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

use super::*;

pub trait MappableOrigin<'a, Ctx: Context<'a>>: Origin<'a, Ctx> {
    fn map<B: Mentionable<'a, Ctx>>(
        self: Arc<Self>,
        map_ok: impl 'a + Send + Sync + Clone + Fn(Arc<Self::Mtbl>) -> B,
        map_err: impl 'a
            + Send
            + Sync
            + Clone
            + Fn(ParseError<'a, OFctr<'a, Ctx, Self>>) -> ParseError<'a, B::Fctr>,
        map_factory: impl 'a + FnOnce(OFctr<'a, Ctx, Self>) -> B::Fctr,
    ) -> Arc<dyn Origin<'a, Ctx, Mtbl = B>>
    where
        OFctr<'a, Ctx, Self>: Factory<'a, Ctx, _Mtbl = Self::Mtbl>,
        Self::Mtbl: MentionableTop<'a, Ctx>,
    {
        let origin_r = self.clone();
        let origin_rb = self.clone();
        let origin: WrappedOrigin<'a, Ctx, B> = WrappedOrigin {
            w_factory: map_factory(self.factory()),
            w_resolve: Box::new(move || {
                let origin = origin_r.clone();
                let map_ok = map_ok.clone();
                let map_err = map_err.clone();
                map_resolve(move || origin.ref_resolve(), map_ok, map_err)
            }),
            w_resolve_bytes: Box::new(move || origin_rb.ref_resolve_bytes()),
        };
        Arc::new(origin)
    }
}

impl<'a, Ctx: Context<'a>, O: ?Sized + Origin<'a, Ctx>> MappableOrigin<'a, Ctx> for O {}

fn map_resolve<'a, Ctx: Context<'a>, A: Mentionable<'a, Ctx>, B: Mentionable<'a, Ctx>>(
    resolve: impl 'a + Send + Fn() -> Resolution<'a, Ctx, A>,
    map_ok: impl 'a + Send + Fn(Arc<A>) -> B,
    map_err: impl 'a + Send + Fn(ParseError<'a, A::Fctr>) -> ParseError<'a, B::Fctr>,
) -> Resolution<'a, Ctx, B> {
    Ctx::fmap(resolve(), move |resolved| match resolved {
        Ok(mentionable) => Ok(Arc::new(map_ok(mentionable))),
        Err(e) => Err(e.map_parse(map_err)),
    })
}

struct WrappedOrigin<'a, Ctx: Context<'a>, A: Mentionable<'a, Ctx>> {
    w_factory: A::Fctr,
    w_resolve: Box<dyn 'a + Send + Sync + Fn() -> Resolution<'a, Ctx, A>>,
    w_resolve_bytes: Box<dyn 'a + Send + Sync + Fn() -> HashResolution<'a, Ctx>>,
}

impl<'a, Ctx: Context<'a>, A: Mentionable<'a, Ctx>> Origin<'a, Ctx> for WrappedOrigin<'a, Ctx, A> {
    type Mtbl = A;

    fn factory(&self) -> Fctr<'a, Self::Mtbl> {
        self.w_factory.clone()
    }

    fn resolve(self: Arc<Self>) -> Resolution<'a, Ctx, A> {
        (self.w_resolve)()
    }

    fn resolve_bytes(self: Arc<Self>) -> HashResolution<'a, Ctx> {
        (self.w_resolve_bytes)()
    }
}