use crate::protocol::eval::EvalError;
use crate::runtime2::*;
use super::CompCtx;

pub enum CompScheduling {
    Immediate,
    Requeue,
    Sleep,
    Exit,
}

/// Generic representation of a component (as viewed by a scheduler).
pub(crate) trait Component {
    /// Called if the component is created by another component and the messages
    /// are being transferred between the two.
    fn adopt_message(&mut self, comp_ctx: &mut CompCtx, message: DataMessage);

    /// Called if the component receives a new message. The component is
    /// responsible for deciding where that messages goes.
    fn handle_message(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx, message: Message);

    /// Called if the component's routine should be executed. The return value
    /// can be used to indicate when the routine should be run again.
    fn run(&mut self, sched_ctx: &mut SchedulerCtx, comp_ctx: &mut CompCtx) -> Result<CompScheduling, EvalError>;
}