/*      $NetBSD: v7fs_file_util.c,v 1.5 2022/02/11 10:55:15 hannken Exp $       */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * 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.
 */

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: v7fs_file_util.c,v 1.5 2022/02/11 10:55:15 hannken Exp $");
#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/param.h>
#else
#include <stdio.h>
#include <string.h>
#include <errno.h>
#endif

#include "v7fs.h"
#include "v7fs_impl.h"
#include "v7fs_endian.h"
#include "v7fs_inode.h"
#include "v7fs_dirent.h"
#include "v7fs_file.h"
#include "v7fs_datablock.h"

#ifdef V7FS_FILE_DEBUG
#define DPRINTF(fmt, args...)   printf("%s: " fmt, __func__, ##args)
#else
#define DPRINTF(fmt, args...)   ((void)0)
#endif

static int replace_subr(struct v7fs_self *, void *, v7fs_daddr_t, size_t);
static int lookup_by_number_subr(struct v7fs_self *, void *, v7fs_daddr_t,
    size_t);
static int can_dirmove(struct v7fs_self *, v7fs_ino_t, v7fs_ino_t);
static int lookup_parent_from_dir_subr(struct v7fs_self *, void *,
    v7fs_daddr_t, size_t);

int
v7fs_file_link(struct v7fs_self *fs, struct v7fs_inode *parent_dir,
    struct v7fs_inode *p, const char *name, size_t namelen)
{
        int error = 0;

        DPRINTF("%d %d %.*s\n", parent_dir->inode_number, p->inode_number,
            (int)namelen, name);
        if ((error = v7fs_directory_add_entry(fs, parent_dir, p->inode_number,
            name, namelen))) {
                DPRINTF("can't add entry");
                return error;
        }
        p->nlink++;
        v7fs_inode_writeback(fs, p);

        return 0;
}

int
v7fs_file_symlink(struct v7fs_self *fs, struct v7fs_inode *p,
    const char *target)
{
        int error;
        size_t len = strlen(target) + 1;

        if (len > V7FSBSD_MAXSYMLINKLEN) {/* limited target 512byte pathname */
                DPRINTF("too long pathname.");
                return ENAMETOOLONG;
        }

        if ((error = v7fs_datablock_expand(fs, p, len))) {
                return error;
        }

        v7fs_daddr_t blk = p->addr[0];  /* 1block only.  */
        void *buf;
        if (!(buf = scratch_read(fs, blk))) {
                return EIO;
        }

        strncpy(buf, target, V7FS_BSIZE);
        if (!fs->io.write(fs->io.cookie, buf, blk)) {
                scratch_free(fs, buf);
                return EIO;
        }
        scratch_free(fs, buf);
        v7fs_inode_writeback(fs, p);

        return 0;
}

int
v7fs_file_rename(struct v7fs_self *fs, struct v7fs_inode *parent_from,
    const char *from, size_t fromlen, struct v7fs_inode *parent_to,
    const char *to, size_t tolen)
{
        v7fs_ino_t from_ino, to_ino;
        struct v7fs_inode inode;
        int error;
        bool dir_move;

        /* Check source file */
        if ((error = v7fs_file_lookup_by_name(fs, parent_from, from, fromlen, 
            &from_ino))) {
                DPRINTF("%.*s don't exists\n", (int)fromlen, from);
                return error;
        }
        v7fs_inode_load(fs, &inode, from_ino);
        dir_move = v7fs_inode_isdir(&inode);

        /* Check target file */
        error = v7fs_file_lookup_by_name(fs, parent_to, to, tolen, &to_ino);
        if (error == 0) {       /* found */
                DPRINTF("%.*s already exists\n", (int)tolen, to);
                if ((error = v7fs_file_deallocate(fs, parent_to, to, tolen))) {
                        DPRINTF("%.*s can't remove %d\n", (int)tolen,
                            to, error);
                        return error;
                }
        } else if (error != ENOENT) {
                DPRINTF("error=%d\n", error);
                return error;
        }
        /* Check directory hierarchy. t_vnops rename_dir(5) */
        if (dir_move && (error = can_dirmove(fs, from_ino,
            parent_to->inode_number))) {
                DPRINTF("dst '%.*s' is child dir of '%.*s'. error=%d\n",
                    (int)tolen, to, (int)fromlen, from, error);
                return error;
        }

        if ((error = v7fs_directory_add_entry(fs, parent_to, from_ino, to,
            tolen))) {
                DPRINTF("can't add entry");
                return error;
        }

        if ((error = v7fs_directory_remove_entry(fs, parent_from, from,
            fromlen))) {
                DPRINTF("can't remove entry");
                return error;
        }

        if (dir_move && (parent_from != parent_to)) {
                /* If directory move, update ".." */
                if ((error = v7fs_directory_replace_entry(fs, &inode, "..",
                            parent_to->inode_number))) {
                        DPRINTF("can't replace parent dir");
                        return error;
                }
                v7fs_inode_writeback(fs, &inode);
        }

        return 0;
}


int
v7fs_directory_replace_entry(struct v7fs_self *fs,  struct v7fs_inode *self_dir,
    const char *name, v7fs_ino_t ino)
{
        int error;

