//! Core module for ADN functionality.
//! Brings [`Mentionable`]/[`Factory`]/[`Origin`] concepts from the original implementation in Python.
//! Allows for more generic behaviour via [`Context`], as opposed to original async-only.

mod addresses;
mod context;
mod diagnostic;
mod hashing;
mod origin;
mod point;
mod points;
mod resolution;
mod resolver_origin;
mod serialization;
mod slice_deserializer;

use std::{error::Error, rc::Rc};

use crate::func::context::*;
use crate::func::*;

pub use self::addresses::Addresses;
pub use self::context::Context;
pub use self::diagnostic::Diagnostic;
pub use self::hashing::{Hash, HASH_SIZE, HASH_ZEROS};
pub use self::origin::{OFctr, Origin};
pub use self::point::Point;
pub use self::points::TakesPoints;
pub use self::resolution::{
    Address, HashResolution, HashResolutionResult, Resolution, ResolutionError, ResolutionFailure,
    ResolutionResult, Resolver, ResolverMap,
};
pub use self::serialization::{Deserializer, DeserializerExt, Serializable, Serializer};
pub use self::slice_deserializer::SliceDeserializer;

/// Helper alias for [`WeakFunctor::F`] of [`FunctorContext::T`].
pub type Wrapped<'a, Ctx, A> = WrapC<'a, A, Ctx>;

/// Fundamental trait for ADN objects.
pub trait Mentionable<'a, Ctx: Context<'a>>: 'a + Serializable {
    /// Type of the associated factory.
    type Fctr: Factory<'a, Ctx, Mtbl = Self>;

    /// Value of the associated factory.
    fn factory(&self) -> Self::Fctr;
    /// See implementation for the definition.
    /// Hash of all the references' points concatenated, ordered, non-unique.
    /// Used for walking over object trees to ensure two objects with different references don't collide.
    fn topology(&self) -> Hash {
        let mut vec = Vec::new();
        self.points_typed(&mut vec);
        Ctx::hash(&vec)
    }
    /// References ([Point]s) to other objects. Typed.
    fn points_typed(&self, points: &mut impl TakesPoints<'a, Ctx>);
}

pub type Fctr<'a, Ctx, A> = <A as Mentionable<'a, Ctx>>::Fctr;

/// Shorthand for the type of vaalues returned by [`Factory::deserialize`].
pub type ParseResult<'a, Ctx, F> = Result<Mtbl<'a, Ctx, F>, <F as Factory<'a, Ctx>>::ParseError>;

pub struct DeCtxT<'a: 'c, 'c, Ctx: Context<'a>> {
    deserializer: &'c mut dyn Deserializer,
    resolver: &'c Rc<dyn Resolver<'a, Ctx>>,
    addresses: &'c mut Addresses,
}

pub trait DeCtx<'a, Ctx: Context<'a>> {
    fn deserializer(&mut self) -> &mut dyn Deserializer;

    fn next_address(&mut self) -> Result<Address, &[u8]>;

    fn resolver(&self) -> Rc<dyn Resolver<'a, Ctx>>;

    fn adr(
        &mut self,
    ) -> (
        &mut Addresses,
        &mut dyn Deserializer,
        &Rc<dyn Resolver<'a, Ctx>>,
    );
}

impl<'a: 'c, 'c, Ctx: Context<'a>> DeCtx<'a, Ctx> for DeCtxT<'a, 'c, Ctx> {
    fn deserializer(&mut self) -> &mut dyn Deserializer {
        self.deserializer
    }

    fn next_address(&mut self) -> Result<Address, &[u8]> {
        self.addresses.next(self.deserializer)
    }

    fn resolver(&self) -> Rc<dyn Resolver<'a, Ctx>> {
        self.resolver.clone()
    }

    fn adr(
        &mut self,
    ) -> (
        &mut Addresses,
        &mut dyn Deserializer,
        &Rc<dyn Resolver<'a, Ctx>>,
    ) {
        (&mut self.addresses, self.deserializer, self.resolver)
    }
}

/// Trait representing deserialisation rules for [Mentionable]s.
/// Crucial for [`crate::rstd::typeless`].
pub trait Factory<'a, Ctx: Context<'a>>: 'a + Send + Sync + Clone {
    /// Type of the associated objects.
    type Mtbl: Mentionable<'a, Ctx, Fctr = Self>;
    /// Type of an error that [`Factory::deserialize`] can fail with.
    type ParseError: 'a + Error;

    /// See [`Deserializer`], [`Resolver`].
    fn deserialize(&self, dectx: &mut dyn DeCtx<'a, Ctx>) -> ParseResult<'a, Ctx, Self>;
    /// Called by finite stream parsers if there's any data left.
    fn extend(&self, mentionable: Self::Mtbl, tail: &[u8]) -> ParseResult<'a, Ctx, Self>;
}

pub type Mtbl<'a, Ctx, F> = <F as Factory<'a, Ctx>>::Mtbl;

pub type ParseError<'a, Ctx, F> = <F as Factory<'a, Ctx>>::ParseError;

pub type ParseErrorA<'a, Ctx, A> = ParseError<'a, Ctx, Fctr<'a, Ctx, A>>;

/// Extension trait for factories.
pub trait FactoryExt<'a, Ctx: Context<'a>>: Factory<'a, Ctx> {
    /// Parse the object from a slice.
    fn parse_slice(
        &self,
        slice: &[u8],
        resolver: &Rc<dyn Resolver<'a, Ctx>>,
    ) -> ParseResult<'a, Ctx, Self>;
}