//! Filesystem-oriented `ioctl` functions.

#![allow(unsafe_code)]

#[cfg(linux_kernel)]

use {

    crate::backend::c,

    crate::fd::AsFd,

    crate::{backend, ffi, io, ioctl},

};

use bitflags::bitflags;

#[cfg(all(linux_kernel, not(any(target_arch = "sparc", target_arch = "sparc64"))))]

use crate::fd::{AsRawFd as _, BorrowedFd};

/// `ioctl(fd, BLKSSZGET)`—Returns the logical block size of a block device.

///

/// This is mentioned in the [Linux `openat` manual page].

///

/// [Linux `openat` manual page]: https://man7.org/linux/man-pages/man2/openat.2.html

#[cfg(linux_kernel)]

#[inline]

#[doc(alias = "BLKSSZGET")]

pub fn ioctl_blksszget<Fd: AsFd>(fd: Fd) -> io::Result<u32> {

    // SAFETY: `BLZSSZGET` is a getter opcode that gets a `u32`.

    unsafe {

        let ctl = ioctl::Getter::<{ c::BLKSSZGET }, c::c_uint>::new();

        ioctl::ioctl(fd, ctl)

    }

}

/// `ioctl(fd, BLKPBSZGET)`—Returns the physical block size of a block device.

#[cfg(linux_kernel)]

#[inline]

#[doc(alias = "BLKPBSZGET")]

pub fn ioctl_blkpbszget<Fd: AsFd>(fd: Fd) -> io::Result<u32> {

    // SAFETY: `BLKPBSZGET` is a getter opcode that gets a `u32`.

    unsafe {

        let ctl = ioctl::Getter::<{ c::BLKPBSZGET }, c::c_uint>::new();

        ioctl::ioctl(fd, ctl)

    }

}

/// `ioctl(fd, FICLONE, src_fd)`—Share data between open files.

///

/// This ioctl is not available on SPARC platforms.

///

/// # References

///  - [Linux]

///

/// [Linux]: https://man7.org/linux/man-pages/man2/ioctl_ficlone.2.html

#[cfg(all(linux_kernel, not(any(target_arch = "sparc", target_arch = "sparc64"))))]

#[inline]

#[doc(alias = "FICLONE")]

pub fn ioctl_ficlone<Fd: AsFd, SrcFd: AsFd>(fd: Fd, src_fd: SrcFd) -> io::Result<()> {

    unsafe { ioctl::ioctl(fd, Ficlone(src_fd.as_fd())) }

}

/// `ioctl(fd, EXT4_IOC_RESIZE_FS, blocks)`—Resize ext4 filesystem on fd.

#[cfg(linux_raw_dep)]

#[inline]

#[doc(alias = "EXT4_IOC_RESIZE_FS")]

pub fn ext4_ioc_resize_fs<Fd: AsFd>(fd: Fd, blocks: u64) -> io::Result<()> {

    // SAFETY: `EXT4_IOC_RESIZE_FS` is a pointer setter opcode.

    unsafe {

        let ctl = ioctl::Setter::<{ backend::fs::EXT4_IOC_RESIZE_FS }, u64>::new(blocks);

        ioctl::ioctl(fd, ctl)

    }

}

#[cfg(all(linux_kernel, not(any(target_arch = "sparc", target_arch = "sparc64"))))]

struct Ficlone<'a>(BorrowedFd<'a>);

#[cfg(all(linux_kernel, not(any(target_arch = "sparc", target_arch = "sparc64"))))]

unsafe impl ioctl::Ioctl for Ficlone<'_> {

    type Output = ();

    const IS_MUTATING: bool = false;

    fn opcode(&self) -> ioctl::Opcode {

        c::FICLONE as ioctl::Opcode

    }

    fn as_ptr(&mut self) -> *mut c::c_void {

        self.0.as_raw_fd() as *mut c::c_void

    }

    unsafe fn output_from_ptr(

        _: ioctl::IoctlOutput,

        _: *mut c::c_void,

    ) -> io::Result<Self::Output> {

        Ok(())

    }

}

#[cfg(linux_raw_dep)]

bitflags! {

    /// `FS_*` constants for use with [`ioctl_getflags`].

