libratman 0.7.0

use crate::types::Ident32;

/// Represent a set of direct peers
///
/// A neighbour is another Ratman router that is directly connected to
/// the current one.  A direct neighbour may know the current device
/// IP address, or the router identification keys of our peers.
///
/// In this context a `Neighbour` represents a set of direct peers that we can
/// pass messages to.  In some cases we may want to address them all, just a
/// subset, or none of them, for example if a packet is being filtered from
/// crossing subnets or when de-duplicating flood events to the origin to
/// prevent infinite replication.
#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum Neighbour {
    /// Send message to all reachable neighbours
    Flood,
    /// Send to all neighbours, except one
    FloodExcept(Ident32),
    /// Exclude this envelope from all neighbours
    ///
    /// Note: your endpoint may ignore this type, since it is filtered
    /// in the ratmand switch.  However, potentially this could change
    /// in the future, so implementing a drop feature anyway may be
    /// warranted.
    Drop,
    /// Encodes a specific neighbour ID
    Single(Ident32),
}

impl Neighbour {
    pub fn maybe_single(&self) -> Option<Ident32> {
        match self {
            Self::Single(id) => Some(*id),
            _ => None,
        }
    }
    pub fn assume_single(&self) -> Ident32 {
        match self {
            Self::Single(id) => *id,
            _ => unreachable!(
                "called assume_single() on something that was not Self::Single(_).  Sad!"
            ),
        }
    }
}