//! Helper for unique identifiers for channels.

use std::fmt::{Display, Formatter};

use std::sync::atomic::{AtomicUsize, Ordering};

/// Counter for allocating unique-ish identifiers for channels.

static NEXT_ID: AtomicUsize = AtomicUsize::new(0);

/// Unique identifier for a channel.

///

/// These identifiers are unique per process.  On 32-bit architectures

/// it's possible to exhaust them if you do nothing but create channels

/// for a very long time; if you do, we detect that and exit with an

/// assertion failure.

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]

pub struct UniqId(usize);

impl UniqId {

    /// Construct a new UniqId.

}

impl Display for UniqId {

}

/// Counter for allocating circuit unique ids.

///

/// We don't use circuit IDs here, because they can be huge, and they're

/// random, and can get reused.

#[derive(Debug)]

pub(crate) struct CircUniqIdContext {

    /// Next value to be handed out for this channel's circuits.

    next_circ_id: usize,

}

impl CircUniqIdContext {

    /// Create a new CircUniqIdContext

    /// Construct a new, unique-ish circuit UniqId

        );

}

#[cfg(test)]

mod test {

    // @@ begin test lint list maintained by maint/add_warning @@

    #![allow(clippy::bool_assert_comparison)]

    #![allow(clippy::clone_on_copy)]

    #![allow(clippy::dbg_macro)]

    #![allow(clippy::mixed_attributes_style)]

    #![allow(clippy::print_stderr)]

    #![allow(clippy::print_stdout)]

    #![allow(clippy::single_char_pattern)]

    #![allow(clippy::unwrap_used)]

    #![allow(clippy::unchecked_duration_subtraction)]

    #![allow(clippy::useless_vec)]

    #![allow(clippy::needless_pass_by_value)]

    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->

    use super::*;

    #[test]

    fn chan_unique_id() {

        let ids: Vec<UniqId> = (0..10).map(|_| UniqId::new()).collect();

        // Make sure we got distinct numbers

        let mut all_nums: Vec<_> = ids.iter().map(|x| x.0).collect();

        all_nums.sort_unstable();

        all_nums.dedup();

        assert_eq!(all_nums.len(), ids.len());

        assert_eq!(format!("{}", ids[3]), format!("Chan {}", ids[3].0));

    }

    #[test]

    fn chan_circid() {

        let chan_id99 = UniqId(99);

        let mut ctx = CircUniqIdContext::new();

        let _id0 = ctx.next(chan_id99);

        let _id1 = ctx.next(chan_id99);

        let id2 = ctx.next(chan_id99);

        assert_eq!(format!("{}", id2), "Circ 99.2");

    }

}