#![no_std]

extern crate proc_macro;

#[cfg(not(test))]
use proc_macro as used_proc_macro;

#[cfg(any(test, feature = "derive"))]
extern crate proc_macro2;

#[cfg(test)]
use proc_macro2 as used_proc_macro;

extern crate alloc;

// #[cfg(test)]
extern crate std;

use crate::used_proc_macro::{Delimiter, Group, Punct, Spacing, Span, TokenStream, TokenTree};

use core::iter::once;

#[cfg(feature = "derive")]
use proc_macro2::TokenStream as TokenStream2;

#[cfg(feature = "derive")]
mod derive;

#[cfg(feature = "derive")]
#[proc_macro_derive(ConstDefault, attributes(cdef))]
pub fn derive_const_default(input: proc_macro::TokenStream) -> TokenStream {
    syn::parse(input)
        .and_then(crate::derive::const_default_derive::derive_impl)
        .unwrap_or_else(syn::Error::into_compile_error)
        .into()
}

#[cfg(feature = "derive")]
#[proc_macro_derive(TransparentNewtype, attributes(twrap))]
pub fn derive_transparent_newtype(input: proc_macro::TokenStream) -> TokenStream {
    syn::parse(input)
        .and_then(crate::derive::transparent_newtype_derive::derive_impl)
        .unwrap_or_else(syn::Error::into_compile_error)
        .into()
}




#[cfg(test)]
mod test_utils;

#[cfg(test)]
mod tests;

mod parsing_shared;

mod splitting_generics;

#[cfg(feature = "macro_utils")]
#[macro_use]
mod macro_utils_shared;

#[cfg(feature = "macro_utils")]
mod macro_utils;

#[cfg(feature = "item_parsing")]
mod item_parsing;


#[cfg(feature = "macro_utils")]
use crate::macro_utils_shared::Error;

#[cfg(feature = "macro_utils")]
type Result<T> = core::result::Result<T, Error>;


#[cfg(feature = "macro_utils")]
#[proc_macro_attribute]
pub fn macro_attr(attr: TokenStream, item: TokenStream) -> TokenStream {
    crate::macro_utils::macro_attr(attr, item).unwrap_or_else(Error::into_compile_error)
}


#[doc(hidden)]
#[proc_macro]
pub fn __priv_unwrap_bound(
    input_tokens: proc_macro::TokenStream
) -> proc_macro::TokenStream {
    let input_tokens: TokenStream = input_tokens.into();

    let mut iter = input_tokens.into_iter();

    let ty_tt = iter.next().expect("__priv_unwrap_bound expected more tokens");
    
    let group = match &ty_tt {
        TokenTree::Group(group) if group.delimiter() == Delimiter::None => group,
        x => panic!("Expected a none-delimited group, found:\n{}", x)
    };

    let mut last_is_plus = true;

    let mut ty = group.stream()
        .into_iter()
        .inspect(|tt|{
             last_is_plus = mmatches!(tt, TokenTree::Punct(punc) if punc.as_char() == '+');
        })
        .collect::<TokenStream>();

    if !last_is_plus {
        ty.extend(once(TokenTree::Punct(Punct::new('+', Spacing::Alone))))
    }

    let args = TokenStream::new();

    parsing_shared::parse_path_and_args("__priv_unwrap_bound", &mut iter, args, |args| {
        args.extend(once(TokenTree::Group(Group::new(Delimiter::Parenthesis, ty))));
    }).into()
}


#[cfg(feature = "macro_utils")]
#[doc(hidden)]
#[proc_macro]
pub fn __priv_rewrap_macro_parameters(input_tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input_tokens: TokenStream = input_tokens.into();
    //std::println!("\n----------------------------\n\n{:?}", input_tokens);
    let out = macro_utils::rewrap_macro_parameters(input_tokens);
    //std::println!("\n\n{:?}", out);
    out.into()
}

#[cfg(feature = "macro_utils")]
#[proc_macro]
pub fn count_tts(input_tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input_tokens: TokenStream = input_tokens.into();
    let out = macro_utils::count_tts(input_tokens).unwrap_or_else(Error::into_compile_error); 
    out.into()
}

#[cfg(feature = "macro_utils")]
#[proc_macro]
pub fn gen_ident_range(input_tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input_tokens: TokenStream = input_tokens.into();
    let out = macro_utils::gen_ident_range(input_tokens).unwrap_or_else(Error::into_compile_error); 
    out.into()
}


#[cfg(feature = "macro_utils")]
#[proc_macro]
pub fn tokens_method(input_tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input_tokens: TokenStream = input_tokens.into();
    let out = macro_utils::tokens_method(input_tokens).unwrap_or_else(Error::into_compile_error); 
    out.into()
}



#[doc(hidden)]
#[proc_macro]
pub fn __priv_split_generics(input_tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
    split_generics(input_tokens.into()).into()
}

fn split_generics(input: TokenStream) -> TokenStream {
    use crate::{
        parsing_shared::out_parenthesized,
        splitting_generics::{PostGenericsParser, SplitGenerics}
    };

    struct UnparsedPostGenerics {
        output: TokenStream,
        output_span: Span,
    }

    impl PostGenericsParser for UnparsedPostGenerics {
        fn consume_token(&mut self, sg: &SplitGenerics, tt: TokenTree) {
            self.output_span = sg.last_span();
            self.output.extend(once(tt));
        }
        fn write_tokens(self, ts: &mut TokenStream) {
            out_parenthesized(self.output, self.output_span, ts)
        }
    }

    let mut input = input.into_iter();
    let macro_invoc = parsing_shared::panicking_parse_macro_invocation(&mut input);

    SplitGenerics::new(input).split_generics(macro_invoc, TokenStream::new(), UnparsedPostGenerics{
        output: TokenStream::new(),
        output_span: Span::call_site(),
    })
}

#[cfg(feature = "item_parsing")]
#[doc(hidden)]
#[proc_macro]
pub fn __priv_split_impl(input_tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
    crate::item_parsing::split_impl(input_tokens.into()).into()
}





// MSRV is 1.41.0, matches was stabilized in 1.42.0
macro_rules! mmatches {
    ( $expr:expr, $pat:pat $(if $cond:expr)?)=>{
        match $expr {
            $pat  $(if $cond)? =>true,
            _=>false
        }
    };
} use mmatches;

// Purely for performance
#[allow(unused_macros)]
macro_rules! try_ {
    ( $expr:expr )=>{
        match $expr {
            Ok(x) => x,
            Err(e) => return Err(e),
        }
    };
    ( $expr:expr, map_err = |$e:tt| $map_err:expr )=>{
        match $expr {
            Ok(x) => x,
            Err($e) => return Err($map_err),
        }
    };
}
#[allow(unused_imports)]
use try_;