// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module os

pub struct FileMode {
pub:
    typ    FileType
    owner  FilePermission
    group  FilePermission
    others FilePermission
}

pub struct FileInfo {
    FileMode
pub:
    size  u64 // size of the file in bytes
    mtime i64 // last modification time in seconds after the Unix epoch
}

pub enum FileType {
    unknown
    regular
    directory
    character_device
    block_device
    fifo
    symbolic_link
    socket
}

pub struct FilePermission {
pub:
    read    bool
    write   bool
    execute bool
}

// bitmask returns a 3 bit sequence in the order RWE, where the bit is set to 1 if the value is true or 0 otherwise.
pub fn (p FilePermission) bitmask() u32 {
    mut mask := u32(0)
    if p.read {
        mask |= 4
    }
    if p.write {
        mask |= 2
    }
    if p.execute {
        mask |= 1
    }
    return mask
}

// bitmask returns a 9 bit sequence in the order owner + group + others.
// This is a valid bitmask to use with `os.chmod`.
pub fn (m FileMode) bitmask() u32 {
    return m.owner.bitmask() << 6 | m.group.bitmask() << 3 | m.others.bitmask()
}

// inode returns the metadata of the file/inode, containing inode type, permission information, size and modification time.
// It supports Windows for regular files, but it doesn't matter if you use owner, group or others when checking permissions on Windows.
// if a symlink is targeted, it returns info on the link, not the target.
pub fn inode(path string) FileInfo {
    attr := lstat(path) or { Stat{} }
    fm := attr.get_mode()
    return FileInfo{
        typ:    fm.typ
        owner:  fm.owner
        group:  fm.group
        others: fm.others
        size:   attr.size
        mtime:  attr.mtime
    }
}