//! Module exposing tunnel-related types shared by clients and relays.

use std::sync::atomic::{AtomicU64, Ordering};

use crate::circuit::UniqId;

use derive_more::Display;

/// The unique identifier of a tunnel.

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

#[display("{}", _0)]

#[cfg_attr(feature = "relay", visibility::make(pub))]

#[allow(unreachable_pub)] // TODO(#1447): use in ChanMgr's ChannelProvider impl

pub(crate) struct TunnelId(u64);

impl TunnelId {

    /// Create a new TunnelId.

    ///

    /// # Panics

    ///

    /// Panics if we have exhausted the possible space of u64 IDs.

        /// The next unique tunnel ID.

        static NEXT_TUNNEL_ID: AtomicU64 = AtomicU64::new(1);

}

/// The identifier of a circuit [`UniqId`] within a tunnel.

///

/// This type is only needed for logging purposes: a circuit's [`UniqId`] is

/// process-unique, but in the logs it's often useful to display the

/// owning tunnel's ID alongside the circuit identifier.

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

#[display("Circ {}.{}", tunnel_id, circ_id.display_chan_circ())]

pub(crate) struct TunnelScopedCircId {

    /// The identifier of the owning tunnel

    tunnel_id: TunnelId,

    /// The process-unique identifier of the circuit

    circ_id: UniqId,

}

impl TunnelScopedCircId {

    /// Create a new [`TunnelScopedCircId`] from the specified identifiers.

    /// Return the [`UniqId`].

}