//! Provides [Atomic]-[Mentionable] interface.

use std::ops::Deref;

use super::*;

/// Generic implementation of a [Mentionable] for [Atomic]s.
#[derive(Clone)]
pub struct AtomicObject<A: Atomic> {
    atomic: A,
}

impl<A: Atomic> From<A> for AtomicObject<A> {
    fn from(value: A) -> Self {
        Self { atomic: value }
    }
}

impl<A: Atomic> AsRef<A> for AtomicObject<A> {
    fn as_ref(&self) -> &A {
        &self.atomic
    }
}

impl<A: Atomic> Deref for AtomicObject<A> {
    type Target = A;

    fn deref(&self) -> &Self::Target {
        &self.atomic
    }
}

impl<A: Atomic> Serializable for AtomicObject<A> {
    fn serialize(&self, serializer: &mut dyn Serializer) {
        self.atomic.serialize(serializer)
    }
}

impl<'a, Ctx: Context<'a>, A: Atomic> Mentionable<'a, Ctx> for AtomicObject<A> {
    type Fctr = AtomicFactory<A>;

    fn factory(&self) -> Self::Fctr {
        AtomicFactory::new()
    }

    fn topology(&self) -> Hash {
        Ctx::hash(b"")
    }

    fn points_typed(&self, _points: &mut impl TakesPoints<'a, Ctx>) {}
}

/// Generic implementation of a [Factory] for [Atomic]s.
pub struct AtomicFactory<A: Atomic> {
    _pd: PhantomData<A>,
}

impl<A: Atomic> AtomicFactory<A> {
    fn new() -> Self {
        AtomicFactory { _pd: PhantomData }
    }
}

impl<A: Atomic> Clone for AtomicFactory<A> {
    fn clone(&self) -> Self {
        Self::new()
    }
}

impl<'a, Ctx: Context<'a>, A: Atomic> Factory<'a, Ctx> for AtomicFactory<A> {
    type Mtbl = AtomicObject<A>;

    type ParseError = A::AParseError;

    fn deserialize(&self, dectx: &mut dyn DeCtx<'a, Ctx>) -> ParseResult<'a, Ctx, Self> {
        Ok(A::o_deserialise(dectx)?.into())
    }

    fn extend(&self, mentionable: Self::Mtbl, tail: &[u8]) -> ParseResult<'a, Ctx, Self> {
        Ok(A::a_extend(mentionable.atomic, tail)?.into())
    }
}

/// Extension trait to provide method-like utilities associated with [AtomicObject]s.
pub trait AtomicObjectExt: Atomic {
    /// Shorthand for getting specific [`AtomicFactory`].
    fn f() -> AtomicFactory<Self> {
        AtomicFactory::new()
    }
    /// Shorthand for getting specific [`AtomicObject`].
    fn m(self) -> AtomicObject<Self> {
        self.into()
    }
}

impl<A: Atomic> AtomicObjectExt for A {}