//! Access test functions.

use crate::fs::{access_impl, FollowSymlinks};

#[cfg(racy_asserts)]

use crate::fs::{access_unchecked, file_path};

use std::path::Path;

use std::{fs, io};

/// Access modes for use with [`DirExt::access`].

#[derive(Clone, Copy, Debug)]

pub struct AccessModes {

    /// Is the object readable?

    pub readable: bool,

    /// Is the object writable?

    pub writable: bool,

    /// Is the object executable?

    pub executable: bool,

}

/// Access modes for use with [`DirExt::access`].

#[derive(Clone, Copy, Debug)]

pub enum AccessType {

    /// Test whether the named object is accessible in the given modes.

    Access(AccessModes),

    /// Test whether the named object exists.

    Exists,

}

/// Canonicalize the given path, ensuring that the resolution of the path never

/// escapes the directory tree rooted at `start`.

#[cfg_attr(not(racy_asserts), allow(clippy::let_and_return))]

pub fn access(

    start: &fs::File,

    path: &Path,

    type_: AccessType,

    follow: FollowSymlinks,

) -> io::Result<()> {

    // Call the underlying implementation.

    let result = access_impl(start, path, type_, follow);

    #[cfg(racy_asserts)]

    let unchecked = access_unchecked(start, path, type_, follow);

    #[cfg(racy_asserts)]

    check_access(start, path, type_, follow, &result, &unchecked);

    result

}

#[cfg(racy_asserts)]

#[allow(clippy::enum_glob_use)]

fn check_access(

    start: &fs::File,

    path: &Path,

    _type_: AccessType,

    _follow: FollowSymlinks,

    result: &io::Result<()>,

    unchecked: &io::Result<()>,

) {

    use io::ErrorKind::*;

    match (map_result(result), map_result(stat)) {

        (Ok(()), Ok(())) => {}

        (Err((PermissionDenied, message)), _) => {

            // TODO: Check that access in the no-follow case got the right

            // error.

        }

        (Err((kind, message)), Err((unchecked_kind, unchecked_message))) => {

            assert_eq!(kind, unchecked_kind);

            assert_eq!(

                message,

                unchecked_message,

                "start='{:?}', path='{:?}'",

                start,

                path.display()

            );

        }

        other => panic!(

            "unexpected result from access start='{:?}', path='{}':\n{:#?}",

            start,

            path.display(),

            other,

        ),

    }

}