fp = fopen(path, "r");
                if (fp == NULL)
                        goto fsvtyp; /* DragonFly */
                else
                        strlcpy(fdpath, path, sizeof(fdpath));
        }

        if (ignore_type == false)
                type_check(fdpath, fp);

        memset(label, '\0', sizeof(label));

        for (i = 0;; i++) {
                if (show_unmountable == false && fstypes[i].unmountable == true)
                        continue;
                fstyp_f = fstypes[i].function;
                if (fstyp_f == NULL)
                        break;

                error = fstyp_f(fp, label, sizeof(label), path);
                if (error == 0) {
                        name = fstypes[i].name;
                        goto done;
                }
        }
fsvtyp:
        for (i = 0;; i++) {
                if (show_unmountable == false && fsvtypes[i].unmountable == true)
                        continue;
                fsvtyp_f = fsvtypes[i].function;
                if (fsvtyp_f == NULL)
                        break;

                error = fsvtyp_f(path, label, sizeof(label));
                if (error == 0) {
                        name = fsvtypes[i].name;
                        goto done;
                }
        }

        warnx("%s: filesystem not recognized", path);
        return (1);
done:
        if (show_label && label[0] != '\0') {
                /*
                 * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
                 *      encodes spaces.
                 */
                nbytes = strsnvis(strvised, sizeof(strvised), label,
                    VIS_GLOB | VIS_NL, "\"'$");
                if (nbytes == -1)
                        err(1, "strsnvis");

                printf("%s %s\n", name, strvised);
        } else {
                printf("%s\n", name);
        }

        return (0);
}