    ///

    /// [`ioctl_getflags`]: crate::fs::ioctl::ioctl_getflags

    #[repr(transparent)]

    #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]

    pub struct IFlags: ffi::c_uint {

        /// `FS_APPEND_FL`

        const APPEND = linux_raw_sys::general::FS_APPEND_FL;

        /// `FS_COMPR_FL`

        const COMPRESSED = linux_raw_sys::general::FS_COMPR_FL;

        /// `FS_DIRSYNC_FL`

        const DIRSYNC = linux_raw_sys::general::FS_DIRSYNC_FL;

        /// `FS_IMMUTABLE_FL`

        const IMMUTABLE = linux_raw_sys::general::FS_IMMUTABLE_FL;

        /// `FS_JOURNAL_DATA_FL`

        const JOURNALING = linux_raw_sys::general::FS_JOURNAL_DATA_FL;

        /// `FS_NOATIME_FL`

        const NOATIME = linux_raw_sys::general::FS_NOATIME_FL;

        /// `FS_NOCOW_FL`

        const NOCOW = linux_raw_sys::general::FS_NOCOW_FL;

        /// `FS_NODUMP_FL`

        const NODUMP = linux_raw_sys::general::FS_NODUMP_FL;

        /// `FS_NOTAIL_FL`

        const NOTAIL = linux_raw_sys::general::FS_NOTAIL_FL;

        /// `FS_PROJINHERIT_FL`

        const PROJECT_INHERIT = linux_raw_sys::general::FS_PROJINHERIT_FL;

        /// `FS_SECRM_FL`

        const SECURE_REMOVAL = linux_raw_sys::general::FS_SECRM_FL;

        /// `FS_SYNC_FL`

        const SYNC = linux_raw_sys::general::FS_SYNC_FL;

        /// `FS_TOPDIR_FL`

        const TOPDIR = linux_raw_sys::general::FS_TOPDIR_FL;

        /// `FS_UNRM_FL`

        const UNRM = linux_raw_sys::general::FS_UNRM_FL;

    }

}

/// `ioctl(fd, FS_IOC_GETFLAGS)`—Returns the [inode flags] attributes

///

/// [inode flags]: https://man7.org/linux/man-pages/man2/ioctl_iflags.2.html

#[cfg(linux_raw_dep)]

#[inline]

#[doc(alias = "FS_IOC_GETFLAGS")]

pub fn ioctl_getflags<Fd: AsFd>(fd: Fd) -> io::Result<IFlags> {

    unsafe {

        #[cfg(target_pointer_width = "32")]

        let ctl = ioctl::Getter::<{ c::FS_IOC32_GETFLAGS }, u32>::new();

        #[cfg(target_pointer_width = "64")]

        let ctl = ioctl::Getter::<{ c::FS_IOC_GETFLAGS }, u32>::new();

        ioctl::ioctl(fd, ctl).map(IFlags::from_bits_retain)

    }

}

/// `ioctl(fd, FS_IOC_SETFLAGS)`—Modify the [inode flags] attributes

///

/// [inode flags]: https://man7.org/linux/man-pages/man2/ioctl_iflags.2.html

#[cfg(linux_raw_dep)]

#[inline]

#[doc(alias = "FS_IOC_SETFLAGS")]

pub fn ioctl_setflags<Fd: AsFd>(fd: Fd, flags: IFlags) -> io::Result<()> {

    unsafe {

        #[cfg(target_pointer_width = "32")]

        let ctl = ioctl::Setter::<{ c::FS_IOC32_SETFLAGS }, u32>::new(flags.bits());

        #[cfg(target_pointer_width = "64")]

        let ctl = ioctl::Setter::<{ c::FS_IOC_SETFLAGS }, u32>::new(flags.bits());

        ioctl::ioctl(fd, ctl)

    }

}