//! The first supported constructor group is the closed nested MessageKind.
//! The core owns its acknowledgment/retirement and validation policies.
use super::*;

pub(super) fn selector() -> FacetSelector {
    FacetSelector::Occurrence(OccurrenceFacet::MessageKind)
}
#[cfg(test)]
pub(super) fn timer_selector() -> FacetSelector {
    FacetSelector::Occurrence(OccurrenceFacet::TimerExpression)
}
pub(super) fn handles(facet: &FacetSelector) -> bool {
    *facet == selector()
}
#[cfg(test)]
pub(super) fn value(project: &Project, id: Id) -> Option<&MessageKind> {
    match project.elements.get(&id)?.shared()? {
        SharedBody::Occurrence {
            body: OccurrenceBody::Exchange { message_kind, .. },
            ..
        } => Some(message_kind),
        _ => None,
    }
}