//! Canonical ID newtypes used across the Prometeu workspace.
//! Keep this crate low-level and independent from higher layers.

macro_rules! define_id {
    ($name:ident) => {
        #[repr(transparent)]
        #[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash, serde::Serialize, serde::Deserialize)]
        pub struct $name(pub u32);

        impl $name {
            pub const INVALID: $name = $name(u32::MAX);

            #[inline]
            pub const fn as_u32(self) -> u32 { self.0 }

            // Temporary helper for places that still index Vec/slots by usize
            #[inline]
            pub const fn as_usize(self) -> usize { self.0 as usize }
        }

        impl From<u32> for $name {
            #[inline]
            fn from(value: u32) -> Self { Self(value) }
        }

        impl From<$name> for u32 {
            #[inline]
            fn from(value: $name) -> Self { value.0 }
        }
    };
}

define_id!(FileId);
define_id!(NodeId);
define_id!(NameId);
define_id!(SymbolId);
define_id!(TypeId);
define_id!(ModuleId);
define_id!(ProjectId);

#[cfg(test)]
mod tests {
    use super::*;
    use std::collections::HashMap;
    use std::mem::size_of;

    #[test]
    fn ids_are_repr_transparent_and_hashable() {
        assert_eq!(size_of::<FileId>(), 4);
        assert_eq!(size_of::<NodeId>(), 4);
        assert_eq!(size_of::<NameId>(), 4);
        assert_eq!(size_of::<SymbolId>(), 4);
        assert_eq!(size_of::<TypeId>(), 4);
        assert_eq!(size_of::<ModuleId>(), 4);
        assert_eq!(size_of::<ProjectId>(), 4);

        // Hash/Eq usage
        let mut m: HashMap<SymbolId, &str> = HashMap::new();
        m.insert(SymbolId(1), "one");
        assert_eq!(m.get(&SymbolId(1)).copied(), Some("one"));
    }
}