extern crate proc_macro2;
extern crate ref_cast;

mod gen;

use self::proc_macro2::{Ident, Literal, TokenStream};
use self::ref_cast::RefCast;
use std::fmt::{self, Debug};
use std::ops::Deref;
use syn::punctuated::Punctuated;

#[derive(RefCast)]
#[repr(transparent)]
pub struct Lite<T: ?Sized> {
    value: T,
}

#[allow(non_snake_case)]
pub fn Lite<T: ?Sized>(value: &T) -> &Lite<T> {
    Lite::ref_cast(value)
}

impl<T: ?Sized> Deref for Lite<T> {
    type Target = T;

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

impl Debug for Lite<bool> {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        write!(formatter, "{}", self.value)
    }
}

impl Debug for Lite<u32> {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        write!(formatter, "{}", self.value)
    }
}

impl Debug for Lite<usize> {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        write!(formatter, "{}", self.value)
    }
}

impl Debug for Lite<String> {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        write!(formatter, "{:?}", self.value)
    }
}

impl Debug for Lite<Ident> {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        write!(formatter, "{:?}", self.value.to_string())
    }
}

impl Debug for Lite<Literal> {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        write!(formatter, "{}", self.value)
    }
}

impl Debug for Lite<TokenStream> {
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        write!(formatter, "`{}`", self.value)
    }
}

impl<'a, T> Debug for Lite<&'a T>
where
    Lite<T>: Debug,
{
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        Debug::fmt(Lite(&*self.value), formatter)
    }
}

impl<T> Debug for Lite<Box<T>>
where
    Lite<T>: Debug,
{
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        Debug::fmt(Lite(&*self.value), formatter)
    }
}

impl<T> Debug for Lite<Vec<T>>
where
    Lite<T>: Debug,
{
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter
            .debug_list()
            .entries(self.value.iter().map(Lite))
            .finish()
    }
}

impl<T, P> Debug for Lite<Punctuated<T, P>>
where
    Lite<T>: Debug,
{
    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter
            .debug_list()
            .entries(self.value.iter().map(Lite))
            .finish()
    }
}
