use futures::{Stream, StreamExt, TryStream, future::ready};

use crate::{Error, Result};

pub trait TryIgnore<'a, Item> {
	fn ignore_err(self) -> impl Stream<Item = Item> + Send + 'a;

	fn ignore_ok(self) -> impl Stream<Item = Error> + Send + 'a;
}

impl<'a, T, Item> TryIgnore<'a, Item> for T
where
	T: Stream<Item = Result<Item>> + TryStream + Send + 'a,
	Item: Send + 'a,
{
	#[cfg(debug_assertions)]
	#[inline]
	fn ignore_err(self: T) -> impl Stream<Item = Item> + Send + 'a {
		use super::TryExpect;

		self.expect_ok()
	}

	#[cfg(not(debug_assertions))]
	#[inline]
	fn ignore_err(self: T) -> impl Stream<Item = Item> + Send + 'a {
		self.filter_map(|res| ready(res.ok()))
	}

	#[inline]
	fn ignore_ok(self: T) -> impl Stream<Item = Error> + Send + 'a {
		self.filter_map(|res| ready(res.err()))
	}
}