/*
 * Copyright (C) 2001-2007 Miklos Szeredi. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY 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 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.
 *
 *  This file is based on include/uapi/linux/fuse.h from Linux. That header
 *  is dual-licensed under the GPLv2 and the above 2-Clause BSD license.
 *  Consequentially, we are sublicensing this file under the latter license,
 *  which is why we have to include it above verbatim.
 */

#pragma once

#include <AK/Types.h>

#define FUSE_KERNEL_VERSION 7
#define FUSE_KERNEL_MINOR_VERSION 39

struct fuse_attr {
    uint64_t ino;
    uint64_t size;
    uint64_t blocks;
    uint64_t atime;
    uint64_t mtime;
    uint64_t ctime;
    uint32_t atimensec;
    uint32_t mtimensec;
    uint32_t ctimensec;
    uint32_t mode;
    uint32_t nlink;
    uint32_t uid;
    uint32_t gid;
    uint32_t rdev;
    uint32_t blksize;
    uint32_t flags;
};

// Bitmasks for fuse_setattr_in.valid
#define FATTR_MODE (1 << 0)
#define FATTR_UID (1 << 1)
#define FATTR_GID (1 << 2)
#define FATTR_SIZE (1 << 3)
#define FATTR_ATIME (1 << 4)
#define FATTR_MTIME (1 << 5)
#define FATTR_FH (1 << 6)
#define FATTR_ATIME_NOW (1 << 7)
#define FATTR_MTIME_NOW (1 << 8)
#define FATTR_LOCKOWNER (1 << 9)
#define FATTR_CTIME (1 << 10)
#define FATTR_KILL_SUIDGID (1 << 11)

enum class FUSEOpcode {
    FUSE_LOOKUP = 1,
    FUSE_FORGET = 2, // no reply
    FUSE_GETATTR = 3,
    FUSE_SETATTR = 4,
    FUSE_READLINK = 5,
    FUSE_SYMLINK = 6,
    FUSE_MKNOD = 8,
    FUSE_MKDIR = 9,
    FUSE_UNLINK = 10,
    FUSE_RMDIR = 11,
    FUSE_RENAME = 12,
    FUSE_LINK = 13,
    FUSE_OPEN = 14,
    FUSE_READ = 15,
    FUSE_WRITE = 16,
    FUSE_STATFS = 17,
    FUSE_RELEASE = 18,
    FUSE_FSYNC = 20,
    FUSE_SETXATTR = 21,
    FUSE_GETXATTR = 22,
    FUSE_LISTXATTR = 23,
    FUSE_REMOVEXATTR = 24,
    FUSE_FLUSH = 25,
    FUSE_INIT = 26,
    FUSE_OPENDIR = 27,
    FUSE_READDIR = 28,
    FUSE_RELEASEDIR = 29,
    FUSE_FSYNCDIR = 30,
    FUSE_GETLK = 31,
    FUSE_SETLK = 32,
    FUSE_SETLKW = 33,
    FUSE_ACCESS = 34,
    FUSE_CREATE = 35,
    FUSE_INTERRUPT = 36,
    FUSE_BMAP = 37,
    FUSE_DESTROY = 38,
    FUSE_IOCTL = 39,
    FUSE_POLL = 40,
    FUSE_NOTIFY_REPLY = 41,
    FUSE_BATCH_FORGET = 42,
    FUSE_FALLOCATE = 43,
    FUSE_READDIRPLUS = 44,
    FUSE_RENAME2 = 45,
    FUSE_LSEEK = 46,
    FUSE_COPY_FILE_RANGE = 47,
    FUSE_SETUPMAPPING = 48,
    FUSE_REMOVEMAPPING = 49,
    FUSE_SYNCFS = 50,
    FUSE_TMPFILE = 51,
    FUSE_STATX = 52,

