//! Supervision signals.
//!
//! Every actor has a supervisor, which is itself just an actor with a
//! `Receiver<Signal>`. When a child actor terminates, the scheduler sends
//! a `Signal` on the supervisor's channel. The supervisor decides what to
//! do — restart, escalate, ignore.
//!
//! For v0.1 there is no built-in restart-intensity cap. That's policy and
//! lives in user code; library is mechanism only.

use crate::pid::Pid;
use std::any::Any;

pub enum Signal {
    /// The child exited normally.
    Exit(Pid),
    /// The child panicked. Payload is whatever `panic!` was called with.
    Panic(Pid, Box<dyn Any + Send>),
}

impl std::fmt::Debug for Signal {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Signal::Exit(pid)     => write!(f, "Signal::Exit({:?})", pid),
            Signal::Panic(pid, _) => write!(f, "Signal::Panic({:?}, ..)", pid),
        }
    }
}

impl Signal {
    pub fn pid(&self) -> Pid {
        match self {
            Signal::Exit(p)     => *p,
            Signal::Panic(p, _) => *p,
        }
    }
}