        /* Search entry that replaced. replace it to new inode number. */
        struct v7fs_lookup_arg lookup_arg = { .name = name,
                                              .inode_number = ino };
        if ((error = v7fs_datablock_foreach(fs, self_dir, replace_subr,
            &lookup_arg)) != V7FS_ITERATOR_BREAK)
                return ENOENT;

        return 0;
}

static int
replace_subr(struct v7fs_self *fs, void *ctx, v7fs_daddr_t blk, size_t sz)
{
        struct v7fs_lookup_arg *p = (struct v7fs_lookup_arg *)ctx;
        struct v7fs_dirent *dir;
        void *buf;
        size_t i, n;
        int ret = 0;

        DPRINTF("match start blk=%x\n", blk);
        if (!(buf = scratch_read(fs, blk)))
                return EIO;

        dir = (struct v7fs_dirent *)buf;
        n = sz / sizeof(*dir);

        for (i = 0; i < n; i++, dir++) { /*disk endian */
                if (strncmp(p->name, (const char *)dir->name, V7FS_NAME_MAX)
                    == 0) {
                        /* Replace inode# */
                        dir->inode_number = V7FS_VAL16(fs, p->inode_number);
                        /* Write back. */
                        if (!fs->io.write(fs->io.cookie, buf, blk))
                                ret = EIO;
                        else
                                ret = V7FS_ITERATOR_BREAK;
                        break;
                }
        }
        scratch_free(fs, buf);

        return ret;
}

bool
v7fs_file_lookup_by_number(struct v7fs_self *fs, struct v7fs_inode *parent_dir,
    v7fs_ino_t ino, char *buf)
{
        int ret;

        ret = v7fs_datablock_foreach(fs, parent_dir, lookup_by_number_subr,
            &(struct v7fs_lookup_arg){ .inode_number = ino, .buf = buf });

        return ret == V7FS_ITERATOR_BREAK;
}

static int
lookup_by_number_subr(struct v7fs_self *fs, void *ctx, v7fs_daddr_t blk,
    size_t sz)
{
        struct v7fs_lookup_arg *p = (struct v7fs_lookup_arg *)ctx;
        struct v7fs_dirent *dir;
        void *buf;
        size_t i, n;
        int ret = 0;

        if (!(buf = scratch_read(fs, blk)))
                return EIO;

        dir = (struct v7fs_dirent *)buf;
        n = sz / sizeof(*dir);
        v7fs_dirent_endian_convert(fs, dir, n);

        for (i = 0; i < n; i++, dir++) {
                if (dir->inode_number == p->inode_number) {
                        if (p->buf)
                                v7fs_dirent_filename(p->buf, dir->name,
                                    strlen(dir->name));
                        ret = V7FS_ITERATOR_BREAK;
                        break;
                }
        }
        scratch_free(fs, buf);

        return ret;
}

struct lookup_parent_arg {
        v7fs_ino_t parent_ino;
};

static int
can_dirmove(struct v7fs_self *fs, v7fs_ino_t from_ino, v7fs_ino_t to_ino)
{
        struct v7fs_inode inode;
        v7fs_ino_t parent;
        int error;

        /* Start dir. */
        if ((error = v7fs_inode_load(fs, &inode, to_ino)))
                return error;

        if (!v7fs_inode_isdir(&inode))
                return ENOTDIR;

        /* Lookup the parent. */
        do {
                struct lookup_parent_arg arg;
                /* Search parent dir */
                arg.parent_ino = 0;
                v7fs_datablock_foreach(fs, &inode, lookup_parent_from_dir_subr,
                    &arg);
                if ((parent = arg.parent_ino) == 0) {
                        DPRINTF("***parent missing\n");
                        return ENOENT;
                }
                /* Load parent dir */
                if ((error = v7fs_inode_load(fs, &inode, parent)))
                        return error;
                if (parent == from_ino) {
                        DPRINTF("#%d is child dir of #%d\n", to_ino, from_ino);
                        return EINVAL;
                }
        } while (parent != V7FS_ROOT_INODE);

        return 0;
}

static int
lookup_parent_from_dir_subr(struct v7fs_self *fs, void *ctx, v7fs_daddr_t blk,
    size_t sz)
{
        struct lookup_parent_arg *arg = (struct lookup_parent_arg *)ctx;
        char name[V7FS_NAME_MAX + 1];
        void *buf;
        int ret = 0;

        if (!(buf = scratch_read(fs, blk)))
                return 0;
        struct v7fs_dirent *dir = (struct v7fs_dirent *)buf;
        size_t i, n = sz / sizeof(*dir);
        if (!v7fs_dirent_endian_convert(fs, dir, n)) {
                scratch_free(fs, buf);
                return V7FS_ITERATOR_ERROR;
        }

        for (i = 0; i < n; i++, dir++) {
                v7fs_dirent_filename(name, dir->name, strlen(dir->name));
                if (strncmp(dir->name, "..", V7FS_NAME_MAX) != 0)
                        continue;

                arg->parent_ino = dir->inode_number;
                ret = V7FS_ITERATOR_BREAK;
                break;
        }

        scratch_free(fs, buf);
        return ret;
}