    // CUSE specific operations
    CUSE_INIT = 4096,

    // Reserved opcodes: helpful to detect structure endian-ness
    CUSE_INIT_BSWAP_RESERVED = 1048576,   // CUSE_INIT << 8
    FUSE_INIT_BSWAP_RESERVED = 436207616, // FUSE_INIT << 24
};

struct fuse_entry_out {
    uint64_t nodeid;      /* Inode ID */
    uint64_t generation;  /* Inode generation: nodeid:gen must
                             be unique for the fs's lifetime */
    uint64_t entry_valid; /* Cache timeout for the name */
    uint64_t attr_valid;  /* Cache timeout for the attributes */
    uint32_t entry_valid_nsec;
    uint32_t attr_valid_nsec;
    struct fuse_attr attr;
};

struct fuse_getattr_in {
    uint32_t getattr_flags;
    uint32_t dummy;
    uint64_t fh;
};

struct fuse_attr_out {
    uint64_t attr_valid; /* Cache timeout for the attributes */
    uint32_t attr_valid_nsec;
    uint32_t dummy;
    struct fuse_attr attr;
};

struct fuse_mknod_in {
    uint32_t mode;
    uint32_t rdev;
    uint32_t umask;
    uint32_t padding;
    uint8_t data[];
};

struct fuse_mkdir_in {
    uint32_t mode;
    uint32_t umask;
    uint8_t data[];
};

struct fuse_rename_in {
    uint64_t newdir;
    uint8_t data[];
};

struct fuse_link_in {
    uint64_t oldnodeid;
};

struct fuse_setattr_in {
    uint32_t valid;
    uint32_t padding;
    uint64_t fh;
    uint64_t size;
    uint64_t lock_owner;
    uint64_t atime;
    uint64_t mtime;
    uint64_t ctime;
    uint32_t atimensec;
    uint32_t mtimensec;
    uint32_t ctimensec;
    uint32_t mode;
    uint32_t unused4;
    uint32_t uid;
    uint32_t gid;
    uint32_t unused5;
};

struct fuse_open_in {
    uint32_t flags;
    uint32_t open_flags; /* FUSE_OPEN_... */
};

struct fuse_create_in {
    uint32_t flags;
    uint32_t mode;
    uint32_t umask;
    uint32_t open_flags; /* FUSE_OPEN_... */
};

struct fuse_open_out {
    uint64_t fh;
    uint32_t open_flags;
    uint32_t padding;
};

struct fuse_release_in {
    uint64_t fh;
    uint32_t flags;
    uint32_t release_flags;
    uint64_t lock_owner;
};

struct fuse_flush_in {
    uint64_t fh;
    uint32_t unused;
    uint32_t padding;
    uint64_t lock_owner;
};

struct fuse_read_in {
    uint64_t fh;
    uint64_t offset;
    uint32_t size;
    uint32_t read_flags;
    uint64_t lock_owner;
    uint32_t flags;
    uint32_t padding;
};

struct fuse_write_in {
    uint64_t fh;
    uint64_t offset;
    uint32_t size;
    uint32_t write_flags;
    uint64_t lock_owner;
    uint32_t flags;
    uint32_t padding;
};

struct fuse_write_out {
    uint32_t size;
    uint32_t padding;
};

struct fuse_access_in {
    uint32_t mask;
    uint32_t padding;
};

struct fuse_init_in {
    uint32_t major;
    uint32_t minor;
    uint32_t max_readahead;
    uint32_t flags;
    uint32_t flags2;
    uint32_t unused[11];
};

struct fuse_init_out {
    uint32_t major;
    uint32_t minor;
    uint32_t max_readahead;
    uint32_t flags;
    uint16_t max_background;
    uint16_t congestion_threshold;
    uint32_t max_write;
    uint32_t time_gran;
    uint16_t max_pages;
    uint16_t map_alignment;
    uint32_t flags2;
    uint32_t unused[7];
};

struct fuse_in_header {
    uint32_t len;
    uint32_t opcode;
    uint64_t unique;
    uint64_t nodeid;
    uint32_t uid;
    uint32_t gid;
    uint32_t pid;
    uint16_t total_extlen; /* length of extensions in 8byte units */
    uint16_t padding;
};

struct fuse_out_header {
    uint32_t len;
    int32_t error;
    uint64_t unique;
};

struct fuse_dirent {
    uint64_t ino;
    uint64_t off;
    uint32_t namelen;
    uint32_t type;
    char name[];
};

/* Align variable length records to 64bit boundary */
#define FUSE_REC_ALIGN(x) \
    (((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))

#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
#define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
#define FUSE_DIRENT_SIZE(d) \
    FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)