// files.rs

//

// Copyright 2019

// Raphaël Gomès <rgomes@octobus.net>,

// Yuya Nishihara <yuya@tcha.org>

//

// This software may be used and distributed according to the terms of the

// GNU General Public License version 2 or any later version.

//! Functions for fiddling with files.

use lazy_static::lazy_static;

use std::fs::Metadata;

use std::iter::FusedIterator;

pub fn get_path_from_bytes(bytes: &[u8]) -> &Path {

    let os_str;

    #[cfg(unix)]

    {

        use std::os::unix::ffi::OsStrExt;

        os_str = std::ffi::OsStr::from_bytes(bytes);

    }

    // TODO Handle other platforms

    // TODO: convert from WTF8 to Windows MBCS (ANSI encoding).

    // Perhaps, the return type would have to be Result<PathBuf>.

    Path::new(os_str)

}

// TODO: need to convert from WTF8 to MBCS bytes on Windows.

// that's why Vec<u8> is returned.

#[cfg(unix)]

pub fn get_bytes_from_path(path: impl AsRef<Path>) -> Vec<u8> {

    use std::os::unix::ffi::OsStrExt;

    path.as_ref().as_os_str().as_bytes().to_vec()

}

/// An iterator over repository path yielding itself and its ancestors.

#[derive(Copy, Clone, Debug)]

pub struct Ancestors<'a> {

    next: Option<&'a HgPath>,

}

impl<'a> Iterator for Ancestors<'a> {

    type Item = &'a HgPath;

    fn next(&mut self) -> Option<Self::Item> {

        let next = self.next;

        self.next = match self.next {

            Some(s) if s.is_empty() => None,

            Some(s) => {

                let p = s.bytes().rposition(|c| *c == b'/').unwrap_or(0);

                Some(HgPath::new(&s.as_bytes()[..p]))

            }

            None => None,

        };

        next

    }

}

impl<'a> FusedIterator for Ancestors<'a> {}

/// An iterator over repository path yielding itself and its ancestors.

#[derive(Copy, Clone, Debug)]

pub(crate) struct AncestorsWithBase<'a> {

    next: Option<(&'a HgPath, &'a HgPath)>,

}

impl<'a> Iterator for AncestorsWithBase<'a> {

    type Item = (&'a HgPath, &'a HgPath);

    fn next(&mut self) -> Option<Self::Item> {

        let next = self.next;

        self.next = match self.next {

            Some((s, _)) if s.is_empty() => None,

            Some((s, _)) => Some(s.split_filename()),

            None => None,

        };

        next

    }

}

impl<'a> FusedIterator for AncestorsWithBase<'a> {}

/// Returns an iterator yielding ancestor directories of the given repository

/// path.

///

/// The path is separated by '/', and must not start with '/'.

///

/// The path itself isn't included unless it is b"" (meaning the root

/// directory.)

pub fn find_dirs<'a>(path: &'a HgPath) -> Ancestors<'a> {

    let mut dirs = Ancestors { next: Some(path) };

    if !path.is_empty() {

        dirs.next(); // skip itself

    }

    dirs

}

/// Returns an iterator yielding ancestor directories of the given repository

/// path.

///

/// The path is separated by '/', and must not start with '/'.

///

/// The path itself isn't included unless it is b"" (meaning the root

/// directory.)

pub(crate) fn find_dirs_with_base<'a>(

    path: &'a HgPath,

) -> AncestorsWithBase<'a> {

    let mut dirs = AncestorsWithBase {

        next: Some((path, HgPath::new(b""))),

    };

    if !path.is_empty() {

        dirs.next(); // skip itself

    }

    dirs

}

/// TODO more than ASCII?

pub fn normalize_case(path: &HgPath) -> HgPathBuf {

    #[cfg(windows)] // NTFS compares via upper()

    return path.to_ascii_uppercase();

    #[cfg(unix)]

    path.to_ascii_lowercase()

}

lazy_static! {

    static ref IGNORED_CHARS: Vec<Vec<u8>> = {

        [

            0x200c, 0x200d, 0x200e, 0x200f, 0x202a, 0x202b, 0x202c, 0x202d,

            0x202e, 0x206a, 0x206b, 0x206c, 0x206d, 0x206e, 0x206f, 0xfeff,

        ]

        .iter()

        .map(|code| {

            std::char::from_u32(*code)

                .unwrap()

                .encode_utf8(&mut [0; 3])

                .bytes()

                .collect()

        })

        .collect()

    };

}

fn hfs_ignore_clean(bytes: &[u8]) -> Vec<u8> {

    let mut buf = bytes.to_owned();

    let needs_escaping = bytes.iter().any(|b| *b == b'\xe2' || *b == b'\xef');

    if needs_escaping {

        for forbidden in IGNORED_CHARS.iter() {

            replace_slice(&mut buf, forbidden, &[])

        }

        buf

    } else {

        buf

    }

}

pub fn lower_clean(bytes: &[u8]) -> Vec<u8> {

    hfs_ignore_clean(&bytes.to_ascii_lowercase())

}

#[derive(Eq, PartialEq, Ord, PartialOrd, Copy, Clone)]

pub struct HgMetadata {

    pub st_dev: u64,

    pub st_mode: u32,

    pub st_nlink: u64,

    pub st_size: u64,

    pub st_mtime: i64,

    pub st_ctime: i64,

}

// TODO support other plaforms

#[cfg(unix)]

impl HgMetadata {

    pub fn from_metadata(metadata: Metadata) -> Self {

        use std::os::unix::fs::MetadataExt;

        Self {

            st_dev: metadata.dev(),

            st_mode: metadata.mode(),

            st_nlink: metadata.nlink(),

            st_size: metadata.size(),

            st_mtime: metadata.mtime(),

            st_ctime: metadata.ctime(),

        }

    }

}

#[cfg(test)]

mod tests {

    use super::*;

    #[test]

    fn find_dirs_some() {

        let mut dirs = super::find_dirs(HgPath::new(b"foo/bar/baz"));

        assert_eq!(dirs.next(), Some(HgPath::new(b"foo/bar")));

        assert_eq!(dirs.next(), Some(HgPath::new(b"foo")));

        assert_eq!(dirs.next(), Some(HgPath::new(b"")));

        assert_eq!(dirs.next(), None);

        assert_eq!(dirs.next(), None);

    }

    #[test]

    fn find_dirs_empty() {

        // looks weird, but mercurial.pathutil.finddirs(b"") yields b""

        let mut dirs = super::find_dirs(HgPath::new(b""));

        assert_eq!(dirs.next(), Some(HgPath::new(b"")));

        assert_eq!(dirs.next(), None);

        assert_eq!(dirs.next(), None);

    }

    #[test]

    fn test_find_dirs_with_base_some() {

        let mut dirs = super::find_dirs_with_base(HgPath::new(b"foo/bar/baz"));

        assert_eq!(

            dirs.next(),

            Some((HgPath::new(b"foo/bar"), HgPath::new(b"baz")))

        );

        assert_eq!(

            dirs.next(),

            Some((HgPath::new(b"foo"), HgPath::new(b"bar")))

        );

        assert_eq!(dirs.next(), Some((HgPath::new(b""), HgPath::new(b"foo"))));

        assert_eq!(dirs.next(), None);

        assert_eq!(dirs.next(), None);

    }

    #[test]

    fn test_find_dirs_with_base_empty() {

        let mut dirs = super::find_dirs_with_base(HgPath::new(b""));

        assert_eq!(dirs.next(), Some((HgPath::new(b""), HgPath::new(b""))));

        assert_eq!(dirs.next(), None);

        assert_eq!(dirs.next(), None);

    }