use std::{    fs::{self, OpenOptions},    io::Write,    path::{Path, PathBuf},}; use quick_error::quick_error; quick_error! {    #[derive(Debug)]    pub enum Error {        IoOpen(err: std::io::Error, path: PathBuf) {            display("Could not open data at '{}'", path.display())            source(err)        }        IoWrite(err: std::io::Error, path: PathBuf) {            display("Could not write data at '{}'", path.display())            source(err)        }        DirectoryExists(path: PathBuf) {            display("Refusing to initialize the existing '{}' directory", path.display())        }        CreateDirectory(err: std::io::Error, path: PathBuf) {            display("Could not create directory at '{}'", path.display())            source(err)        }    }} const GIT_DIR_NAME: &str = ".git"; const TPL_INFO_EXCLUDE: &[u8] = include_bytes!("./assets/baseline-init/info/exclude");const TPL_HOOKS_APPLYPATCH_MSG: &[u8] = include_bytes!("./assets/baseline-init/hooks/applypatch-msg.sample");const TPL_HOOKS_COMMIT_MSG: &[u8] = include_bytes!("./assets/baseline-init/hooks/commit-msg.sample");const TPL_HOOKS_FSMONITOR_WATCHMAN: &[u8] = include_bytes!("./assets/baseline-init/hooks/fsmonitor-watchman.sample");const TPL_HOOKS_POST_UPDATE: &[u8] = include_bytes!("./assets/baseline-init/hooks/post-update.sample");const TPL_HOOKS_PRE_APPLYPATCH: &[u8] = include_bytes!("./assets/baseline-init/hooks/pre-applypatch.sample");const TPL_HOOKS_PRE_COMMIT: &[u8] = include_bytes!("./assets/baseline-init/hooks/pre-commit.sample");const TPL_HOOKS_PRE_MERGE_COMMIT: &[u8] = include_bytes!("./assets/baseline-init/hooks/pre-merge-commit.sample");const TPL_HOOKS_PRE_PUSH: &[u8] = include_bytes!("./assets/baseline-init/hooks/pre-push.sample");const TPL_HOOKS_PRE_REBASE: &[u8] = include_bytes!("./assets/baseline-init/hooks/pre-rebase.sample");const TPL_HOOKS_PRE_RECEIVE: &[u8] = include_bytes!("./assets/baseline-init/hooks/pre-receive.sample");const TPL_HOOKS_PREPARE_COMMIT_MSG: &[u8] = include_bytes!("./assets/baseline-init/hooks/prepare-commit-msg.sample");const TPL_HOOKS_UPDATE: &[u8] = include_bytes!("./assets/baseline-init/hooks/update.sample");const TPL_CONFIG: &[u8] = include_bytes!("./assets/baseline-init/config");const TPL_DESCRIPTION: &[u8] = include_bytes!("./assets/baseline-init/description");const TPL_HEAD: &[u8] = include_bytes!("./assets/baseline-init/HEAD"); struct PathCursor<'a>(&'a mut PathBuf); struct NewDir<'a>(&'a mut PathBuf); impl<'a> PathCursor<'a> {    fn at(&mut self, component: &str) -> &Path {        self.0.push(component);        self.0.as_path()    }} impl<'a> NewDir<'a> {    fn at(self, component: &str) -> Result<Self, Error> {        self.0.push(component);        create_dir(self.0)?;        Ok(self)    }    fn as_mut(&mut self) -> &mut PathBuf {        self.0    }} impl<'a> Drop for NewDir<'a> {    fn drop(&mut self) {        self.0.pop();    }} impl<'a> Drop for PathCursor<'a> {    fn drop(&mut self) {        self.0.pop();    }} fn write_file(data: &[u8], path: &Path) -> Result<(), Error> {    let mut file = OpenOptions::new()        .write(true)        .create(true)        .append(false)        .open(path)        .map_err(|e| Error::IoOpen(e, path.to_owned()))?;    file.write_all(data).map_err(|e| Error::IoWrite(e, path.to_owned()))} fn create_dir(p: &Path) -> Result<(), Error> {    fs::create_dir_all(p).map_err(|e| Error::CreateDirectory(e, p.to_owned()))} pub fn repository(directory: impl Into<PathBuf>) -> Result<(), Error> {    let mut cursor = directory.into();    cursor.push(GIT_DIR_NAME);     if cursor.is_dir() {        return Err(Error::DirectoryExists(cursor));    }    create_dir(&cursor)?;     {        let mut cursor = NewDir(&mut cursor).at("info")?;        write_file(TPL_INFO_EXCLUDE, PathCursor(cursor.as_mut()).at("exclude"))?;    }     {        let mut cursor = NewDir(&mut cursor).at("hooks")?;        for (tpl, filename) in &[            (TPL_HOOKS_UPDATE, "update.sample"),            (TPL_HOOKS_PREPARE_COMMIT_MSG, "prepare-commit-msg.sample"),            (TPL_HOOKS_PRE_RECEIVE, "pre-receive.sample"),            (TPL_HOOKS_PRE_REBASE, "pre-rebase.sample"),            (TPL_HOOKS_PRE_PUSH, "pre-push.sample"),            (TPL_HOOKS_PRE_COMMIT, "pre-commit.sample"),            (TPL_HOOKS_PRE_MERGE_COMMIT, "pre-merge-commit.sample"),            (TPL_HOOKS_PRE_APPLYPATCH, "pre-applypatch.sample"),            (TPL_HOOKS_POST_UPDATE, "post-update.sample"),            (TPL_HOOKS_FSMONITOR_WATCHMAN, "fsmonitor-watchman.sample"),            (TPL_HOOKS_COMMIT_MSG, "commit-msg.sample"),            (TPL_HOOKS_APPLYPATCH_MSG, "applypatch-msg.sample"),        ] {            write_file(tpl, PathCursor(cursor.as_mut()).at(filename))?;        }    }     {        let mut cursor = NewDir(&mut cursor).at("objects")?;        create_dir(PathCursor(cursor.as_mut()).at("info"))?;        create_dir(PathCursor(cursor.as_mut()).at("pack"))?;    }     {        let mut cursor = NewDir(&mut cursor).at("refs")?;        create_dir(PathCursor(cursor.as_mut()).at("heads"))?;        create_dir(PathCursor(cursor.as_mut()).at("tags"))?;    }     for (tpl, filename) in &[        (TPL_HEAD, "HEAD"),        (TPL_DESCRIPTION, "description"),        (TPL_CONFIG, "config"),    ] {        write_file(tpl, PathCursor(&mut cursor).at(filename))?;    }     Ok(())}