use std::fmt::Display;

use crate::fs::{id_mapping::IdMapping, AsIter, FileSystem, Mountpoint};

use super::{Stack, Stackable};

#[derive(Clone, Debug, PartialEq, Eq)]
pub enum FuseOverlayOption {
    CloneFd,
    MaxIdleThreads(isize),
    MaxThreads(usize),
    AllowOther,
    AllowRoot,
    SquashToRoot,
    SquashToUid(usize),
    SquashToGid(usize),
    StaticNLink,
    NoAcl,
    UidMapping(IdMapping),
    GidMapping(IdMapping),
}

impl Display for FuseOverlayOption {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self {
                FuseOverlayOption::CloneFd => "clone_fd".to_string(),
                FuseOverlayOption::MaxIdleThreads(n) => format!("max_idle_threads={n}"),
                FuseOverlayOption::MaxThreads(n) => format!("max_threads={n}"),
                FuseOverlayOption::AllowOther => "allow_other".to_string(),
                FuseOverlayOption::AllowRoot => "allow_root".to_string(),
                FuseOverlayOption::SquashToRoot => "squash_to_root".to_string(),
                FuseOverlayOption::SquashToUid(uid) => format!("squash_to_uid={uid}"),
                FuseOverlayOption::SquashToGid(gid) => format!("squash_to_gid={gid}"),
                FuseOverlayOption::StaticNLink => "static_nlink".to_string(),
                FuseOverlayOption::NoAcl => "noacl".to_string(),
                FuseOverlayOption::UidMapping(map) => format!("uidmapping={map}"),
                FuseOverlayOption::GidMapping(map) => format!("gidmapping={map}"),
            }
        )
    }
}

#[derive(Debug)]
pub struct FuseOverlay {
    fs: Stackable,
    options: Vec<FuseOverlayOption>,
}

impl Stack for FuseOverlay {
    fn lower_dirs(&self) -> impl Iterator<Item = &std::path::Path> {
        self.fs.lower_dirs()
    }

    fn upper_dir(&self) -> Option<&std::path::Path> {
        self.fs.upper_dir()
    }

    fn work_dir(&self) -> Option<&std::path::Path> {
        self.fs.work_dir()
    }
}

impl Mountpoint for FuseOverlay {
    fn options(&self) -> impl Iterator<Item = impl Display> {
        self.options.as_iter()
    }
}

impl FileSystem for FuseOverlay {
    fn mount(&mut self) -> std::io::Result<()> {
        todo!()
    }

    fn unmount(&mut self) -> std::io::Result<()> {
        todo!()
    }
}