path: root/src/file.rs

use std::ascii::AsciiExt;
use std::env::current_dir;
use std::fs;
use std::io;
use std::os::unix;
use std::os::unix::raw::{blkcnt_t, gid_t, ino_t, nlink_t, time_t, uid_t};
use std::os::unix::fs::{MetadataExt, PermissionsExt};
use std::path::{Component, Path, PathBuf};

use unicode_width::UnicodeWidthStr;

use dir::Dir;
use options::TimeType;
use feature::Attribute;

pub enum Type {
    File, Directory, Pipe, Link, Special,
}

pub struct Permissions {
    pub file_type:      Type,
    pub user_read:      bool,
    pub user_write:     bool,
    pub user_execute:   bool,
    pub group_read:     bool,
    pub group_write:    bool,
    pub group_execute:  bool,
    pub other_read:     bool,
    pub other_write:    bool,
    pub other_execute:  bool,
    pub attribute:      bool,
}

pub struct Links {
    pub count: nlink_t,
    pub multiple: bool,
}

pub struct Inode(pub ino_t);

pub enum Blocks {
    Some(blkcnt_t),
    None,
}

pub struct User(pub uid_t);

pub struct Group(pub gid_t);

pub enum Size {
    Some(u64),
    None,
}

pub struct Time(pub time_t);

pub enum GitStatus {
    NotModified,
    New,
    Modified,
    Deleted,
    Renamed,
    TypeChange,
}

pub struct Git {
    pub staged:   GitStatus,
    pub unstaged: GitStatus,
}

impl Git {
    pub fn empty() -> Git {
        Git { staged: GitStatus::NotModified, unstaged: GitStatus::NotModified }
    }
}

/// A **File** is a wrapper around one of Rust's Path objects, along with
/// associated data about the file.
///
/// Each file is definitely going to have its filename displayed at least
/// once, have its file extension extracted at least once, and have its stat
/// information queried at least once, so it makes sense to do all this at the
/// start and hold on to all the information.
pub struct File<'a> {
    pub name:  String,
    pub dir:   Option<&'a Dir>,
    pub ext:   Option<String>,
    pub path:  PathBuf,
    pub stat:  fs::Metadata,
    pub xattrs: Vec<Attribute>,
    pub this:  Option<Dir>,
}

impl<'a> File<'a> {
    /// Create a new File object from the given Path, inside the given Dir, if
    /// appropriate. Paths specified directly on the command-line have no Dirs.
    ///
    /// This uses `symlink_metadata` instead of `metadata`, which doesn't
    /// follow symbolic links.
    pub fn from_path(path: &Path, parent: Option<&'a Dir>, recurse: bool) -> io::Result<File<'a>> {
        fs::symlink_metadata(path).map(|stat| File::with_stat(stat, path, parent, recurse))
    }

    /// Create a new File object from the given Stat result, and other data.
    pub fn with_stat(stat: fs::Metadata, path: &Path, parent: Option<&'a Dir>, recurse: bool) -> File<'a> {
        let filename = path_filename(path);

        // If we are recursing, then the `this` field contains a Dir object
        // that represents the current File as a directory, if it is a
        // directory. This is used for the --tree option.
        let this = if recurse && stat.is_dir() {
            Dir::readdir(path).ok()
        }
        else {
            None
        };

        File {
            path:   path.to_path_buf(),
            dir:    parent,
            stat:   stat,
            ext:    ext(&filename),
            xattrs: Attribute::llist(path).unwrap_or(Vec::new()),
            name:   filename.to_string(),
            this:   this,
        }
    }

    pub fn is_directory(&self) -> bool {
        self.stat.is_dir()
    }

    pub fn is_file(&self) -> bool {
        self.stat.is_file()
    }

    pub fn is_executable_file(&self) -> bool {
        let bit = unix::fs::USER_EXECUTE;
        self.is_file() && (self.stat.permissions().mode() & bit) == bit
    }

    pub fn is_link(&self) -> bool {
        self.stat.file_type().is_symlink()
    }

    pub fn is_pipe(&self) -> bool {
        false  // TODO: Still waiting on this one...
    }

    /// Whether this file is a dotfile or not.
    pub fn is_dotfile(&self) -> bool {
        self.name.starts_with(".")
    }

    pub fn path_prefix(&self) -> String {
        let path_bytes: Vec<Component> = self.path.components().collect();
        let mut path_prefix = String::new();

        if !path_bytes.is_empty() {
            // Use init() to add all but the last component of the
            // path to the prefix. init() panics when given an
            // empty list, hence the check.
            for component in path_bytes.init().iter() {
                path_prefix.push_str(&*component.as_os_str().to_string_lossy());

                if component != &Component::RootDir {
                    path_prefix.push_str("/");
                }
            }
        }

        path_prefix
    }

    /// The Unicode 'display width' of the filename.
    ///
    /// This is related to the number of graphemes in the string: most
    /// characters are 1 columns wide, but in some contexts, certain
    /// characters are actually 2 columns wide.
    pub fn file_name_width(&self) -> usize {
        UnicodeWidthStr::width(&self.name[..])
    }

    /// Assuming the current file is a symlink, follows the link and
    /// returns a File object from the path the link points to.
    ///
    /// If statting the file fails (usually because the file on the
    /// other end doesn't exist), returns the *filename* of the file
    /// that should be there.
    pub fn link_target(&self) -> Result<File, String> {
        let path = match fs::read_link(&self.path) {
            Ok(path)  => path,
            Err(_)    => return Err(self.name.clone()),
        };

        let target_path = match self.dir {
            Some(dir)  => dir.join(&*path),
            None       => path
        };

        let filename = path_filename(&target_path);

        // Use plain `metadata` instead of `symlink_metadata` - we *want* to follow links.
        if let Ok(stat) = fs::metadata(&target_path) {
            Ok(File {
                path:   target_path.to_path_buf(),
                dir:    self.dir,
                stat:   stat,
                ext:    ext(&filename),
                xattrs: Attribute::list(&target_path).unwrap_or(Vec::new()),
                name:   filename.to_string(),
                this:   None,
            })
        }
        else {
            Err(filename.to_string())
        }
    }

    /// This file's number of hard links as a coloured string.
    ///
    /// This is important, because a file with multiple links is uncommon,
    /// while you can come across directories and other types with multiple
    /// links much more often.
    pub fn links(&self) -> Links {
        let count = self.stat.as_raw().nlink();

        Links {
            count: count,
            multiple: self.is_file() && count > 1,
        }
    }

    pub fn inode(&self) -> Inode {
        Inode