use std::{borrow::Cow, path::PathBuf}; use bstr::BStr; use crate::Path; ///pub mod interpolate {    use std::path::PathBuf;     /// Options for interpolating paths with [`Path::interpolate()`][crate::Path::interpolate()].    #[derive(Clone, Copy)]    pub struct Context<'a> {        /// The location where gitoxide or git is installed. If `None`, `%(prefix)` in paths will cause an error.        pub git_install_dir: Option<&'a std::path::Path>,        /// The home directory of the current user. If `None`, `~/` in paths will cause an error.        pub home_dir: Option<&'a std::path::Path>,        /// A function returning the home directory of a given user. If `None`, `~name/` in paths will cause an error.        pub home_for_user: Option<fn(&str) -> Option<PathBuf>>,    }     impl Default for Context<'_> {        fn default() -> Self {            Context {                git_install_dir: None,                home_dir: None,                home_for_user: Some(home_for_user),            }        }    }     /// The error returned by [`Path::interpolate()`][crate::Path::interpolate()].    #[derive(Debug, thiserror::Error)]    #[allow(missing_docs)]    pub enum Error {        #[error("{} is missing", .what)]        Missing { what: &'static str },        #[error("Ill-formed UTF-8 in {}", .what)]        Utf8Conversion {            what: &'static str,            #[source]            err: git_path::Utf8Error,        },        #[error("Ill-formed UTF-8 in username")]        UsernameConversion(#[from] std::str::Utf8Error),        #[error("User interpolation is not available on this platform")]        UserInterpolationUnsupported,    }     /// Obtain the home directory for the given user `name` or return `None` if the user wasn't found    /// or any other error occurred.    /// It can be used as `home_for_user` parameter in [`Path::interpolate()`][crate::Path::interpolate()].    #[cfg_attr(windows, allow(unused_variables))]    pub fn home_for_user(name: &str) -> Option<PathBuf> {        #[cfg(not(any(target_os = "android", target_os = "windows")))]        {            let cname = std::ffi::CString::new(name).ok()?;            // SAFETY: calling this in a threaded program that modifies the pw database is not actually safe.            //         TODO: use the `*_r` version, but it's much harder to use.            #[allow(unsafe_code)]            let pwd = unsafe { libc::getpwnam(cname.as_ptr()) };            if pwd.is_null() {                None            } else {                use std::os::unix::ffi::OsStrExt;                // SAFETY: pw_dir is a cstr and it lives as long as… well, we hope nobody changes the pw database while we are at it                //         from another thread. Otherwise it lives long enough.                #[allow(unsafe_code)]                let cstr = unsafe { std::ffi::CStr::from_ptr((*pwd).pw_dir) };                Some(std::ffi::OsStr::from_bytes(cstr.to_bytes()).into())            }        }        #[cfg(any(target_os = "android", target_os = "windows"))]        {            None        }    }} impl<'a> std::ops::Deref for Path<'a> {    type Target = BStr;     fn deref(&self) -> &Self::Target {        self.value.as_ref()    }} impl<'a> AsRef<[u8]> for Path<'a> {    fn as_ref(&self) -> &[u8] {        self.value.as_ref()    }} impl<'a> AsRef<BStr> for Path<'a> {    fn as_ref(&self) -> &BStr {        self.value.as_ref()    }} impl<'a> From<Cow<'a, BStr>> for Path<'a> {    fn from(value: Cow<'a, BStr>) -> Self {        Path { value }    }} impl<'a> Path<'a> {    /// Interpolates this path into a path usable on the file system.    ///    /// If this path starts with `~/` or `~user/` or `%(prefix)/`    ///  - `~/` is expanded to the value of `home_dir`. The caller can use the [dirs](https://crates.io/crates/dirs) crate to obtain it.    ///    It it is required but not set, an error is produced.    ///  - `~user/` to the specified user’s home directory, e.g `~alice` might get expanded to `/home/alice` on linux, but requires    ///    the `home_for_user` function to be provided.    ///    The interpolation uses `getpwnam` sys call and is therefore not available on windows.    ///  - `%(prefix)/` is expanded to the location where `gitoxide` is installed.    ///     This location is not known at compile time and therefore need to be    ///     optionally provided by the caller through `git_install_dir`.    ///    /// Any other, non-empty path value is returned unchanged and error is returned in case of an empty path value or if required input    /// wasn't provided.    pub fn interpolate(        self,        interpolate::Context {            git_install_dir,            home_dir,            home_for_user,        }: interpolate::Context<'_>,    ) -> Result<Cow<'a, std::path::Path>, interpolate::Error> {        if self.is_empty() {            return Err(interpolate::Error::Missing { what: "path" });        }         const PREFIX: &[u8] = b"%(prefix)/";        const USER_HOME: &[u8] = b"~/";        if self.starts_with(PREFIX) {            let git_install_dir = git_install_dir.ok_or(interpolate::Error::Missing {                what: "git install dir",            })?;            let (_prefix, path_without_trailing_slash) = self.split_at(PREFIX.len());            let path_without_trailing_slash =                git_path::try_from_bstring(path_without_trailing_slash).map_err(|err| {                    interpolate::Error::Utf8Conversion {                        what: "path past %(prefix)",                        err,                    }                })?;            Ok(git_install_dir.join(path_without_trailing_slash).into())        } else if self.starts_with(USER_HOME) {            let home_path = home_dir.ok_or(interpolate::Error::Missing { what: "home dir" })?;            let (_prefix, val) = self.split_at(USER_HOME.len());            let val = git_path::try_from_byte_slice(val).map_err(|err| interpolate::Error::Utf8Conversion {                what: "path past ~/",                err,            })?;            Ok(home_path.join(val).into())        } else if self.starts_with(b"~") && self.contains(&b'/') {            self.interpolate_user(home_for_user.ok_or(interpolate::Error::Missing {                what: "home for user lookup",            })?)        } else {            Ok(git_path::from_bstr(self.value))        }    }     #[cfg(any(target_os = "windows", target_os = "android"))]    fn interpolate_user(        self,        _home_for_user: fn(&str) -> Option<PathBuf>,    ) -> Result<Cow<'a, std::path::Path>, interpolate::Error> {        Err(interpolate::Error::UserInterpolationUnsupported)    }     #[cfg(not(windows))]    fn interpolate_user(        self,        home_for_user: fn(&str) -> Option<PathBuf>,    ) -> Result<Cow<'a, std::path::Path>, interpolate::Error> {        let (_prefix, val) = self.split_at("/".len());        let i = val            .iter()            .position(|&e| e == b'/')            .ok_or(interpolate::Error::Missing { what: "/" })?;        let (username, path_with_leading_slash) = val.split_at(i);        let username = std::str::from_utf8(username)?;        let home = home_for_user(username).ok_or(interpolate::Error::Missing { what: "pwd user info" })?;        let path_past_user_prefix =            git_path::try_from_byte_slice(&path_with_leading_slash["/".len()..]).map_err(|err| {                interpolate::Error::Utf8Conversion {                    what: "path past ~user/",                    err,                }            })?;        Ok(home.join(path_past_user_prefix).into())    }}