use crate::ffi::OsString;
use crate::{fmt, vec};

pub struct Env {
    iter: vec::IntoIter<(OsString, OsString)>,
}

// FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
pub struct EnvStrDebug<'a> {
    slice: &'a [(OsString, OsString)],
}

impl fmt::Debug for EnvStrDebug<'_> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_list()
            .entries(self.slice.iter().map(|(a, b)| (a.to_str().unwrap(), b.to_str().unwrap())))
            .finish()
    }
}

impl Env {
    pub(super) fn new(env: Vec<(OsString, OsString)>) -> Self {
        Env { iter: env.into_iter() }
    }

    pub fn str_debug(&self) -> impl fmt::Debug + '_ {
        EnvStrDebug { slice: self.iter.as_slice() }
    }
}

impl fmt::Debug for Env {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_list().entries(self.iter.as_slice()).finish()
    }
}

impl !Send for Env {}
impl !Sync for Env {}

impl Iterator for Env {
    type Item = (OsString, OsString);
    fn next(&mut self) -> Option<(OsString, OsString)> {
        self.iter.next()
    }
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.iter.size_hint()
    }
}